Another sawmill

[Hauk]

A little progress report on the mill.
I am not very familiar with the proper terms, but here is a little essay in making the legs for the sawbench. Please feel free to insert proper terms!


The legs are built in a sort of "two sets in one" fashion.


Sanding one of the legs. Even the double length of the legs makes for a pretty short piece.


The frame  is then cut in two.


Sanding the legs to exact length.


Test setup of the bench.



Next up is diagonal bracing. A lot of angles to be sanded, but that is the next chapter!

[finescalerr]

I just learned one important thing: To make more jigs for sanding and construction. I didn't realize how many are necessary for excellent results. -- Russ

[Frederic Testard]

That's totally right, Russ. Even pieces that will be done only once sometimes require jigs. Reproductibility is one point, and accuracy is another one.

[Ray Dunakin]

I like that sanding jig -- good idea!

What are you using for the chopping jig, with the slider?

[jacq01]

  Havard,

  this coming along very nicely.
  To make most of the parts of my mill, simple purpose jigs were extensively used.
  The sawblades you treated, look very good, the last 2 series are in my opinion too heavily treated.  The blades look like burned metal.

  Btw. Norgwegion bands are not always dull. Last weekend, in a town close to mine, a norwegion hardmetal band Mayhem, was arrested and locked up as they wrecked their hotelroom completely. Damages in excess of Euro 5000,- plus staying costs.  They were released this afternoon after the money was paid by their manager.

  Jacq

[Hauk]

I like that sanding jig -- good idea!

What are you using for the chopping jig, with the slider?

It´s the lesser used end of an vernier caliper!

Since the legs were going to bee sanded after cutting it was ok to just use a single edge razor blade and a free-hand cut.

Regards, HH

[Hauk]

  this coming along very nicely.
  To make most of the parts of my mill, simple purpose jigs were extensively used.
  The sawblades you treated, look very good, the last 2 series are in my opinion too heavily treated.  The blades look like burned metal.

  Btw. Norgwegion bands are not always dull. Last weekend, in a town close to mine, a norwegion hardmetal band Mayhem, was arrested and locked up as they wrecked their hotelroom completely. Damages in excess of Euro 5000,- plus staying costs.  They were released this afternoon after the money was paid by their manager.

Jacq

Thanks for the feedback!
I agree that the blades are somewhat too dark. It could all have been solved by blades etched in steel or nickel silver...

I would love to see some of your jigs, I have not made any real jigs for this project other than the totally overkill CNC milled corian ones:


I am also a bit unhappy with the strength of my glue joints. My procedure for gluing is this:

1. Sand to get as good a glue surface as possible as possible
2. Remove dust with damp rag.
3. Pre glue both parts with thinned white glue. Let dry
4. Glue parts with full-strength white glue.
5. Always clamp or weigh down

Suggestions for improvement?

Regards, Håvard H

[marc_reusser]

Wow impressive Corian jig!

I don't know if it helps re. the gluing, but I tend to use the yellow carpenters glue instead of white glue, IMO it bonds better and dries quicker.

I do have a question re. your approach to staining though....curious as to your process. I see that you stain and then cut your pieces. Seems a bit odd to me because you then have to go back in and touch-up ends, and risk the chance of having unstained areas/slivers show somewhere. You also risk loosening/softening any glue joints when/if you stain after assembly. I personally tend to cut all my pieces, stain them, and then assemble.

M

[jacq01]

  Havard,

  I'll have a look around. As most are/were purpose made, many have been discarded after use. Limited life after the required amount.
  Pending on amount needed I used styrene/carton/wood as a jig, much like you have done.
  I'll take pictures of the concrete casting jigs and other ones I'll make.

  Jacq

[Hauk]

Wow impressive Corian jig!

I don't know if it helps re. the gluing, but I tend to use the yellow carpenters glue instead of white glue, IMO it bonds better and dries quicker.

I do have a question re. your approach to staining though....curious as to your process. I see that you stain and then cut your pieces. Seems a bit odd to me because you then have to go back in and touch-up ends, and risk the chance of having unstained areas/slivers show somewhere. You also risk loosening/softening any glue joints when/if you stain after assembly. I personally tend to cut all my pieces, stain them, and then assemble.

M

I am almost hesitant to show those corian jigs, they are just too much. But when you have unlimited access to a CNC mill and corian, such things are bound to happen!

I have read about this yellow glue in the american model press, but I havent been able to translate it into a locally available product. Have to look into it.

Regarding the staining approach, I like to stain full lenghts of stripwood. I belive this is faster, even if I have to touch up cutting ends.
I have never really thought about it , but another reason I just came up is that the ends takes stain much better than the sides, so they need far fewer layer of stains. I don´t know if that made any sense really!

Regards, Håvard H

[marc_reusser]

Havard,

It does make sense...in a pragmatic way. I guess I just see it as more work, more difficult and a better chance of something going wrong.   

I find an advantage of staining the precut wood is also the chance for more randomness/variation among wood color, because you can leave in assorted pieces for different lenths of time, and in different shades of stain (yes, you can do this with whole pieces as well...but there the human tendency is to cut sim. pieces/parts from the same strip...so each of those will have the same coloring). The other part is that you dont have to re-sand and then touch up the faces of the pieces where you had to sand/clean-up after sanding the ends.

....just a different way.

The yellow glue here is typically called/sold as  "Carpenters Glue" and it is made by several mfrs.  There is even one that is more brownish than yellow, that is waterproof when dry.....though I don't use this on my structures.  Maybe check with local wood-working suppliers?

M

[MrBrownstone]

Hey Hauk,

Man I really like that Jig you made.... overkill I think not.... would work just fine for me...  

I am going to start back on the train stop build when I get back to LA. (looks like I will be away from home for a couple more weeks)

Mike

[lab-dad]

I use yellow "carpenters glue" also
May be Nick O will chime in and translate for us (him being a carpenter of sorts over there)
I bet we would all like to get one of those corian jigs!
Wonder if Santa has access to a CNC and some ........
-Mj

[shropshire lad]

I use yellow "carpenters glue" also
May be Nick O will chime in and translate for us (him being a carpenter of sorts over there)
I bet we would all like to get one of those corian jigs!
Wonder if Santa has access to a CNC and some ........
-Mj

  What word(s) are you having problems with in particular ?  Is it "carpenter" or is it "glue" , or both ? If you can be a bit more specific then I might be able to help .

  Nick ( calling me a carpenter might be putting it a bit strong . More like "wood butcher" )

[RoughboyModelworks]

I am also a bit unhappy with the strength of my glue joints. My procedure for gluing is this:
Regards, Håvard H

Havard:

The reason you're having problems with glue joints is that end grain has NO glue strength. The framing in your photograph is entirely assembled with butt joints, one of the weakest joints in wood-working. This is one of the primary joint lessons you learn as an apprentice cabinet-maker. We had it beaten into us. That's why we've developed half-lap joints, dovetail joints, mortice & tenon joints, and so on. The purpose of joint design is to overcome the inherent weakness of end grain joints in as economic a fashion as possible. Regardless of the size of the wood involved or the glue used, end-grain has no glue strength. Think of wood grain as a bunch of fibers and channels (which is essentially what it is). When glued along the sides or face, the glue will wrap around the fibers and form a reasonably solid connection. However, when you put glue on end grain, it travels down the length of the fibers and channels away from the joint face and has nothing to grab on to relative to the joint. Any joint that relies solely on glue will be much weaker than a joint that derives its strength from glue in combination with a sound mechanical connection.

Now, in modelwork, often the pieces to be joined are small and there is no strain on the joint so you can get away with gluing end-grain joints in very small pieces. Ultimately, however, they will fail. If you need strength, such as for the floor framing, you would do well to cut rebates into the stringers for the cross members to fit into when glued. This can be done easily with a jig on a miniature table saw, such as the Preac. I published an article titled "A Sticky Subject" on this issue and the gluing method described briefly below in Issue 31 of the Narrow Gauge & Industrial Railway Modelling Review. There are also some drawings of basic woodworking joints. It's been out-of-print for a while, so perhaps it's time to republish that piece on the blog.

If you don't want to go to that trouble, then you might try the old Ambroid/Acetone glue method. I've used this exclusively for years on model wood-frame construction. Essentially you dilute Ambroid cement in Acetone. I've found about a 40% Ambroid/60% Acetone mix seems to work best but you should experiment. The important thing is you want it thin enough to brush without building up a thick layer of cement. Then, precoat both pieces in the precise area to be joined. On end grain pieces, put on 2 or 3 coats. It will absorb into the end grain of the wood. Let it dry, then assemble the pieces into position in your jig. Once in place, flow a drop or two of straight Acetone into the assembled joint. It will quickly flow into the joint and evaporate from the outside surfaces. It will soften the inner layers of Ambroid/Acetone mix on opposing faces of the joint and effectively weld the two pieces together. This can be done with pre-stained and weathered pieces, though not pieces that have a heavy layer of paint on them in the joint areas, as long as you're careful with the Acetone. It's an old technique and one that I've found to be very reliable, quick, clean and strong as long as you work carefully. I have board-by-board plank-on-frame structure models that have been built this way that have withstood packing, shipping and several moves with no broken glue joints.

Paul