Hello Everyone,

For school I took a class called Co-Op, it is a work placement which I am doing for one semester. 

I am quite lucky in my placement in that it is a fabrication shop specializing in residential fabrication. They do thing like stainless steel furniture, stainless steel railings, as well as 'forged' railings.

I have been sent to the ornamental corner of the shop to help out the guys there. I have been forging fishtails, and bending them on the bending machine into scrolls.

TLTR: I have access to a fully equipped fab shop

 

When I am not helping someone out I have time to work on my own projects. This is great because I can use a MIG welder, full sized horizontal bandsaw, and there is a SCRAP PILE!

 

I was working a on Guillotine tool today, one like in this link : http://web.archive.org/web/20041014213636/keenjunk.com/sketchbk/rw21009.htm

 

I welded up one of the holders for the dies with a proper sized die inside. My problem and question come from this.

As a result of the heat distortion, the holder tightened up real well. I managed to remove the die, and a proceeded to try to file the opening to the correct size, problem is not amount of filing, frustration, and cursing will get the die to enter the holder properly. EDIT  (It will fit, but only if it is forced a certain way, it is really not ideal)

TLTR: Welding heat distortion is ruining my project.

 

QUESTION

How to I weld the guillotine tool die holder so it will not shrink, causing the die not to be able to enter?

Why not get you a piece of metal, or wood (probably be better with wood) in with the die while welding it up.  That way when it swells or distorts it will press against the wood and not completely shut on the die your using.  Could try that to see if that would work for what your doing. 

 

Of if you wanted to heat the piece back up and wedge a larger die in there to open it up more it may work but i would try the other first to see if it would work.

I did try to place the die in there when welding. The welding closed it so tight I had to put it in the vise to knock the die out.

I will post pics tomorrow.

Wrap the die material in a piece of brown paper bag then clamp the holder around it and weld.

so why not grind on the die?  Much easier than trying to file out the holder.

I did try to place the die in there when welding. The welding closed it so tight I had to put it in the vise to knock the die out.

I will post pics tomorrow.

 

 

I understand that, but why not try to put a small piece or sliver of wood in with the die so when it swells the wood acts as a bushing.  So then after you have welded it you can knock the die with the wood bushing out and your die should slide freely.

Personally, assuming all the parts are mild steel,  I would try this:

- place dies back into Guillotine tool

- place Guillotine tool dies-side down into coal forge

- slowly heat the dies *and* the die holders to a bright red heat

- place Guillotine tool in a nice safe place to slowly cool

 

Dies should now move fine.  Remove dies and clean off any scale.

 

Think about and decide what process or processes may be involved in this method.

Wrap the die material in a piece of brown paper bag then clamp the holder around it and weld.

I will try this tomorrow, any particular reason for brown paper vs. More common white?

so why not grind on the die?  Much easier than trying to file out the holder.

If it where only one die that world work, but with half dozen dies, it is easier to file one set if holders to fit a set detention then the other way around.

First try heating the assembled peice and let it cool, normalizing may solve your problem, if not, reheat and forge to fit.

If the paper does not work, I will try heating and cooling.
I will let you guys know how it goes and post some pics tomorrow.
Than you all for your help.

Brown paper grocery bags are thicker than newspaper or copy paper, and two wraps of those would have wrinkles. Old business cards work well too for small projects, just not big enough to wrap around the die easily.

 

Put a business card between the two halves of a set of tongs while riveting, then burn it out when finished, Viola', perfect clearance.

 

FYI, the ABANA website has a tutorial on making guillotine tools.

Short pieces of steel banding material work well for shims.

My progress up to today, it is almost done. I just need to dill a hole for the spring and make the spring.
After welding this up this one, I definitely understand why most on the market are drilled and assembled mechanically opposed to welding. This one took allot of fiddling.

 

Had to re-upload the pictures, my phone uploads them sideways.

Pics are gonna have to be sideways it seams.

When making tools that need clearance we always put in a business card.  On another vein when drilling a hole in two pieces of metal side by side (each piece winds up with 1/2 a hole) insert a business card.  The bit will follow the softer material (the business card) and the bit will not wonder and the hole will be centered.

Thanks Wayne!  I think you just saved me a few drill bits and a couple pieces of good steel in the near future!  that is....if I don't forget... :unsure:

I think your problem was in the order of the welding in combination with the location, and distance of the weld. from the sounds of it, the long side of the die holder warped. causing the center of the long side to bow in on the die itself, correct? this was caused by welding the U shaped holder onto the long side of the holder. The heat, and subciquent shrinkage of the welded area pulled the outside of the long section together causing the inside to curve in. Welding the U onto the long section before welding the sections of the holder together would have helped prevent this. also welding the U onto the short side of the holder would have also helped. In addition, using shorter welds to minimize the heat imput into the material would have also helped.

The question on cold clearance set up. Shim the set up with paper or fussiness card stock. Then stitch weld so you reduce heat draw. Paper runs at roughly .001 to . 002. In the end, the fit will be better than some engine tolerances I have dealt with. Good setup and a slow and steady approach will serve you well.

A well made tool will lady you a lifetime. Good luck with your project.

Peter

Problem: female portion of the item being welded shrinks, making hole too small for male portion to fit properly.

 

All metal shrinks, distorts, warps, twists, bends, buckles, goes funky, etc. This is called thermal expansion and each type and grade of materials have their own rate of thermal expansion. Stainless steel is HORRIBLE. I have done an exceptional amount of fine tolerance fabricating (sub .005") due to aerospace and military specifications are nice friendly. :-)

 

Solutions:

1) Play in favor of the shrinkage. Oversize the female orifice and let it shrink to the size you want.

2) Correct the shrinkage after welded. Either increase the size of the female (machine, file, bore, sand, grind, polish, drill) to fit the male shank or reduce the size of the male (machine, file, grind, sand, polish) to fit the female orifice.

 

-Hillbilly