How to make this part ?

[sardine]

Got to make a replica of this gun sight , the dished piece has a radius of about 2 " , I'm looking for a piece of steel I can salvage a section of which already has this dished shape, it seems like a shape I could find on a wheel rim, hub cap, metal plate or dish ect..

Any one seen anything like this shape or any idea how to form it from flat ( without welding it from pieces ) ?

 

[CompoSimmonite]

Vespa VBB wheels have similar profile.
https://royalspares.com/products/new-wheel-rim-primered-3-5x8-4-bolt-fits-vintage-vespa-vbb

 

[mike 109444]

Old metal ash tray ?

 

[sardine]

Old metal ash tray ?

Looks about right but probably made of very very thin metal.

 

[Dcal]

Have you precise dimensions and metal thickness required?
I'm sure someone will have something that will fit the bill.

I made formers and pressed out bungs for a floor pan, they look similar but probably don't have enough of a dish.

 

[addjunkie]

Enamal plate! Or pie dish

 

[daedalusminos]

It's surprisingly easy to make custom pressed parts like that, the 'dies' are just made from cut plate offset the correct amount and of the correct thickness...something like this:

 

[piman]

Hello Sardine,

as the above post suggests using a form. It doesn't need to be made of metal though, for a one off a piece of hard wood is suitable as well. I would make it as a negative, i.e. the outside of the piece. It's not quick but patience will get you there. If you are able to make a form from metal, heat can be used as well which will speed up teh forming.

Alec

 

[armalites]

Land Rover Series spare wheel bonnet mount looks pretty close but they make a good chunk of money these days

https://picclick.co.uk/Land-Rover-Bonnet-Mounted-Spare-Wheel-Carrier-Series-143018698050.html

The strut tops on some cars have a dished profile like that too.

 

[ajlelectronics]

Brake disc?

 

[steviec_lj]

Pudding tray?

https://www.amazon.co.uk/Profession...ocphy=1006823&hvtargid=pla-438314728694&psc=1

 

[sardine]

Looks like the original is about 2mm thick.

 

[Parm]

Is this any good to you?

I’ve had it for years, only one. It’s off an MOD flight case

 

[sardine]

Is this any good to you?

I’ve had it for years, only one. It’s off an MOD flight case

View attachment 194293 View attachment 194294 View attachment 194295

Right shape but two small I'm afraid, the OD needs to be about 120 mm , I reckon the sides of the quadrant are 60 mm on the original.

 

[Maker]

Machine it from solid.

 

[Brad93]

Press that out

 

[SierraV6]

It's surprisingly easy to make custom pressed parts like that, the 'dies' are just made from cut plate offset the correct amount and of the correct thickness...something like this:View attachment 194224

What thickness do you use for the backing plate? I’m hoping to use this process as it looks extremely useful but obviously I don’t want the dies flexing.

Also, what capacity press do you use? My current one is only 10t but it’s a good quality old machine that does actually deliver 10t (or slightly more), unlike some of the cheap rubbish I’ve used!

If you have any other tips feel free to share (PM me if you’d prefer not to hijack this thread!), thanks.

 

[Brad93]

10 Tonne will do that no problem. You could do that in a decent flypress.

Your plate on which you build the stamp and former needs to be a decent thickness. Then the form needs to be the right thickness to make your part to the right dimension.

 

[daedalusminos]

What thickness do you use for the backing plate?

Also, what capacity press do you use?

The backing plate was 10mm, but I used the press spreading plates (25mm) top and bottom as well.

I've got a 'cheap' 20T Chinese press with gauge and probably took that to 15T, the problem is not so much forming the general shape but leaving a good finish without ripples.

 

[Dcal]

A couple of photos of how I made a few bungs for my alfa should give you an idea of the process I used.
Steel was 1.2mm thick galv.
I had to stiffen up the top die as it was flexing but that was because they were made out of whatever I had in the scrap pile and I didn't want to start again.
Before I got a lathe I just cut the dies out of plate and cleaned the edges with a grinder.

I don't want to clutter up this thread but there is bit more detail in post 142 in my alfa 75 rebuild thread.