Acrylic? sheet supplier and moulding? bends

[picclock]

Hi

I tend to use clear packaging material that is usually vacuum formed over various products for odd applications. I think the material is acrylic, although it could be polycarbonate - I don't know how to tell them apart. Anyway, I've sort of decided to get hold of some virgin material and fold/bend/mould or form it to my requirements.

So firstly, how do I identify which material it is, and secondly apart from vacuum forming what are the best ways forming the material. My immediate use is to replace a clear cover which i made with two pieces and replace it with a one piece. possibly forming it with a heat gun over a piece of wood. The material measures 0.9mm thick.

Bearing in mind that I'm in the UK can anyone recommend a supplier to use ?

Best Regards

picclock

 

[HS93]

How big is it vacuum forming is so easy just goggle vac forming and there will be dozens of demo's on utubee we made a vac former for about £3 plus a vacuum cleaner plus a loan of a oven for ten min. we made some bits for boats and it is so easy

Peter

 

[picclock]

Hi Peter

The bit I have in mind is a bit large for that - around 0.7M long. May be possible to get it into the oven using angles. Already have a 'real' vacuum pump. So what material did you use and what was the thickness ? Tried model shops but they don't do the size.

BTW, how did your stepper controller for the mill turn out ?

Best regards

picclock

 

[HS93]

this is the place then

http://www.sarik-vacform.com/

the mill is fine all the hardware is working great ,I am using my Kwakers RT controller at the moment ,my hands are bad so cannot do fine soldering I have bought all the bits to build the small unit to drive the stepper driver and it will be a bit easeyer when it is finished it has been a good mod .
was it you that also had the Wm 14 if so did you find out about oil or grease in the gear box ?

Peter

 

[Omnimill]

I've used both acrylic and polycarbonate in the past and tell the difference by looking at it edge on - polycarbonate has a purple colour. The problem is getting the temp just right, too hot and you may get bubbles in it. Commercially they ensure it's dry before they attempt bending.

Vic.

 

[picclock]

@ HS93

Hi Peter

Sorry to hear about your hands - if I was closer I'd do it for you.

Greasing the WM14. I have swapped out the motor on mine, and in order to do so removed the thick metal plate on which it mounts. This gives easy access to the early part of the gear system. which seems very well made. The manual shows a disassembly drawing on P1 of the part list section of the manual. PM me if you need a copy. FWIW mine was well greased up as far as I could see when I changed the motor.

Best Regards

picclock

 

[John Rudd]

Bearing in mind that I'm in the UK can anyone recommend a supplier to use ?

Best Regards

picclock

I use these people as they are not too far from me.....

http://www.plasticonline.co.uk/

 

[Duncan.e]

Polycarbonate is incredibly tough, but scratches very easily, whereas Acrylic tends to be brittle, but does not scratch as easily....

When I was working, we made leisure boat instruments with polycarbonate lenses that were hard coated to give them scratch resistance - the best of both worlds.

Duncan

 

[Omnimill]

I went to the trade counter of this company the other day, very helpful and cut to any size you want.

http://www.ljc.co.uk/

Vic.

 

[HS93]

@ HS93

Hi Peter

Sorry to hear about your hands - if I was closer I'd do it for you.

Greasing the WM14. I have swapped out the motor on mine, and in order to do so removed the thick metal plate on which it mounts. This gives easy access to the early part of the gear system. which seems very well made. The manual shows a disassembly drawing on P1 of the part list section of the manual. PM me if you need a copy. FWIW mine was well greased up as far as I could see when I changed the motor.

Best Regards

picclock

thank you for that , what happend to your motor?

Peter

 

[picclock]

@ Peter

The motor failed under warranty. I believe the original cause of this was a damaged or split brush which caused excessive heat on the brush holders resulting in a ground fault which tripped out the mains and cooked the controller. Motor and controller replaced under warranty. Picture of brushes removed from original motor.

After seeing the brushes from the original motor I reasoned that the holder had probably melted because of the brush overheating as only half of it was in contact with the commutator. Although I had fitted and used the replacement motor by this time I decided to check out the new brushes. One of the brushes in the replacement motor was cut at an angle of around 20 degrees, ensuring point contact of the brush only, which would probably overheat, then crack and fail like the first one. I bought a new set of brushes from Arc Euro (size on photo) and junked the replacement motor set.

An awful lot of pain and delay for the sake of a small piece of carbon, and a very frustrating experience. If it had happened 3 weeks earlier they would have fixed it for me on site - the machine was just over 6 months old.

So if your still awake ;D it's probably worth checking the brushes.

Best Regards

picclock

 

[winklmj]

Have you seen this:

http://bbs.homeshopmachinist.net/showthread.php?t=47611

 

[picclock]

hi winklmj

Yes, I saw that some time ago. What's neat is the amount of shrinkage that the bottle will deform to. But its not suitable size wise for my needs - hence need to find a local supplier if possible as longish stuff doesn't travel well.

When I made a fan cowling for my mill motor I picked up a plastic pipe adapter from Wickes which had the correct motor/fan diameter dimensions. I also used a mains powered fan.

Best Regards

picclock

 

[graemetbrown]

I tend to use clear packaging material that is usually vacuum formed over various products for odd applications.

So firstly, how do I identify which material it is, and secondly apart from vacuum forming what are the best ways forming the material.

Bearing in mind that I'm in the UK can anyone recommend a supplier to use ?

If you have been using packaging material, it should have the recycling code and polymer type on it somewhere.

http://en.wikipedia.org/wiki/Resin_identification_code

Clear vac formed packaging is commonly PET (polyethylene terephthalate), the stuff used for soft drink bottles.

Vac forming is better, but you can also manually stretch form most thermoplastics. Not sure how it would work for large parts, but I've used the following method up to about 6" square. The bigger the part, or thicker the sheet, the more force you'll need to do the job.

This method should work for any fairly thin thermoplastic sheet, but I've only used it with acrylic (Perspex) and Polystyrene. Helps to have an assistant, unless you have an extra set of arms......

Unless you plan on mass production, make the tool in wood or MDF. Make the plug to the shape and size you need, then cut an opening the shape of the plug in a piece of chipboard/MDF to make a frame. Make the opening in the frame larger than the plug by the sheet thickness and screw on some sort of supports to make enough clearance for the plug when pushed through the frame.

fix the sheet over the opening and if it's too big for the oven, heat it evenly with a hot air gun. Once the plastic starts to sag, quickly push the plug into it and hold it there until everything cools down. I found it was easiest to do it all on the workshop floor and just stand on it to keep the plug in place.

Being in Oz, I can't help with UK suppliers, but I found the one I use in the Yellow Pages, under 'Plastics'.

Regards,
Graeme

 

[deverett]

For a bending 'apparatus', you might have a look at Harold Hall's rig. Looks pretty simple and will probably bend polycarbonate as well as acrylic sheet.

http://www.homews.co.uk/page178.html

Dave
The Emerald Isle