PM 141 Acting Weird Lately - Ideas

[Brent Ring]

Hi All,

Long time since I posted last, been out of the shop a little, coaching a little club hockey, and being a grandpa! Back in the shop, and started working on my 1973 PM 141 bandsaw. Normally I keep a 1/2" 3 T blade on it. All of the sudden, it started making noise, and I shut it off and looked. The blade had come partially out of tension, and the bottom tire was all wrapped around the inside portion of the lower wheel axle. Got the tire off, cleaned everything up, put a new lower tire on, and put the blade back on. It did it again within about 5 minutes. I ordered new blue urethane tires, put them on, and it did it again. Cleaned it all up, put a new 1/4" blade on, and it did it again. Arrgh!!!

This last time, I noticed that the tension was not where I left it when I put it back together. It lowered and reduced tension. I suspect that whats causing the blade to catch the tire and cause it to bind up behind the wheel. I had partially glued the bottom tire on last time(hairspray), so the tire did not come off completely, which was good.

I am a bit lost as to what would cause that to happen. I bought the saw used about 8 years ago and it has run top notch until now.

Any thoughts on how to get this back running reliably?

Brent

[mark kosse]

Howdy Brent, are you saying hairspray was your adhesive for the tire? I'm guessing if you contact cement the tire on, problem will be solved.

[Chris Hachet]

I would agree with Mark...

[Randall J Cox]

Have you checked your tension spring - could it be broken?

[Doug Ladendorf]

I have a 141 just two years older than yours. Wonderful saw. The wheels are not crowned so I don't know that the urethane tires are right for that saw. Typically you would install rubber tires and crown them a-la: https://www.youtube.com/watch?v=zz04k-GMF38

Was the original tire that came off rubber or urethane?

Doug

[Van Huskey]

The wheels are not crowned so I don't know that the urethane tires are right for that saw. Typically you would install rubber tires and crown them a-la: https://www.youtube.com/watch?v=zz04k-GMF38

Was the original tire that came off rubber or urethane?

Doug

The originals were rubber as they were for all 141/143 saws. They do make replacement urethane tires now for some of the crowned tire saws but not sure if they actually have a crown built into them but urethane seems too soft for that purpose. The OP did not say if he ordered tires specifically made for the 141 or not, if not it is almost certainly the issue, if they are urethane tires for the 141 it still may be the issue.

My guess is the old tires were shot and the new tires don't work for the application. WMPrice sells correct rubber tires for the 141 on eBay, Bobby at Woodworkers Toolworks most likely does too.

[Doug Ladendorf]

Agree. I wasn't particularly clear in that last sentence. I was asking if the tire that came off in the beginning of the story above was also urethane, replaced at some earlier time. Rubber tires are the way to go.

[Brent Ring]

Thanks for the responses. Rubber tires were the originals. I had urethanes on for over 5 years before this problem came up. I am thinking the tension spring is the problem. I have a bad habit of leaving the saw blade under tension. The 2 sets of urethanes that I have ordered are supposedly for the PM141, according to the advertisement. One set was orange and the other blue.

My thought is to replace the spring and see what happens.

Unless someone has some more compelling advice.

[mark kosse]

Well Brent, I'm not saying it's not the spring but I've had lots of 141's, 81's, 28-200/350's that have never had the tension removed in their long life. Maybe try re gluing too. It would be a cheaper first step. Family Dollar sells a squeeze tube of contact cement for 1.50 and it's plenty to do those tires.

[Brent Ring]

I just took off the original tension spring. Not broken. With out any tension, it measures 2.75". I checked the wheels and there does not seem to be any play in them at all. My thought was maybe a bearing had worn. When it was running, it would make a noise, that made me think a bearing could be bad. Still looking for ideas.

[Brent Ring]

The tires I have on currently are these - [COLOR=#333333][FONT=&quot]












http://i.ebayimg.com/images/g/4fgAAOSwKOJYI3YW/s-l64.jpg






http://i.ebayimg.com/images/g/LB4AAOxycSdRyvr7/s-l64.jpg








[CENTER][TABLE="class: vi-centerclass"]
[TR]

[Brent Ring]

BLUE MAX ULTRA DUTY URETHANE BAND SAW TIRE SET FOR POWERMATIC MODEL 141 - From Ebay

[Joe Kaufman]

Are both male and female threads for the tensioning rod in good shape, not worn or damaged?

[Joe Kaufman]

Lock the tension adjustment with a washer and nut after it is set. See if that corrects the problem.

[Brent Ring]

I will give that a shots and get back to you!

[Brent Ring]

Hi Mark,

I can tell that the Urethane tires are crowned. It was a bear to get the tilt adjustment perfect to keep the blade centered. It would move forward or backward on the wheel if I did not get it perfect. I may need to get rubber tires.

[lowell holmes]

When that happened on my 14" Jet band saw I ended up buying new tires at a Rockler store on the Sowthwest Freeway, Houston. After I put them on, no further issues have cropped up.

This was at least 5 years ago. I had to nuke the tires in the microwave in order to stretch them to put them on the wheels.

It was fixed, no further problems have cropped up.

[Brent Ring]

Threads look good!

[Brent Ring]

OK, here is where we are:

1. Replaced Upper Wheel Bearings
2. Replaced Urethane Tires with Glued on Rubber Tires
3. Added a new Tension Spring
4. Checked lower bearings - Did not require replacement
5. Checked wheels coplanarity (is that a word?) Wheels are coplanar - although I dont know how that could play out exactly, considering that the tracking wheel tilts the top wheel and could take it out of being coplanar.

I had about 4-5 cuts that worked great and then all of a sudden, after finishing a cut, the blade jumped between 1/8" to 3/16" of an inch forward, out of the guides. While it did not come off of the wheel, it came very close. I retracked it, and noticed that when it is centered on the top wheel, it is sitting about an 1/8" forward on the bottom wheel. Tension stayed where it was set. I did notice that I had forgotten to set the lower thrust bearing. I would be surprised if that were the issue, but one never knows.

It is currently loaded with a 1/4" blade that has seen less than 15 cuts.

Any thoughts on why the blade would jump like that? I think that may be what I was experiencing all along. I don't like the idea of it jumping forward like that, especially if I load a 3/8" or 1/2" blade.

Thanks,

Brent

[Van Huskey]

Did you crown the tires or buy pre-crowned tires? If you are using un-crowned tires that could be the source of your issue.

[Brent Ring]

Van, I did crown them. I watch a video on the concept of aligning the gullet of the teeth on the blade with the center of the wheel. I am going to give that a try. I have always just centered my blade, but I am game to try something new. There were two very thin, bent washer that were sitting in a pile of sawdust when I took apart the pulley section near the bottom wheel bearings, on the pulley side. I wonder if those were some type of shim. They were bent over about 25% of the width of the washer.

I am wondering if they were there to shim the bottom wheel a little more straight. It was clear they did not work as a washer normally does.

How would you tell if the bottom wheel needed to be shimmed or not?

[Brent Ring]

Well, the saw is back in action! I put a new Timberwolf 3/8" 4T blade on it, and followed guidelines to only worry about setting the gullets of the teeth on the center of the wheel, right on the crown. Got all of the guides adjusted to just barely not touching the blade, and cut a few pieces. Now working like I remember it before. Love that saw. Just wish it had better dust collection. Thanks to all of the advice. As always, I can count on 'Creekers' to help out!

Brent

[Van Huskey]

Glad you got it figured out! BTW that looks like about a 5.8 pitch you are leading in your avatar?

[Brent Ring]

Glad you got it figured out! BTW that looks like about a 5.8 pitch you are leading in your avatar?

Hi Van,

That is. "Turbo Fly" is the name of the route. Its down in Maple Canyon, near Freedom Utah. https://www.mountainproject.com/v/turbo-fly/106757333. In the winter, it ices up just to the left, and they ice climb on it.

I need to update my avatar. That pic was taken quite a few years ago, before a back surgery, and the 5th scope on my knee. I have not put on a harness since my back surgery, May of 2015. I miss it a little.

Do you climb?

Brent

[Van Huskey]

Do you climb?

Brent

Enough to accurately guess that was a 5.8 from the pic... :)

Not nearly as much now. I grew up trad climbing then moved to the cheating bolted stuff then on to mountaineering but the majority of the time I spent on the granite pitches of Western NC. Now I just take a trip or two a year, follow a rope gun up a few pitches and sit back and watch the new crop of hard men (and women) and drink a few. After the 5th funeral we attended my wife ask me to reconsider alpine climbing and I did but I usually do something like Ranier every year.