Breaking Bands

Gary_B · February 21, 2011, 05:39:35 PM

I know on my TK 1220 they are very tight fit.....so tight that yesterday when I was attemping to change one of the belts on my wheel, I was stretching the new one with a screwdriver and broke the new belt, I was trying to avoid trying to get the twist out of the belt before installing.... :( As I was struggling with the belt I was thinking about Obama stating we need better education......all I thought about was we need a better design on these wheels..maybe our technology could inprove :D

Tom · February 21, 2011, 06:46:12 PM

Loose belts were used and are continuing to be used by Woodmizer, the industry leader of thin kerf band mills. Tight V-belts are a "re-invention" by the public and a selling tool of other manufacturers who have used every opportunity at their disposal to try to unseat Woodmizer from their position of having created standards.

It's not that tight belts won't work and not that the looser belts won't work, it's that the looser belts do work and provide easier belt changes and maintenance. If there is any one thing that tight V-belts do, it is to help prevent sawdust from getting beneath the belt and into the wheel groove where it can form a hard lump and cause the spinning wheel to be out of balance. Those of us who have used the loose belts on the wheel will experience this problem from time to time, but find that its frequency isn't enough to warrant fighting the difficult changing of belts that a tight-belt system causes.

It's best to follow your manufacturer's recommendation first. Then you can experiment with other things if you find that your manufacturer is full of bull.

TLahti · February 21, 2011, 07:03:48 PM

Thanks for the clarification, Tom. I never liked the loose belt concept. I will consider a tight belt the next belt change...
Terry

Kansas · February 21, 2011, 07:29:30 PM

Everything Tom says is true, but I do want to add one thing. Tight belts last a lot longer than loose belts. We have done it both ways. We are back to the loose belts, just because its easier to put them on.

Gary_B · February 21, 2011, 08:02:41 PM

Do you think I could run a B57 instead of a B56 on a Tk 1220....if so I will give it a try,

Peter Drouin · February 21, 2011, 08:16:54 PM

Your right Tom loose belts work just fine. 8) 8)

pineywoods · February 21, 2011, 08:25:02 PM

This argument (loose versus tight belts on bandwheels) has been going on for years. Truth is, the loose belts just don't look right, but time has proven them to be a highly successful approach. My wm calls for B57 (loose) belts and they work just fine. I once put a B58 belt on the idler side. Talk about loose, but it worked just fine. If you have trouble with stuff getting under the belt, most likely have another problem that's causing it.

Magicman · February 21, 2011, 09:53:16 PM

I just replaced my B57's last week. I looked back and they had sawed over 200mbf. That's a lot of turning. The idle wheel started making a rumbling noise. Investigation showed that the belt had thinned, actually mashed flatter and stretched. The band was not contacting the wheel, but was very close.

I had not realized how much the belts had stretched until I put new ones on. Anyway, that took care of the noise.

ladylake · February 22, 2011, 05:28:26 AM

1000 hours or so on a belt is good, it makes sence that loose belts can get junk under them once in a while , also that they will wear faster with the belt going in and out of the groove all the time. I'll stick with my B56 Goodyear belts and learn a few new words once in a while. Steve

Magicman · February 22, 2011, 08:30:34 AM

The ones that I just replaced had been on the mill 1000 hours, which is remarkable. In the past, I've had a broken band to slice a belt.

Since this thread is about breaking bands, I'll add that a badly worn belt allowing the band to contact the wheels, will break bands.

Gary_B · February 26, 2011, 08:37:21 AM

Well I finally replaced both belts on the wheels, replaced the guide bearings , went over everything as far as adjustments, had do alittle tweaking, I had to resaw a couple pieces of 2" lumber, seems to be cutting fine. Until the weather breaks and I can give her the real test we will see. Sometimes problems can be a bit of confusing, when you get frustrated, but I guess when you step back and look at the way a manual band mill works its not that complicated, not alot of moving parts, but if the maintance is'nt kept up, it comes back and bites you. When I was changing the guide bearings I also noticed one of the bearings had froze up, which could have lead to my problems. The new bearings I installed, I drilled a 1/16 hole in side of shield so I can shoot some grease in on a daily basis.
Thanks for everyones help.

ladylake · March 01, 2011, 05:44:26 AM

Give us a report after you run a few new bands for a while, you might still be breaking the old ones as they might have been cracked already. Steve

Gary_B · March 29, 2011, 08:17:30 PM

Well here is the latest update.....I replaced both belts....what a job that was...I cut down a hard maple over the weekend and wanted to see what it looked like on the inside, so I loaded it on the mill, I was using another older but sharp blade, made one past, flipped the log over, started on the second cut and bang, the blade both in two places and at the same time cut one of the belts on the wheel.... I ordered a box of new blades Saturday, bought another belt, after 3 hours, finally got it on, went down and checked the mill for anything that didnt look right, checked the new guide bearings, ran a string line from wheel to wheel that was perfect, I put another old band on just to see what it look like when I spun the wheel several times, looked perfect, when I get the new blades, I will give it a try and see what happens, the only thing left is the idle and drive bearings. I didnt know sawing could be so much fun.....

Paper Maker · March 29, 2011, 11:10:25 PM

I run a TK B20 with solid steel wheels. Mine was doing the same thing. After I would make a cut is usually when the blade would break.After making a few adjustments I couldn't keep a blade on. I realize that they are different style wheels and the fix for the problem may not be the same. But after a machinest checked my wheels he found out that the drive wheel had a .025 runout. Thats not much. I don't know how it would affect a belt type wheel, but it may be something to look at. Good luck.

isawlogs · March 29, 2011, 11:12:28 PM

I am confident that dee new blades will solve your problem. Older blades that have been sharpened over time gets cracks in dee gullet of the tooth and even if you don't see them with your eye you may be able to see them on dee broken blades with a magnafying glass. Look at thee crack/break line and see if you can locate new /old crack.

ladylake · March 30, 2011, 06:08:11 AM

i agree, try new blades as most of the old ones are cracked. Steve

Gary_B · March 30, 2011, 06:39:18 AM

Thanks for all the confidence in the new blades we will see 8), maybe hindsight, when I picked the blades up from the amish fellow after he sharpened them said he was selling blades now, just let him know what size I need.
One other thing ive noticed seems like I have a bit more saw dust built up in the wheel enclosure, like its not throwing the dust out...thinking maybe the blades might not have much set, and its more like a powder. The very little of cutting I have down the lumber is very smooth.

ladylake · March 30, 2011, 07:21:58 AM

Depends on what kind of logs your sawing, some sawdust sticks some doesn't. With too little set there wont be much sawdust left on the log, the more set the more sawdust left on the log. Steve

Gary_B · March 30, 2011, 09:40:08 PM

New blades arrived today....tomorrow will be the test, I have assortment of logs to start sawing, the first will be some white ash, that should be a pretty test, followed by cherry, locust, popular, pine.

isawlogs · March 31, 2011, 10:33:22 AM

If I was having issues with my mill, I would not be using white ash as a test log. ;) If it is possible to work out, reverse the sawing order of your logs :P

ladylake · March 31, 2011, 01:19:51 PM

May as well test on tough wood, you'll get the results quicker. Steve

Tom · March 31, 2011, 02:19:05 PM

The results you get might not have anything to do with the mill, but rather the log. One of the best ways to start solving a problem is to back yourself up to a point in history where the problem didn't exist, then go forward, changing and examining things one at a time.

One of the biggest problems people make, when they are trying to solve a problem, is to change a whole bunch of things at once. If they get rid of the problem, they don't know what solved it. If they don't get rid of the problem, they don't know if one of the fixes is causing it.

Problem solving has to be methodical. Getting in a hurry and "shotgunning" the problem with assumed solutions will often just hide the problem in deeper and murkier water.

Jerry · March 31, 2011, 02:59:14 PM

You tell them Tom the older generation has already learned our lessons. Take it one step at a time is always the best solution. :D :D :D :D :D

ladylake · March 31, 2011, 03:47:18 PM

Those ash logs will have to be sawed sooner or later, if the mill works in them it should work in most wood. Far as breaking blades that can sneak up on you or hit like a hammer like when I got that bad batch, I broke 4 in 1/2 hour. Steve

Gary_B · March 31, 2011, 05:50:33 PM

Tom I cannot agree with you more at this point, I think I did everything opposite of what you suggested :( First of all I really dont think the problem was in the v belt....due to no sign of wear on the wheels where the blade would be making contact...I tried it out today with a new ripper 37 blade, I sawed about 60 bd ft. of ash, and decided the log was'nt worthy of sawing, changed over to a cherry log and sawed around 80 bd ft of cherry, I didnt break a blade but still things dont seem right with my mill, On my TK 1220 I can observe the top of the blade as the mill is running, I can see the back side of the wheel it self so I was keeping and eye on that today and when the blade came in contact with a small knot I could see the blade flexing at the top, it looked like the teeth were dipping down atleast a 3/8 of a inch after leaving the drive side wheel. I increased the tension to see if that helped, no change I shut the mill down every other cut just to see how the blade was tracking on the wheels, they remained the same time after time, the lumber I cut today was perfect, no waves, no black marks but I still am not sure, I thinking something isnt right Im not sure if other mill owners can see the top part of there bands as there saw is running and if this is normal. I wish there was another 1220 mill close by. I noticed in another post someone was comparing a TK and Woodmizer mill and someone suggested maybe purchasing the one that is the closest, Im starting to think thats a good point in buying a mill. Its not like you can have a service tech come out and correct your problem when you are 800 miles away. Thank God for this forum.....