This is my vacuum former machine which I just finished. The top part consists of a Centroform 18x27" heater and platen. The lower I pieced together myself from an old 1/2 hp air compressor, air tanks and a vacuum motor.
You have an amazing setup, I myself am about to build my own vacuum former but I was only going to use my twin motor shop vac, I assume this would be the high volume low pressure method, why do you use a vacuum and tank and when do you use it? Do you turn off the pump, lower the plastic then open the valve of the tanks or do you have both pump and motor runners together at the same time? Sorry for all the questions this is so interesting.
Thanks, glad you like it! Well first off I'm far from an expert on this still, so don't take my opinions as gospel truth. I only have done a few draws on this machine too, to be honest. I used a vacuum and tanks for a lower volume but higher pressure vacuum. I to get a deeper draw I might pull the bulk of the air out with the vacuum motor, and then get pull a little more with the tanks. I normally would leave the vacuum motor going while I add the vacuum of the tanks. The manifold of the unit isn't super air tight (probably because I'm using a reducing window with no seals) so I like to keep the vacuum going to hold the pressure better. Hope that helps some.
You are awesome, Thank you for replying and more importantly thank you for sharing your knowledge, sometimes when you start something new it's a little difficult finding specific information. Especially when you're building a machine, I will share my build with you once I finish it. Out of interest, I have a pump and a 12L tank that I use to degass silicone, do you think I can get away with using the 12L vessel as a tank instead? save money and space I am thinking. I guess I can try and see. Again thanks for the reply. T
I think it's worth a try to see if it will work. The tanks I have are only 2 gallons each for a total of 6 gallons or about 23 liters. Not a huge volume either in my opinion. I think your manifold size and seal you achieve on it will effect how big of a tank you''ll need too. Looking at the big picture, though, your shop vac is going to be about 90% of the pull, and many people get along just fine with nothing more then that for a vacuum source. Anyway, good luck with your build and if I can help you out in any way, just ask.
Yes, the heating elements plug into their own 110V outlet. That's the way it came from the factory to make it easier for people to find a power source for it. Each heater is rated at 12.5 amps, both being 25 amps, so you have to be aware of the limit of the breaker you're running off of and anything else that might be drawing power at the same time.
Hi, Can I ask? I plan to make a dome-shaped product extends from acrylic material. The size of the elongated dome shape is: Length: 3 meters Width: 90 cm Height: 30 cm Thickness of acrylic sheet: 8 & 10 mm. What I want to ask is: 1. How many degrees Celsius heat should be used? 2. How large is the capacity of the vacuum suction machine should be used? Thanks.
I'm sorry I can't really help you too much with that, as I have not worked with acrylic or anything that large or thick of material. The melting point of acrylic is 160 degrees Celsius so I can only guess just under that. With such a thick sheet your heat up is going to be slower but your cool down will be too, so I can only theorize vacuum capacity isn't going to be as critical as long as you get a good seal, and can reach good pressure. A vacuum pump in conjunction with a higher volume vacuum motor may be a good idea since you're working with fairly thick material. I would suggest putting your material in a dry box for at least a day or two, to get rid of moisture in the material. I don't know about acrylic but I know poly-carbonate tends to hold moisture and bubbles up badly if not dried first. Sorry I can't be of more help, but I just don't have much experience with vacuum forming much less the perimeters you have in mind.
hi, I'm doing this kind of project for my final project of undergraduate degree. May I ask these questions? 1. is that kind of heating elements arrangement heat evenly throughout the plastic sheet? I'm still under uncertainty which type of heater should I choose, is that wire heater just like yours, or using ceramic infrared heater. 2. speaking of the vacuum tanks, do you really calculate the volume required for given forming area? Thanks before, have a wonderful day!
To answer your questions, 1. I actually have not used the unit's heaters for heating a sheet of plastic yet. The large size seemed nice at the time I bought it, but when you want to make a small part, it's a waste to have to use a big sheet. I actually build a reducing window for the plastic holding frame and the platen. It's 1 foot square and I use a large toaster oven for heating it. Being inside a convection oven like that does heat pretty evenly. I don't have a ton of experience on the matter, but I'd go with the ceramic infrared heater myself. I actually did buy a pair of those for my original plan of building the unit myself from scratch. 2. No, I've never sat down and calculated volume of vacuum needed for the forming area. I find the vacuum motor alone sufficient for most jobs.
...Also wanted to say, good luck with your project! I'm not the most knowledgeable person, but I'll certainly give my 2 cents if you have any other questions along the way. :)
