Dimple dies

[excossack]

Recently I had a metal shelf made for the back of the 110. Comprising of, 1.2mm steel sheet, with some box section either side and some 5mm strips to raise the height of the shelf. Measures 147cm wide x 50cm deep.
I was surprised at the weight of it... 14kg

So I was thinking I need (in the words of Binky) to add lightness....1" dimple dies might do the job to add extra strength and remove some weight?

 

[mike 109444]

A good read.... This chap likes his dimples
http://retrorides.proboards.com/thread/129271/1946-morris-series-rear-panel?page=35

 

[stuvy]

Colin chapman was the originator ofnjust add lightness there a bad copy at best

 

[8ob]

Sand tracks are made in loads of different sizes and materials, may be cheaper to swap your shelf for something ready made.

Bob

 

[excossack]

Thanks for the replies. Having already had the shelf made, seems daft not to use it. I hadnt considered sand tracks

 

[anto44]

I've a set of dimple dies from dimple dies uk on ebay, good quality and work brilliantly. I use a hydraulic pull ram to operate them.

 

[excossack]

That's who I have seen selling the dimples. I was planning on using an impact gun to press the two halves together.

 

[AndersK]

This is a simple way to make dies if you have a router. Just a hole in Oak or something else, fillet or chamfer the edge with a router.
You can press or tap the edges down with pretty much anything softer than the metal to avoid marks.

The other slots visible was made with the same technique.

( Did not press in place, pic just to illustrate)

 

[Dcal]

This is how I achieved something similar to what I think you are after.
Dimple dies would have been easier but I was trying to replicate existing sizes and spacing.
If you have a press, it is pretty simple and if you have lots to do it's worth the set up time.

https://www.mig-welding.co.uk/forum...the-brink-hopefully.81348/page-7#post-1305219

 

[knighty]

is most of the weight not in the box section/supports etc. ?

 

[excossack]

There will be some weight in the box section but might look good (and an good excuse to dimple?)

 

[hotponyshoes]

The sheet will weigh about 7kg or so.
If you could replace half of it with holes that's a 3.5kg saving.

You could get fancy and dimple the box and drill the bars if you wanted.

 

[excossack]

Can you get dimples that small? 3.5kg based on how many holes?

 

[anto44]

This is the kit I bought, the smallest die is for a ⅜" hole and the largest is for a 2" hole.

I use the dimple dies with this hole punch set I bought off Ebay.

The set of dimple dies on their own were about twice the price of the complete hole punch set.
It's a very effective way to remove huge amounts of weight while increasing strength at the same time, especially when used in conjunction with a bead roller. It also makes a nice aesthetic touch to a project.

 

[excossack]

Nice set of dimples!

 

[hotponyshoes]

Can you get dimples that small? 3.5kg based on how many holes?

I have a set that go down to maybe a 10mm hole.
You would need enough holes to remove half of the metal, probably not all in small holes though as it's not exactly a quick process however you do it.
I would go for the bigger 50mm ones but the dimples make the panel a lot stiffer so you could reduce the thickness of the steel as well.
If you dimpled the whole sheet 0.8 might be stiff enough. 1mm dimpled would be fine to replace 1.2mm solid.

Just do some test pieces before starting it because if you cut all the holes first you might find once you dimple the first one the new raised edge gets in the way of the punch/die for the next one.

If you are after maximum weight saving you can pattern it out to fit smaller ones inbetween larger ones.

 

[Parm]

All seems like a lot of work for fairly little reward.

Is it not worth considering a shelf made out of mesh or similar ?

 

[hotponyshoes]

Another thing for the op to think about if this shelf is already made,

If you have a plain bit of sheet, make the hole then start to press the dimple die in as the die starts stretching the metal the sheet will start to fold up and go all over the place, looks a bit like a flower.
As you get near to the end of the die the 2 halves coming back together will clamp down and flatten the sheet around the newly formed dimple.

I would normally put all the dimples in then weld/fix the sheet into the frame work. I would think if the sheet is fixed into a frame first you might get some problems with rippling and warping. For something glike a shelf in a truck that might not even be an issue.

I have also found that a lot of holes will stretch the whole sheet slightly but I'm mostly using thicker alloy so might not be an issue.

As parm says, it is a lot of work.
Weldmesh with support or a sheet of 0.8mm with a couple of bits of 3x20mm flat tacked under for support would probably be lighter anyway!

 

[pressbrake1]

I made my dimple dies from scrap hydraulic rod steel

 

[hotponyshoes]

I made my dimple dies from scrap hydraulic rod steel

That's the best way to do it.
You can get the exact profile you require then.
The ready made ones are fine but give a different shape of dimple depending on how they are made and how thick the metal is.

Buying/making a matching set gives you the most chance of all the holes looking the same but if you put a 50mm dimple into 1mm and 2mm sheet they won't quite match.
You could also make them to match whatever hole cutting tools you have.
I bought a set but they (like most) were imperial sizes so I had to invest in some imperial hole cutters as well!
If you have the stock, a lathe and the skills then make them up.
Unfortunately I only have 2 of those 3 things!