Circle mill blade heating

ddcuning · February 08, 2014, 05:30:08 PM

Over Christmas I had a problem with blade wobble so I took the blade off and had it hammered just so I was sure of its condition. The blade on the mill is a 54" F style. So, I got the blade back, aligned the head blocks and set the lead and with a new set of teeth, I thought I was ready to go. I collected ten logs of poplar last week and got up early to saw this morning. Now it is almost dark and I didn't produce a single board today. Within the first two cuts, the blade heated in the inner region and walked out of the log. We reset lead to 1/32 of an inch, same thing. We checked and re-aligned the headblocks to the saw. They were 1/16 inch out, re-set the lead to 1/32 and got worse results. Re-set the lead to 1/16 and the blade only got 3 ft into the log before we had heat near the mandrel and we were done. I am at a loss. We have checked and rechecked the lead, sharpened teeth and aligned headblocks all day without a single board produced. Anyone with lots of circle mill experience up for a flight to NC to figure this thing out? I am buying!

Dave C

Buddyw · February 08, 2014, 05:59:19 PM

You running the correct RPM'S ?

ddcuning · February 08, 2014, 06:26:30 PM

The blade was hammered to 600 rpm and the rpm meter read between 585 an 600 rpm so we were right on speed.

Dave C

Possum Creek · February 08, 2014, 06:27:19 PM

It kind of sounds like your blade is losing speed. 190 hp is plenty of power but it has to get to the saw, if your belts are not slipping check the pto clutch it may not be holding. Try not to get discouraged I am sure your problem will be corrected shortly. PC

lyle niemi · February 08, 2014, 06:35:42 PM

was the blade hammered fr the proper direction.... left hand or right hand

beenthere · February 08, 2014, 06:41:04 PM

What lyle suspects, is what I would wonder too. The wrong blade hammering for the mill.

ddcuning · February 08, 2014, 06:50:07 PM

Blade was hammered as RH and is indicated by the person that hammered it so I think it is ok. PTO has new clutches in it and seems strong. The blade doesn't seem to loose speed, it just walks over. I could check the prm of the blade while in the wood to confirm speed. Belts are tight though. It flipped the carriage off the tracks one of the times. I went through the efficient sawmill book, checked everything but can't find the issue. We worked on it all day making adjustments with no progress. Very frustrating after spending three years to rebuild this mill.

Dave C

lyle niemi · February 08, 2014, 06:53:58 PM

Quote from: ddcuning on February 08, 2014, 06:50:07 PM
Blade was hammered as RH and is indicated by the person that hammered it so I think it is ok. The blade doesn't seem to loose speed, it just walks over. It flipped the carriage off the tracks one of the times. I went through the efficient sawmill book, checked everything but can't find the issue. We worked on it all day making adjustments with no progress. Very frustrating after spending three years to rebuild this mill.

Dave C

Do yu have another blade to try??? I would love to take a flight but my wife prolly wouldnt let me go..lol

ddcuning · February 08, 2014, 06:56:09 PM

I have two other blades but neither has been hammered. It should be warmer down here than up there Lyle! At least no snow.

Dave C

lyle niemi · February 08, 2014, 06:56:53 PM

Another thing to try is increasing your RPM and see what that does

lyle niemi · February 08, 2014, 07:00:34 PM

Quote from: ddcuning on February 08, 2014, 06:56:09 PM
I have two other blades but neither has been hammered. It should be warmer down here than up there Lyle! At least no snow.

Dave C

I had one of my blades getting repaired so in the meantime I had takin a blade off this other old mill I have and tried it out, I still got the old blade on, didnt have to do nothing to it except change the teeth and shanks. Try out the other blades and see what they do

ddcuning · February 08, 2014, 07:04:08 PM

Thanks for the advice Lyle. I will bump the speed and make sure the belts are tight and see how that goes. If that doesn't pan out I will try my 48 and see how it does.

Dave C

chopperdr47 · February 08, 2014, 07:05:44 PM

I had a similar problem with my Frick but it had not been cutting right before hand. You have done what I would have.

The only thing that I would think of is checking that the dish of the blade is away from the log and the guide pins are set correctly. If there was a wobble, that could be an indication of a worn collar or drive pins.

There are some guys here on the forum I'm sure you will hear from. They are very knowledgeable and they are getting me straight.

Good luck and I'll be watching to see what gets you back on track.

lyle niemi · February 08, 2014, 07:11:21 PM

Quote from: ddcuning on February 08, 2014, 07:04:08 PM
Thanks for the advice Lyle. I will bump the speed and make sure the belts are tight and see how that goes. If that doesn't pan out I will try my 48 and see how it does.

Dave C

you should prolly do it tonight cause if ya dont you wont be able to sleep, at least thats what happened to me..lol

ddcuning · February 08, 2014, 07:18:59 PM

You are probably right Lyle, I won't sleep but the folks near the saw probably wouldn't appreciate me firing it up tonight. I will hit it tomorrow.

Dave C

GeneWengert-WoodDoc · February 08, 2014, 07:24:47 PM

It is quite unusual to get heat near the mandrel, as the log is not touching that part of the saw...assuming you have a 10" collar. What can cause heat is the bearings, but you would notice that before cutting. The second cause is that the blade is slipping. So, let's look more closely at the collar. You should have one collar, the fixed one, that is flat as a pancake. Then you have the loose collar which is dished so that only the outer rim touches the blade and that region of the blade makes contact with the flat collar.

Finally, and I do wonder if this is the issue, there should be a pin that fits between the collars and is inserted into the saw plate itself. This makes sure that the blade does not move on the mandrel. If the pin is missing, then the blade will likely move when under the tension of sawing and this will heat the mandrel...that is, the collars alone cannot hold the blade firmly To avoid shearing this pin the first time the blade is used, back the blade with you hand against the pin and then tighten the collar. This back pressure is to make sure that the saw is in contact with the pin when it hits the log...if it were loose, the blade would go whipping back a small amount and potentially shear the pin. The hole in the saw would show an oval shape as well. So, maybe you need a new pin.

lyle niemi · February 08, 2014, 07:33:18 PM

Dave C, I reread your post. can you tell me exactly what you did when you reset your lead

ddcuning · February 08, 2014, 07:43:54 PM

With regards to the mandrel, we checked the flatness and it was 4 thousandths out. The tolerance is 10 thousandths so we should be good there. The outer plate has a 3 thousandths taper as it should. I replaced the pins on the blade so they are new. We checked bearings and they are cool also. This is the reason I am so stumped. We have gone through everything during the rebuild and all should be right.

Lyle, to set the lead we marked a tooth, measured to the first headblocks then rotated the saw 180 degrees and repeated. We reset it at 1/32, 1/16 and then 1/8th inch and it never got better. We reset it back to 1/32 at the end of the day.

Dave C

Possum Creek · February 08, 2014, 07:46:13 PM

How did that saw do before you had it hammered? You said it had a wobble but could you cut with it at all? Does it stand straight when up to speed? How does it do sawing a small log? Can you hear the governor open up? I have all kinds of questions. PC

lyle niemi · February 08, 2014, 07:50:02 PM

Quote from: ddcuning on February 08, 2014, 07:43:54 PM
With regards to the mandrel, we checked the flatness and it was 4 thousandths out. The tolerance is 10 thousandths so we should be good there. The outer plate has a 3 thousandths taper as it should. I replaced the pins on the blade so they are new. We checked bearings and they are cool also. This is the reason I am so stumped. We have gone through everything during the rebuild and all should be right.

Lyle, to set the lead we marked a tooth, measured to the first headblocks then rotated the saw 180 degrees and repeated. We reset it at 1/32, 1/16 and then 1/8th inch and it never got better. We reset it back to 1/32 at the end of the day.

Dave C

did you losen all the bearings on your mandrel or just the one at the saw?

ddcuning · February 08, 2014, 07:54:36 PM

I never have been able to saw with it. When we started it up, I had heating at the mandrel and wobble but it did cut a few boards. That was before Christmas. We then had the blade hammered and yes, it stands up and looks straight at speed. After a short cut, it now walks out and lays over on the guide pin. The log we were trying to saw was the top of the tree and only 8" in diameter. The engine never changes speed due to size and I didn't listen closely or observe the governor when we were in the log.

Dave C

ddcuning · February 08, 2014, 07:56:09 PM

Just the one at the saw Lyle. I had always been told to adjust there and not on the pulley end.

Dave C

lyle niemi · February 08, 2014, 08:01:00 PM

Quote from: ddcuning on February 08, 2014, 07:56:09 PM
Just the one at the saw Lyle. I had always been told to adjust there and not on the pulley end.

Dave C

Hw many bearings do you have on the mandrel?? I have three. If you dont losin them all you will put strain on your shaft and cause the blade to wobble.

Possum Creek · February 08, 2014, 08:02:19 PM

Just one more question, how fast are you feeding that baby full speed, creeping along, or somewhere in between?

ddcuning · February 08, 2014, 08:03:17 PM

My mill only has two. I didn't think about stressing he shaft. The blade stands up at speed when it is cool. It just overheats almost instantly as you enter the cut.

Dave C