VPI 16.5 Problem

Hi, picked up a used VPI 16.5 here on audiogon--eventually the law of used had to catch up to me, I guess. Worked great for about a dozen albums, but since then the vacuum seems to overpower the turntable--having no knowledge of how the turntable works, it is acting like there was a loose drive belt. So, vacuum really, really works, motor for turntable works, turntable spins (though sometimes starts slowly and then speeds up to normal operating speed), but when both on, turntable stops rotating (motor continues). Any ideas before I take to a repair shop? Thanks very much.

I have 12 beautifully cleaned albums, though.
Are you making sure the plastic "nut" on the spindle is tight? If its the least bit loose, the vacuum on mine will stop the record.
Kmulkey is right. When I first purchased the 16.5, I came to the same conclusion you did. But pulling off the platter I found that the set screw on the bottom of the platter was loose. I tightened it enough for the flat side of the spindle to fit snug against when re-attached, and it has worked perfectly ever since. Happy listening!
Yep. It's usually because the plastic nut on the spindle has not been tightened or because one forgot to screw it on at all.
Thanks very much, that is encouraging. I tightened the plastic nut as much as I dared, so I will try Bikerduud's suggestion. Is there any trick to taking off the platter? Does it unscrew or just slide off?

Thanks again.
You should be able to pull it off with a firm grip.
The only thing that I've ever had go afoul in nearly 270,000 cleaning cycles with the HW-16.5 is that the screws that hold the platter shaft to the motor arbor worked loose. If the other suggestions made here for things to check to solve the problem don't work, try checking this.

You would need to tip the machine on its side and remove the bottom panel to do so. If they are loose, be sure to orient the shaft straight and vertical before you tighten them. You may also want to put a drop of Loctite on each screw before you tighten them.

Happy listening.

Jim Pendleton
Osage Audio Products, LLC
One other tip, while you're at it. The vacuum tube can be adjusted and the slot should not point straight down (180 degree position). Per instructions I received from VPI, it should be at the 185 degree position when viewed from the spindle. Thus it will be slightly "open" to the film of liquid as the platter rotates. Also the tube should not extend more than 1/16" beyond the edge of the record.

I bought my 16.5 new and it was out of adjustment from the factory. A friend had even more problems with his new unit until it was adjusted per these instructions.
One other thing, the plastic nut to hold down the record needs to be put on so that the solid (as opposed to the hollow) end is facing up, not down. If you do it wrong, that will also cause the record to stop spinning. Has happened to me on occasion.
A common, and easily rectifiable problem with the 16.5.

The center of the cork mat is removeable. that this carefully off. Then you will see 3 attachment screws that hold the Platter to the Motor-Platter Arbor. Remove them, and lift Platter off.

There is commonly, two Allen Locking Set Screws that hold the Platter-Motor Arbor to the actual Electrical Motor Shaft. Loosen these Allen Locking Set Screws to fist make note of the ground flat on the Motor Shaft.

You want to insure that these 2 locking screws are locked down upon the flat of the Motor Shaft to insure correct tightening of the Arbor to Motor Shaft.

Once the Arbor has been correctly positioned, and tighted to Motor Shaft, then you may re-install Platter to Arbor, re-install center cork cutout, and you're done!

This more than likely occurs, due to the heating-cooling cycles of the motors, and the screws work loose after awhile.

While toying with the machine, get familiar with it, there's noting you can really hurt. Check things like making sure Drain Hose is properly tightened to the Recovery Tank inside, and that all appears to be in order. Always make sure when doing a cleaning run, that you fully clamp the drain hose shut tight, and get in the habit of every 1/2 dozen records or so, to drain the Recovery Tank. Failure to do so, will damage the Vacuum Motor. Mark
Do not just try to pull the platter off. I had a similar issue and the splindle was loose. Around the spindle there is a part of the cork which is removable (I used an exacto knife). Under that there are three screws. You can then see the spindle and it is anchored by two hex screws. Mine needed to be tightened, yours may too.
I will give all this a try tonight given time, and let people know. Thanks for all the help.
JHSJHS I posted a thread recently on AudioAsylum with a detailed step by step on this, in the Vinyl area, just search on vpi 16.5, it was yesterday, with detailed instructions on how to crank down the hub set screws. This is a common issue and most likely the cause of your record stopping spinning. Hope this helps.
I found the following on Audio Asylum (thanks to Cjnolan), and followed it except for the loctite suggestion, as I didn't have any. I will do that later. It worked, and I am back in business. Thanks, all!

--Remove the center cork piece. I use a very small flat head screw driver to prop it up. It's helpful to make a little mark with a sharpie so you can align this piece right when you put it back on (a little dot on the seam is all)
--Unscrew the 3 screws holding the platter, remove the platter
--You will see 8 screws. 4 smaller, 4 larger.
--Remove the 4 smaller screws
--Remove the 4 larger screws and remove the metal plate. Note when you remove the last one, the motor will be free and can drop into the box. No big deal, you can reach it easily. I use a screw driver to sort of prop up the motor/gearbox assembly.
--Now you need to look a at the hub mounted to the motor. You'll see 2 hex screws that hold the hub to the axle. There should be no ability to twist the hub without the axle turning and the hub should not slide up and down except for a little slack in the axle bushings. Basically, it should be tight.
--You will need a hex wrench or hex driver. Remove the 2 hex screws. Make sure the aluminum hub is pressed down on the shaft and the holes are centered to where they've been cranked down in the past (you should see marks on the shaft)
--Use a little BLUE loctite (this is the removable one!). Put a very small amount (I mean, just enough to cover the bottom 2 threads is enough, not even a drop) on the threads of one of the hex screws. Screw it in hand tight. Do the same for hex screw #2.
--Crank these both down good and tight. But not TOO tight, this is aluminum we're talking about. I like to tighten each side a little at a time so the torque is even on both sides.
--Reassemble in reverse. Be careful when cranking down the screws that go into aluminum (the platter and hub screws) and the screws that go into wood (the 4 smaller screws). Don't strip them or cross thread them. You'll have a bad day if you do.
I was able to tighten those hex screws without removing the eight regular screws. A standard allen wrench should be able to reach at a slight angle to tighten them. I've since bought a set of allen wrenched with ball ends just for this application. Good luck.
Jhsjhs - Glad this worked for you.

The suggestion of using a ball-end driver to tighten them w/o having to remove the motor assembly is a good one. I didn't have a ball-hex driver in this size hand.

I didn't bother to check the hex driver size, does anyone know what it is off hand?
My unit has a grinding noise as it rotates, quite irritating, is this normal and if not does anyone know how to fix it?
I believe the grinding noise is normal. I bought mine new and it's been making a noise that I'd describe as grinding ever since. The unit works fine, however. RCMs are pretty crude in design and I think motor noise reduction is not really a top design priority given their purpose.

I too had the same problem as the OP at the beginning, initially solved by using a rubber washer under the plastic knob as otherwise I had to tighten the knob to the point I was concerned I might either break the knob or damage the record label. For some strange reason, the problem worked itself out and I now don't use the washer and don't have to tighten the knob as hard for the platter to keep spinning with the vacuum pump on. Seems the parts needed simply to break in.
I had the same problem until I took off the backing on the cork mat. The cork mat has adhesive on the back.

Problem solved.