Thanks, Dick. That might very well be it. I noticed that the belt gets aufully loose at very high speeds. I'll give it a once over and see.
[OP]
Contributor
Thanks, Dick. That might very well be it. I noticed that the belt gets aufully loose at very high speeds. I'll give it a once over and see.
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[OP]
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Dick, you are a genius! I checked the upper pulley, the one that the variable speed handle makes go in and out, thus creating a larger or smaller pulley and BAM, there was the problem. The outter of the two discs that make up the pulley was set about 1/8" out too far. I moved it in and BAM she runs very close to what the marks on the variable speed indicator show. When set at 550, I'm running at about 600; when set at 800, I'm running at about 850; when running at 1150, I'm dead on. I know that those are merely guides, not exact rpms. That's fine with me...at least they are approximately where they should be. I was just having issue with the lathe running about 60+% faster than the indicator marks.
On that note, the slowest speed I can get now (when I turn the handle all the way down to the STOP position) is 392 rpm. Oh, the reason that it runs in the STOP position is that we disabled the automatic STOP position shut off switch.
The upper lathe belt still is a little sloppy at top speed of 2100 rpm, but I'm not really worried about it because I don't think I'll be running that high much...if ever.
Thanks, again, Dick for figuring that one out for me.
Oh, BTW, the middle pulley (the one that is spring loaded) moves very smoothly. I assume this is the part you all talk about that needs care and to be kept clean....
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I can't believe you're posting pics of your bride's rear end ...Originally Posted by Mike Cruz
Wait till she finds out!!!
Seriously, looks great!
[OP]
Contributor
Maybe this'll help...
Naw, my wife's backside is MUCH purdier!
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Mike,
I'm glad you are getting it figured out!
One thing though...One half of both the spindle pulley and jackshaft pulley sets should be spring loaded and move. One side of each pulley is fixed with a set screw/c-clip and the other side should slide smoothly in both directions but be spring loaded toward the fixed half. It sounds like your top pulley half might be a little stiff or stuck! This should eliminate the upper slack belt issue.
Take care,
Dick
[OP]
Contributor
Dick, if I've got this right, the jackshaft pulley is the pulley in the middle, between the motor pulley and the spindle pulley. On my lathe, as it probably is in most/all like it, that one has a large spring that changes that pulley's effective diameter by moving the outside half of the pulley. The inside fixed half of the pulley is the other half of the pulley that goes to the motor...which is fixed. The spring feels strong and moves very freely.
On the Spindle pulley, the outside pulley is fixed (with a set screw) and the inside one is the one that moves, but not spring loaded. It, I believe, is directly linked to the manual VS controller. So then when you move the controller left and right, you are pushing the inside half of the pulley in and out. So, it isn't/can't be stuck. It changes with speed change. When at it's slowest speed position, the belt is good and tight. It only gets sloppy at high speeds (over 1600 rpm...which, I will likely never need). On an interesting note, the labeling on the controller goes up to 2100 rpm, but there is no way for me to even get the handle to the 2100 mark, the inside half of the spindle pulley hits the cover before I can get there. But the belt is way too loose to handle the 2100 spot anyway.
It just hit me that maybe my controller is in the wrong position, in other words, rotated too far left, not enabling the controller to go all the way to the 2100 mark, but when I have the controller all the way in the other direction, it is dead nuts on the STOP indicator. And since I've taken the controller off and put it on a couple of times now, I dont' really think there is a way to mess it up. I think it can only go in one way...
The only other thing I think it could be is that the belt (while it doesnt' look bad at all) may be a little old and may not be as wide as it used to be, therefore not creating as much of a difference between each of the pulley sets. Who knows. Maybe I'll call PM and spend $300 on a new belt.
Anyway, thanks for your help...
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Mike,
As far a the upper end speed you might need...........there are times I turn spindles at over 2500 rpm, and on a couple occasions, I have turned at over 3000 rpm. You get better and smoother cuts at high speed on some applications..........
The reason I bring this up, is so that if your lathe is capable of the higher speed, then if you can, you should get it so that it will run to factory specs or better. You might not think at this early stage you would ever use the higher rpm settings, but as you get to be more experienced, you will want to use the higher settings...........most all turners do, so if possible, get all you can while working your PM90 over!
Looking good so far!
Remember, in a moments time, everything can change!
Vision - not just seeing what is, but seeing what can be!
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Thanks, Roger. I will keep that in mind and see what I can do. So, do you think a new belt is in order? If so, is this one of those things that I really ought to get from PM, or just get it anywhere? I'm a linkblet kinda guy, have them on pretty much all my machines, but don't think it is my best bet, IF it would even work, for this one. The belt is one of the wider varieties with ribs on the inside.
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It won't work on the PM90 Mike, you need a specific belt. As I didn't have a jackshaft model, I can't give you specific guidance. However, you could pose this question over at OWWM.org and someone there will give you a precise and quick response. I would recommend Gates Belts myself, they are a premium price generally but if you're looking at using this for a while - the extra cost is WELL worth it.
Cheers,
mike
Contributor
Mike,
There is a company out of wisconsin, I believe, which has a site called Belts4less.com, and they are a division of Belarus Tractor. They have pretty much any belt you could want. I think you could get an idea from them of what is available. I bought 3 for my new Grizzly G0698, just because I wanted the spares, and they are high quality.
Take a look at their site, and then if you aren't sure of which you need, then their reps can help you if you call the contact number. I had my belts in 2 days from ordering..........super customer service!
Last edited by Roger Chandler; 11-16-2010 at 4:08 PM.
Remember, in a moments time, everything can change!
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I am curious to know where you picked up the tachometer.
John Altberg
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Contributor
Yeah, Mike, sorry, I meant to make that clear...I really like linkbelts, but I assumed that they would not work or at least would not be ideal for this situation.
Roger, thanks for the link, but for now, I think I'm not gonna need 'em! I went to the shop, got out my tools, and went to work. I took the speed controller off and really gave it a once over to figure out HOW it worked. I made sure everything was working smoothly, and it is. I took off the belts so I could play with everything without fighting the motor. Figured out where the inside spindle pulley half (the one that moves) was when in its furthest out (away from the headstock), which is in the STOP position. Adjusted the outter spindle pulley half to be flush with it. Tightened the collar to set it. The, I put the top belt back on, and gave the whole thing a good looking over. The ONLY thing that I could see that could be adjusted (to solve the problem of the belt getting so loose at highest speeds) was the middle pulley (with the big spring). So, I took off the upper belt, loosened the bolts (NOT easy to get to), and dropped it as far as it would go (only about 1/4" from where it was before). Put the lower belt back on, put the upper belt back on...aaaaand...voila! My lowest speed (in the old STOP position) is now 335. All the marks 550, 800, 1150, 1400, and 1600 are almost dead nut on...within 5 to 10 rpm!
The one challenge I have is that I can't really turn the controller handle all the way to the 2100 mark because the inside spindle pulley half will retract all the way back to the headstock and start to rub. BUT, juuuuuust before it rubs, I hit 2100 rpm anyway! What is a little difficult is that sure I can see that with the cover off, but with the cover on, I would have to rely on hearing it rub...not too good... BUT with my digital tach, as long as all runs properly, I can stop my rpm at 2100...which will avoid rubbing. That said, I am working with Dan Hintz on making a new marking strip for the controller. My PM90 is not the kind that has the controller with huge numbers cast into the speed controller. There is a 5/8" aluminum strip that goes around the circumferance of it with rpm numbers. I'm just going to replace it. Dan is going to make one with his laser engraver. I can't wait to replace the old one.
On that note, since I have a VFD and a digital tach, I'm considering just putting 1-10 on the strip, to give me an idea of where I am on the scale of the reeves drive as opposed to putting rpm numbers on it. That way, if they change for whatever reason, I won't have conflicting numbers. But, as with anything, electronics don't last forever, so by having actual rpms on the strip isn't a bad idea. I just haven't decided yet...
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[OP]
Contributor
John, I got it here:
http://mkctools.com/tachoptions.htm
On this page there are 4 tachs. Really there are two different ones. Each kind is shown with and without a box. The one kind (about $100) is the tachometer, the other is the tachulator which gives you the option of not just spindle rpm, but also SFM (surface feet per minute), so it can/will figure out how many feet per minute of surface area go around. It was explained to me that this has more of an application on metal lathes. I didn't need that so I went with the regular tach in a box. If I had it to do over, I probably would have opted out of the box because I had/have to build a custom box for it and the pot anyway. The guy there is very helpful and great with explanation. He's had one of these units on his lathe since 2002 or something.
IF I were into "making things work", there was a tach on Ebay for $10. It didn't look as nice as this, had a smaller display, and didn't come with anything else...just the tach. That is why you would have to make things work because you would have to find a sensor that is compatible...etc.
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Mike,
Wooo Hooooo!!! Sounds like you have hit pay dirt! This is just great for you, and to boot, you now know the workings of your lathe in a way that will enable you to trouble shoot in the future should any problems arise, which is not likely. That PM 90 is one work horse of a lathe.
Congrats, Buddy, I am really happy to see things come together for you........now on to the cosmetic issues, like rust removal and paint, and getting everything shiny and slick for the banjo, tailstock, etc.
Won't be long now, and bowls will be coming off at a pace where the tools will be a-smokin"
Just a thought related to paint.........Grizzly green is really similar to that PM 90 finish, and Grizzly does sell paint as a replacement part.........just in case you wanted to check it out, of course you can take a chip to a paint store, and they can match it up exactly [I think]
Last edited by Roger Chandler; 11-16-2010 at 5:33 PM.
Remember, in a moments time, everything can change!
Vision - not just seeing what is, but seeing what can be!
[OP]
Contributor
Thanks for all your excitement for me. You sound like you are almost more excited than me! NOT! But close...
Believe it or not, Borg Green Rustolium matches perfectly!
I have been thinking about this whole refinishing thing, and someone else's suggestion is starting to sound better and better. Sand blasting it myself! I really don't want to, but since I am in the "I'm gonna do it myself anyway" mode, well, I might as well give it a try. A local Creeker has one and has offered to lend it to me. I'll try it out on a nice day on the small parts...handles and tailstock. If all goes well, I might use it for the rest of the lathe. It is one of portable ones, not a cabinet model. I found one of these units for sale on CL for $80, but didn't pounce on it quickly enough. I'm not planning to take the whole thing apart and do a total on it. At least, that isn't the plan...
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