Lennox (pullmax) shrinking problems

[suhrsc]

Hello,
I was hoping someone might be able to help me get these dies figured out.

I recently bought a Lennox Tru-edge machine and it came with a set of shrinking dies.

I have been trying to get them set up.
It seems no matter where I place them in relationship to each other I am getting tooling marks on the aluminum I am working with.

I tried to polish off the dies a bit more then they were but I don't want to remove any material that might be necessary for them to actually work.

The major lines are on the top of the metal on the back of the upper die... on either side of the recess.... there is a bit of a tighter radius at this point which I believe is causing it... but I don't want to take it away too much as it seems thats where the compression is happening to actually gather the metal?

Here are a few photos of the dies.

Does anyone have any insight?
or photos of your dies that work well?

These do actually work to shrink the metal and after rolling in the English wheel I got a nice blended shrink but the tooling marks are still there, which will cause problems if it is needed to leave a part in bare metal.

thank you
Zach

[BarryA]

Hey Zach

There will always be a trade-off: Aggresive shrink vs. Marking. Blending and polishing may help to some degree. You may not entirely resolve the issue though. And lose the efficacy of the dies.
You don't show the marking. Others could give their input on how yours compares.

That said there is a vendor (Clay Cook?) offering phenolic thumbnail dies for aluminium. I'm guessing for just this reason...

[jlrussell4]

Stan Fulton also offers a plastic die set to lessen the markings.

[suhrsc]

Thank you Barry and Jim
I forgot to take a photo of the aluminum last night... and posted this morning from work

I was thinking that your reply might be the answer.... dealing with the marks related to the the amount of work going on...

I will have to look into the softer dies if it poses too much of a problem... Just got the machine running over the weeked... so haven't spent a ton of time yet

Thanks!
Zach

[Pete's Metalshaping]

Do you know who's dies they are? It looks like they have quite a few marks on them from someone trying to clean them up. There is such a thing as tuning these dies; which would involve figuring out where the contact points are.

[Rick (madera)]

It looks to me that you don't have enough clearence on the upper die above the thumb. The material should not touch the upper at that area.
good luck

[suhrsc]

thanks
I have no idea who made them

The marks on them are from me cleaning them up with a scotchbrite pad ... they were a bit rusty when i got them... its more of a brushed finish on the dies... I figured I would polish them up once I got the shape tuned in better

the marks im getting on the metal are not from that though.... the metal is getting gouges in it...

Rick, I see what your saying... maybe I need to grind a bit deeper there
I am actually getting gouge marks on the inside(bottom of panel) also, right in the center...

should the contact area be U shaped or just a flat behind the male and female shapes?

thanks!
Zach