Bandsaw vibration going up and then back down???

[Ted Drain]

I picked up a new Rikon 10-325 last month and have been pretty happy with it. The only thing I didn't like is that there seems to be more vibration that I would like. I decided to try balancing the wheels following the instructions from this page:

http://wiki.owwm.com/BandsawBladeBalancing.ashx

I placed a dial indicator on the outer corner of the table (measuring horizontal movement), removed the blade, and found .006" of movement from the lower wheel. Adding 1/2 oz of weight to one spot brought this down to < 0.001. After this step, I'm thinking how fantastic this is and how great this is going to be...

I mounted a 1/4" blade, tensioned it, and turned the saw on. 0.001! Fantastic! I left the saw running for a minute and as I'm watching it, the vibration starts growing. It went all the way up to .030" and then back down to zero again and then repeats. What the heck?

I tried a 1/4" blade (Highland hardware), a 3/4" wood slicer, and the 5/8" blade that came with the saw - they all show the same massive oscillation in the vibration. I'm really at a loss here. If it was some kind of natural frequency, I would expect the vibration to start small and then grow until it hits some steady state value but this is going up and then back down. The saw moves so much at the peak that it's easy to see with your eye.

Any thoughts? I'm really at a loss here. I'll be calling Rikon tomorrow to see if they have any ideas...

[Tri Hoang]

bad bearings?

[Jeff Miller]

Try giving it a little more tension and see what happens........just a thought.




JEFF:D

[William Falberg]

Your wheels are both slightly out of balance. When the heavy sides line up the imbalance becomes noticeable. As they're not perfectly the same diameter, they'll run in and out of phase and the vibration will come and go accordingly. The solution is to re-balance the wheels more accurately with the tires you have on, and make sure they can't slip around on the wheels. There are instructions in my book on how to balance your wheels and the jig you can make to do so.

[Chris Walker]

Ted- did you find a solution to the vibration? I'm having exactly the same problem with a new Rikon 10-325. No vibration for a minute or so, followed by a minute of very obvious vibration.

[Dan Karachio]

Hello Rikon if you are reading this, just a FYI, but I will not be buying this saw until I see a manufacturer sourced solution to this - and that does not include new saw owners making jigs to get their brand spanking new saws running correctly.

[Joe Wiliams]

Could this be of help?

http://www.rikontools.com/lowerwheeladjustments.pdf

[Dan Karachio]

Hey guys, seriously, I would like to hear updates about this being resolved. It is selfish - I was planning to buy one soon.

[Myk Rian]

Your wheels are both slightly out of balance. When the heavy sides line up the imbalance becomes noticeable. As they're not perfectly the same diameter, they'll run in and out of phase and the vibration will come and go accordingly. The solution is to re-balance the wheels more accurately with the tires you have on, and make sure they can't slip around on the wheels. There are instructions in my book on how to balance your wheels and the jig you can make to do so.
+1 on this. That's my guess.

[glenn bradley]

Hey guys, seriously, I would like to hear updates about this being resolved. It is selfish - I was planning to buy one soon.

Looks like you may need to PM Ted directly and ask(?).

[Chris Walker]

Many thanks for the helpful suggestions. I figured it out tonight. The saw is on an HTC mobile base. The rubber levelers on the front may not have provided enough support. I put wood blocks under the front of the mobile base to provide solid support and it solved the oscillating vibration. Not what I would have predicted, but it worked.

The saw is terrific- adjustability of the guide post, lower wheel alignment, etc provides a huge improvement over my older 14" inch jet. I did replace the blade and the stock guide wheels with the microadjustable version from Carter, mostly because it is much easier to set the lower wheels. I'd buy it again in an instant.

Chris

[Ted Drain]

No solution yet but some improvement. I put a 1/4 oz weight at 0, 90, 180, 270 and measured the amplitude of the vibration - using that I found the minimum spot and put a weight there. It was still too big but better than without the weight. I repeated again with another 1/4 oz weight and got a spot about 30 deg off from the first weight. That reduced the oscillation - it's mostly constant now - but still too large. My next step is to retry these steps with 1/8 oz weights and keep repeating until (hopefully) the vibration is minimized.

I know it's not my base - mine is on concrete and I have about 200 lbs of dirt (in a bag) and old weights in the base. I do think that the mounting of the saw on the base could be greatly improved - there just isn't much bearing surface. Because of this, the saw frame can definitely move even when the base is secure. I might have to add some plywood between the two...

I emailed Rikon CS and never heard anything back. Didn't try calling them.

[Ted Drain]

ps: I did the lower wheel adjustment to set the tracking already.
pps: I still think the Rikon is a really nice saw - especially for the money.

[Ted Drain]

One other item - the author of the article in my original link emailed me and said he's seen this on one old saw and it was caused by one of the bearings in the upper wheel being out of round. As the bearing precessed, it causes the oscillation. If nothing else works, replacing the bearings will be my next step...

[Gary Muto]

I never had a vibration problem but I had a tracking concern and Rikon helped me through the adjustment before the bulletin was available. I suggest calling Rikon directly. I spoke with Rod and he was very knowledgeable and helpful. Let us know how oyu make out.

[Paul Johnstone]

Many thanks for the helpful suggestions. I figured it out tonight. The saw is on an HTC mobile base. The rubber levelers on the front may not have provided enough support. I put wood blocks under the front of the mobile base to provide solid support and it solved the oscillating vibration. Not what I would have predicted, but it worked.

Chris

I am late to this thread, but I was going to suggest something simliar
When I first set up my Rikon, there was a lot of vibration. The culprit was that my cement floor was not level/smooth. Putting the saw on a mobile base supported it on "4 points" as opposed to the entire base. Made a huge difference.

I highly recommend that everyone check out floor issues first before going in and adjusting factory settings on things like wheel adjustments, etc. I'm sure not every machine is perfect out of the factory, but most have pretty decent QC now.

[Michael Panis]

My Rikon 10-345 was my first bandsaw. I thought it vibrated too much, but didn't have anything to compare it to. I called Rikon and they were great to deal with. Turns out my top wheel was not properly balanced. Now the saw hums smoothly.

[Ted Drain]

My Rikon 10-345 was my first bandsaw. I thought it vibrated too much, but didn't have anything to compare it to. I called Rikon and they were great to deal with. Turns out my top wheel was not properly balanced. Now the saw hums smoothly.

How exactly did they help? New wheel?

[Ken Fitzgerald]

Ted,

Why don't you try calling them?

[Michael Titone]

I am a mechanical engineer working as a vibration consultant for rotating equipment. I have never balanced a bandsaw, and I am a newby at woodworking in general.

The fact that the vibration comes and goes does match with the theory that you may have the two wheels somewhat unbalanced. Then as another poster stated, the vibration comes in and out of phase creating the beat vibration. There are fancy ways to analyze this, but balancing seems to be helping. You could balance both wheels to the point that balancing is no longer helping, then if you still have vibration, you could probably conclude that unbalance is not the problem.

For a more systematic approach to balancing, you can try googling on "four run balancing without phase". This is essentially what you are doing, but by plotting the results and drawing circles, you should be able to get the weight angle and amount very close. There is site called vibronurse that provides a web based graphical application for using this technique. I have heard of this technique for years, but I have never had to use it.

I think that combining this approach with the approach suggested in the previous link that was specific to bandsaw balancing might help.

Good luck.

[Ted Drain]

For a more systematic approach to balancing, you can try googling on "four run balancing without phase".

FYI: here is the best site I could find - not much info out there from what I could see.

http://www.vibronurse.com/NoPhaseBalance.html


Ted,

Why don't you try calling them?

I'm going to - just haven't had time. I was hoping an email would be good enough...