Vacuum pump diagram

[Max Taylor]

I have the Gast quarter-horse vacuum pump with all the fittings, gauge etc. Does anyone have or can write a diagram as to how it all comes together? At this point I am dead in the water. Maybe if I had a diagram to get me started I could get somewhere.Thanky, Max

 

[webturner]

look here:

http://www.laymar-crafts.co.uk/tip42.htm

 

[Owen Lowe]

Here's a pic of my vac system. It's really quite simple.
Working from the pump to the lathe:
1) short section of copper tubing connected to the inlet side of the pump;
2) air filter canister with copper tubing "L" down to an easily reached height;
3) a brass "T" fitting with a hose barb connected to one leg; connected to the hose barb is a length of rubber air hose running to another hose barb inserted in the Oneway rotary vac. adapter.
4) piping from the "T" continues straight down to a 1/4 turn gas valve that regulates the amount of room air being drawn in by the pump - and thus the amount of vacuum pressure drawn through the lathe.

I don't have a gauge in my setup as I've never felt the need for one. Sufficient vacuum pressure exerted against a turning is dependent, not only on the task to be performed, but on the volume of the cavity the turning is sucked against - and it changes a fair bit from turning to turning and vac. chuck to vac. chuck. In other words, if 20 inches of pressure is sufficient to hold a 12", 1/2" walled bowl how much is needed to hold a 14", 1/4" walled bowl without distorting or cracking the walls - what about an 8", 1/8" walled piece? Only experience and visual inspection at the time of drawing the vacuum will tell.

 

[Dave Peebles]

Hi Max,

Here is a diagram off the Oneway site. I used it as a guideline for my set-up. I did add a filter to mine to keep the fine dust out of the pump.

http://www.oneway.on.ca/vacuum/images/vaccuum_kit.gif

Best wishes,
Dave

 

[Bill Boehme]

I see a number of things that could be improved upon the diagram given by Laymar. Referring to the diagram below here is a list of things that could be done better:

1. The inline filter could be a lot more useful by placing it close to the rotary adapter rather than placing it at the pump. A lot of dust can accumulate in the line if it is done the way shown by Laymar.
2. Use a needle valve to regulate vacuum rather than a ball valve -- it is far easier to control. A ball valve is good for ON-OFF control, but not good for making minute adjustments.
3. Place the vacuum gauge closest to the rotary adapter and place the regulator valve downstream towards the pump. Doing so will give a better vacuum reading for the chuck than doing it the way that Laymar shows it.
4. Add a pair of BALL valves next to the vacuum pump. It seems that too many people throw away the instruction manuals for their vacuum pumps and do not perform a proper shut-down procedure. Proper shut down calls for a period of time running the pump with the inlet port plugged and a period of time with the inlet port wide open. Ball valves will work great for this purpose -- use a brass T on the pump inlet and connect one valve to open to atmosphere and the other to open or close the line to the vacuum chuck. Doing this will allow you to perform a proper shutdown procedure.

 

[laymarcrafts]

boehme I read with interest your suggestions and the use of my diagram.

1] I placed the Filter as clode to the Pump Inlet as possible so that ANY ingress of Dust is trapped, any joint in the piping or failure of upstream filters could result in Dust getting into the Pump. The Filter is there for a purpose and you should not be too concerned about the amount of Dust it is exposed too.

My experiance is that in the 3 years this has been in use I have cleaned the Filter only once.



2] If you really want infinite control the Needle Valve is the solution but they are both expensive and, in my opinion, uneccessary.

I get adequate control if needed but generally it remains closed.

3] Positioning of the Gauge is irrelevent, a Vacuum is that a total negative pressure in the system you will get the same Reading whereever you have the Gauge on such a small volume.

Incidently my adaptor is not a rotary adaptor but a fixed adaptor.

4] Not sure about this shut down procedure, it is not mentioned in my instruction manual???

3 years of use, at least 200 woodturnings attached, and it is still performing well, you do not have to overcomplecate it.

Richard