Home made tools? Lets see them!

[Hauk]

Ambitious model builders often need tools that can´t be found on the shelves of Home Depot (Or Clas Ohlson for us Scandinavians).
Using the Internet it is incredible what you can get hold of, but still there are tasks that nobody has made a tool for, or the special tools are just too damn expencive.

Making your own tools could be an option. 
Here are some tools that for me have turned out to be absolutely lifesavers.



This sanding jig was made when I faced the task of making a lot of mitered corners on an architectural model in wood. Precision and neatness did count, to make a long story short.  The jig was built to be used in combination with a large horizontal stational power sander (clamp the wood  and place jig on sanding belt until the aluminium is all that touches the sand paper.) but it also works on a piece of plate glass with a sheet of emery cloth taped down with double sided tape. In the contact area with the wood I  machined  a broad (around 2-3" wide) slot with a depth of around 0,5 mm. Not absolutely neccesary, but it makes it so much easier to get the 90deg angle in addition to the 45deg angle. The jig is built so the 45deg angle comes out a bit sharper to ensure a good fit when gluing.


For gluing the parts I built this corner clamp. Not my invention, I know. But i needed one fast, and cheap. Having access to a large mill at the time, I machined the faces in a similiar fashion to the jig. Helps a lot to get parts aligned up.

Last, the "Pièce de résistance" (Pun absolutely intended). I am totally addicted to resistance soldering, and I had for a long time wanted a tweezer type hand piece. A price tag of around $ 140 is a bit stiff, so I decided to try to make my own set:



You need hefty electrical wires ( I used regular 220V cables), good bananaplugs and be sure to make nice, snug soldered or terminal type conections. Or else you end up with heat in all the wrong places.

I like to brag, so I can assure you that this little beauty works like a charm! That it took me so long to make this gem is one of the great mysteries of the universe. Some of the parts I need to hold during soldering is smaller than a grain of rice, so I can´t even begin to explain how nice it is to have a  tweezer that is also a soldering iron that can you turn on and off with just a flick of a (foot)switch!

So what is *your* favourite home made tool?

[finescalerr]

I us a brass bar as a straight-edge. That is about the limit of my ability to create a tool, much like pushing "start" on a microwave oven is about the limit of my cooking skills. Is it any wonder, then, that I find your tools impressive? -- Russ

[Ray Dunakin]

So far my homemade tool list is pretty short. There's the "piece of hacksaw blade mounted in an X-acto handle" that I used to scribe simulated wood grain into styrene siding. Then there's the "brass toothpick" with one end rounded, which I used when sculpting figures.

One thing I've always wondered about... on those resistance soldering things, isn't there a risk of electrocution if your hand slips and comes into contact with the electrodes?

[MrBrownstone]

Hey are not those "ColdHeat" handheld soldering things resistance soldering tech

It would explain how 4 double A's can solder in seconds,  I have one and it works pretty good on PC boards useing silver solder.

Just really never investigated it's inner workings.. I now have a reason though... 

Mike

[RoughboyModelworks]

much like pushing "start" on a microwave oven is about the limit of my cooking skills. -- Russ

Well now I know why you've always been so svelte...

Paul

[Hauk]

One thing I've always wondered about... on those resistance soldering things, isn't there a risk of electrocution if your hand slips and comes into contact with the electrodes?

In practice, I think it is almost impossible to get an electric shock from the output of a resistance soldering unit.
I use the tweezers with my fingers in firm contact with both brass bars. Never felt a thing.

[marc_reusser]

Great stuff Havard.  I am sure it is completely safe....but you are a far braver sould than me to make a home-made resistance set. 

Good thread.....just sorry, I don't really have anything much to share...I tend to make/rig-up/improvise all my needed tools, jigs and stuff as I go...and they are usually just short-use/disposable items.  Those that I do keep/have are just basic substrates to work with...such as a glass plate laminated with various grades of sand-paper, or an acrylic bed for the mill that can be fly-cut level to to maintain perpendicular (and has lips and edges that are milled into it to fit parts/pieces square to the mill without a lot of measuring and set-up).....or something as basic as small blocks of wood with sized hole in them to hold glue and paint bottles from tipping over when I am working with them.

[Hauk]

Great stuff Havard.  I am sure it is completely safe....but you are a far braver sould than me to make a home-made resistance set. 

Not that brave, actually. The transformer and footswitch was bought readymade. Only made the tweezers myself to save some money.

By the way, the RSU setup was one of my best modelling investment. I still can´t use a regular soldering iron worth a damn.

-Håvard

[Younger]

Althougn not original or unique, I have a selection of squared blocks of aluminum and brass, useful for weighting an assembly, providing an edge to "bump" two pieces together for gluing, providing an instant square corner, etc.

One of the things I use frequently are a couple of miniature T-squares, one commercial and one homemade. I use them to create and work out simple designs on 4" x 6" file card stock. As the cards are square, I can use the T-squares on all four sides to draw my lines. I also use the T-squares on squared pieces of styrene to layout simple assembly jigs.

Two strips of styrene glued together create a spacing tool for assembling lapped siding. The tool "hooks" the previous siding piece to provide the correct spacing for the next piece. The picture should be self explanatory.

-Younger

[RoughboyModelworks]

This Marking Knife is a tool I made twenty years ago and continue to use on a regular basis. I published an article on the design, construction and use of Marking Knives back in 1996 in the Narrow Gauge & Industrial Railway Modelling Review, Issue 26. I just updated and republished that article on the Roughboy blog. Rather than repeat all that here again, I've just posted the pics and brief text to explain why you need to make yourself one of these and throw out all those scribers, pencils, pens and ultra-fine point sharpies you use for layout work... 



The most important feature about the Marking Knife is its blade. Made from a high-speed steel cabinet scraper, it is bevelled on one side only, the back side is lapped flat. It is equally effective on wood, cardstock, styrene or metal. The contrasting woods on the handle are not for aesthetic purposes but serve a specific function that greatly increases the ease of use of the tool, as explained below. The rendering below shows the basic construction, something you can make in a few hours. For more details of the construction, materials and info on proper sharpening, check out the article on the blog.



Why is this knife better than a sharp hobby knife, scalpel, any other sharp double-bevel knife, scriber, pencil, marker or pen? The answer lies in the blade's flat back. As the drawings below illustrate, the flat back allows the knife to line up precisely with the straight edge and mark a vertical line precisely at the indicated dimension. All the other implements, being bevelled on both sides or round, will scribe a line at some distance from the straight edge causing inaccuracy. This distance will vary depending on how the tool is held while the line is being marked. Pencils and markers have the added disadvantage that the point wears down as the lines are being marked, introducing even more inaccuracy. And, is it the left edge, center or right edge of the pencil or marker line that is your desired dimension? In addition, the double bevel edge and conical points of scribers and pencils will tend, especially when marking on wood, to follow the grain pattern of the wood introducing more inaccuracy. The single-bevel blade uses this tendency to its advantage. The pressure of the grain on the front bevel serves to push the flat back of the blade against the straight edge, making it much easier to mark accurate layout lines. If you are working with wood and plan to remove stock with a chisel, say cutting a joint, you can insert the edge of the chisel in the line produced by the marking knife for absolute accuracy (assuming your chisel is sharp that is). You now have a layout tool that will fully exploit the accuracy inherent in precision squares and straight edges. You will no longer need to scribe a reasonably accurate line, cut your stock extra long, then take it to the sander to sand up to almost the right dimension, then continue the sand-test, sand-test, sand-test process to get a correctly dimensioned piece. Measure twice, cut once is the rule.



The reason for the contrasting woods on the handle? This provides a very simple method of discerning the back from the front of the blade while working, without having to examine the knife edge itself. This is more important than you might think. If you are holding a straight edge in position on a piece of stock, your eyes are focused on maintaining the correct position of the straight edge. You don't want to look away to determine which is the front or back of your marking knife before marking your layout line. By looking away, your straight edge is likely to move. The contrasting woods make it very easy to determine the back from the front without averting your eyes.

Paul

[MrBrownstone]

Hey Paul,

I totally agree... with the one sided bevel

I use something very close to what you made (the red hand pad is the flat side of the knife)... BTW I like that alot... how big is it?
you sell those?

Mike

[RoughboyModelworks]

Thanks Mike... no I don't sell them. Besides, everyone here has the skills to make their own . Make yourself another blade, pointed like in my example and you'll have a marking knife. By the way, the two cutting edges coming to a point allow the knife to be used right or left-handed. The knife is 3/4" W. and 5 1/2" L., large enough to handle easily and give you good control but not so big as to be too bulky in the hand. I think if I had to make one again, I'd put shallow finger depressions on the sides of the knife where the handle pieces taper towards the blade, but it's worked fine as it is for twenty years so there's not much incentive to do that, just a thought.

Paul

[Krusty]

I find the usual rivet embossing tools, designed for use with brass or nickel-silver sheet, a bit too heavy duty to really work well with styrene. Instead I prefer to use simple presses knocked up from 50mm brass hinges.

The male part is a piece of steel spring wire turned to a point at the business end. The stump is a short piece of brass or bronze wire. A hole is drilled in each wing of the hinge, more-or-less in line, then the punch is soldered into one wing and the stump into the other. They should protrude enough to make contact with each other when the two wings of the hinge are parallel. The punch is tapped against the stump  to centre punch it, then a hole is drilled in the stump the diameter of the rivets to be represented. The depth of the hole isn't important, but it should be quite a bit deeper than the rivets are high. For larger rivets the very tip of the punch can now be just slightly rounded off with emery polishing paper – just enough so that it will push the styrene into the hole in the stump, not punch a hole. The edges of the stump are filed back to leave just a thin wall equal to the gap between the most closely-spaced rivets that are to be reproduced.

[Krusty]

The position of the rivets-to-be is best indicated by the faintest of scribe lines on the back of the styrene sheet. You can then slide the tip of the punch into this groove, thereby ensuring that they end up in a straight line. The spacing of the rivets along the line can be marked in pencil, or with closely-spaced rivets, if you have a reasonably sensitive touch, you can form one rivet then slide the stump up to it, so that the thickness of its wall sets the spacing. Then it's just a matter of pressing the two halves of the hinge together to emboss the rivets. You can feel the amount of resistance in the styrene sheet increase as you get close to the finished height of the rivet, making it easy to get them all the correct matching height.

There will be some distortion in the styrene around the rivets. If you're embossing rivets at the edge of a sheet (say, one of the panels of a wagon body), you will need to run a file along the edge after you've embossed all the rivets to straighten it up again. If you're forming rivets on a narrow strip (say one arm of a piece of angle) you will have to emboss them on a larger sheet of styrene, then cut out the strip – if you try embossing rivets along a pre-cut strip of styrene it will just curl and/or split.

The styrene will sometimes be a bit reluctant to come away from the press after you've embossed a rivet. If you happen to knock off one of the rivets don't panic. It's easy enough to emboss a few spare rivets on a piece of scrap styrene, slice one off with a scalpel and weld it in place over the missing rivet. The scar on the work-piece from the missing rivet seems almost to grab the replacement, so alignment is very straightforward.

[Krusty]

I've made these presses in a variety of sizes over the years from 0.2mm to 0.5mm. You can emboss a lot of rivets before any wear becomes apparent, at which point it's easy enough to bash out a new one. They work with any thickness of styrene from 0.125mm to 0.5mm. For larger-size rivets the Tichy plastic mouldings look a little bit better, but embossed rivets work well in smaller sizes. The ones in this photo are 0.4mm diameter (and the close-up view shows I really need to do something about better-looking channel and angle sections; but they're not the subject here – that's my excuse and I'm sticking to it).