3DP Vacuforming

[chappyman66]

I posted this on another forum, but maybe it's useful here. Maybe not....lots of folks here already have this figured out. This is just how I have learned to do it.

The best way is to have a file for the glass. In the case of the Mirage, -nimrod- kindly provided a separate file with the glass pieces all included.


I take the glass file, and copy/delete as needed to get all of the glass pieces as separate items.

Then I scale my body to my desired print size, and fit the glass into the body in the CAD program, adjusting width / height as needed to make it fit correctly.
I thicken each part by using the Duplicate function (CTL+D in TinkerCAD) and raising the new part 0.2mm or so, and the repeating the CTL+D 8-10 times so the part is stacked up thicker. Group those duplicate, so each piece of glass is thicker but has the proper outside shape.

Then I place all of the glass pieces together on a plate so I form all parts for the car at once.


Note that the blue is a piece I placed under the rear window to support it, or the buck collapses under vacuum. A similar piece is inside the main windscreen and side windows but I already grouped those. On this buck I placed holes (they look like cylinders in the picture) in the plate to help draw everything down nice and tight. They become holes when I select and export the buck for printing.

I print this buck at 100% infill and 0.06 - 0.1 layer height. When it's done I smooth it with needle files and sandpaper.

I use a dental forming machine from Amazon, about $100 USD. I form the windows using 0.020 PETG sheet (also Amazon).

The best practice is to mount and heat the sheet, and once it is warm and sagging place the buck under it on the machine bed and then draw the plastic down over the buck while moving the heater head off the bed. Then I pull the sheet/buck out of the machine, let them cool, and repeat as needed. If you heat the sheet with the buck in place, the buck can get soft and deform slightly (another reason for using 100% infill).

For the F50 GT that I made for the Crap Car proxy, I copied the body file, removed everything but the windscreen, used CTL+D on the windscreen, and then a supporting shape to make the buck. Then I copied the grouped windscreen object (green in the photo), and made it a hole to remove the windscreen from the original body file, leaving the correct size hole for the vac formed windscreen.


The last option is for when the body file comes with no windows at all, and I just use various shapes in TinkerCAD to get something that looks and fits pretty close, then make my buck out of that. It takes patience and trial/error, but I did that for the 917-20, and it worked out well.

Hope this helps.

[Kevan]

I have one of those vacuform machines and only used it once with a buck made from air dry clay using a 3D printed bodyshell as a mold. It worked but wasn't pretty.
I did 3D print a window buck and should have filled the inside...it's amazing how much downforce 1 atmosphere is

[Kevan]

...oh one thing I forgot to ask, do you scale the finished face down to allow for the thickness of the petg?

[mattb]

I have an old Mattel vac form toy. I can make decent screens using resin as a buck. The temp of the plastic doesn't seem to soften it. I have my vac hooked to a shop vac. I heat the plastic with a butane torch till it sags.

[chappyman66]

Hey Kevan , I have a couple interesting warped bucks as well. The support does matter. And no, I don't scale anything down, I just trim to fit. The material stretches, so I don't know if it's consistent or not. So trimming is a better option.

And mattb , I just can't control the torch heat that well. You are more skilled, I had to buy the machine to get consistency.

[Barc 1]

Thanks for sharing. I used to use my shop vac and a heat gun with a wooden box for a forming. I sprung for a proper vac former soon after I got my 3 D printers.

I have moved away from individual sets of glass. I created a flattened cone as a buck and found it be good for creating universal glass. It is surprising how well this works. Once formed I cut the shape in half. I then place the half over the model and trace outline onto the glass and trim it to fit. This will work well for most production based race cars, and I can get two or 3 windshields from each pull. 906, and P4 type bodies I do have specific bucks for which were used back when I cast resin cars as there shape is very unique, much like your example.

[alexis in greece]

Thanks for sharing.I replaced quite a few heavy windshields with light vacformed ones by copying the originals filled with plasticine to prevent collapsing,had no problems so far

[chappyman66]

alexis in greece yes, that absolutely works well. But for 3DP bodies you have to make your own master.

And as Kevan says....ask me how I know about collapsing a mold under vacuum.....😂😂

[mattb]

It's always hit or miss heating the plastic with the torch. Failure rate isn't much of an issue with this stuff. Only takes a couple minutes and if it turns out junk, I just do another one!

[Phil Kalbfell]

A small toaster oven makes a great heater for use with Vac forming.

[HO RacePro]

Back in the early 1970's, as a graduate student, I was involved in developing vacuum formed plastic medical braces. When I came on board they were using a laboratory vacuum pump. Very high vacuum, but very low volume. I replaced that with a -- get this -- Sears canister vac. Small and cheap, and could only pull a few inches of vacuum, but moved lots of volume. And that worked better, especially when a hole opened in the plastic, which sometimes happened. You really only need a few inches of vacuum.

A shop vac is overkill. But hey, overkill isn't a bad thing.

Now, nearly half a century later, I've occasionally thought about doing some in-home vacuum forming. Interesting to hear of folks doing it.

Ed Bianchi

[red73mustang]

I posted this on another forum, but maybe it's useful here. Maybe not....lots of folks here already have this figured out. This is just how I have learned to do it.

The best way is to have a file for the glass. In the case of the Mirage, -nimrod- kindly provided a separate file with the glass pieces all included.


I take the glass file, and copy/delete as needed to get all of the glass pieces as separate items.

Then I scale my body to my desired print size, and fit the glass into the body in the CAD program, adjusting width / height as needed to make it fit correctly.
I thicken each part by using the Duplicate function (CTL+D in TinkerCAD) and raising the new part 0.2mm or so, and the repeating the CTL+D 8-10 times so the part is stacked up thicker. Group those duplicate, so each piece of glass is thicker but has the proper outside shape.

Then I place all of the glass pieces together on a plate so I form all parts for the car at once.


Note that the blue is a piece I placed under the rear window to support it, or the buck collapses under vacuum. A similar piece is inside the main windscreen and side windows but I already grouped those. On this buck I placed holes (they look like cylinders in the picture) in the plate to help draw everything down nice and tight. They become holes when I select and export the buck for printing.

I print this buck at 100% infill and 0.06 - 0.1 layer height. When it's done I smooth it with needle files and sandpaper.

I use a dental forming machine from Amazon, about $100 USD. I form the windows using 0.020 PETG sheet (also Amazon).

The best practice is to mount and heat the sheet, and once it is warm and sagging place the buck under it on the machine bed and then draw the plastic down over the buck while moving the heater head off the bed. Then I pull the sheet/buck out of the machine, let them cool, and repeat as needed. If you heat the sheet with the buck in place, the buck can get soft and deform slightly (another reason for using 100% infill).

For the F50 GT that I made for the Crap Car proxy, I copied the body file, removed everything but the windscreen, used CTL+D on the windscreen, and then a supporting shape to make the buck. Then I copied the grouped windscreen object (green in the photo), and made it a hole to remove the windscreen from the original body file, leaving the correct size hole for the vac formed windscreen.


The last option is for when the body file comes with no windows at all, and I just use various shapes in TinkerCAD to get something that looks and fits pretty close, then make my buck out of that. It takes patience and trial/error, but I did that for the 917-20, and it worked out well.

Hope this helps.

This is great info and will be helpful with thickening certain body files in Tinker Cad!

With fitting the glass to the bodies, Would it work to just adjust the glass size in Cura or other slicer to match the percentage or scale of the body? I really struggle with lining things like Wings or glass using Tinker Cad.

Thanks, Chet

[chappyman66]

I use TinkerCAD for almost everything. I usually scale figures in CURA but most everything else is done outside CURA.
The alignment tool makes it easy, as well as changing the movement scale. You can pretty much put things wherever you want. I make sure it fits the body. If the Vacform is a little big, it's easy to trim.