Troubleshooting CNC Vacuum Pump Problems

CNC owners discuss a grab bag of possible vacuum pump issues. November 23, 2008

Our Weeke BP100 is saying we need more vacuum. Has anyone ever taken apart the pump to check the vanes? Our manual does not have an exploded view.

Forum Responses
(CNC Forum)
From contributor D:
I had just replaced vanes in a vacuum pump. It was a Rietschle pump, dry vane type, pretty straightforward. All I did was take the end off the pump (opposite the motor) and there they were. Slip out the old, blow out any pieces, and slip in the new, bolt the end back on and re-grease - good to go. The vanes for my pump were $233 each x 5... Ouch. Mine failed prematurely - they shattered at startup. I guess rare, but does happen.

From contributor T:
Are you sure the error is for vacuum?

From contributor M:
A graphite jobber has made graphite vanes for me (for 2 different pumps) at a small fraction of the cost for factory replacements. I supplied the specs (dimensions, angles, etc.) and they made replacements as good as original. Saved hundreds of dollars.

From contributor G:
Try They should have an exploded view of the pump you have.

From contributor I:
It might be wise to ask... What brand/model pump do you have on this machine?

From contributor H:
We have a Homag BOF311, not the same machine, but same parent company. We have 3 pumps piggybacked and have been running this CNC for about 5 years. A couple of years ago I opened the pumps to look at the veins and they were like new. Are you sure you don't have a clogged line? Have you cleaned the main filter in a while?

From contributor A:
A few weeks back we also had a vacuum problem with one of our machines - a Biesse Rover 346. The pump is a Becker. I checked the veins and they were fine, then I checked and cleaned the filters, but none of this helped with the low vacuum amount we were getting. Then I noticed that one of the gaskets on the cover which contains the two small filters was put on wrong and was not sealing the vacuum. Pretty simple thing to overlook, since it looks as if it is placed correctly, but it only goes on one way. After I turned the gasket around everything was fine.

From contributor C:
Vacuum, seems like we never have enough. I have found that the following things will always boot holding power. I am running a 40hp Dekker. Point 1 - always edgeband your spoil board. +5% to 8% by eliminating edge leakage. Point 2 - keep several different sized pieces of Masonite around to shield off leak areas. Any time your work piece doesn't cover your spoil board, the holding power is compromised. Point 3 - look for dust crossing your table gaskets. Check them for tears and size. They do wear out. Slight warp on spoil boards due to humidity change will cause leakage and facilitate the need to resurface your spoil board. Both sides for maintained accuracy.

From contributor N:
Wow - you're running a 40HP Dekker and it's not enough? What kind of work are you doing? Are you at higher elevation? We're thinking about getting a Dekker liquid ring to boost our vacuum. We have 2 Becker 10HP dry vane pumps. We can't cut faster than 16 metres a minute on small parts.