Will this FUD forming press tool work?

[Lemosteam]

Trying to home-grow a tender or passenger car electrical pickup design...

What say you- will this tool below work?

Half etched 0.25mm phosphor bronze etch (orange part, .125mm thick at axle pockets), placed into a FUD lower die,(dark green), FUD upper shoe placed atop to trap the etch in all degrees of freedom (light green). Clamp together to a cast iron surface. Hardened pin with 50 degree ground spherical ball point dropped into the shoe, tap with a brass hammer or push down with a drill press...

[mmagliaro]

I don't know how hard that FUD stuff really is.  Do you think it can stand up to the pressing and hammering?
How about the holes that the pin goes through to make the cone dimples.   Will those holes spread or
enlarge from the stresses?

Other than that, I don't see why this wouldn't work.

My only other worry would be the contact strip thickness.  .125mm is .005".  I think that's too thin.
The inserts inside something like the Kato Mikado or Bachmann tender trucks is more like .015".
However, if you are thinking that this would be a retrofit that has to fit inside the frames of a Microtrains truck,
then .005" is probably necessary to fit in there.  I'm not sure it is sturdy enough, though.

[C855B]

I suspect FUD may be too brittle for this, and you'll get a lot of breakout around the die holes. WS&F is probably too compressible.

Great idea, however - poor man's tool and die. If it were me, I'd try the FUD and see how many uses you can get out of it. I was looking at Shapeways' steel, but the material description offers all sorts of caveats about precision issues.

Good solution for limited-production locomotive trucks, too. For sure, keep us posted!

[peteski]

I think that FUD is way to brittle and soft to support the phosphor bronze while the pin is making a dimple in it.  I also agree with Max that the contact strip is too flimsy for is intended purpose.

Have you considered making the forming press out of printed metal (like stainless steel)?  The resolution should be fine enough for its intended purpose and the surface finish also doesn't matter.

[Lemosteam]

Metal is out of the question.  The min detail height is larger than the etch is thick.

I thought FUD was brittle too, until I taped this:

https://www.facebook.com/john.lemerise/videos/10205757834969755/

The blocks will be solid for 5-6mm beyond the point.  I'm not talking one huge whack here, just light taps with a brass hoppy hammer or continuous press with the drill press handel.

Experimented on wood, the point kept breaking through, but with a backing material to stop the pin, I should be able to prevent that.  The cone on the pin will be the same as the cone in the lower die.

Max, those Kato and Bachmann pieces are fineblanked and formed simultaneously in one hit which is why they have to be that thick, otherwise, I guarantee they would be thinner.
 

.25mm Phosphor bronze is fairly stiff.

[up1950s]

Can a custom hole punch , the type that looks like pliers be made or modified ? Center punch the contact strip , align the pin by feel , then squeeze till it feels right . have a cigarette and repeat .

[narrowminded]

Great idea.  No FUD.  It doesn't look like there are any features on that part other than the dimples you're trying to create, are there?  If not, you don't need the full profile pocket.  You could have the center pin as you have in the fixture then a couple of locator pins on the perimeter that it registers to for position.  They would extend into the upper guide block to assure that it has that block properly positioned and therefore the dimples properly located.  The upper die should be lightly clamped to hold the sheet flat around the dimple, not allowing it to lift but also not trying to clamp it so hard that it can't draw the material it needs for dimpling without acting as a punch and just breaking through.  You want it to be able to draw down in.  For the die and for testing you might get away with just a block of  MDF with steel pins but for quantity runs steel should be used.  Mild steel will probably work for quite a few pieces.  Stop by a machine shop and get some square drops or even check the hardware store for larger size key stock.

As you go you may find it beneficial to be able to control the depth of the punch/ dimple and that might be accomplished by making your punch from a threaded bolt with the head removed.  You could use a nut on the threaded portion to control the depth of the punch, stopping against the upper die block.  Hope some of that is useful.

[Lemosteam]

Thinking that the 1/2 etch will stretch before the sides draw in.  The dimple is about 0.6mm deep.  It really is not going to take that much force to do the dimple before it breaks the FUD. 

If I can do this on a piece of pine, I think I can achieve better in a trapped environment.

[Chris333]

Wouldn't that jig be easy to mill out of brass?

[Lemosteam]

Wouldn't that jig be easy to mill out of brass?

Sure If I had a mill!  But not for $8.

[bbussey]

No way I would use FUD/FXD for that.  If I were to try it with a RP die, I would render it in SWF.  When SWF have some thickness to them, they are very strong, and there is no intricate detail relief you're trying to render here.  Not to mention SWF will be less costly than FUD/FXD.

[up1950s]

http://www.amazon.com/Dimple-Pliers-Hooked-Black-PLR-726-15/dp/B008SGDTOM

This could form the dimple . Then turn the brass contact strip over and flatten the rim area with a brass tube and whacker .

[SkipGear]

I've done this before just using steel blocks. My dimple hole was just a hole countersunk with a drill bit. If you want to make an alignment jig, do it in brass the thickness of your side plate and have it fold over and overlap the edge of the lower steel block. Clamp an upper steel plate on top, with holes drilled for the punch. This will keep the sheet from folding and crinkling.

All this can be done with just a drill press and a dremel. if you are having the pieces photo etched, you could have two templates created at the same time, with half etch folds to align them over the steel plate. the first would just have small holes to mark the center hole for the axles and some alignment pins. The second would be your alignment guide for holding the part while punching it.

[Lemosteam]

No way I would use FUD/FXD for that.  If I were to try it with a RP die, I would render it in SWF.  When SWF have some thickness to them, they are very strong, and there is no intricate detail relief you're trying to render here.  Not to mention SWF will be less costly than FUD/FXD.

Maybe I'll print it in both media.  It's only 28mm wide.

Correction, the FUD version is &28- maybe SWF is the better way to go, alkthough I don't like the output of SWF at all.

[Lemosteam]

Well some testing results are in:
Black tool is BSF , white tool is FUD.  Both tools withstood the drill press punch test without breakage.  However if you look closely at the die indentation on the right of the die (the position that I did the test on), the BSF was too soft and the punch and material thickness indented the die, where on the FUD die, nothing happened.  I sort of expected these results as I know the FUD would be quite thick and would have a harder surface, so I am sticking with the FUD.  I have no idea how many forming events the tool can endure, but I'll find that out later.

The formed material you see on the pics is 0.25mm thick brass, my etching (orange CAD part above) will be Phosphor Bronze half-etched in the pocket area.  For comparison, the Bachmann mild steel stamping is shown in the first picture.

Obviously further testing is required, but this proves the concept will work, on brass anyway.  Since I have only formed one pocket another test will be die draw across the length of the etching.  I may have to fabricate a two-pin punch to form both pockets simultaneously so that the contact strip stretches evenly but I am hoping the pin in the center will prevent that and i won't have to.

Give me some tender truck etch dimensions for your 0-6-0 @mmagliaro !