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Scott
4th September 2013, 12:40 PM
I've been toying with the idea of setting myself up with a vacuum chuck for a while. After popping into the woodturning club this morning one of my fellow members made his own chucking system (ingenious little setup by the way Lionel). Having what I need to do in my head to make the chuck I now need to locate a vacuum pump. Whilst it's ok to temporarily use a vacuum cleaner, a cleaner will eventually burn out after prolonged use. Does anyone have any ideas where I can buy/locate a dedicated vacuum pump for my needs? Has anyone made their own chucking system?

Thanks in advance.

wood hacker
4th September 2013, 01:59 PM
Scott

Not having a vacuum chuck myself I can only comment from things I've heard but one advantage of a vacuum cleaner over a vacuum pump is the volume. Whilst the VC will never develop the level of vacuum the pump will, if the seal between the chuck and the work piece isn't the best the higher volume or air being pulled by the VC will compensate for this better than the lower volume for the pump. Not sure if this is entirely correct but it sounds plausible.

cheers
WH

Scott
4th September 2013, 02:12 PM
Cheers WH, I can see your logic. Problem with a VC is that when using them at a constant vacuum they will overheat and in some case, cark it. I saw a vacuum pump today and it's extremely effective, even at low pressure. The trick is to get an effective seal.

turnerted
4th September 2013, 04:55 PM
Scott
Plenty of vacuum pumps available on ebay.
One big disadvantage to using a vacuum cleaner is the noise.
Ted

Scott
4th September 2013, 05:59 PM
Scott
Plenty of vacuum pumps available on ebay.
One big disadvantage to using a vacuum cleaner is the noise.
Ted

Thanks Ted. Most of the pumps on eBay are refrigeration pumps, can you use those?

Master Splinter
4th September 2013, 06:50 PM
Yes, you can use the fridge pumps.

Chris Parks
4th September 2013, 07:01 PM
The vacs commit suicide because they overheat due to no air flow, so Cooling the motor down with a fan should work. Not ideal I know but if needs must be met then it should work.

steamjunkprops
4th September 2013, 08:02 PM
Dont use a fridge pump unless you want a paperweight in a short time, fridge pumps are made to pump coolant and will quickly overheat without said coolant. Check out http://www.bettervac.com.au/. The company i work for bought one from these guys and they are a solid unit for a reasonable price. The one we use is able to get a perfect vacuum in a couple seconds.

Master Splinter
4th September 2013, 08:23 PM
That's fridge pumps as in "these are for pumping air out of the refrigerant lines prior to filling with R14 (or whatever)", but many people have also used old fridge compressors to make their own vac pumps on the cheap.

Making A Fridge Compressor Into A Vacuum Pump (http://www.instructables.com/id/Making-A-Fridge-Compressor-Into-A-Vacuum-Pump/)

steamjunkprops
4th September 2013, 08:32 PM
Sorry, i shall re iterate, i am talking about the compressor not the one for getting air out of the lines.

Scott
4th September 2013, 08:36 PM
Dont use a fridge pump unless you want a paperweight in a short time, fridge pumps are made to pump coolant and will quickly overheat without said coolant. Check out Carbon Vane Becker Side Channel Blowers DVP Vacuum Pumps Australia (http://www.bettervac.com.au/). The company i work for bought one from these guys and they are a solid unit for a reasonable price. The one we use is able to get a perfect vacuum in a couple seconds.

Thanks Steamjunkprops, appreciate the recommendation. Is there any particular pump you'd recommend for the application?

steamjunkprops
4th September 2013, 08:52 PM
Thanks Steamjunkprops, appreciate the recommendation. Is there any particular pump you'd recommend for the application?

Its worth giving them a buzz and talking to them about your requirements and use for it. From memory they were really helpful and friendly

Scott
4th September 2013, 08:54 PM
Its worth giving them a buzz and talking to them about your requirements and use for it. From memory they were really helpful and friendly

Thank you :)

smiife
4th September 2013, 09:18 PM
hi scott,
not sure if you are interested but there is another option
i have a vac chuck that runs of my air compressor
just a box that has a couple of venturi elements
and a pipe with a hollow tube thru the head stock
hook up the air and away you go!!!!!!!!!
i can photograph for you if interested ???
cheers smiife:2tsup:

Scott
4th September 2013, 09:21 PM
hi scott,
not sure if you are interested but there is another option
i have a vac chuck that runs of my air compressor
just a box that has a couple of venturi elements
and a pipe with a hollow tube thru the head stock
hook up the air and away you go!!!!!!!!!
i can photograph for you if interested ???
cheers smiife:2tsup:

Now that sounds like a good idea, photo's would be great, thank you. I'll PM you with my email address :)

hughie
5th September 2013, 09:09 AM
hi scott,
not sure if you are interested but there is another option
i have a vac chuck that runs of my air compressor
just a box that has a couple of venturi elements
and a pipe with a hollow tube thru the head stock
hook up the air and away you go!!!!!!!!!
i can photograph for you if interested ???
cheers smiife:2tsup:


Smiife how much vacuum do they pull? the best I have seen with reasonable volume has been around 46% which I would have thought be a bit low.

If you do go for a full blown vac pump you and dont buy top end of the market [ which is expensive ] then you will need to fit a small bleed valve to prevent pump damage.

Osbojo
5th September 2013, 12:19 PM
You could try this one:
Air Operated Powered Vacuum Pump Venturi System Power Vacumm | eBay (http://www.ebay.com/itm/AIR-OPERATED-POWERED-VACUUM-PUMP-VENTURI-SYSTEM-POWER-VACUMM-/280962733502?pt=LH_DefaultDomain_0&hash=item416aaf15be).
Cheap enough to experiment with and says it will achieve 28" Hg (about 40 Torr or 90% vacuum) . The down side to venturi is the noise from your compressor.

Refrigeration pumps are ok. They don't pump refrigerant but are used to evacuate the system before charging. This one:
3 CFM Single Stage Rotary Vane Vacuum Pump R410A R134 HVAC A C Air Refrigerant | eBay (http://www.ebay.com/itm/3-CFM-Single-Stage-Rotary-Vane-Vacuum-Pump-R410a-R134-HVAC-A-C-Air-Refrigerant-/360727181157?pt=LH_DefaultDomain_0&hash=item53fd03f765)
reckons it can achieve 5 mBar (about 95% vacuum). I've used similar to this in spectroscopy systems.

I wonder how much difference the higher vacuum makes given that 100% vacuum means 14psi (~1kg/cm2). For a 7.5cm circular chuck that's 44kg holding the job to the chuck or 22kg @ 50% vacuum. Would have thought that even 50% vacuum would be overkill for most work (and maybe even destructive in some instances).

Anyway, I'd be interested to see how you go as I've been thinking about doing the same thing.

Toymaker Len
5th September 2013, 12:25 PM
Recon medical vacuum pumps come up occasionally on the Aust/NZ luthiers forum. Very good quality.

dai sensei
5th September 2013, 03:38 PM
Vacuum cleaners work Ok but are noisy. Vacuum pumps work, but care needs to be taken especially with thin walled objects, full vacuum can collapse the timber object.

turnerted
5th September 2013, 05:29 PM
My vacuum pump, bought on ebay is rated at 4.2cfm and as others have said ,it is a pump to evacuate refrigerent lines not to pump refrigerent.I also found that buying the various pipe connections cost about the same as the cost of the pump.It was some time ago and I think about $300 all up.Have a look at TTIT's web site I think he has details of his vacuum system there. I got most of my information from him.
Ted

smiife
5th September 2013, 09:20 PM
hi guys,
sorry i have not replied earlier,work keeps getting in the way of my hobby:~
the system i have is a ''holdfast'' vacuum generator,not sure of the technical
jargon but it pulls 20+in Hg,and the ''safe'' minimum is 12 in Hg,not sure what
that all means but i have never lost a piece yet,there web site is ,TMI Products woodturning tools cyanoacrylate adhesive sharpen gouge vacuum chuck hollowing carbide (http://www.holdfastvacuum.net)
sorry i am not sure how to do the linky thing!!!!!!!!!!
i am sure if you have a compressor already ,this is a good way to go
i will get some photos together on the weekend and send them
or post on here,as i have said this week has been a bit busy:~
cheers smiife:2tsup:

p.s. not sure how the link came up,but it is there now
just went on the website,and remembered i got it from craft supplies usa
went on there site and they are selling for $160.00
hope this info helps,i would recommend this system to anyone
certainly works well

TTIT
5th September 2013, 10:26 PM
........... Vacuum pumps work, but care needs to be taken especially with thin walled objects, full vacuum can collapse the timber object.?? Did you discover this the same way I did? :B


....................not sure of the technical jargon but it pulls 20+in Hg,and the ''safe'' minimum is 12 in Hg,...................I try to keep mine around 15Hg using the bypass valve - anything higher and! . . see note to Neil above :B:B

Ed..
5th September 2013, 11:23 PM
I bought myself one of those 4 cubic ft/min 2 stage vacuum pumps off ebay a few years ago when I wanted to do some fibreglass infusion molding and just connected it to a 300lt water tank heater which I picked up from a scrap metal merchant This gave me extra vacuum reserve if neccessary, it took about 20-25 minutes to get down to almost pure vacuum and then I just switched the pump off and closed the valves in the line. I have no idea how much vacuum you need for a chuck but I would imagine that a water heater would hold way more than you would require. At least this way the pump would not be running continously and if the vacuum was starting to run out due to leakage, you could always switch the pump on again.

Cheers

Ed.

subarna
7th September 2013, 01:37 AM
Hey Scott,

Lots of vacuum pumps are available on ebay. Alternatively, you can have a look onto engineering supply companies. As I know they might have it on lower price. We have it on Tizaro also. You can check if you get any that meets your need.

rsser
8th September 2013, 04:18 PM
FWIW I've had hours of use out of an ordinary domestic vac, just with a couple of 3mm bleed holes drilled in the line close to the headstock.

My scientific measure of load is the rise in pitch :rolleyes:

smiife
9th September 2013, 08:13 PM
hi scott,
sorry, i have been a bit busy,but did manage to get a bit of turning/photographing
on the weekend,hope these photos help to explain what setup i have
if you need any more help just let me know:;
sorry the pics are not great:doh:
cheers smiife:2tsup:


284666284667284668284669284670284672284673284674

Scott
9th September 2013, 10:31 PM
sorry the pics are not great

Nope, that's perfect Smiifie, thank you. Where did you get the holdfast from?

Scott
9th September 2013, 10:36 PM
You could try this one:
Air Operated Powered Vacuum Pump Venturi System Power Vacumm | eBay (http://www.ebay.com/itm/AIR-OPERATED-POWERED-VACUUM-PUMP-VENTURI-SYSTEM-POWER-VACUMM-/280962733502?pt=LH_DefaultDomain_0&hash=item416aaf15be).
Cheap enough to experiment with and says it will achieve 28" Hg (about 40 Torr or 90% vacuum) . The down side to venturi is the noise from your compressor.

Refrigeration pumps are ok. They don't pump refrigerant but are used to evacuate the system before charging. This one:
3 CFM Single Stage Rotary Vane Vacuum Pump R410A R134 HVAC A C Air Refrigerant | eBay (http://www.ebay.com/itm/3-CFM-Single-Stage-Rotary-Vane-Vacuum-Pump-R410a-R134-HVAC-A-C-Air-Refrigerant-/360727181157?pt=LH_DefaultDomain_0&hash=item53fd03f765)
reckons it can achieve 5 mBar (about 95% vacuum). I've used similar to this in spectroscopy systems.

I wonder how much difference the higher vacuum makes given that 100% vacuum means 14psi (~1kg/cm2). For a 7.5cm circular chuck that's 44kg holding the job to the chuck or 22kg @ 50% vacuum. Would have thought that even 50% vacuum would be overkill for most work (and maybe even destructive in some instances).

Anyway, I'd be interested to see how you go as I've been thinking about doing the same thing.

Thanks for the links Osbojo. Only problem with those pumps is that they're U.S. based, I'd have to get some sort of transformer. I'm interested in Smiifie's solution and will post a little more once I know where I'm heading.

smiife
10th September 2013, 08:20 PM
Nope, that's perfect Smiifie, thank you. Where did you get the holdfast from?

hi scott,
i got it from craft supplies usa,there web address is Pen Making, Bowl Turning, Wood Lathes, Wood Blanks, and Turning Tools for Woodturners | Craft Supplies USA (http://www.woodturnerscatalog.com)
look it up just go to the chucks section and vacuum chucks
hope this helps
i tried to find similar in aussie but could not find anything ,i always
try to source tools etc at home first,but could not....
cheers smiife:2tsup: