Miehle V50X vacuum HELP!!!!!

I have put new carbon vanes into the vacuum side of the pump tandem and cannot get the recommended 15” vacuum at the top of the feeder. I have tried everything I can think of, took apart the pump a second time and still only 4-3” vacuum. I went so far as eliminate the valve on the non-op side of the press, same result. I have Big Foot suckers on the press and all they do is flutter, won’t even extend. The blower side works fine I even thought of swapping the pumps to see if there was a difference with the direction it was turning. Has anyone hooked up a separate vacuum pump on one of these??? I am open to any and all suggestions for help.
Thank you all in advance.
Jim

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The vanes when new are a trifle longer than the slot they fit into so when the end casting is bolted back on it will not seat properly. The vanes have to be filed flush with the end of the pump body before reattaching the end cap—or it leaks. That’s probably why you can’t get the air right.

fritz

Fritz-
So I should file the edge down, what should I use, a metal file. I don’t want to break any of them. What problems would I create if I were to file too much off?
Thanks for the info.
Jim

I’ve been told this by the fellow who runs Jack Beall Vertical Service. When I had this same problem, it was with new vanes but I had a rebuilt pump on hand and used that instead. When I talked to him he said “oh, you have to file ends of the vanes flush with the body of the pump.” He said to use a fine tooth mill file, do it gently as the carbon will file fairly easily until you reach metal. Then you have a snug fit. Clean up the filed material and reassemble. Pumps need to be cleaned periodically with a good degreaser as these pumps pick up oil out of the air from the running press, thus all the filters on the air system—mostly for air borne oil, then for lint, offset spray, etc. George Mills told me to use Robinol made by Anchor, but they may be history as I don’t find anything in a quick web search. I still have several gallon cans of the Robinol.

Fritz

Maybe to make it clearer, file the vanes while inserted into the slots, not out of the pump. This way the end of each vane will be the same length as the pump body. Vanes too long keep the end of the pump from being from being tightened properly and could bind up the pump from even turning. The file, used carefully, will not mess up the steel of the pump.

fritz

They must be fitted
Did that back in the day
Remember sand paper on table top
Carefully hold vane vertical (plumb) move over sand paper
Try to keep new edge square
Check often by placeing vane back in roter
Stop When vane length is same as roter
I think file is too aggressive
Good luck
Press on,
James ‘Mac’ McGraw

I am way too busy to have time to disassemble the pump and try the “filing” to see if it works. I will have to wait until Saturday and see how it goes.

So if the “vanes” are too wide then I will get very little vacuum?

This was the issue that prompted me to replace the vanes in the first place. How short can the vanes be and still be usable?

If I switch the pumps will running the other direction cause other issues if the “filing” does not increase the vacuum.

Question, Could I just reroute the hoses rather than swapping the pumps around? The other opening will have the opposite suction/blast of air, correct??
Jim

J F Sir, the whole essence of the vane type vacuum pump is that, with the rotor being eccentric within the body of the pump, the vanes have to be very close fit and tolerence, to seal in both directions, i.e. in rotary form, (so that in centrifugal motion the vanes fly out to contact the polished wall of the pump body!!) and end play by the rotor has to be virtually Zero, by implication the vanes have to be also, precise tolerance within the slots in the rotor, which is why *Filing* to fit has to be accurate!!!. . Reversing the rotation is almost certainly a non starter? with the end plate off examine (by turning by hand) which rotation produces the vacuum and picture what will happen in reverse???
Carbon is easy to work on, finds its own level and fit in normal operation, and by this token although supplied (in U.K.) in completely flat section top and bottom, when fitted and run for a very short time contoured itself to fit the circumference of the chamber, and could at least once be turned (the carbon vanes) over 180 degrees.
Even though the intakes for the pump(s) have good filters, Paper dust, Anti Set Off spray and similar, are very abrasive to the Carbon, and end up with tram lines in the face!!! Hence turning once, but only if all else has failed.?
And YES, auxilliary vacuum source is, and has been used as a stand by/keep you running method, good quality vacuum cleaner with simple *T* piece in the vacuum supply line works, in tandem of course!!
Here in the U.K. at one point, V.M. s, were re-equipped with modified pumps, for both pressure and vacuum with rubber diaphragm style units, in place of carbon vane(s) or vice versa.
In the Spiritual Home of Miehle, Goss, Dexter? is this still a possibility.
***A little trawl of the internet, looking up the problems with the “WANKEL” rotary engine, with regard to sealing the rotor and the vanes, in relation to the body, might help the learning curve for the vacuum pump in question!!!*** . . In essence the same principles.

The vane must slide and move easily in the roter slot
Vane must be free to extend out of slot to follow, toutch and seal against inner surface in pump chamber
Press on
James McGraw

Don’t know about Verticals, but on some rotary pumps, it was standard maintainance to disconnect the hoses and run a little kerosene through the pump. This flushes the dust that fouls the pump as the vanes wear down in ordinary use (there could also be a filter to remove external matter from the air infeed, and another for the outflow, and these should also be cleaned regularly). Reconnect hoses and let the oiling reservoir restore normal functional environment..

I haven’t seen a Miehle vacuum pump, but as Mick indicates, rotary vane pumps have zero clearance and should be checked for any scoring or other damage that could interfere with the seal.

I would be wary of using mineral abrasives like sandpaper… loose abrasive could find its way into the works and score the pump surfaces. Careful filing as Fritz mentions, would be my choice if the vanes sit proud in the pump.

Carbon Vanes, for vacuum pumps, Here in U.K. at least until mid/late 80,s it would have been matter of course, for replacement carbon vanes, to pick up the landline and order 2/3/4 sets from, *LE CARBONE* in glorious downtown Sussex, U.K.
Le Carbone,!! Makers of All things, Carbon and Carbon related, still in ***Existence*** but Probably/Sadly no archives or Records for V.M. application(s)?? . Still left.
You must have surely, in The States, many Companies that still produce carbon products. Inc. Carbon Vanes.!!!
Just a thought or possibility. Good Luck Mick

I have received the carbon vanes from:
Jack Beall vertical service
Carpentersville, Ill
Phone 1-847-426-7958
I have received other parts for the Miehle Vertical from them in the past. They were the ones who mentioned I should have 15” of vacuum up at the feed end. Nothing was mentioned about “fitting” the vanes to get proper vacuum.
I will update after the weekend if there is any success or not.
Thank you all for your input, keep posting if anyone has any input.
Jim