Help - stuck faceplate!

[Brian Glendenning]

My wife and I got a PM3520C late last year to get into turning. Over the Christmas holidays we were doing some small bowl turning, we left one on the faceplate overnight, and the next day when we came back to get the faceplate off, we couldn't - it was stuck. (A PM rep subsequently said that this usually happen when you get a catch which stops the late altogether. We certainly have had this happen but don't recall whether it did with this particular bowl. He also said to prevent this from happening again to get a washer, which we now have).

Googling it seemed like the usual solutions are to hit the wrench with a hammer or get more leverage. Hitting it with a hammer didn't do it, so I tried more leverage. I put a long (maybe 36") woodworking clamp on the flats and put my weight on it. I apparently broke the spindle lock mechanism since it only turned with some effort and the spindle lock wouldn't disengage.

PM authorized a repair (yay), which took 3 months (boo - I guess 3520C parts were backordered). When I got the headstock home (we're in a small town an hour away from where it was repaired) this weekend and unwrapped it, we discovered that the unit does appear to be repaired (spindle lock can engage / disengage, spindle does turn frequently) but ... the faceplate is still on and still seems to be stuck. Arggh.

I don't want to break it again, but I'm really at a loss of what to try. (I also tried WD40, and also mildly heating the faceplate (warm not hot) with a heat gun).

 

[Gerald Lawrence]

Might try Lock ease. Another option is instead of steady pressure try tapping your extension clamp with several medium taps . This should not put too much pressure on the spindle lock.

One more idea is to make a clamp to hold the spindle in place and not use the lock. Have done this but not for a stuck faceplate

 

[Richard Coers]

Screw a 3', 2x4 to the faceplate and smack it with a mallet. If it's a small faceplate, you may have to use small bolts if you can't get behind it to drive screws. Don't use any of the arbor locks or index pins. Just smack it to see if the shock will release it.

 

[Bill Boehme]

Screw a 3', 2x4 to the faceplate and smack it with a mallet. If it's a small faceplate, you may have to use small bolts if you can't get behind it to drive screws. Don't use any of the arbor locks or index pins. Just smack it to see if the shock will release it.

Also put the drive belt in the low speed range. This will give you the highest back driving moment of inertia. Do what Richard said, give it a good fast smack ... no wimpy stuff ... using light or even moderate taps probably won't work and for each tap that doesn't break the faceplate free the shock load is mostly absorbed by the bearings. With enough tapping the bearing races could possibly suffer fretting or false brinelling damage.

 

[john lucas]

Definitely put liquid wrench or some such penetrating oil on it. Let it sit and tap it with a mallet frequently to create vibration so the penetrant will get in there. Ideally you need to heat the faceplate to make it expand but it needs a lot of heat really quickly or you will end up also heating the spindle which won't do you any good. (BTDT) You probably will have to engage the spindle lock but I would try to lock the handwheel first. You can do this somewhat by putting a wedge between the handwheel and motor but a better way may be to cut a half hole in a couple of pieces of 2x4 so it will fit around the handwheel. Leave a gap so you can clamp the 2x4's together and leave them long enough to lock against the motor or the bed. The put a long piece of board on the faceplate and hit that with a hammer.
In the future just put a light oil like Air compressor oil on the spindle and faceplate mating surface. Screw the faceplate in until it's snug and then tighten it some more with the wrench or tommy bars. I quit using the nylon washer many years ago and after using the oil have not had a chuck or faceplate lock on or come loose since.

 

[Damon McLaughlin]

Did you check to see that the set screw on the faceplate is backed off? If its not backed out you won't be able to get the face plate off no matter what.

 

[Brian Glendenning]

Did you check to see that the set screw on the faceplate is backed off? If its not backed out you won't be able to get the face plate off no matter what.

Yup, took them all the way out to be safe.

 

[lynn cranmer]

A big pipe wrench can be used to lock the handwheel in place and then you will not damage the spindle lock and can use more leverage .

 

[Leo Van Der Loo]

If you can weld or have a fiend who can, take a piece of flat steel and drill a couple of holes in it the same distance as the holes in the faceplate so you could bolt that piece onto the faceplate, but first weld a large nut onto the steel (about in the center of the flat steel.
screw/bolt the steel onto the faceplate and get and use an impact gun, it will remove the faceplate.

Don’t use the spindle lock, it isn’t made for removing stuck faceplates or other.

My first choice would be a long piece of flat steel rather than the 2X4 (it is too soft and gives), and screw that to the faceplate, whack that hard, maybe twice, but it should get that stuck faceplate off every time.

 

[Mark Wollschlager]

Stuck faceplates and chucks are 'usually' result from not being tightened on the spindle and when the lathe is started the inertia of the steel and wood snaps it on really hard.
You normally do not need to use tools to tighten a faceplate or chuck, just give them a snap after screwing them on the spindle.
Always ensure that the mating surfaces between the spindle threads, back of spindle, faceplate or chuck are clean
The use of washers opens potential cans of worms.
Problems can arise if the washer is not really flat, or has crud trapped between it and the other mating surfaces.
The only times I have had to use a washer were with chucks on old spindle turning lathes that had a very small shoulder on the threaded spindle.
That's not a problem with the 3520.

 

[Charlie Knighton]

Rite of Passage

there will be a time when you can smile when it happens to someone else.....only covered if happens in class

 

[John Spitters]

Mark has given the best advice about what most likely caused the problem in the first place, and on how to avoid this problem in the future. If when putting on your chucks or faceplates make sure the spindle boss and it’s mating surface on the chuck are clean of any debris then for that last little bit of thread give them a little snap, this will give you a firm mating of the two surfaces
As to removing the faceplate get the proper fitting wrench on it, do not engage the spindle lock, have the lathe belt set at its lowest setting. Now get a dead blow mallet make sure you have a good grip on the wrench and give that wrench one very good whack.

 

[Mike Johnson]

When I get one stuck on the spindle I use one wrench on the spindle and brace it against the tool rest and put another wrench on the face plate, I then take a mallet or hammer and give the wrench on the face plate a sharp strike. I always use a thin plastic washer about the thickness of a plastic milk jug container between my bowl chucks and the spindle face, this prevents the threads from locking tightly and provides a fraction of an inch of cushion to break the threads loose. A brass shim would also provide the same function as the brass is softer then the hardened steel and allows threaded joints to be taken apart easily.

 

[Brian Glendenning]

OP here. Thanks everyone for the advice. The fellow at the service center was apologetic that he hadn't resolved the underlying problem, so we will bring it back up to him (he's an hour away, but the headstock is still on a pallet so it's relatively straightforward to get it back to him). This thread will be great if/when the problem recurs, and for everyone else in future who has a similar problem and is googling for solutions - it is much better than what I was able to find.

I'm a bit confused whether using a washer is best practice or not. The recommendation came from PM technical support in my first call to them.

Anyway, thanks everyone for the input. Clearly I should have posted here first thing rather than months after the problem first occurred...

 

[John Spitters]

Just a thought here, I had an issue a while back after roughing out some very wet London Plane.
Generally after turning wet wood I do a full cleanup of my lathe and surrounding area.
I will use compressed air to remove wet shavings and moisture from the lathe then do a wipe down with paper shop towels, with this process I will remove the tailstock from the lathe and the live center, also the banjo and tool rest from the banjo after which I will do a final cleanup with WD40. The chuck would also be removed and or a Morse taper in the headstock.
However this time I neglected to do this, come morning I found that my tool rest was rusted solid within the banjo and it took a lot of effort to free it, lesson learned. Is it possible you were turning wet wood?

 

[William Rogers]

I never use a plastic washer and don't want to add any additional misalignment. I realize we are wood turners and things are not as precise as metal turning, but the more I can eliminate the better. I do put never seize on the spindle threads and have never had a stuck chuck or faceplate. About once a month I coat the threads.

 

[Michael Nathal]

I can't disagree with any of the arguments for NOT using a plastic washer. .

Wow, Curtis, a triple negative!! Took me three times to figure out what you were saying

 

[john lucas]

It's not the alignment that is the problem with the nylon washers it vibration and chatter. Most noticeable on longer turnings.

 

[Brian Glendenning]

Hi everyone, OP here.

So I took the lathe back to the service center, and in trying to get the faceplate off himself the repair person broke the spindle lock the same way, which made me feel a bit better! He did then fix it again and got the faceplate off (not sure what he did differently). He said that the one metal was harder than the other (don't know if the faceplate or the spindle), and moreover one set of threads needed to be deburred and he thought that the serrations were significantly adding to the gripping power.

In any event, it is fixed, back in my shop, and working great. I was worried that all the banging, prying, etc, might have done something to the bearing or alignment, so I measured the runout both on the rim and face of the faceplate, and both are less than 0.001", both with and without the thin washer I got from craft supplies. Despite the opinions above about these washers, I think I'll run with one for a while until the trauma recedes from memory.

Thanks again everyone for all the great input, which I hope to not ever use, but should be helpful for the next poor person searching for an answer to this problem!

 

[Mike Johnson]

You can use just about any kind of plastic for the washer even a sheet of Mylar or plastic sleeve for a sheet of paper can make a thin washer which will prevent the two metal faces from locking up. I use several different sized hole punches to punch a few washers at one time and keep them on the head stock so they are always readily available when needed.

 

[hockenbery]

I used washers we cut from plastic milk jugs for a few years in the mid 90s.
Stopped using them because they didn’t reduce vibration over the washer less metal to metal contact of a tightened chuck or faceplate.

 

[William Rogers]

Glad you are up and running. The washer debate is one that will never end. I put some never seize on the threads once a month.

 

[Richard Coers]

Hi everyone, OP here.

So I took the lathe back to the service center, and in trying to get the faceplate off himself the repair person broke the spindle lock the same way, which made me feel a bit better! He did then fix it again and got the faceplate off (not sure what he did differently). He said that the one metal was harder than the other (don't know if the faceplate or the spindle), and moreover one set of threads needed to be deburred and he thought that the serrations were significantly adding to the gripping power.

In any event, it is fixed, back in my shop, and working great. I was worried that all the banging, prying, etc, might have done something to the bearing or alignment, so I measured the runout both on the rim and face of the faceplate, and both are less than 0.001", both with and without the thin washer I got from craft supplies. Despite the opinions above about these washers, I think I'll run with one for a while until the trauma recedes from memory.

Thanks again everyone for all the great input, which I hope to not ever use, but should be helpful for the next poor person searching for an answer to this problem!

That sure is anti-climactic. All that help and no answer.