Coil molds

[waltr]

Yep! Still making them. It gets easier as I have made so many now. Probably 5 or 600. Anyone know where I can get forms made on a CNC mill? All mine are painstakingly made with a jigsaw. The wooden forms don't last forever, plus they shrink a little over time.

Are you sealing the wood forms?
A coat of good primer/paint should keep the wood's moisture content constant which should then maintain dimensions.

There are a number of smallish CNC shops around that could make accurate forms.
They do have a minimum setup change and then shop rate. Wild guess is at least $100 per form to make.
Also best to supply them with 3D Cad files.

Wonder if a 3D printed form would hold up to vacuum forming?

[dbanner]

Maybe a good idea to use some kind of concrete mix to make molds. Just pour into one of your plastic shells you already made and when its dry, just remove/cut away/tear off plastic. Now you have a strong mold that will not warp or shrink over time. Low-tech idea

[Wahyu]

my homemade coil molds



video ;

[Tim]

For my press-mold coils I use PVC downpipe. Cut along length then melt/flatten in a 100C oven. These press-molds are a bit wrinkly near the top edge, but this may work better in a vacuum mold. As a cheap source of stock (I get mine from the dump) it may be worth a try for you vacuum-molders ???

So, Don..did you ever get that msg about the molds for sale on Ebay??

[Tim]

my homemade coil molds

Very good wayhu. Would you consider selling a couple to a neighbor in Oz? I'm sure the postage would be reasonable. Shoot me a PM sometime?

[Nandor]

Very nice shells Wahyu, they look like factory made!
What kind of material do you use, ABS os something else?

[CDI]

Very nice shells Wahyu, they look like factory made!
What kind of material do you use, ABS os something else?

My friend is using PS and ABS, both are good, but ABS is a little stronger. Thikness of both is 2mm.

[Wahyu]

Very nice shells Wahyu, they look like factory made!
What kind of material do you use, ABS os something else?

Thank Nandor, i use ABS 1.8mm

[Wahyu]

Very good wayhu. Would you consider selling a couple to a neighbor in Oz? I'm sure the postage would be reasonable. Shoot me a PM sometime?

yes i can selling that, Thank Tim ^_^

[Hyena]

My friend is using PS and ABS, both are good, but ABS is a little stronger. Thikness of both is 2mm.

I bet it is not PS, but HIPS (high impact polystyrene). I use it too in 3mm.

It is very similar to ABS as you can see here: https://www.makeitfrom.com/compare/A...lystyrene-HIPS
ABS is little bit stiffer, therefor a bit harder to mold. Anyway its feasable.

And one more thing I want to say... NEVER turn it around! I noticed comments like "I use it up side down, because I can hide inperfections..." That shiny surface is not only fancy feature. It very often contains UV shields and other protective layers, which you definitely want to have on the outer surface!!!

[dfbowers]

Hi,Tim. I thought I saw something from you about some vacuum forming equipment? My home brew setup works great for most things I need. The only limitation I have is that my bed on 16"x16", minus what the plastic needs to stretch leaves me with about 11" x 11" of usable area.
Plus.. to maximize material I buy my ABS in rolls of 48" x 96" ... around $4.00 in material per shell

[Tim]

I just had a ring around Adelaide. ABS 2-3mm, 2.4x1.2m (48"x96") $AUD 85. About the same Don. For now I will stick with Crazy-tech and wayhu if he can accommodate, but I might make a molder to try some pvc downpipe for the hell of it.

[sinclairuser]

I was thinking about what someone else said in the thread, about casting concrete to make a coil form I bet with some reinforcement some of that really fine self levelling cement might work, or that synthetic stone they mould with epoxy and crushed stone.
another idea I had was what about coating the wooden moulds with gel coat paint?, if the whole coil form was coated it would help make it last longer, at the end of the day if it only doubles the lifespan of the mould its a winner.

[Hyena]

I was thinking about what someone else said in the thread, about casting concrete to make a coil form I bet with some reinforcement some of that really fine self levelling cement might work, or that synthetic stone they mould with epoxy and crushed stone.
another idea I had was what about coating the wooden moulds with gel coat paint?, if the whole coil form was coated it would help make it last longer, at the end of the day if it only doubles the lifespan of the mould its a winner.

I would be careful with concrete. And epoxy (if it does not contain lot of fiberglass) too. IT is just too fragile. As I am not gently when it comes to pulling stencil out of molded cover, wood/plywood/plastic are the winners

If you want to prolong wood lifespan, coat it several times with nitro varnish (or epoxy) or something with similar hardness and water resistance.

Anyway the simplest method to produce molding stencil is CNC milling

[dbanner]

Some concrete mix(re-enforced with glue) is not fragile, as I see it in weider barbel weights