dimple dies

[BrokenBiker]

need to make a set of dimple dies for the top plate of my side steps.

will be attempting to press 2mm steel and will be using some threaded rod and an impact to apply the force as its all ive got at the moment.

the top die isnt an issue, i know what that needs to look like, but does the bottom die need to be a negative of the top die, accounting for the thickness of material, or does it just need to support the outer edge of the finished dimple?

im not going for anything drastic, just a subtle dimple around the edge of the 48mm holes i will be drilling to give a bit of strength, bit of style and hopefully stop mud gathering too much on them

i will be using part of a volvo coach hafl shaft to make them, once ive determined if it needs annealing or not

 

[Screwdriver]

2mm, believe it or not, you'd probably get away with a solid 3d print.

<edit> yes, mirror + thickness and check out YouTube. Plenty info out there but great to discuss here also.

<edit2> Ron Covell is your man (on YT). Lots of great practical tips on exactly this process.

 

[Screwdriver]

i will be using part of a volvo coach hafl shaft to make them, once ive determined if it needs annealing or not

Overkill unless you're planning to punch the hole at the same time!

 

[BrokenBiker]

2mm, believe it or not, you'd probably get away with a solid 3d print.

ok thats good to know...i dont know why i just assumed 2mm would put up a fight

 

[BrokenBiker]

Overkill unless you're planning to punch the hole at the same time!

its what i have in the right diameter (and plenty of it), so may as well use it...wont be punching the hole, will be using a hole saw in pillar drill for that.

 

[Screwdriver]

ok thats good to know...i dont know why i just assumed 2mm would put up a fight

It does depend on radius and dimple depth of course but a small dimple on a largish radius (2 inches) should be fine in 2mm. I am assuming similar forces to a press because I would use a press, not a thread but I guess they're the same thing up to a point.

 

[BrokenBiker]

It does depend on radius and dimple depth of course but a small dimple on a largish radius (2 inches) should be fine in 2mm. I am assuming similar forces to a press because I would use a press, not a thread but I guess they're the same thing up to a point.

it will be a pretty shallow angle, not very deep...more to give it a more professional looking finish than anything else...the sheet is only going to be 200mm wide and there will bracing underneath as well so not really worried about strength, but dont want just a flat sheet on there and dont like the grooves in the current steps

 

[Screwdriver]

Well worth it, they do look amazing.

 

[Screwdriver]

TLDR: uses a selection of punch flare and dimple dies for variety of hole sizes. Deburs with a step drill.

 

[hotponyshoes]

The sheet will start to distort ad you close the Die up. As you near the end the 2 halves of the die pull flat together and strighten the sheet back out so you need the flat radius around both halves rather than just the top one.

Hydraulic press is smoother than an impact and you probably would get away with 3d printed if you had access to one of those. Not sure regular pla or abs would stand up to an impact driver but you could give it a go

I'd use a high tensile nut/bolt rather than Threaded bar , grease the threads and stack a few greased washers either side. Or use a thrust bearing with spanners.

 

[Matchless]

In my experience (limited) you only need a top die and a ring to support the bottom at the OD of the dimple minus the thickness x2, make the top die and try it on a piece of scrap.

 

[BrokenBiker]

The sheet will start to distort ad you close the Die up. As you near the end the 2 halves of the die pull flat together and strighten the sheet back out so you need the flat radius around both halves rather than just the top one.

Hydraulic press is smoother than an impact and you probably would get away with 3d printed if you had access to one of those. Not sure regular pla or abs would stand up to an impact driver but you could give it a go

I'd use a high tensile nut/bolt rather than Threaded bar , grease the threads and stack a few greased washers either side. Or use a thrust bearing with spanners.

i can probably get a high tensile bolt on my travels, may single thread the bottom die if i can get a large enough bolt, there are some pretty heft bolts in the skip in work

 

[BrokenBiker]

In my experience (limited) you only need a top die and a ring to support the bottom at the OD of the dimple minus the thickness x2, make the top die and try it on a piece of scrap.

i think there will be a fair bit of trial and error involved...ive got some pieces of the box and tube cut as practice pieces for the welding and a few scraps ready for practice ruins on the coping to get the top of the 40mm box to sit flush with the top of the 48mm tube so the sheet sits flat and is supported properly