Bandsaw resaw problem

[daniel lane]

May as well PM Van on this, but I figured I'd ask everyone in case someone else has had a similar issue -

I've got a Rikon 14-325 deluxe bandsaw and have done a little resawing with it - nothing crazy, some 10" wide poplar, a few other bits here and there. The other day I resawed some 4" wide purpleheart and the blade started wandering all OVER the place. Really bad issue with deflection to the right. I thought I had the fence set, but figuring it was no big issue, I pulled it back to in front of the blade to finish the cut - figuring I could pivot off the back of the fence, instead of adding the resaw bar in the middle of a cut. Well, in addition to the deflection (which I've not seen before, but this was the hardest stuff I've resawed), I can't tell if the blade was jumping in the stock (slow feed) or if it was deflected into the blade clearance insert, but it kept jumping off the table with loud pops and the insert finally shattered. This was with only 3" of wood cut!

Anyone see this before? What did I do wrong? I have the saw tensioned right according to the Rikon on-saw tension gauge (I'm using a 3/4" Laguna resaw blade), but this scared the &#$%@ out of me, with the jumping and the popping and the throwing of the plastic bits everywhere and the glayvin...

On a related note, anyone know where to get zero-clearance inserts for the 14-325? I'm short any insert at all, at the moment...


Thanks,

daniel

[Jerry Thompson]

Taake a look @ the bandsaw tuning post just below yours,

[daniel lane]

Thanks, Jerry, but looks like about the only thing in there that might be relevant is that drift can be adjusted with tracking. This is with a carbide resaw blade, so much of the semantic argument is irrelevant.

Re-reading my post, I don't think I was terribly clear in my question - I'm trying to figure out why a saw that did not change setup from resawing 8" wide poplar (I measured this morning) and 3" wide cherry suddenly had all sorts of problems with 4" purpleheart. My guess is that the harder wood may have been a factor, but I'd never seen such a radical change in drift before. Essentially, I resawed the cherry directly against the fence and shut down, then detensioned the blade. Next time I came up to the saw (admittedly a week or two later) I retensioned the blade, checked out and turned on the saw, and started resawing the PH against the fence - and it immediately started off with a drift about 10*-15* to the left (needed to correct by shifting back of board to the right). I'm thinking the popping was the blade hitting the insert and the wood jumped when the insert popped back upward, so I'll discount that for now and focus on the large drift change without a change in saw setup. Anyone else ever seen anything like this?

While I find a new blade clearance insert and wait for it to show up, I plan on doing a thorough inspection of the saw, but so far, nothing seems awry...


daniel

[Rick Fisher]

I am impressed that the Rikon 14-325 can tension a 3/4" resaw blade. Most 14" saws would have a tough time with that blade.

Blade wander is gonna be either guides, dull blade, speed of cut, or tension.. I wonder if its tension.. The harder wood may have really shown the problem.

The 14" Super saws handle the bigger blades, Hammer, Laguna.. I would suspect tension.. regardless of what the gauge says ..

On my saw, I can run the bands sloppy loose and make easy cuts.. I have done it just to try it out.. but as soon as there is hard work involved, I have to set the tension hard..

[Joe Kaufman]

Highland Woodworking has the replacement table inserts 4 for $18. http://www.highlandwoodworking.com/table-inserts-for-rikon-bandsaws.aspx

I have the same saw and the tension gage is blade length dependent, so don't rely on the gage. Be careful resawing short lengths, the plastic insert won't support the stock at the beginning of the cut as the blade tends to pull and rotate the stock down into the insert. I messed up a woodslicer blade under these conditions. My experience and reaction was similar to yours. You may have bent or put a kink in the blade, try a softer wood to see if the blade performs as it did previously. In my experience, Purpleheart is very tuff and dificult to work.

[daniel lane]

I am impressed that the Rikon 14-325 can tension a 3/4" resaw blade. Most 14" saws would have a tough time with that blade. Blade wander is gonna be either guides, dull blade, speed of cut, or tension.. I wonder if its tension.. The harder wood may have really shown the problem. The 14" Super saws handle the bigger blades, Hammer, Laguna.. I would suspect tension.. regardless of what the gauge says ..

Well, I admit it's on the far edge of its capabilities, but it's clearly marked for handling a 3/4" blade and I've done well with it in the past. Frankly, I was surprised, as well, and it's why I bought that particular saw, even when I was mostly doing pens/etc. Regarding tension, I'm thinking that's probably it. I may research it a bit more, but I thought it was tensioned well - I don't just rely on the gauge on the machine, I also do the push test and get a feel for it. I'll see how much harder I can tension without fear, otherwise I'll research what will be the first to break and try it again. :)


Highland Woodworking has the replacement table inserts 4 for $18. http://www.highlandwoodworking.com/table-inserts-for-rikon-bandsaws.aspx

Thanks, Joe - I've been combing the web looking for some zero clearance inserts that will fit, but it's good to have a supply of the OEM parts. I'll see what else I can get them to throw in a box and place an order tonight.



I have the same saw and the tension gage is blade length dependent, so don't rely on the gage. Be careful resawing short lengths, the plastic insert won't support the stock at the beginning of the cut as the blade tends to pull and rotate the stock down into the insert. I messed up a woodslicer blade under these conditions. My experience and reaction was similar to yours. You may have bent or put a kink in the blade, try a softer wood to see if the blade performs as it did previously. In my experience, Purpleheart is very tuff and dificult to work.

I did not measure the blade, but admit that I assumed when I ordered a 111" blade, that's what I got. Since it's a spring-loaded needle gauge, I wonder that it's that much blade length dependent, but you've got a good point and I should check it out. Thanks!

Regarding the small pieces, I was referring to width (thickness when resawing) - all the pieces I cut are at least 9" long, most are at 12" or longer. I appreciate the warning, but it's something I've heard before and won't do.

With the BS out of commission until I get a throat insert, I resawed some stuff on the TS this morning. Wasn't an ideal situation, but frankly a WWII thin kerf doesn't waste much more than the 3/4" carbide blade on the BS, and this was easy to do after getting the safety setup in place. A good alternative for the harder exotic woods, until I figure out what's going on.

Thanks, all.


daniel

[Howard Acheson]

A couple of observations. First, almost all the band saw gurus will recommend not using a blade wider than 1/2" for resawing on a 14" machine. The blade is not correctly fully supported by the tire and will be prone to wandering.

Second, it sounds like the blade my be dull and/or damaged. How are your other blades behaving?

[Van Huskey]

Someone already mentioned Highland for the inserts...

I am travelling so not a lot of time but my first inclinations would be tension OR a dull blade. Given it is a Laguna RK and you haven't used it a lot I would discount the blade. Sounds like tension to me... How much more room do you have on the coils of the spring to increase tension (do NOT bottom it out)?

[Andrew Hughes]

Hi Daniel,I dont think you did any thing wrong with your saw set up .I do remember trying to resaw some ebony with resaw king and the blade would grab and pop.But it would cut walnut no problem.I thought the same thing with the plate flexing.Its been a while but i think the blade cut the ebony after it was sharpened.I see your in Ca. Daley saw in south gate is a were i sent my rk blade.I thought they did a better job than Laguna Tools.Its been few years so maybe things have changed? Hope this helps Andrew

[Curt Harms]

I made some zero clearance inserts from "1/4"" plywood using a procedure similar to making zero clearance inserts for a table saw. Cut disks slightly oversized, tape a centered factory insert to the plywood blank and trim with a flush trim router bit. I drilled several holes to enhance dust collection. You may or may not need to use a bit of tape to shim flush. Of course this requires an intact insert to start. Re the tracking problem I'd go along with tension. As far as I can tell the tension gauge on the 10-325 is primarily for entertainment purposes :p. I guess it helps, once I get a blade performing well to note the tension setting then return to that setting if the blade is removed and replaced.

[Bill White]

I'm in the same camp with those who think a 3/4" blade on a 14" BS is really pushing the tensioning capabilities. I use a 1/2" 3tpi for resawing.
Bill

[Erik Loza]

I'm in the same camp with those who think a 3/4" blade on a 14" BS is really pushing the tensioning capabilities. I use a 1/2" 3tpi for resawing.
Bill

Agreed: Don't go bigger than 0.50" on a saw that size.

Best of luck with the project.

Erik Loza
Minimax USA

[Richard Coers]

Purpleheart is your problem, not the band saw. It can have mica in the grain, and will dull tools almost instantly. It machines like rock. I still have the only board I bought of purpleheart. I made a little box for my daughter and swore I would never machine it again.

[Van Huskey]

Before we all condemn the choice of blade keep two things in mind, it is a steel spined saw AND it is a thin gauge band .025" so although the saw may not be able to get up near 30,000 psi for the carbide blade to be perfectly happy it should be able to get enough to work fine. I would crank the tension up to just before the coils bottom out on each other and try again. PH is HARD but that blade and the HP on that saw should have no real issue with it at 4".

BTW I would go back and test it with a softer wood to ensure everything about the blade is still fine, then honestly given the issues I would resaw the PH on the TS ( a pain but in this case maybe a better idea) unless you are trying to cut veneer.