Home Made Vac Former - Forming RC bodies

[yogi-bear 2315]

49 minutes ago, matman said:

Ok , 3D noob , whats CMYK ?.  

ok, most inkjet printers and nearly all offset printers make up all available colours in a print from just 4 colours (and using the white sheet). They are Cyan, Magenta, Yellow and blacK. So ideally if you had the right coloured filaments, you should be able to mix and print other colours, which is great if you say printing a figurine etc.

49 minutes ago, matman said:

Thanks for the web site .  I will look into it & see what i can scan , I'm sure my card is CUDA compatible .

I was going to buy that printer two weeks ago , BUT i didn't want to jump in ( as this is what i do normally ) .

Yeah, the other reason I was going to try that software is that they have a free (but limited) version. I did from some other software that stitches photos together like 123D Catch, and does a better job, but there is a lot of manual work involved.

49 minutes ago, matman said:

Yes i know what you mean THE LEARNING OF SOFTWEAR   << This is what stopped me from gettng the printer . 

I'm so close to just jumping in & getting that 3D printer & get on with it . Learn on the way , As i know this will 

be 1st of meany  .  Maybe a good starter 3D printer ? as it's ready .   

I don't think you can go too wrong with that machine, and a quick google reveals the earlier models review well for the price range. I'm tempted to get it myself, especially if you get it too.

[matman 1499]

15 minutes ago, yogi-bear said:

ok, most inkjet printers and nearly all offset printers make up all available colours in a print from just 4 colours (and using the white sheet). They are Cyan, Magenta, Yellow and blacK. So ideally if you had the right coloured filaments, you should be able to mix and print other colours, which is great if you say printing a figurine etc.

Yeah, the other reason I was going to try that software is that they have a free (but limited) version. I did from some other software that stitches photos together like 123D Catch, and does a better job, but there is a lot of manual work involved.

I don't think you can go too wrong with that machine, and a quick google reveals the earlier models review well for the price range. I'm tempted to get it myself, especially if you get it too.

Well i'm Very keen to get one , Like i have hit BIN & then backed off   .  

 

Ok , i'm a proud owner of a 3D printer & i got some more filament's as well . It's your fault YOGI-BEAR !!!!   . 

NOW over to you M8 HAHA . If you look at site 8 is now avallable , OMG i hope i did the right thing  .

[yogi-bear 2315]

13 hours ago, matman said:

Well i'm Very keen to get one , Like i have hit BIN & then backed off   .  

 

Ok , i'm a proud owner of a 3D printer & i got some more filament's as well . It's your fault YOGI-BEAR !!!!   . 

NOW over to you M8 HAHA . If you look at site 8 is now avallable , OMG i hope i did the right thing  .

awesome! I'll be ordering one this week as well, just waiting for some customers to pay me, which should be about middle of the week. I was also toying with getting the wanhao duplicator i3, a mate has one, but I think I'll get the one you've got, but either seem to be a good buy and I think it will be good to see the differences. I also realised I got confused with the name and thought it had 4 heads, but no its version 4 with dual heads, which make sense.

Make sure you post pics when you get it!

[yogi-bear 2315]

ok, this year I decided its time to improve the vac former I'd made half way through last year. While I can vac form 1 mm HIPS or 0.75 PETG, I can't vac form polycarbonate or thicker ABS, so time for some improvements 

Issues with the initial vac former included:

• the frame is a very bad design, didn't get a good grip in the plastic,
• I can't get enough heat into the polycarbonate, especially the corners of the frame
• the sliding mechanism would loosen and so the frame would tilt  
• there were other issues with air leaks too, so I was never going to achieve high vacuum with the vacuum pump.

So to start with, I made a new metal frame. I ended up going with right angle top and bottom as I want to be able to add in sections later on to hold smaller pieces of plastic sheets. I also switched to toggle clamps to lock down the frame.

Then I made new metal swing arms and mounted them into the vac former. Initially I wanted to use bearings to help with the mechanism sliding, but in the end a block of wood with graphite powder as lubricant did the trick! This sits firm between the uprights and there is very little movement.

 

There is still a bit to do, the frame has gaps that need to be filled so there is even pressure around the frame to grip the plastic. I need to upgrade the oven a little and make it deeper as there wasn't enough heat getting into the corners. For this I am just going to buy another oven and end up with 8 elements.  I'll also make the oven more shallow, I think I have too large an air gap above the elements and its losing too much heat.

A test video of it in action.

 

[yogi-bear 2315]

ok, finally a bit of an update. Still getting webbing and have switched to vac forming in 1.5 mm which ABS as thats all I can get thats not PETG and is useable as a body that can be driven. I did try 0.35 mm Polycarbonate but I'm not getting enough heat into the plastic for it to soften enough, but more on that later.

I was also finding that the thicker ABS wasn't secure in the frame  those cheap chinese toggle clamps I bought weren't up to the job, and the ABS would pull out from the centre. So for the time being I've switched to bolting the frame together. When I can source some decent toggle clamps I might switch back.

 

With better clamping I gave a reverser mould a go. This is a reverse copy of a cockpit set. This is how I suspect retro racing has vac formed his car bodies. Done properly it will give good detail on the outside.

 

after vac forming,

 

and closeup. Lost a bit of detail, which I think is mainly to not getting enough heat into the plastic (this was 1 mm polystyrene sheet). I'd tried this early with 0.5 mm polystyrene sheet and had gotten excellent detailing. I also knew I wasn't getting enough heat into the corners of the frame holder.

 

 

So I bought another cheap oven and cut that up, putting the elements and controls of each oven on one side each of the vac former. This gives me a total of 8 heating elements and I concentrated two each into the ends. Sorry, the pic is a bit dodgy. With the extra heat, I'm keen to give polycarbonate another go. I should probably cut down the height of the heating box and fill in all those holes, but I'll test it first.

 

and I also made a new control panel. Its been tested to ensure the house won't burn down, but a proper go will have to wait until the weekend.

 

This is what I will try and vac form, each of the Mark 1 Cortina, Mark 1 Escort and Mark 2 Escort in 1.5 mm ABS and hopefully .375 mm polycarbonate.

For the Mk 1 Escort I've had a go at adding more definition to the panel lines, plus added in more vacuum vent areas.

[Wooders28 4718]

You've really put alot of work into this, and it's looking like you're efforts are being rewarded.

Some great tips,I checked out my lexan stock (what's left after 'temporally' covering a broken shed window etc) , it's 1mm, so when I get to eventually making one (5yrs?? Where's the time gone!?!) I'm going to need some heat!

[yogi-bear 2315]

9 hours ago, Wooders28 said:

You've really put alot of work into this, and it's looking like you're efforts are being rewarded.

Some great tips,I checked out my lexan stock (what's left after 'temporally' covering a broken shed window etc) , it's 1mm, so when I get to eventually making one (5yrs?? Where's the time gone!?!) I'm going to need some heat!

cheers wooders!

I too have 1 mm stock too, but its roofing material class, not too sure if that makes a difference. And I bought the 0.375 mm as a test, but I think I can use it for the windows as well when I make ABS bodies, well thats the plan.

[Wooders28 4718]

23 minutes ago, yogi-bear said:

I too have 1 mm stock too, but its roofing material class, not too sure if that makes a difference.

I hope not, I think that's what I've got!

 

[matman 1499]

Good to see you starting on the moulds & they look great .

The ABS look fantastic . Just love the mk 1 escort & cortina .  Should be able to make spoiler kit

for them as well if it's in ABS , as it can be glued on to look like the 1:1 cars . I had front & rear on my mk1 escort  

in the younger days . Great job so far Yogi .  Just can't wait to see the finished body . 

[yogi-bear 2315]

On 29/03/2017 at 5:08 PM, Wooders28 said:

I hope not, I think that's what I've got!

 

that pretty much looks like the stuff I have. But not to worry it turns out. So, I tried out the extra heat on some ABS. I ran it at max temp. like I'd done previously, took my eye off for a couple of seconds and the ABS started to overheat. It didn't form very well, but it meant I now had plenty of heat.

So I then tried something a little easier, 0.75 mm PETG. I also took more care setting up the buck, and apart from the webbing it formed quote well.

Some nice detail in the grille area too.

Just have to work out how to get rid of the webbing.

I tried a couple of variations on the base, but always the same.

 

Well, despite the webbing, its promising. So I gave 1 mm polycarbonate a go.

I ended up overheating the polycarbonate too!, but it still formed quite well. I got bubbles in the sheet, which I'm lead to believe is from overheating it. The definition of the form was not too bad considering it started to split on one side.

Also still getting the webbing. There seems to be only two options to fix that. The easiest option is placing objects to the side to draw off the excess stretched plastic. I managed to do this very early on.

My other option is to try a reverse mould, forming the plastic into the mould instead of over it. So I will try both.

I've got a couple of minor upgrades left on the vac former, but otherwise its now pretty much done. I'll continue in a new thread on the Ford Mk1 Cortina, and Mk 1 and 2 Escort bodies.

[Mannyp1980 49]

This looks very promising, the detail on the grill is awesome.

[yogi-bear 2315]

hmm, I can't believe the last 3 months has gone by so quickly! Work has been really busy and I've not had a lot of time to make much. I was hoping that my vac former was done for a while. However after trying to vac former some engine covers in ABS for a friend I've decided to change a few things. I had lots of issues getting the right temperature and getting the heat into the corners of the frame holder. This meant lots of issues getting a good seal to vac form with. 

Polycarbonate is still a fair bit easier to do but this is about the best I can get forming 1 mm polycarbonate bodies. Not too bad, but still getting a bit of webbing where I don't want it.

 

and a test trim and paint. The wire rims I'd bought for an MGB, but I don't mind them in this car either. You'll notice the window is a bit fuzzy. I'd made new molds and mis-calculated the amount of plaster needed, so filling half-way up through the windscreen I needed to add more in and this was the result. At least I am getting a reasonable amount of detail on the grille etc. What can't be seen is how thin the plastic is below the grille. Its almost like paper. Because the mould sits right up against the frame and so a little bit of plastic has to stretch a lot. The issue is the same at the back. The rest of the body feels nice and strong though so I happy to stick with 1 mm.

 

 

 

I need to improve the frame, making it stiffer and easier to achieve a seal when the corners don't soften properly. To get a better seal, I've opted to try sealing around the base of the frame directly onto the table top.  For the new frame I've worked out a design that will use 8 mm thick steel bar instead of the 25 mm square tubing I was going to use. That will give me an extra 35 mm or so in each direction which might help with the thinning at the ends.

I've also come across a spring loaded hinge design so I can insert different plastic thicknesses and still have constant pressure along the sides of the frame. To finish the frame I'll use two toggle clamps.

I want to more away from manually operated valves too and switch to solenoid valves. This will make switching on the vacuum etc much easier and quicker. So a bunch of these in 12V and 24V where purchase off the internet. These are off by default and open when the right voltage is passed though. All I need are some push button switches.

 

For the frame I am going to have to weld that in steel. To do that properly I'm going to need somewhere to do that, so I've made myself a small welding table from scrap square tubing I had and bought a 4 mm steel plate to top it off and some castors to make it portable. In hindsight 4 mm might not be enough so that'll probably get upgraded to 6 mm  or thicker at some point. Now that work as quietened down a little, I'm hoping to get the frames made fairly quickly. 

 

[graemevw 823]

My first job was at a company that made rc aeroplane kits.

I used to do the vac forming, among other things.

 

I dont know if it will help, but rather than just a buck placed on a universal board, all the molds were mounted on their own board.

The holes in the board varied. In areas where you would get webbing, there were bigger holes in the board so the vacuum had chance to evacuate those areas first.  Make sense?

There werent many holes in the base board at all if I remember right. Nearly always tiny through holes in the bucks though.

 

[yogi-bear 2315]

6 hours ago, graemevw said:

My first job was at a company that made rc aeroplane kits.

I used to do the vac forming, among other things.

 

I dont know if it will help, but rather than just a buck placed on a universal board, all the molds were mounted on their own board.

The holes in the board varied. In areas where you would get webbing, there were bigger holes in the board so the vacuum had chance to evacuate those areas first.  Make sense?

There werent many holes in the base board at all if I remember right. Nearly always tiny through holes in the bucks though.

 

thanks for the tip. I had been drilling small holes in the molds, especially in deep recesses. This definitely helped, but hadn't really tried a proper base for them, still I don't think I was getting a good seal around the base either.

 

[yogi-bear 2315]

6 hours ago, graemevw said:

I dont know if it will help, but rather than just a buck placed on a universal board, all the molds were mounted on their own board.

The holes in the board varied. In areas where you would get webbing, there were bigger holes in the board so the vacuum had chance to evacuate those areas first.  Make sense?

 

that definitely sounds like a good idea, I will try that one as soon as I can.

[graemevw 823]

Yeah, I read earlier you were using small holes.

 

My vac forming was 23 years ago so memory is vaugue, but the bucks were on boards that covered the whole base I think, there were holes but only really at areas near the buck so all the vacuum was pulling from near the mould.

 

As you have it its pulling the plastic down onto the base too soon I think, without pulling in certain areas first.

 

As I say, vauge memories and I was a 17 year old doing what i was told rather than knowing the process technically, but our vac formed pieces were good quality.

I seem to remember the moulds being made from some metalic looking resin, they were hard and heavy, but they obviously had to last!

[yogi-bear 2315]

36 minutes ago, graemevw said:

Yeah, I read earlier you were using small holes.

 

My vac forming was 23 years ago so memory is vaugue, but the bucks were on boards that covered the whole base I think, there were holes but only really at areas near the buck so all the vacuum was pulling from near the mould.

 

As you have it its pulling the plastic down onto the base too soon I think, without pulling in certain areas first.

yeah, I think you are right about that, but with my current setup I don't know how to change that. I've seen some of the industrial ones blow air up into the plastic first, but that's a bit beyond me at the moment.

36 minutes ago, graemevw said:

As I say, vauge memories and I was a 17 year old doing what i was told rather than knowing the process technically, but our vac formed pieces were good quality.

I seem to remember the moulds being made from some metalic looking resin, they were hard and heavy, but they obviously had to last!

yeah, I need to move onto a better resin or material, but they get a lot more expensive! So while I am fooling around with it, I'll use cheap plaster. My next choice will be hydrostone, which should set literally like rock. Then eventually resin with metallic fillers, or if I can set up my cnc machine properly, maybe aluminium versions.

[mman2005 443]

Awesome thread!! 

[yogi-bear 2315]

On 9/16/2017 at 3:42 AM, mman2005 said:

Awesome thread!! 

Thanks mman2005!

[yogi-bear 2315]

So last week I managed to get some 0.55 mm thick galvanised steel sheeting and some 32 x 8 mm steel bar. The gal sheeting is for making a new heater box. My first attempt was crude and there is too many holes and too much space above the heating elements, so heat control isn't very good. Hopefully this new one will fix all that. This is the box that holds the heating bars. I was pretty happy with this until I realised I'd made it 5 mm too wide.

 

Its just held together with rivetts. I measured and pre-drilled all the holes for the heating bars to try and make it as even as possible.

 

When installing the heating bars I, I realised I'd made it about 5 or 10 mm too wide, so out with the hammer.

 

This is the section for the control box that will sit on top and also protect the connections to the heating bars.

 

I have a pan brake for folding metal, but its a little limited and this was as far as I could get.

 

Finished heater and control box. I'll still have to secure the power cables though, plus make a protective cover for the rear, but first I will test it.

 

Next step is to re-make the frame that holds the plastic, hopefully that will only take a week or so.

[yogi-bear 2315]

ok, so managed to get the new heater box installed. Plus I made and installed a new holding frame. This version has clamps and a spring loaded hinge at the back so I can put any thickness material in without having to adjust it. Testing with PETG, I was getting good results, however had lots of trouble heating either HIPS or ABS. There is still lots of issues getting the heat into the corners and heating takes a long time. So I'm now tempted to switch the heater box to infrared heating lamps. I'll have to custom make it, but its means I'll get better control over heating. Infrared heaters are much more efficient and only heat the plastic, not relying on heating the air first. So its a lot quicker to heat and you have more control.

 

 

[topforcein 1764]

i can see the orders flocking in when that beauty is up and running

[yogi-bear 2315]

so I did some more vac forming today. I was hoping to use polycarbonate but that wouldn't soften properly and had to switch back to PETG. I'd added step anti-slip tread tape (which is basically some sandpaper with hi-tac glue on it) to the frame to help secure the plastic. Plus I used window seal along the bottom to get a better seal once the frame comes down. (pic is of the frame upside down)

This make a noticeable difference to the forming, as even just the vacuum cleaner seams to have more power now, and as a bonus I am getting a lot less webbing too. I don't use a mounting block for the mold this is probably helping to reduce webbing.

 I also tested and realised I can leave the plastic protective film on. If you look closely at some of the pics, you can see surface scratches, thats just in the protective film, which will be handy to have once paint time comes around.

 

 

I think with a little bit of experimentation I'll get rid of the webbing almost entirely. Now I just have to sort out the heating. It has got me a little stumped though, as the heating should be better than what I had before.  So now I am working out how to build and infra red setup. I was hoping to buy something pre-made, like car paint heaters, but I suspect I will have to custom make a setup. Not too hard, just have to make sure I wire it up correctly or things will go bad real quick!

I also managed to make a cast of the Mark 1 Cortina. Now I am using hydro stone, and after some experimentation worked out that to get the best results I need it to go off for about 10 to 13 mins before I pore it into the mold. This greatly reduce the number of bubbles and a number of other defects I was getting previously. I'm going to let this dry another couple of days before I use it to vac form.

 

[max69vk 708]

Just read this thread from start to finish & have found it really interesting. I'm loving those retro shells & the detail on them is fantastic. It's been around 20+ years since I've done any vac forming, luckily I had access to to a machine at my school & used to make about a dozen Celica shells for my TA01 (I had a habit of trashing them as my driving ability never quite matched my ambition).

This got me thinking with regards to your issue with 'webbing' issue you are experiencing on the moulds, something that I very clearly recall is that the base plate the mould sat on was not a sheet with holes drilled in but more of a perforated mesh (see example pic below) to maximise the area that the vacuum would be working across. I believe that while using the 'holes in board' method could be used to increase vacuum in certain areas, it's actually a lot easier to block or cap off a vacuum hole with the hot material forming over it therefore actually reducing the vacuum pull in that specific area, the mesh should prevent this. No idea if this of any use for you or not, but you seem to be trying a lot of different things so this could be something else to add to the list. 

[yogi-bear 2315]

4 hours ago, max69vk said:

Just read this thread from start to finish & have found it really interesting. I'm loving those retro shells & the detail on them is fantastic. It's been around 20+ years since I've done any vac forming, luckily I had access to to a machine at my school & used to make about a dozen Celica shells for my TA01 (I had a habit of trashing them as my driving ability never quite matched my ambition).

This got me thinking with regards to your issue with 'webbing' issue you are experiencing on the moulds, something that I very clearly recall is that the base plate the mould sat on was not a sheet with holes drilled in but more of a perforated mesh (see example pic below) to maximise the area that the vacuum would be working across. I believe that while using the 'holes in board' method could be used to increase vacuum in certain areas, it's actually a lot easier to block or cap off a vacuum hole with the hot material forming over it therefore actually reducing the vacuum pull in that specific area, the mesh should prevent this. No idea if this of any use for you or not, but you seem to be trying a lot of different things so this could be something else to add to the list. 

Thanks that is good to know. I have seen some people use that, but to date haven't tried it. I will give it a go though as I am nearly there with solving it.