Fingers crossed it'll cut ally

**Tenson** · 01-10-2012

Oh I also forgot to say, the surface of anodized aluminium is non-conductive, but the surface is easily scratched through to the conductive bulk. It is most definitely worth earthing the chassis so if any high voltage comes in contact with it, the power can sink to ground instead of the person who might be touching it. Wherever you connect the earth tag make sure it is well connected to the bulk of the material since the surface layer does not conduct.

**blackburn mark** · 04-10-2012

Originally Posted by Tenson

Oh I also forgot to say, the surface of anodized aluminium is non-conductive, but the surface is easily scratched through to the conductive bulk. It is most definitely worth earthing the chassis so if any high voltage comes in contact with it, the power can sink to ground instead of the person who might be touching it. Wherever you connect the earth tag make sure it is well connected to the bulk of the material since the surface layer does not conduct.

yea.. i sussed that one out in the end.. its kind of suprising that anodized aluminium is none conductive

**Fivetide** · 03-10-2012

Love the vacuum pad idea Mark, will do something but a bit different, I am inspired though :) .. I went to school in Blackburn ...

**blackburn mark** · 04-10-2012

I went to school in Blackburn ...

you poor sod... i went to boarding school in shropshire (not as posh as it sounds)

will do something but a bit different

if you can get your hands on a pump that will pull a good hard vacuum a vacuum plate full of o-rings might come in handy.
...we want pictures :)

**Fivetide** · 04-10-2012

Originally Posted by blackburn mark

...we want pictures :)

done on my thread

**m.marino** · 22-04-2013

Mark,

I have an idea of setting up jigs for cutting parts and using your idea of a syringe, with a valve to create the vacuum to hold them down. Where do you get your syringes from? I would be hooking the tubing into a block of HDPE that would be shaped so that flat surface on the bottom would have vacuum draw against them to help hold the piece in place. If you could let me know where you got those from and/or what you consider good pricing I will post some pictures of the pieces once they are assembled and working.

The other idea I am looking at in a vacuum bed made out of a solid surface (Hi-MACS or Corian). Which since they are non porous could be a very useful option instead of steel or aluminium. Also a good bit easier to machine and assemble.

Michael

**blackburn mark** · 22-04-2013

PM me your address and I'll send you a slack handful (work was binning old stock so they didn’t cost me anything)

the idea works quite well for specific tasks like engraving lots of the same item but for a larger bed/pads it would take quite a bit of effort to draw out the static volume.
Remember to put the one way valves close to your syringe to get maximum draw

The way I had mine set up it worked like a by bicycle pump but in reverse

**birchy** · 22-04-2013

If it were me, I'd be looking at suction cups of some sort. Maybe some of these: 2 Acupuncture Massage Suction Cup Heat back Pain Relief | eBay but it might be difficult to remove the work piece once it was under vacuum.

The other option might be to use dent pullers like these: Mini Dent Puller Bodywork Panel Remover Removal Tool Car Van Suction Cup Glass | eBay but attach them to the machine and activate them with an air cylinder or some other mechanical actuator.

On the syringe theme, you could use air cylinders to create a vacuum. You could either use one air cylinder and actuate it manually or use 2+ with one as the actuator (i.e. you feed one with compressed air and it then pulls the other(s) to create a vacuum). Air cylinders are not cheap to buy new but can be manufactured at home if you have a decent lathe. Hydraulic cylinders are another option (minus the oil!). Or the scrap yard...

**Ross77** · 23-04-2013

Might have the wrong end of the stick as I haven't read all posts from the beginning but if you are looking for a vacuum pumps then most compressors can used the other way around, especially the diaphragm pumps.

Clarke Mini Air Compressor - Wiz - Machine Mart Bit pricey but easy to mod, just fix a tube to the intake filter plate and keep the output open. depending on the amount of vacuum you need you could use the smaller 12v tyre inflates or even a fish tank aerator.

**GEOFFREY** · 23-04-2013

Originally Posted by m.marino

Mark,

I have an idea of setting up jigs for cutting parts and using your idea of a syringe, with a valve to create the vacuum to hold them down. Where do you get your syringes from? I would be hooking the tubing into a block of HDPE that would be shaped so that flat surface on the bottom would have vacuum draw against them to help hold the piece in place. If you could let me know where you got those from and/or what you consider good pricing I will post some pictures of the pieces once they are assembled and working.

The other idea I am looking at in a vacuum bed made out of a solid surface (Hi-MACS or Corian). Which since they are non porous could be a very useful option instead of steel or aluminium. Also a good bit easier to machine and assemble.

Michael

Michael, I made a vac bed using grey pvc. Bottom sheet 20mm, top sheet 6mm with 5mm round gasket/o ring seals. this works very well. I can send you dxf (if I can find it!) of my vac table if you wish to give an idea of what I did if you wish. G.