Hello modelers
The next project I would like to share with you is the bucket chain excavator Ertmer KB 1. The model is made entirely of brass, should be functional and is still in progress.
First some information about the prototype.
Use and operation of bucket chain excavators
The basic principle of a bucket chain excavator is to dig the material to be conveyed with buckets attached to an endless chain. The excavated material is dumped in lorries next to the excavator. While the bucket chain runs continuously, the excavator moves slowly forwards and backwards on its track. If the slope angle becomes too steep due to the progressive excavation progresses, the tracks of the excavator and the light railway are moved away from the edge of the excavation. The tracks are therefore only laid on a leveled surface.
Only relatively soft materials such as clay, sand or gravel can be mined with a bucket chain excavator, because only the dead weight of the bucket ladder guarantees the pressure of the buckets.
Depending on topographical conditions, bucket chain excavators can work in low or high cut. In deep cuts, the levelling piece at the front of the bucket ladder levels the bottom of the pit.
(Sketche from http://dachziegelarchiv.de/seite.php?kat_typ=15&max=1&sei_id=28535 (http://dachziegelarchiv.de/seite.php?kat_typ=15&max=1&sei_id=28535))
In America in the 19th century during the gold rush large floating bucket chain excavators (dredges) were used for gold mining. Tony Beets brought two of them back to life in recent years as you can see: https://goldrush.fandom.com/wiki/Viking_Dredge (https://goldrush.fandom.com/wiki/Viking_Dredge)
The Prototype
Manufacturer | Maschinenfabrik Willy Ertmer, Ludwigshafen, Germany |
Type | KB 1
(the number indicates the size, 0 = small to 3 = large) |
Serial No. | 810 |
Year of construction | 1947/1948
(Order placed Aug. 1, 1947, Delivered Jan. 12, 1948) |
Drive | Three-phase electric motor with belt drive (leather belt) |
Excavation capacity | 14 – 22 m3/h |
Dredging depth or height | Up to 6 m |
Today's location | Feldbahnmuseum Wiesloch, Wiesloch, Germany |
The machine was used at the Enzinger brickworks in Eiselfing near Wasserburg am Inn from 1948 to 1976. After that, the excavator stood unused for years, until it was finally completely ingrown by a dense forest. In October 2010 the excavator was recovered by club members and brought to Wiesloch. In 2012 the excavator could be repaired and rebuilt in its original condition.
The excavator is one of the last known operational bucket chain excavators of the 1940s in Germany. In terms of year of construction, it is probably the last of its kind.
Further information can be found on the website of the Feldbahnmuseum Wiesloch https://feldbahnmuseum-wiesloch.de/fahrzeuge-technik/baumaschinen/ertmer-eimerkettenbagger.html. (https://feldbahnmuseum-wiesloch.de/fahrzeuge-technik/baumaschinen/ertmer-eimerkettenbagger.html.)
The following video shows the excavator idling: https://www.youtube.com/watch?v=qFwKiMqrjdI (https://www.youtube.com/watch?v=qFwKiMqrjdI)
Bernhard
Bernhard
What scale is this going to be??
It should be a fine looking piece of equipment when done.
Looking forward to your next post.
Jerry
Jerry, the model is 1:35 scale.
Bernhard
I look forward to seeing what you create. -- Russ
Very interesting project!
Greetings Bernhard from a chilly corner of England . I shall be watching your build of the eimerkettenbagger with great interest as I have wanted one in this scale for nearly ten years . I do not have the skill or the patience to build one for myself , so I will just watch you build yours . Of course , if you fancy building two rather than one then I am sure I could find a home for the second one !
Nick
Bernhard very interesting and demanding project.
Nick, you probably have the skill. Anyone who can build a 1:35 structure brick by brick probably can build anything. -- Russ
Quote from: finescalerr on October 28, 2019, 12:06:53 PM
Nick, you probably have the skill. Anyone who can build a 1:35 structure brick by brick probably can build anything. -- Russ
Not true , Russ . What Bernhard proposes to do is skilled engineering where as what I do is repetitive bodging of the highest order . There is very little comparison between the two types of modelling . But thanks for your vote of confidence .
Nick
Nick:
Russ is right. I just started building brass models once, after having worked with "normal" 1:87 model trains for years.
However, this project is quite complex, so I will leave it at one piece. But if required I can serve you with many photos, a 3D model and a complete set of drawings.
Thank you guys for following the tread.
Next step is the construction.
In spring 2017 I made a trip with my friend Werner to the Feldbahnmuseum Wiesloch, which is about three hours by car from us. There we measured and photographed the excavator together.
With several sketches and over 250 photos as a basis, the question arose how a set of drawings could be created for the realization of a functional model. On the drawing board, as I learned 50 years ago, or with a 2D CAD? The best solution seemed to be to create a 3D CAD model. However, this was completely new territory for me. After some searching and comparing I finally decided to use the free software SketchUp for this. It is intuitive and relatively easy to learn. Many hours later I was the proud owner of a full-scale 3D model with all the relevant details.
For a better overview, I already divided the excavator into 13 assemblies during the creation of the model. These were all detailed.
After the completion of all drawings, a look at the parts list shows that the excavator consists of over 1,100 individual parts!
Bernhard
Quote from: Bernhard on November 03, 2019, 02:35:34 AM
After the completion of all drawings, a look at the parts list shows that the excavator consists of over 1,100 individual parts!
Bernhard
Wow. Quite a challenge!
Have you decided what materials and techniques you are going to use in the model? From the drawings it looks that a lot of the parts could be photoetched.
The drawing alone is terrific. -- Russ
Very impressive Bernhard!
And the size in 1:35 scale will be impressive too!
Franck
Wow! Great work on the 3D drawings.
Bucket thing on you tube //www.youtube.com/watch?v=Iu00w9AJMJY
Barney
or even https://www.youtube.com/watch?v=Iu00w9AJMJY
Hauk
The excavator is mainly constructed of angle- and U-profiles, flat iron and sheet metal. Everything is welded or screwed (no rivets!).
All the sheet metal parts are actually etched.
Although the construction looks very filigree, it is quite stable. This is also noticeable in the finished model assemblies.
Barney
Thanks for sharing the link. It shows a typical application of these excavators.
Bernhard
The model
The biggest challenge in the realization of the excavator are the buckets. These are only about 12 x 11 x 6.5 mm small, with a wall thickness of 0.2 mm.
That's why I took care of these parts first.
From a dozen photos ...
... and a hand-drawn sketch ...
... one of our young designers created a 3D scale model for me.
The first idea was to have the buckets produced as a 3D printed part. However, this failed because of the minimum wall thickness of 0.4 mm for such parts. That would have been optically wrong.
That's why I explored the possibilities of casting the part. After a long unsuccessful search, I came across a possible supplier at a model building fair in autumn 2018. After a short examination, the owner immediately said that this would not be a problem. He could even cast the parts in nickel silver. He cast me a sample part within two weeks, and behold:
All I can say is I was thrilled! Realized down to the last detail, true to size and stable. If the paint is scraped or scratched by use, no yellow brass shines through. Although the offer of CHF 16.00 per piece (with a requirement of 16 pcs.) was not a bargain, it was definitely worth its price.
I thought this solved the problem, ordered the missing 15 buckets and turned to the first assembly of the excavator.
But then, after a longer waiting time, the big disappointment: the supplier did not answer any more to my questions about the delivery date. The company was apparently closed before he had delivered the missing parts to me.
Since then I have searched unsuccessfully for an alternative supplier.
So now the urgent question to the Forum is: does anyone know of a fine casters in Switzerland, Germany or anywhere in Europe who could cast these parts?
Bernhard
Hi Bernhard
Take a look here:
http://www.brogioli-casting.ch/
Peter, thank you for the link. I know Brogioli Casting. They have seen the sample part. They tried to cast it, but unfortunately without success.
It's possible you would find a commercial jeweler more helpful. A guy who creates parts for the fashion industry probably could do what you want. No, I don't know anybody but that might be a niche you could explore. -- Russ
Signs and miracles still happen! After I was in contact with Hydrostat about the problem, I simply tried to call the supplier of the sample part again this morning. He didn't answer again, but then he actually called back an hour later!
He shut down the company for the last 10 months due to certain problems. But now he is back at work with new energy and a new printer. And my buckets are to be delivered by the end of November at the latest.
I am really relieved!
Bernhard
Quote from: Bernhard on November 08, 2019, 02:06:56 AM
Signs and miracles still happen! After I was in contact with Hydrostat about the problem, I simply tried to call the supplier of the sample part again this morning. He didn't answer again, but then he actually called back an hour later!
He shut down the company for the last 10 months due to certain problems. But now he is back at work with new energy and a new printer. And my buckets are to be delivered by the end of November at the latest.
I am really relieved!
Bernhard
Excellent news! A caster that can cast walls 0.2mm thick is close to what I would call a casting genius. Do you know if he is open for more business? I would love to try his services.
Look forward to see the bucket castings!
Hello Bernhard,
congratulations and I am certainly as excited about the result as you are.
I'm glad you didn't have to follow up on my suggestion. Please post photos of the parts when you receive them. -- Russ
That first casting is amazing. I'm glad you can still get the rest of them from the original supplier.
Bernhard, could you tell us a little more about the master for the casting?
Is it entirely handmade?
How was the master for the casting made?
Thank you guys for your interest in the castings and for your support.
Hauk, the supplier of the parts is Pfister Feinguss in Lengnau, Switzerland (https://www.pfister-feinguss.ch/ (https://www.pfister-feinguss.ch/)).
He told me that he wants to focus on jewellery and model making in the future. So your chances are good.
Hauk and Paul, what you see in replay #27 is not the master, but already a casting. At the beginning of the manufacturing process is my step file of the bucket. This enables the supplier to print a wax plot for each individual part. You can imagine that the handling of these thin-walled wax parts is already a challenge. The parts are then casted in a vacuum casting machine.
Now I'm excited about the series!
Bernhard
Great looking project. Like the buckets. It looks like something I would have built in my earlier days. I probably would have fabricated the buckets and chain myself.
Bill Hudson
Quote from: Bernhard on November 10, 2019, 06:10:57 AM
Hauk, the supplier of the parts is Pfister Feinguss in Lengnau, Switzerland (https://www.pfister-feinguss.ch/ (https://www.pfister-feinguss.ch/)).
He told me that he wants to focus on jewellery and model making in the future. So your chances are good.
Thanks a lot for the link!
I checked out their webpage and Facebook page, and it is incredible what this company can achieve.
https://www.facebook.com/pfisterfeinguss/ (https://www.facebook.com/pfisterfeinguss/)
Scroll down to the O-scale wagon braking gear, it is almost unbelievable that it has been cast as one piece. This is truly state of the art.
Quote from: Hauk on November 11, 2019, 06:03:02 AM
I checked out their webpage and Facebook page, and it is incredible what this company can achieve.
https://www.facebook.com/pfisterfeinguss/ (https://www.facebook.com/pfisterfeinguss/)
Scroll down to the O-scale wagon braking gear, it is almost unbelievable that it has been cast as one piece. This is truly state of the art.
Wow!
Now that the problem with the buckets has been solved, it finally starts with the realization of the excavator. The first subassembly is the base frame.
For soldering most parts I use the holy grail of soldering technology, a resistance soldering device!
I also built a few adjustable stops which I can attach to the soldering plate.
This way the parts can be positioned better, as you can see here when soldering the base frame.
For the precise soldering of the wheel mountings I mill a solder jig out of an MDF board.
The frame and the four mountings are inserted into the jig and can now be soldered.
The preliminary result. The floor panel and the railing are still missing.
Bernhard
Disgustingly adequate design and fabrication. -- Russ
Fantastic!
Thanks guys.
Here we go with the travel drive, which is built into the base frame.
The main parts manufactured are the two wheel carriers, which accommodate the wheels and the motor. The first is made of a solid brass block.
After some machining work on my new milling machine (a WABECO F1200) ...
...
Quote from: Bernhard on November 18, 2019, 07:19:14 AM
After some machining work on my new milling machine (a WABECO F1200) ...
Looking sharp!
Happy with the Wabeco?
I am seriously considering buying one.
Yes, I'm very pleased. I can only recommend it. Good quality, no China rubbish.
Bernhard
Let's move on.
... the part must now be separated from the clamping attachment with a circular saw blade.
It's done! The ball bearing for the drive shaft and the two slide bearings for the axle are still missing.
The second wheel carrier is created in a similar way.
And here the provisionally mounted travel drive, still without drive motor.
This is the base frame with the mounted travel drive. A first test shows that everything rotates and moves as intended.
However, I had to separate the motor mount from the wheel carrier afterwards. Otherwise it would not have been possible to remove the drive from the base frame.
Bernhard
Good golly, Miss Molly!!!! -- Russ
Wow! Fantastic work!
Next step: the two side frames.
So that both frames are exactly the same, I mill a solder jig out of an MDF board for the assembly. I do this on the rotary table because some of the profiles are 45° inclined.
All profiles for the two frames are cut to exact length and mitred where necessary.
The material: U-profile 2.5 x 1.5 x 0.3 mm.
The profiles are placed in the jig and then soldered at the points of contact.
And here's the current result.
All sheet metal parts for the entire casing of the excavator are etched from 0.2 mm thick brass sheet.
The two frames and the cover sheets are glued together to form a solid box.
First mock-up of the finished box on the base frame.
Bernhard
Remarkable. -- Russ
Great construction and implementation, thank you for showing.
Quote from: Bernhard on December 06, 2019, 07:30:58 AM
The profiles are placed in the jig and then soldered at the points of contact.
Very interesting build!
What material did you use for the jig?
By the way, any news on the castings?
Wow!!
Excellent work! Don't tell me you solder the joints together with that match!! ;)
Jerry
Thanks guys for your interest.
Hauk:
I usually use MDF boards (medium-density fiberboard) for the soldering jigs. They can be milled very well, with clean edges. However, thin bridges tend to break off easily. For more demanding gauges, e.g. for the bucket ladder, I use Pertinax (hard paper).
I haven't received the castings yet, but I am sure that they are in progress. I will keep you up to date.
Jerry:
Fortunately I have other instruments for soldering!
The whole construction is partly soldered and partly glued.
Bernhard
The next subassembly is the chain drive.
As drive I use a small Faulhaber motor with a planetary gear.
First the drive beam is milled.
This is followed by the clamping piece for fastening the motor.
Then the two pillow blocks for the drive wheel bearing must be manufactured.
Milling the raw form.
Use a quarter-circle cutter to mill the rounding of the block.
Drill the hole, then cut off the individual parts with the circular saw blade.
The finished parts.
On the right you can see some smaller blocks which will be used on the bucket ladder.
And here's the finished drive.
The drive wheel is still missing. I will do that when the chain is ready, so that it fits exactly.
I wish you all a happy new year and a lot of fun with model building.
Bernhard
Satisfactory. Thank you for posting your progress and happy new year. -- Russ
Your work is very impressive. (I don't know enough to comment beyond that, but I recognize excellence when I see it).
Holy cow, that is some impressive work! Those tiny pillow blocks look like they're not much bigger than the eye of a needle.
Since it is actually all very small, it is a gigantic work.
Hi Bernhard.
Happy New Year.
this is a very nice piece of model engineering you are a very good machinist. Was this your profession?
cheers
Thank you for your interest, and to all a happy new year.
Kim, I'm an engineer, not a mechanic. But I worked for many years in technical sales for a company that builds special machines for the watch industry, among other things. I learned a lot from them!
Let's start the new year with the production of the casing for the drives. Here the situation on the prototype and the model.
First of all I milled again a gauge for soldering the two inner frames.
In this one the two mirrored frames are soldered.
The two finished frames.
Over the frames come the sheet metal parts, which are etched.
That's pretty good so far.
This is followed by the more complicated casing of the chain drive. The parts are also etched, and must now be assembled into a box.
Since I had little experience with etching at that time, I disassembled the casing into individual parts. It would have been simpler to draw a flat projection with bending edges.
The lower part is already finished.
The upper inner side part must be halved so that the cover can be put on later, after the chain drive wheels have been mounted.
Add a few more prominent screws, ...
... and the top is also ready.
And here's the cover.
And with that this subassembly is also finished. The cover is only loosely attached and does not fit exactly yet.
As can be seen on the prototype photo, the casing has no door. To hide the unsightly parts of the drives, I decided to give the model one.
The hinges consist of tubes with a diameter of 1/0.6 mm and strips 1.5 x 0.3 mm.
Of course, the door also needs a latch.
And there's the door.
Bernhard
If I had known it was that easy to build an excavator, I'd have built a couple last week! -- ssuR
Truly amazing work!
Quote from: finescalerr on January 05, 2020, 11:09:22 AM
If I had known it was that easy to build an excavator, I'd have built a couple last week! -- ssuR
I gather this week is fairly free for you , so I'll buy the second one you build from you .
Nick
Quote from: finescalerr on January 05, 2020, 11:09:22 AM
If I had known it was that easy to build an excavator, I'd have built a couple last week! -- ssuR
Well you certainly got the lead out ???
This could be a banner year for you! And just to bust your chops to bad you don't have a magazine to get your work published in!!! ::)
Jerry
Excellent workmanship
Barney
The next subassembly is somewhat simpler: the bucket ladder support.
Also for this part I make a soldering jig first.
The individual profiles are soldered together here.
And there's the support.
And this is how it is attached to the model
Bernhard
Disturbingly adequate. -- Russ
Marvelous!
Bernhard, if I see it that way, I might also like such a model. But such a bucket chain excavator unfortunately does not fit my "Klosterstollen".
Helmut,
I know the problem too. Recently found this video on the Internet:
https://www.youtube.com/watch?v=1RJfnk2S330 (https://www.youtube.com/watch?v=1RJfnk2S330)
Since then I've been thinking about building such a beast. It doesn't fit to my other works either, but the modelling challenge would appeal to me.
Yes, those ore unloaders of the great lakes the operator's cabin were just above the jaws he rode the arm into the hold then back out -crazy. Your bucket excavator is looking great.
cheers
Now we come to one of the more sophisticated subassemblies:
the bucket ladder.
It consists of three parts:
- The upper part, which is permanently mounted in the machine.
- The middle part, which is made up of three parts: two short headers and a long central part. This was obviously available in different lengths, because I have seen old photos of excavators that had a much shorter bucket ladder.
- The levelling piece with the chain wheels.
Let's start with the upper part.
It is important that the width of the chain guide at the bottom of the bucket ladder fits exactly, because the chain has only a few tenths of a millimeter of play.
The production is done in three steps:
1.) Solder a left and a right side frame.
2.) Connect the two side frames at the top with cross profiles.
3.) Attach the stiffeners.
First a soldering jig for the side frames is milled, this time into a Pertinax plate.
And these are the prepared parts for the whole upper part of the bucket ladder.
The two soldered side frames.
For step 2, another jig from Pertinax is milled, ...
... and soldered the cross profiles on this one.
The soldering jig is pulled out...
... and in step 3, we put the stiffeners in place.
Now the bottom plate in this piece of the bucket ladder is still missing. For this I first mill a bending jig out of wood.
A soft annealed brass sheet is bent over this. It is important that the width is exactly right, because the sheet must be fitted exactly at the bottom of the bucket ladder.
Then the excess of the sheet metal is carefully milled off. Here the milling is done in a synchronous way so that the milling cutter presses the brass sheet against the gauge and not away from it.
The U-shaped sheet is separated into two parts.
The bending gauge is converted to a soldering gauge with an additional piece.
The finished bottom plate.
And here is the finished upper part of the bucket ladder. The four support rollers for the chain are mounted only after painting, so that no paint mist gets into the bearings.
But then the nasty surprise: the bucket ladder does not fit into the excavator. I did not use a spacer for the bucket ladder when assembling the two side frames. So I had to try to push the two side frames carefully a few tenths of a millimeter apart without damaging anything.
Fortunately it worked! Now the bucket ladder can be installed.
Bernard
Hello Bernhard,
congratulations absolutely outstanding craftsmanship.
Thank you for showing.
I am so impressed, not only with this latest assembly but with the entire model so far, that I have no idea what to say. -- Russ
Incredibly impressive!!
Ditto.
Quote from: Bernhard on January 19, 2020, 02:10:43 AM
Fortunately it worked! Now the bucket ladder can be installed.
Glad it worked out. Fantastic project!
Have you received the casting for the buckets, by the way?
Quote from: finescalerr on January 19, 2020, 01:14:11 PM
I am so impressed, not only with this latest assembly but with the entire model so far, that I have no idea what to say. -- Russ
Now that's saying something!! ;)
Looks beautiful.. Excellent workmanship.
Jerry
Lovely construction work - excellent in all ways
Barney
In between some good news: 15 months (!) after ordering I finally got the buckets! I am very pleased, but see for yourself.
And out of which material did the caster cast them now? From 925 silver!
His explanation: because of the low wall thickness of 0.2 mm the liquid metal solidifies very fast, before it can fill the whole mould. He was therefore forced to cast the parts on a precious metal casting machine where temperatures of up to 1'200 °C are reached.
Fortunately, the change of material has no major impact on the price. Only CHF 9 more on the whole order, but the parts are very light.
Quality and dimensional accuracy are impeccable. I only have to adjust the parts a little bit after the sprues have been cut off.
Now I'm waiting for the laser-cut chain plates, then nothing more stands in the way of completion
Bernhard
Quote from: Bernhard on January 30, 2020, 02:14:04 AM
In between some good news: 15 months (!) after ordering I finally got the buckets! I am very pleased, but see for yourself.
And out of which material did the caster cast them now? From 925 silver!
His explanation: because of the low wall thickness of 0.2 mm the liquid metal solidifies very fast, before it can fill the whole mould. He was therefore forced to cast the parts on a precious metal casting machine where temperatures of up to 1'200 °C are reached.
Fortunately, the change of material has no major impact on the price. Only CHF 9 more on the whole order, but the parts are very light.
Quality and dimensional accuracy are impeccable. I only have to adjust the parts a little bit after the sprues have been cut off.
Now I'm waiting for the laser-cut chain plates, then nothing more stands in the way of completion
Bernhard
Insane! But the parts look great. How much in total did the parts set you back?
And how does paint adhere to silver?
Hi Hauk
For 21 buckets I finally paid CHF 340. That seems a lot in the first moment. But if you consider the work and the quality, the unit price is certainly justified. And exactly with these parts I did not want to save money. Bungled parts would definitely not fit to the excavator.
I don't want to paint the buckets because the paint is rubbed or scratched during operation. I first see if the silver tarnishes naturally. If necessary I try to chemically blacken it.
Bernhard
I think the parts are worth the price. Anything less might spoil the model. After all, if you were to place a value on the quality of your work and the time you have invested, the buckets would be inexpensive by comparison. -- Russ
There are a number of chemical blackening agents which can be used to color the silver. Check with a company which specializes in supplying materials for the trade and for hobbyists who manufacture custom jewelry.
Hello Bernhard,
please look here (https://www.youtube.com/watch?v=EFBnroFaTpg) there is something to brown for silver.
Just great what you're doing.
Those turned out great!
Quote from: Bernhard on January 30, 2020, 02:14:04 AM
In between some good news: 15 months (!) after ordering I finally got the buckets! I am very pleased, but see for yourself.
And out of which material did the caster cast them now? From 925 silver!
His explanation: because of the low wall thickness of 0.2 mm the liquid metal solidifies very fast, before it can fill the whole mould. He was therefore forced to cast the parts on a precious metal casting machine where temperatures of up to 1'200 °C are reached.
Fortunately, the change of material has no major impact on the price. Only CHF 9 more on the whole order, but the parts are very light.
Quality and dimensional accuracy are impeccable. I only have to adjust the parts a little bit after the sprues have been cut off.
Now I'm waiting for the laser-cut chain plates, then nothing more stands in the way of completion
Bernhard
Outstanding. I've heard of tiny handles and so on being cast in silver for it's higher flowability. But this is just amazing. Congrats!
I will definitely go along with the tone of all the comments.
cheers
Thanks for your interest and your advices.
But let's continue now with the middle section of the bucket ladder.
The procedure is basically the same as for the upper part.
Once again, a jig is milled into a Pertinax plate...
... the necessary parts for the two side frames are prepared, ...
... and the two side frames are soldered together.
The jig for soldering the cross profiles is made in three parts. Otherwise it could not be removed from the frame after soldering.
The outer cross profiles are soldered on.
Now the jig is unscrewed, removed from the frame and then screwed together again. Then the frame is placed upside down on the jig for soldering the internal cross sections.
Then the stiffeners are attached.
Now a few turned parts have to be made.
The chain deflection rollers are pre-turned and then, because four holes still have to be drilled in two of the rollers, they are finished on the rotary table on the milling machine.
The finished rollers.
Then a few support rollers have to be turned.
The flange bearings for the support rollers are a particular challenge.
Because they are so small, 3D printing is out of question, and I have no access to a CNC machine for milling.
My good friend Werner finally stepped in and milled the parts for me on his copy milling machine.
For this purpose I prepared two models made of aluminum. These are 5 times bigger than the workpieces.
The finished parts, milled from the solid with a 1 mm milling cutter!
Unfortunately it is difficult to photograph the parts adequately with the mobile phone camera.
And this is the new, provisionally attached part of the bucket ladder. Here, too, the rollers are not mounted until after painting.
Bernhard
Most satisfactory. How long did it take to complete the work you have just described? -- Russ
Engineering in miniature thats what its all about - an excellent project
Barney
Extremely beautiful work. But I would like to know where you found that giant match that you show with the parts.
Bill Hudson
Amazing stuff!
Russ:
I didn't write down the hours. In any case, this is a long-term project.
I started in April 2017 with a visit to the Feldbahnmuseum Wiesloch and measuring the excavator. Then about a year passed until the 3D model and all details were drawn. Since then I am working on the realization. Next week I should get the last missing parts, the laser-cut chain links. Then I just have to assemble the chain, paint everything and finish it - and then I have to look for a new project.
Although I'm retired, of course I didn't work on the bucket chain excavator all the time. I also built other models in between, and I also have other interests.
Bill:
The match is a special design for people who can't see too well.
That's about the amount of time and effort I expected, Bernhard. Nobody can build a model of such superb quality by taking shortcuts. -- Russ
The levelling piece on the bucket ladder is still missing. Fortunately, this is a little easier to build.
The side parts are also soldered together in a jig.
For soldering the cross profiles I use again the jig for the middle part of the bucket ladder.
And also on this part some stiffeners have to be added.
The two chain deflection rollers are pre-turned first.
Then the inner contour is milled out on the rotary table on the milling machine.
This is where it gets exciting. Now the spaces between the spokes must be milled free with a 1 mm milling cutter.
After I broke off six cutters, my friend Werner sharpened a single cutter for me, which is a bit more stable. With this I could finish milling both rollers without breaking any more tools.
Then the rollers must be carefully cut off from the tensioning attachments.
Finally, the ribs are attached to the spokes, then the pulleys are ready.
But they are not mounted until the chain is finished. The chain gets the right tension due to the final position of these rollers.
Further I need two hangers with pulleys, from which the bucket ladder and the levelling piece are suspended.
Both brackets have the same function, but look different. Obviously at that time they used what was at hand.
The hangers are brought into shape with the help of two bending gauges.
The finished hangers.
And here the finished, pre-assembled bucket ladder on the excavator.
When I look at the result now I have to say: the builders of the excavator knew what they were doing. Although the construction seems to be quite fragile, it is surprisingly stable, even in the model.
Bernard
That is excellent work!
You have some serious modeling skills! -- Russ
Beautiful work!!
Jerry
Holy cats, that is some terrific work! The construction of the spoked rollers alone is impressive!
Thanks, guys, for reading along.
Now a few smaller attachments have to be realized.
Let's start there with the winches for adjusting the bucket ladder.
First, two pillow block bearings are created for the pulleys.
The rope drums are turned quickly.
Now we need four side plates.
I found the worms and worm wheels at a supplier for micro model parts in the internet.
Now the crank and the clamps. As on the original the crank can be removed of course.
And this is what it looks like when it is attached.
Bernard
Nice!
Phew, that is some nice work. Just for nitpicking: Did you manage to get those helically toothed gears visible inzthe prototype pic? It's not obvious from the picture.
Cheers,
Volker
The what Volker?
Outstanding model Bernhard. How are you going to finish it?
cheers
Hi Volker
Here a better picture of the winches. For the model I found worm wheels with 30 teeth and module 0.2.
Hi Kim
Last week I got the last parts, the laser-cut chain links. Now I just have to assemble everything (the chain consists of 512 parts!) and paint it. Peanuts!
Bernard
Bernhard,
thanks for the picture. Which diameter is such a worm wheel?
Volker
Volker, the worm has the following data: m = 0.2 / dt = 2.4 mm / L = 3.5 mm. The worm wheel: m = 0.2 / z = 30 / dt = 6 mm / B = 1 mm. I found the parts here: https://www.sol-expert-group.de/ (https://www.sol-expert-group.de/).
The next small assembly is the closing flap on the discharge hopper.
The flap is used to close the discharge hopper, while a full tipper truck is exchanged for an empty one while the excavator is running.
The flap is soldered together on a small jig.
Then there are a few small levers to be done.
Screw the small levers together with M0.8 screws, ...
... and the movable flap is ready.
Bernhard
Your work is unbelievable!!
Jerry
Most satisfactory. -- Russ
Brilliant!
Amazing Bernard!
Thank you, guys. I hope you are all healthy.
Continue by the bucket chain excavator with the railing on the operator platform.Originally, the operator's platform was provided with a weather protection. The photo shows the excavator in its original condition, before the recovery and restoration.
Photo from http://www.feldbahn-riedlhuette.de/Riedlhuette/2010_Eiselfing_Bergung_Eimerkettenbagger_und_Steinbrecher/2010_Bilderuebersicht_Nr_B.htm (http://www.feldbahn-riedlhuette.de/Riedlhuette/2010_Eiselfing_Bergung_Eimerkettenbagger_und_Steinbrecher/2010_Bilderuebersicht_Nr_B.htm)
But I'll rebuild it to its present condition.
The necessary parts are quickly made.
A slot must be milled in the base plate.
And the parts can already be assembled.
The last attachments are now the handbrake and the gear levers for operating the excavator.
The hand brake with the characteristic cast crank.
The two levers (one for switching the chain on and off, and one for selecting the direction of travel) and the bearing block.
The gate for the locking of the gear levers.
And all attached to the excavator.
Now the next important work is on the agenda: mounting the chain with the buckets.
Until then: stay healthy!
Bernard
Phew, this keeps being amazing. What a pity you decided to build it in the current state. The hood had a lot of character!
It is impressive to see this project progress.
It gets better as you go.
I suspect the lad has a modicum of talent. -- Russ
Awesome!
The housing for the operator certainly was interesting.
Thanks, guys.
Hydrostat and Ray, I'm sure you have a point. But with the housing, you wouldn't have been able to see all the nice details like for example the winches. I also like the clean lines and the highly visible construction of the excavator without the housing.
Bernhard
I was looking through my archives last night and found a huge archive of lo-res Feldbahn photos. One caught my eye and I've attached it. I have no idea who the modeler is or how old the photo might be although it's probably no more than about 15 years old. -- Russ
Quote from: finescalerr on March 31, 2020, 11:47:48 AM
I was looking through my archives last night and found a huge archive of lo-res Feldbahn photos. One caught my eye and I've attached it. I have no idea who the modeler is or how old the photo might be although it's probably no more than about 15 years old. -- Russ
I have also been collecting photos of eimerkettenbaggers (that's German for bucket chain excavators!) for a number of years and also have that image in my collection. However , I can't access them at the moment .
I still can't see why Bernhard couldn't build two at the same time and sell one to me !
Feel free to post more Feldhahn photos . I can't get enough of them .
Nick in plague free Shropshire (well , almost) .
Hi Bernard.
Really a piece of wonderful jewelry.
cheers
I would never have guessed that anyone else had also built a model of that excavator.
Thank you guys for your interest.
Russ, thanks so much for posting. I also have quite a collection of pictures, but I've never seen this before. Definitely an excellent model. It's always inspiring to see things like this.
Nick, if I were to get a model like that paid by the hour, you'd probably have to rob a bank. Besides, I just don't have the time because I've got so many projects in the drawer.
Stay healthy
Bernhard
Quote from: Bernhard on April 01, 2020, 01:43:23 AM
Thank you guys for your interest.
Russ, thanks so much for posting. I also have quite a collection of pictures, but I've never seen this before. Definitely an excellent model. It's always inspiring to see things like this.
Nick, if I were to get a model like that paid by the hour, you'd probably have to rob a bank. Besides, I just don't have the time because I've got so many projects in the drawer.
Stay healthy
Bernhard
Bernhard,
I have been looking to move on some of the money I got when me and the gang hijacked the armoured payroll truck the other year and one of your machines would fit the bill nicely . Just let me know when it is done and I will forward the cash to you . Rubles OK for you ?!
Here is one in action that I think I saw at a show in Germany a few years ago . Obviously not as good as yours , but not bad all the same . https://m.youtube.com/watch?v=LIgKT05FDl4.
I look forward to seeing what else you have got in the drawer , other than your socks !
Keep up the exceptional work,
Nick
Nick, we'd better talk about those rubles in private.
Nice video. The model may be a little rough, but at least it runs. I'd be amazed at the scale it's built to.
I will report on my other projects in due course. Stay curious.
Bernard
I hope you are all healthy and in good spirits despite the lockdown.
The last big challenge before painting and assembly is the assembly of the chain with the buckets.
The chain consists of
282 links, the inner ones with a thickness of 0.5 mm, the outer ones with 0.3 mm
188 rivets
16 spacers
16 buckets
This means a total of 502 parts, which now have to be assembled.
The stretched length of a chain strand is 601.6 mm.
It's gonna be a real patience job. So here we go.
For a long time I have been thinking about how I can produce so many chain links rationally. Finally I decided to have them etched from nickel silver.
The etched plates looked good so far.
On closer inspection, however, a few serious problems became apparent:
- Seen with a magnifying glass, the edges of the parts look like in the sketch below. This is actually normal, and is neither noticeable nor significant for other parts. With the links, however, it can be seen with the naked eye, and the contact area of the chain is reduced by 2/3 of the thickness.
- But the more serious problem is that the parts were slightly too big. I had considered the undercutting in the drawing, but apparently the effect cannot be quantified exactly. Unfortunately, the masses were different for the two sheet thicknesses.
The holes were too small in the 0.3 mm links and not properly etched through in the 0.5 mm links.
Conclusion: normally I have made good experiences with etched parts. In this case, however, the whole production is sent to the bin as unusable.
After a lot of thought I decided to try laser cutting.
When I showed the parts to a sheet metal processing company near us, they just laughed. Their laser cutter has a working range of 3 x 4 m and can cut sheets up to 25 mm.
Finally I found a supplier in Germany who made the links for me, for a however sinful price.
The pleasing result: the parts are absolutely accurate to size. The rivets and the spacers fit into the holes without rework.
However, all 282 parts have a fine cinder burr on the underside, which I have to remove on a whetstone.
After the tip of my right index finger has grown back, all parts are now ready for the assembly of the chain.
I start the assembly by assembling chain sections with 6 links.
For this I have milled a gauge from Pertinax again.
The outer and middle links are inserted into it. I painted the ends of the links with a felt pen. This is to prevent that solder flows into the chain when the rivet is soldered and the links are soldered as well.
Now a layer of cigarette paper is inserted to ensure minimal play between the links.
Then the inner links are put on and the rivets are soldered to them.
The first of 32 sections is ready. The rivets still have to be shortened and sanded.
Now the complete chain is assembled step by step from the parts. For this purpose I have made another jig from Pertinax.
Two sections are added to the chain. Then the spacer is soldered in.
Then the bucket is soldered to the two chain strands with the resistance soldering device.
Thus the chain grows bit by bit.
And now once again there is frustration and standstill on the bench. I have ordered 200 rivets, but somehow 6 are missing now to finish the chain! And the supplier of the rivets has closed the shop because of Covid19.
Let's wait and see, and get on with the sprocket.
Stay healthy and creative!
Bernhard
Bernhard, Despite etchings that got binned, laser cinder burr removing, cleaning, aligning, soldering, assembling
most of 502 parts al you have lost is 6 rivets. I would have lost what is left of my mind! Fantastic work!
Wunderbar !
Thanks, guys. Bill, luckily I have other projects to help me pass the waiting time.
Bernhard
Who made your rivets? and what size are they?
Bill Hudson
Hello Bernhard, was you needed for rivets maybe I can help out.
Thanks for your help, guys.
The size of the rivets is 0.8 mm, and they have a special head. So I want to use the same ones again to make sure the chain is exactly the same width over the whole length. That's important so it doesn't jam. I got them from the Knupfer company in German. Replenishment is ordered, but I have no confirmation yet. I don't know if they can and want to deliver to Switzerland.
Bernhard
Just outstanding, excellent demonstration of fine scale modeling.
Bernhard, if you tell me you are building the model just to keep your hands busy and, since you have limited space where you live, you plan to throw it out or give it away when it is complete ... I will murder you ... even though your patience and craftsmanship are satisfactory. -- Russ
What mind-boggling work! Fantastic!
When this wonderful is complete and time comes when you need to make room for something else, I'm sure there must be a museum somewhere that would love to have it.
Russ and Ray, don't worry, I plan to build a second module for the bucket chain excavator to present it on. However, I actually have quite little space in my workshop, because my 4 x 2 m H0 layout is still standing there and slowly getting dusty. I will probably have to part with it soon.
Bernhard
Hmmm, why do I always have the impression this must be a watchmaker at work??? ::)
Peter, you're not entirely wrong. In fact, for many years I sold machines for making watch parts.
Bernhard
Bernhard, you must find a place in your home to display, or at least store, your model permanently. -- Russ
Meanwhile the reordered rivets have arrived and the chain is finally assembled. It is easy to move along the whole length, and fits (very tightly) into the guides in the bucket ladder.
While I was waiting for the missing rivets, I made the chain drive wheels, ...
... and soldered them together in a soldering jig exactly fitting the width of the chain.
The finished chain drive wheel, ...
... and this is what the chain drive looks like when provisionally assembled.
For the next step I will disassemble the excavator completely, clean all parts in an ultrasonic bath and prepare them for painting.
Bernard
Flawless.
Satisfactory. -- Russ
Excellent - +5 stars
Barney
After dismantling the individual subassemblies once again in the overview:
The travel drive
The cain drive
The closing flap for the discharge hopper
The upper section of the bucket ladder
The middle section of the bucket ladder
The levelling piece
The bucket ladder support
The chain with the buckets
A few small parts, among others the builders plate
In the first step all loose small parts are chemically blackened.
The remaining parts are prepared for priming.
For primer I have chosen this time a solvent-based paint for industrial application, but it can be applied with the airbrush gun if diluted appropriately.
But this happens if you spray this paint too dry (with too much air, too little paint): it solidifies in the air to a candyfloss like web. This must be carefully removed before further painting.
After drying, the primer appears in a light rust red. This corresponds almost exactly to the color tone, which, weathered and faded, is still partially visible on the prototype.
Now follows the "rusting" of the surfaces. This is quite time-consuming. The paint is not sprayed, but different brown and rust tones are dabbed on with a small sponge. Finally a brown/grey wash is applied.
The surface with the rust and the partly underneath still visible primer does not correspond badly to the prototype.
Now the bucket chain excavator can be reassembled step by step.
Bernhard
The painting and assembling are looking very good.
The "candy floss" from spraying the paint looks like cobwebs coated with flakes of rust.
Hello Bernhard
Great work! The rusty surface ist very well reproduced.
Satisfactory.
At this point I shall disclose that, in contrast to Bernhard's clean, neat organization, during construction my workbench and sub-assemblies generally resemble the devastation from a large bomb explosion. Some have suggested I look like that, too.
Russ
Fantastic! The rusty/faded/worn paint looks very authentic.
That candy floss is interesting, I've never seen that happen before.
Simply successful Swiss precision work.
Thanks guys for still following this thread.
There are successes to report. The bucket chain excavator can finally be assembled definitely!
First the closing flap is attached to the discharge hopper.
Next, traction drive and chain drive are installed again.
The bucket ladder support follows. The guy ropes are made of stainless steel with a diameter of 0.27 mm and 49 (!) strands.
Now the chain support rollers must be mounted on the upper part of the bucket ladder, ...
... then it can be installed in the frame.
Then the chain support rollers are attached to the middle part of the bucket ladder.
On a piece of track the bucket chain excavator can be provisionally installed.
The middle part of the bucket ladder is installed.
Now the chain can finally be pulled in for the first time. But I had to find out that the 4 pulleys at the joints of the bucket ladder are 0.9 mm too big. After I had made a suitable replacement, the chain could be pulled in completely.
Now also the levelling piece can be finished. The carrier for the deflection rollers must be positioned so that the closed chain has the correct pre-tension.
It fits!
This allows the levelling piece to be painted and completed, ...
... and then installed.
Finally, the adjusting ropes for the bucket ladder and the levelling piece are mounted. These are also made of 0.27 mm stainless steel.
And with that the bucket ladder excavator is finally finished!
On closer inspection of the photos, I saw that the ropes are partly not lying correctly on the pulleys and the rope drums. This will of course be corrected. Furthermore I will patinate the ropes.
The only downer: I decided with a heavy heart to remove the chain drive. In fact, the chain is very difficult to pull through the guides due to the low clearance. The risk is too great that it will tear through the operation.
If the model is now unfortunately not functional, it is at least absolutely scale. On this scale it is difficult to meet both requirements at the same time.
The project has kept me busy since April 2017, with some more or less long interruptions.
...
...
...
Let's move on to the next project!
Bernhard
Bernhard, I hope you are not too disappointed that the chain drive isn't fully finctional. In this situation your choice of absolute accurate scale was a good one.
The completed model is fantastic. The fact that it also might have worked is phenominal! Before moving on to your next project I will linger here to admire
what you have built!
See how simple that was?
Now, to amplify what Bill wrote: Your model need not function to be superb. Many stunning models on this forum are static. After all, they are MODELS.
This is a very impressive project. Most satisfactory.
Russ
iTS FANTASTIC !!! Miniature engineering at its best - just keep the excellent work coming and I agree with others most models don't always have to work
Barney
What an exceptional model!
Jerry
I am afraid I have to disagree with the others , and that you have failed miserably . How hard can it be to make it operational ? If they can do it in 1:1 Scale surely you should be able to do it in 1:35 Scale . That is just not good enough . All you can do now is to box it up and send it to me . I will then look after it and examine it in fine detail and will prepare a report to explain where you went wrong . You will then be able to act on my report when you make the next one .
In addition I have in my possession a number of suitable diesel locomotives and skips to build a diorama . This could then go some way to reducing the disappointment of your sub-par model .
Please don't take this as criticism , but we all need to learn from our mistakes .
Nick
Nick, thanks for your generous offer. But I already know what the problem is. It's the rivet heads on the outside of the chain that sometimes hook the guide at the bottom of the bucket ladder when run in. This guide is interrupted at every part of the bucket ladder, which multiplies the problem areas.
But at least the excavator moves back and forth, and the adjustment of the bucket ladder is functional.
And of course I will build a small diorama on which the bucket chain excavator can be presented adequately. I will report about it.
Bernard
Nick, go stand in the corner ... again! -- ssuR
And Stay there !! and while you are doing nothing build one yourself !!! Or finish off my Keystone Skimmer
Barney
Even without being fully functional this model is still a marvel to behold! The fault is not in the model but in the fact that real-world physics can't be scaled down to match it.