pcmeiners
Well-known member
Vacuum pump stator repair advice
Just purchased an Edwards e2m12 vane vacuum pump, very cheaply, knowing repairs were likely. The second HV stage should look like the above.
Someone must have done some machining on it with a lathe, to remove scoring, leaving unfinished rough cut marks, nothing like the smoothness of the above stator. Beside the rough machining, near the ports there is a slight low depression, guessing about 1/32 to 1/64" front to the back of the pump.
From my little knowledge of machining, I assume the repair should have been done with a mill. The HV stator has phenolic vanes pushing again the walls, springs are used to apply pressure on the vanes. The vanes wear away with use, at least 1/2" at end of life, so there quite a bit of leeway. The entire piece has been slightly hardened but can be scratched fairly easily.
Assuming the previous "repair" has not brought the stator too much out of spec, any ideas of the amount of time a machine shop would take to mill the interior to circularity with a smooth surface as above; I see no reason a full 1/8" could not be added to the diameter of the interior. The rear of the pump was not touched, so the work would only concern the side wall. One pump repair depot offers flame sprayed stainless, to bring messed up stators to OEM specs, I do not care if it is back to OEM specs as to the diameter, the vanes allow for a good bit of diameter deviation. the thought of heating this part to flame spray bothers me as to possible warp and hardening affects. At this point I can not make any measurements, lost most of my tools thanks to Sandy.
Edwards part depots wants >$625.00 for a new stator. Any thoughts?
Just purchased an Edwards e2m12 vane vacuum pump, very cheaply, knowing repairs were likely. The second HV stage should look like the above.
Someone must have done some machining on it with a lathe, to remove scoring, leaving unfinished rough cut marks, nothing like the smoothness of the above stator. Beside the rough machining, near the ports there is a slight low depression, guessing about 1/32 to 1/64" front to the back of the pump.
From my little knowledge of machining, I assume the repair should have been done with a mill. The HV stator has phenolic vanes pushing again the walls, springs are used to apply pressure on the vanes. The vanes wear away with use, at least 1/2" at end of life, so there quite a bit of leeway. The entire piece has been slightly hardened but can be scratched fairly easily.
Assuming the previous "repair" has not brought the stator too much out of spec, any ideas of the amount of time a machine shop would take to mill the interior to circularity with a smooth surface as above; I see no reason a full 1/8" could not be added to the diameter of the interior. The rear of the pump was not touched, so the work would only concern the side wall. One pump repair depot offers flame sprayed stainless, to bring messed up stators to OEM specs, I do not care if it is back to OEM specs as to the diameter, the vanes allow for a good bit of diameter deviation. the thought of heating this part to flame spray bothers me as to possible warp and hardening affects. At this point I can not make any measurements, lost most of my tools thanks to Sandy.
Edwards part depots wants >$625.00 for a new stator. Any thoughts?
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