Saw Hammering

Farm Mechanic · October 25, 2020, 02:57:32 PM

I didn't describe that very well. The build up was where the collars clamp the saw.

moodnacreek · October 25, 2020, 03:21:20 PM

I presume the saw runs flat at tractor idle and slightly above and then starts to wave back and forth. And then it should straighten up at say 450 and up to 540. If you had it hammered all this would have been discussed. The run out you are finding i s not the big problem right now. When you sawed what happened? If the saw did not heat or wobble bad but ran in 3/8" at the end of the log then you are close. To put a mill together with a perfect mandrel and decent saw and just start cutting would be a miracle. To try it out and almost be able to cut a straight line would be a good start. Imagine a guy who is not a mechanic trying to do what you are. Perhaps you need to paper the collars. I would like to see that saw run at 540 on a test mandrel to prove it could run flat if only in the air. I have gone so far as to take a saw to another mill to test it. Gotta go do some work til dark.

Farm Mechanic · October 25, 2020, 03:52:48 PM

I was able to saw a decent load of lumber last evening but the wobble bothers me. The boards are true for the most part. When I try to saw a wide board, the full width of the blade that is when the saw heads towards the carriage which I believe is the lead but I don't think I can reduce lead with the blade wobble. So my plan was to eliminate or reduce wobble and then fine tune lead.

moodnacreek · October 25, 2020, 07:29:15 PM

F.M. you are doing much better than I thought. The deeper cuts will test you. With a coarse tooth saw and a max. cut the saw will often saw in. Gigging back along the saw tells alot. The real test is the last board thickness. Also the face of the turned cant. There are so many factors. I would stop worrying about the collars. Another thing, Are you using stand all teeth? I don't like them but on a low powered mill in hardwood they can make a big difference.

Farm Mechanic · October 25, 2020, 07:37:06 PM

Yes I am using stand all bits. With the wobble now after cleaning the saw and doubling the run out I don't think I'll be able to saw. I think my issue is the blade. The saw doc that hammered it did not have a test mandrel or any way to check run out. He just used a straight edge and tension gauge and said it was good. I do have an F pattern 48" saw With 42 teeth I can try but I know I won't have enough power to run it properly or at least I don't think.

Ron Wenrich · October 26, 2020, 10:21:58 AM

Does the saw wobble in the cut?

Farm Mechanic · October 26, 2020, 11:24:56 AM

Yes it does wobble in the cut.

moodnacreek · October 26, 2020, 12:40:04 PM

Like Don P. mentioned, paper shim between the fixed collar and saw. I have never done it. They say oil the paper so it sticks where you put it. Gasket paper maybe. Is sounds like your saw is not true.

Farm Mechanic · October 26, 2020, 12:49:55 PM

What kind of paper do I use? how thick?

Farm Mechanic · October 26, 2020, 12:51:13 PM

I think I have a bent saw that didn't get corrected during hammering.

moodnacreek · October 26, 2020, 06:59:20 PM

Quote from: Farm Mechanic on October 26, 2020, 12:49:55 PM
What kind of paper do I use? how thick?

Manila envelop ? Say a third of the circle to attempt to shim the blade wobble out. Not really the thing to do but if you make it run straight it would show you for sure what's wrong. You have the mag. base dial indicator so a pair of scissors and some oil, I would try it if I only had one saw.

Farm Mechanic · October 26, 2020, 07:25:43 PM

I think I have a total of 7 saws I could try. Would it be better to try a different saw before paper shimming? I do not know what shape the other saws are in. I just picked the one that looked the best and required the least Amount of horsepower, installed new bits, had it hammered and here we are.

moodnacreek · October 26, 2020, 08:16:46 PM

What we both need is a 4' straight edge. You would stand a saw up vertical and see how flat it is on the log side. Most old saws I have found are missing teeth [shoulders] or are dished away from the log meaning they where run long past needing hammering or got wedged in an accident. The saw you are using, every time you handle it, hold it at the top and shake it. While this won't make you or I an expert it will give you a feel for the tension you need in a saw. If your saw is stiff and it should be to run tractor pto, and you grab one that is floppy in the center you mill won't spin it fast enough to stretch it flat. [ or something like that]. Try anything that looks like it might work. It's easy to waste time, I do it every day.

Farm Mechanic · October 26, 2020, 08:34:19 PM

I'll straight edge some saws and start trying then. In the meantime I will see if the saw hammerer can take another look at the one they hammered that still wobbles. Long term plan is to put the F pattern 48" saw on. What kind of horse power would I need to run this saw properly? I realize I need to make the mill saw great before I get too ahead of my self but I want to be on the lookout for a power unit, jack shaft and bearings. The best time to find something is when you don't need it.

Farm Mechanic · October 26, 2020, 08:36:07 PM

Thanks for all the help by the way. I know everyone is busy and posting advice and helping out is not a short task. Your efforts are very much appreciated.

Don P · October 26, 2020, 10:11:50 PM

You have the power to run one of the other saws in air and in smaller or softer wood, that will help narrow down whether it is blade or mandrel. The runout on the fast collar from memory "should" be within 3 thousandths so that seems good but how it works while its running is the real tell. It sounds like you are close to having it.

Ron Wenrich · October 27, 2020, 11:01:56 AM

I used a paper shim in the past on an old mill. I only used a piece or 2 of paper out of a pocket notebook. It worked okay. My saw doc discouraged the method, as it doesn't solve where your problem is located and didn't let your collars touch the saw the way it is designed to. I'll also note that the mill I used it on had old collars. I checked the collar contact by putting chalk on the collar, and mounting the saw. Then, took it off to see how much of the collar is contacting the saw.

One thing I used to figure out which side to put the paper on was to mark each tooth on the saw when it was stopped. I opened the saw guides so nothing was rubbing the saw. The, you simply mark each tooth with an -, o, or +. The - moves away from the log side guide, the + moves toward, the o is in the middle. Add a plus as it gets closer to the guide or a - as you go away. At the farthest point, you'll have some ++ or --. Use more if you like. But, you'll have your saw mapped out as to where the wobble is coming from. If I remember, I shimmed on the - side of the saw at the collar.

Rigg · October 27, 2020, 08:14:10 PM

What kind of tractor do you have powering it? How much horsepower?

I'm not an expert by any means, but I have a International UD 14A with supposedly 75 hp on a PTO powering a 48 in F style blade with 48 teeth. It does fine in pine and poplar and starts struggling with oak.

I'd probably try that 48 F with 42 teeth.

Farm Mechanic · October 27, 2020, 08:32:15 PM

Ron,

I talked to the company who hammered the saw today and he's going to look and see if he has a decent saw to loan me while he fixes mine. So hopefully that will be the tell tale. I still might try other saws this weekend just to see how they do.

Rigg,

I currently am powering the mill with a Massey Ferguson 270, About 55 pto hp I believe.

Farm Mechanic · November 29, 2020, 01:30:10 PM

What would cause my saw to heat in the center?

Farm Mechanic · November 29, 2020, 02:42:52 PM

I had a 44" saw that did pretty well just wobbles a bit even after 2 hammerings. I then had a 48" saw hammered and put it on and it doesn't wobble at all but it is warming in the center. What all issues could be causing this?

moodnacreek · November 29, 2020, 06:13:58 PM

Quote from: Farm Mechanic on November 29, 2020, 02:42:52 PM
I had a 44" saw that did pretty well just wobbles a bit even after 2 hammerings. I then had a 48" saw hammered and put it on and it doesn't wobble at all but it is warming in the center. What all issues could be causing this?

Either there is bearing heat or the saw plate is touching something. Get your point and click thermometer out and start that mill up cold and figure it out. Don't saw, just let in run at sawing speed and see if the bearing warms up and if this'heat' migrates into the saw around or in the collar. As little as 4 degrees can throw the saw off. If that doesn't do anything saw and check again. It takes almost nothing to warm the saw center. Logs that spring before you can turn them or logs that saw hairy. The swedge or set in the teeth is everything, more so than sharpness.

Don P · November 29, 2020, 06:25:50 PM

One more thought is look at your sawdust, is it small chips or fine dust. If you're spilling fine dust it can heat things up too.

Rigg · November 29, 2020, 07:59:35 PM

Could be not enough lead. Also not running as fast as its hammered for. Teeth?

Something wedged where its not supposed to be? Board splitter not lining up right?

Farm Mechanic · November 29, 2020, 08:30:21 PM

Nothing wedged rubbing the blade, I just put new teeth in. I'm running between 540 and 600. Was supposedly hammered for 540 it seems to run the truest a little over 540. This is the first time I have used this saw. The 44" sawed great under the same conditions, just wobbles a bit but never heated. I might note the 44" had 24 teeth and the 48" has 44. I am under powered and have to use the slowest carriage feed speed. I sawed a walnut log and it did great, then I tried to saw an ash and that's when the trouble started. Lead seems to be okay, not sawing towards the carriage or rubbing the log on the back side, also the bearings stay cool.