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| Bandsaw wavy cut http://www-.luthiersforum.com/forum/viewtopic.php?f=10101&t=45533 |
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| Author: | Cablepuller [ Mon Apr 13, 2015 12:33 pm ] |
| Post subject: | Bandsaw wavy cut |
Hi Have bought a small bandsaw and yes it was a cheapy but im governed by a ruthless head of finance (the wife) Have followed the setup instructions and added plenty of tension..yet the dam thing wont cut straight lines.. i had to remove the guide rail and fight it by moving the wood otherwise it veers off course Anyone know if its just a case of cheap blade replacement or is there something else amiss Cheers 
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| Author: | Cablepuller [ Mon Apr 13, 2015 12:36 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Heres a pic of the beast 
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| Author: | Bri [ Mon Apr 13, 2015 12:41 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
What size of blade are you using? |
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| Author: | wbergman [ Mon Apr 13, 2015 12:42 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
One reason can be a bad blade that has the teeth offset more to one side than the other. |
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| Author: | Cablepuller [ Mon Apr 13, 2015 12:43 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Bri wrote: What size of blade are you using? Not sure bri it came with the saw |
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| Author: | WudWerkr [ Mon Apr 13, 2015 1:24 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
( 1 ) check the guides . If they are open too much that will cause drift . ( 2 ) how wide is blade ? to narrow a width "not thickness " can add to that issue ( 3 ) yes a cheap blade could be the issue as well |
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| Author: | Alan Carruth [ Mon Apr 13, 2015 1:41 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Most bandsaw blades seem to want to cut a bit off to one side or the other. What you do is find out what the 'drift angle' is by putting a small piece of wood through freehand, following a mark that's parallel to one side. Once you find the angle that makes the saw cut along that line set up the fence for that angle. Yeah, I know; not trivial. If the cut is crooked; drifting to one side or the other sometimes, and maybe changing drift from time to time, it's a sign that you're pushing the saw beyond it's limits, and probably not keeping the feed rate even. The blade can heat up if you push it too fast, or it can clog up with dust, either of which will cause it to drift. Those small saws really don't have much capacity. |
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| Author: | Cablepuller [ Mon Apr 13, 2015 1:42 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Just opened it up and its not even on the guides Check out the pics what a load of crap  
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| Author: | Pmaj7 [ Mon Apr 13, 2015 1:46 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Had you adjusted them earlier? |
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| Author: | Ken McKay [ Mon Apr 13, 2015 2:15 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Replace those with wooden dowels and press them against the blade make sure it doesn't touch the teeth though. Oak ebony is best we're just about any wood. Sent from my iPhone using Tapatalk Ken |
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| Author: | WudWerkr [ Mon Apr 13, 2015 2:26 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Ken McKay wrote: Replace those with wooden dowels and press them against the blade make sure it doesn't touch the teeth though. Oak ebony is best we're just about any wood. Sent from my iPhone using Tapatalk Ken Should be upper guides and lower guides. Exactly and I would say thats 99% of the issue ![[:Y:]](./images/smilies/smiley20.gif "Thumbs Up") Also while you have it open check the back bearings the blade rides against , are they spinning freely ? If not , when you apply cutting pressure it causes friction and tries to make blade turn.
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| Author: | Cablepuller [ Mon Apr 13, 2015 2:36 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
pat macaluso wrote: Had you adjusted them earlier? No this is how it came.. very poor.. it wasnt on the upper bearing either pat.. |
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| Author: | Cablepuller [ Mon Apr 13, 2015 2:39 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Ok thanks wudwerkr all sorted.. checked and the guides above and below wernt anywhere near the blade.. this is how it came... cheapness comes at a cost... have re aligned all of the guides and it is now cutting straight !!! Thanks all for the input
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| Author: | dzsmith [ Mon Apr 13, 2015 3:30 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
I'd suggest shoving a shop vac hose in the thing to suck out the sawdust. |
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| Author: | Tai Fu [ Mon Apr 13, 2015 4:09 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Probably a dull blade as well, especially if you have to fight it. |
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| Author: | Glenn_Aycock [ Mon Apr 13, 2015 4:46 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
In case it isn't obvious, that ball bearing behind the blade supports the back of the blade, which should not run along side of the bearing. It should be adjustable in and out to accommodate different size blades and helps to keep the blade centered on the wheel. Clearance should be about 1/16 or less. Also, if the guides are graphite or ceramic, keep them. Put a dollar bill between the blade and guides and snug them up. Remove the bill and the clearance should be about right. That's why your cuts are wavy. Good luck. Glenn |
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| Author: | Glenn_Aycock [ Mon Apr 13, 2015 4:50 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Also, I advise cleaning all that crud off the interior, and it looks like you need new tires too. I can't quite tell, but they look badly worn. |
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| Author: | Tai Fu [ Mon Apr 13, 2015 4:55 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Most the time the blade that came with bandsaws are dull... |
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| Author: | cphanna [ Mon Apr 13, 2015 7:08 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Okay... First, clean the interior, as advised. Next, get a new, sharp blade. Next, set those blade guides or replace them. If you replace them, set the replacements. You can see this demonstrated and read about it online. I set mine so that I can just slip a piece of thin paper between the blade and the guide on each side. When you've done all that, your blade might still have a bit of drift. Read Alan Carruth's post about blade drift until you understand what he is saying. He has given VERY good advice about adjusting for blade drift. Best of luck! |
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| Author: | dzsmith [ Mon Apr 13, 2015 7:17 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Don't be discouraged with the small bandsaw. I made several electrics with a 9-in Ryobi saw. I have a 14" saw now, and I fitted the 9-inch with a fine blade. I still use the heck out of my 9-incher. Keep the guts clean. Your saw probably has a vacuum port on it. |
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| Author: | Glenn_Aycock [ Mon Apr 13, 2015 9:23 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
My first band saw was the 9" Ryobi. I wish I still had it. I mostly use my big one for resawing and I hate reconfiguring it to cut tight curves. One of these days I'll pick up one from CL. |
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| Author: | dzsmith [ Mon Apr 13, 2015 9:49 pm ] |
| Post subject: | Re: Bandsaw wavy cut |
Glenn_Aycock wrote: My first band saw was the 9" Ryobi. I wish I still had it. I mostly use my big one for resawing and I hate reconfiguring it to cut tight curves. One of these days I'll pick up one from CL. Yeah, I spend at least an hour doing a blade swap, cleaning, and setup. I have a 3/4" 2 TPI blade on it now. I'm resawing Mesquite until I run out. |
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| Author: | Michael.N. [ Tue Apr 14, 2015 6:06 am ] |
| Post subject: | Re: Bandsaw wavy cut |
A good blade will make a difference, although it's quite possible that the blade on the machine now isn't the one that was shipped with the saw. Buy your blades from Ian at Tuffsaws. These small Bandsaws usually have a little trouble putting enough tension on the blade, hence why they use thin gauge. Wider (or deeper) blades are also harder to tension, so buy 1/4" rather than 1/2" if the work allows. The side guides will almost certainly be just plain metal rods, they look to be Steel. The small bandsaw that I had were of Brass. On my larger 14" Bandsaw I removed the bearing guides and used some turned Bubinga (end grain) soaked in WD40. You can literally touch the blade with these. Your bandsaw should be OK providing the wood isn't too deep or too hard. Forget trying to cut 3" Ebony, for example. |
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| Author: | whiskywill [ Wed Apr 15, 2015 10:26 am ] |
| Post subject: | Re: Bandsaw wavy cut |
Michael.N. wrote: Buy your blades from Ian at Tuffsaws. I'll second that. Together with a good set up, you'll cut anything within the capacity of the saw. |
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| Author: | Pmaj7 [ Wed Apr 15, 2015 11:27 am ] |
| Post subject: | Re: Bandsaw wavy cut |
Cablepuller wrote: Have followed the setup instructions.. That did not include adjusting the guides? |
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