These blades are made for walkin' - Scroll Saw Woodworking & Crafts Message Board

Arcy · 07-01-2008, 04:36 AM

Well, actually it was the saw that was walking. The whole thing. Table and all. Just picked up and wandered off several feet away from where I started. Halfway through a cut I realized that I was facing a different direction than I started and was bumping into the workbench.

After hitting the off switch, moving everything back in place, and releasing and retensioning the blade everything seemed back to normal, but I’m not quite sure what caused this so I can make sure it didn’t happen again.

My first thought was that I shouldn't have rudely mocked the old enchantress who had come seeking shelter at my door, but upon further reflection I suspect there's a more rational cause.

I’m guessing that my blade tension was too high, but I’m not sure if that could have that dramatic an effect. I had been tending towards pushing the wood sideways against the blade rather than forward into it, and have been concentrating on fixing that. I don’t know how I was doing at the time. From the recent thread on jumpy wood (ha! Your wood only jumps! My whole machine dances! Beat that!) I could have been making too tight a turn for the blade I was using (I don’t know the actual size, but after buying some new labeled blades, it was pretty darn big), but I don’t think I was doing anything dramatically sharp. Likewise, I hadn’t gone too far after inserting the blade, so it should have been sharp. I was cutting 1/2” plywood, and had confirmed the table to be square not long before.

Any suggestions for what to watch out for would be appreciated!

Thanks,
Rob

Ramjet · 07-01-2008, 06:08 AM

I've heard of washers and dryers moving around but not a saw .What surface is the saw mounted on ? If is a cement floor , you may want to put a rubber mat between the floor and stand to absorb some of the vibration . Try turning your speed control down . Top speed can cause a vibration , as in mine . What make of saw is it ? You'll get more help once a little more info is known .

Arcy · 07-01-2008, 06:22 AM

Thanks. It's a Dremel 1671 on a cement floor. It only has two speeds, so I can't readily adjust the top speed down. It's bolted to a metal stand that appears to be matched to it.

I hadn't thought of putting a mat under the machine, but will do so. I have a rubber mat to make it more comfortable for me to stand on. I guess I should consider the saw's comfort too

--Rob

Mick Walker · 07-01-2008, 10:35 PM

Rob, I doubt that too much tension on the blade would cause your saw to walk. Too little tension would make it vibrate but it shouldn't walk. I would check for any loose nuts or bolts. Something must be way loose to make it vibrate that much. Pushing sideways on the wood will usually cause the blade to break. Wish I could be more help, maybe other Dremmel owners can advise you as to what is causing so much vibration.

Dragon · 07-02-2008, 01:42 AM

LOL
Diane

minowevie · 07-02-2008, 09:52 PM

Rob, do you have your saw bolted down to the floor? I have a Hegner, and it is soooo stable, but then I am not. I find I push my saw around with my knees, if I am sitting. and so on. but I have to bolt it to the floor. do you think that might be one of the problems. Or. you might be blasting away with the roung speed with the roung blade, and soo not squir to the table. but probley just need to bolt that monster down. and let it cut. your friend Evie

Arcy · 07-03-2008, 02:01 AM

Quote:

Originally Posted by Mick Walker

I would check for any loose nuts or bolts. Something must be way loose to make it vibrate that much.

Thanks Mick,

Nothing appears obviously loose, but it's hard to tell without disassembling more than I'd like to so long as the problem is in remission. I haven't had any similar problems since, so for now I'll leave well enough alone beyond general stabilizing.

It wasn't immediately after, but within an hour of when I was fiddling with installing the quick-change blade adapters. I'm thinking that I knocked something out of wack then, and when I adjusted the blade it fell back into place. Another theory is that I managed to run it at its resonance frequency (Tacoma Narrows Bridge - Wikipedia, the free encyclopedia). Or again, magic

Quote:

Originally Posted by Mick Walker

Pushing sideways on the wood will usually cause the blade to break

Oh yeah. I've definitely done THAT

Better now, though. Most of the time.

--Rob

Arcy · 07-03-2008, 02:10 AM

Quote:

Originally Posted by minowevie

Rob, do you have your saw bolted down to the floor?

Thanks Evie,
It's not bolted down, and I really cannot do so. I don't have a lot of room and need to move it between storage and use. I should be able to add a shelf on the stand's braces and add a sandbag for stability.

--Rob

lucky788scroller · 07-03-2008, 02:13 AM

Any chance your blade was in upside down??

Arcy · 07-03-2008, 03:46 AM

Quote:

Originally Posted by lucky788scroller

Any chance your blade was in upside down??

I don't think so. This was a pretty large blade, so I hope I'd have seen that. I released and reset the tension after the tango, but didn't remove the blade, and it cut fine both before and after. I assume that a blade wouldn't cut well upside down. Or would it cut the same, except for tearing out the top instead of the bottom? I'll have to check my piece to see what it looks like. I don't recall noticing any significant tear out from the blade, but I could easily have missed it if it was small.

--Rob