Introduction & Vibration ?

[Mike Stephens]

Just like to start of by saying hello my name is Mike and I like wood. Ive been a woodworker for the past twelve years and am currently running a cabinet shop on LI New York. I only just recently found my way into wood turning and I have to say I'm loving the freedom. It's very relaxing, your not all over the shop on this machine and that machine and back again. I found this forum researching wood turning and really appreciate the wealth of information available. Not to mention the great group of people providing it.

I bought a Rockwell 46-111 with a 1/2hp motor that looked to have very little use. The lathe was mounted on the Steel stand with casters that was an option for this lathe. The motor was mounted under the lathe, hanging from the top of the stand. Well when I got the lathe home and set it up there was a lot of vibration when the belt was put on and none with the belt off. So I added a bottom shelf made out of 1" MDF to add weight made a top out of 1 1/2 MDF veneered with ASH and Banded with Mahogany adding even more weight. Last I mounted the motor to the shelf I put in and added another 150# of weight to the shelf.
One last thing I made sure the pulleys were lined up. Now when I started it the vibration is dampened to probably 70 percent less then it was but I'd like even less vibration. Now for the question. Is there anything else I can do.

I think adding some pics might help. So give me an hour and I'll have some up.

Thanks and I look forward to getting to now all you sharpie turners better,
Mike

[Mike Stephens]

Here are some pics any feedback would be appreciated. Maybe a link belt would do the trick.

Thanks,
Mike

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[Steve Schlumpf]

Mike - Welcome to the Creek! Looks like you have a really nice setup so far! Very nice work on the stand!

Vibration is one of those things that everyone has to fight. Your idea of a link belt may or may not help but it won't hurt anything. A lot of times vibration is caused because the bed of the lathe is not level, or is slightly twisted because it was torqued down a little more in one corner, etc. A quick check is to make sure the headstock and tailstock line up.

Most lathes have vibrations at certain speeds - that why variable speed is so popular. Does your lathe have the same vibration issue at all speed positions? How are the bearings in the headstock? Lots of options here..... hopefully others will chime in and we'll get this figured out.

[Don Carter]

Mike:
Welcome to the Creek! You will find lots of info here. Steve has just about covered the things that I would look at. Changing to a link belt won't hurt anything. Is the belt you have on now a new belt? Sometimes older belts get stiff or have flat spots on them.

I would second Steve's suggestion of checking the the alignment of the tailstock and headstock. If there is a twist in the bed, it can cause vibration. And also check level in all directions.

I hope you track it down.

All the best.

Don

[Mike Stephens]

Thanks for the responses. The lathe is level and I checked all the bolts holding the lath down. The bearings are tight and seem fine.Also the centers line up. What I did discover was when I cited down the belt when the lathe was off is that the belt itself does not appear to be cut straight. I think this is causing the vibration. I got the belt from Ace Hardware so I think I'm going to give the link belt a try. As is, the machine is ok to turn with but I'm a little anal about my machinery.

Like I said I only just started turning but I am very ambitious. Right now I am just practicing using my tools. I have lots of questions and am thankful and appreciate this forum.

Mike

[Richard Madison]

Mike,
There appear to be two hold-down tabs on the motor mount board. Do these tabs apply belt tension, or is there some play in the motor mount pivot even when the tabs are in the "locked" position. If the latter, your vibration may be caused by the relatively light weight motor repeatedly trying to climb a long, whippy belt. As a test you could make a couple of spacers to fit under the motor board and clamp the board solidly against them so it is not free to move. Be careful not to apply too much tension to the belt, as it would of course be bad for motor and spindle bearings. Very little belt tension is required to transmit 1/2 hp.

[Jeff Nicol]

Mike, With the motor that far away from the headstock there is more chance to have a belt with defects in it (bad joint, kink, wobble) to compound the vibration. So I would move the motor closer and get a shorter belt or put an ideler wheel some where to stop the belt slap a bit. But the link belt will definitley help. If you could get some v-groove pulleys they would be more stable also. One more thing machined pulleys are better too but costly. Almost forgot the wooden motor mount is not the best either, should be steel and welded to the shelf brackets if possible.

Lots to think about!

Jeff

[Mike Stephens]

Richard I will try clamping down the Motor today. Jeff when I got the lathe the motor was mounted under the top and there was 3X the vibration. I do understand that having a longer belt can cause vibration. So would you suggest making the platform that the motor is mounted on higher and using a shorter belt. As for the wood that the motor is mounted on it's 1" maple plywood. I can try to get steel but I am not set up for steel work and with all the other things I want for turning paying a machinist is out of the question.

Here is a bad pic of the lathe when I bought it. You can just make out How the motor was mounted according to Rockwell's directions.

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I think I will get a link belt work on the motor mount some more and if I have to raise the motor closer to the head stock. If anybody out there has engineered how there motor is mounted I would love to see some pictures.

Thanks,
Mike

[Jeff Nicol]

Mike, buy how the old picture looks the stand is not what I would call sturdy! You could build a box and fill it with sand and put it on the bottom shelf, then fill with sand to dampen vibration. Make sure that you attach the side legs to the box to create a continuous stand. I did this for my cheapy chinese lathe and that cured it of all the vibrations. I still have to make a better motor mount as it is still a piece of 3/4" plywood. I think also does the motor do all the belt tensioning? If it does and there is not a positive mechanical tightening device, the bouncing of the motor and belt and every thing can add to vibration. I wish you lived across town so I could stop in and give you a hand! I have lots of steel and welders to do that kind of stuff!

Hope all our comments and ideas lead to a good solution!

Jeff

[Rusty Smith]

It looks to me like the pully on the motor and headstock are not aligned in the last picture. This may or may not cause the vibration but I would think it wouldn't help the situation.

[Mike Stephens]

Thanks everyone for all your suggestions. I have gone back to the drawing board and did a little re-engineering. I will post an up-date when I am finished.

Mike