Log pulls away from rear dog when passing blade

[Fearski]

I have an old rr howel 00 mill 46 inch blade just rehamered collars reconditioned track strait only sawed 1 log it keeps pulling away from rear dog as it is going past blade what can I do thanks fearskii

[beenthere]

What are the measurements between the carriage and the sawblade without a log and without running the saw blade? Does it track straight along the carriage rails?

Or do you think the sawblade is carrying/forcing the log away from the rear headblocks?

[Fearski]

Saw blade seems to be pulling log from carage every thing measures right thanks

[moodnacreek]

Where is the saw going? Make like a 1/2" pull, feed in and back out, break off slab to see kerf. Keep feeding and gigging back. Saw line should always be the same with no step in or out of the log or cant.  It sounds like you are leading in [to the log] and the saw is being bent as you go and springs back and brings the log with it. Miss filed teeth and many other things can cause this.

[Ron Wenrich]

Species and size of log may make a difference.  I'd tend to think of several things that could be wrong.  One is the lead.  Another is feeding too fast for the hp you have.  Belt slippage may be a factor.  Saw guides may be pushing your saw, which would give you excessive lead.  After the cut, does the saw move or wobble?

If that all seems good, it could be in the carriage or dog.  If a log isn't dogged good, the log can be pulled out when sawing. 

To trouble shoot, I'd start with another log or another cant to see if the condition continues.

[Fearski]

Thanks for help will check out suggestions to help fix thanks will let know if it fixes problem

[moodnacreek]

A bar receiver can do that. Just a thought.

[DanielW]

If you just had the collars machined and blade hammered it sounds like you know what you're doing, so apologies if I make any suggestions that you've already checked. One of the major causes of saws pulling is from a saw plate that's dished, so a lot of my points focus on that:

- The first/easiest thing I'd check is the lead: A lot of folks run too much lead, which will cause the saw to pull the log/cant away from the carriage. On older mills with saws that have lost their tension and carriage tracks that aren't straight, you often end up having to run more lead for it to cut at all. If your saw badly needed hammering, your collars were rough, and/or your track not quite straight, chances are the lead was set pretty high before you did the work to it. Now that you've fixed all those issues you'll have to go back and re-adjust the lead to where it should be for a well-tuned mill. Something like 1/16" for a 46" saw should be plenty, and a good starting point. But every saw behaves a little differently, so you may have to play around with it a little.

- When the collars were machined, were they machined as a matched pair, with the OD turned together? Was their a little taper on the outer 1/2" or so leading to a hollow in the centre? Does the pilot bore of the loose collar fit nice and snug over the mandrel to make sure it's perfectly matched to the fast collar? If the collars are slightly mismatched and not clamping the saw perfectly equal/opposite, they can dish the saw when they're tightened up. Even a small, imperceptible difference in how they mate can sometimes dish a saw significantly. If it's dished with the concave side toward the carriage, it'll pull as you described. One of the most common issues I've seen with saws not behaving is collars needing to be machined, but perhaps the second most common is collars machined incorrectly.

- What data was given to the chap hammering the saw? R.H. vs. L.H. mill? Most hammermen now tend to ask which side of the saw is the 'log side', rather than if it's a RH or LH mill, because it eliminates any potential to get told the wrong info. Ex: One guy I know frequently gets incorrectly being told a saw is from a LH mill because the blade's on the left of the carriage from the operator platform, or a twin scragg where the saw on the left has to be hammered right and the saw on the right has to be hammered left. Sounds like you know what you're doing, however, so I doubt that's the issue.

- If you have a good, accurate straight edge and your saw's sitting plumb, check both sides of the saw. A saw plate will either be a single gauge/thickness, or a dual gauge (like an '8/9', meaning it will be a thicker 8-gauge toward the centre, and a thinner 9-gauge towards the rim). Usually smaller saws are single gauge, larger saws are dual gage. A 46" saw could be either. Place your straightedge on the carriage side between the shanks so the teeth aren't influencing it, and you should see it perfectly flat on that side. Place it on the opposite (board) side and it should be perfectly flat if it's a single gauge plate, or have a slight bulge toward the eye if it's a dual gauge. If the bulge is on the carriage side, it's been hammered as the wrong hand.

-- The saw should never, ever be concave on either side (falling away from the straight edge towards the eye). It should be either perfectly flat on both sides, or flat on the log side and convex on the board side. If anyone tries to tell you that the saw should be 'dished' concave to stand up straight when it's run up to speed, don't listen to them. The only time you MIGHT have a concave plate would be for a very large, very thin plate run at really high RPM, which a 46" Howel certainly is not. If it's concave on one side, you need your saw hammered again.

- How are your teeth filed? If they're slightly angled one way or another the blade can really dive toward the high side, and will pop back once it nears the end of the cut.

- Make sure the guides are as close as possible to the saw without influencing it. Ideally you should do the final adjustment while it's running, but you have to be uber-careful with your fingers when doing that. If it's hammered properly and the collars are true, you should be able to get them good enough without it running.

- Are you sure your bearings are good with absolutely no slop/play? A little bit of play can cause the saw to do funky things.

- How's your mill positioned/stored? Is it in the sun, or near a heat source? When a saw plate is hammered properly, a little bit of heat on one side can make a big difference on how it behaves. Especially if it's got a fair bit of tension near the centre of the plate. If one side of it's been facing the sun all day, it can impart a surprising amount of dish to the saw and it'll run like garbage. Until you've seen it a few times it's hard to believe, but it does certainly make a difference. Same thing with a bearing that's on its way out: If the bearing's running hot, the eye and bearing-side of the saw will get heat, which will dish it.

- Have you put a tach on it to verify your RPM? Even if you theoretically know your pulley sizes and tractor RPM (I'm presuming it's run with a tractor if it's a Howel?), you'd be surprised at what a little belt slip or an old/inaccurate tach on the tractor can do. If you're not running it at the intended RPM, it'll dive, dish, pull, and do all sorts of other funky behavior. Most folks I've helped get tractor-powered mills up and running tend to start off running them way too slow. You'll probably really have to wind it up to get the right RPM.

- Hopefully your tractor/power source has enough power to keep the blade running at a consistent RPM? Some folks are able to run the little Belsaws in softwoods with 30 HP or so, but most mills have much faster feed speeds and shorter tooth pitch than a Belsaw. You probably need at least 45 HP or so, depending on your feed rate and what you're cutting. If you don't have the power you need, it might run at the right RPM under a no-load condition, but bog down in the cut, causing the saw to dive/pull. Most circle mills will need a lot more than 45 HP (one of mine has a 170 HP Detroit on it), but the Howels are meant to be a slower tractor/belt mill, so it's probably not as demanding as others. If you're not running a tractor, whatever power unit you have needs to have a governor. A Car/truck engine with the tranny output bolted to the mandrel won't cut it: Even though it might have more than enough HP, it won't regulate its speeds, so it'll slow down and dive/pull in the cut. On the other end of the spectrum, make sure you don't over power your mandrel. It bugs me to see folks with 80+ HP on a small mill like a Belsaw. The 1 3/4", 1045 mandrel on a Belsaw would twist off long before it used 80 HP, so it's just a waste of fuel and a risk of damaging the mill.

- If still misbehaving, once you've made a cut or two, feel the saw. See if it's hot towards the rim, hot towards the eye, hot all over, or cool all over. That'll tell you if something's awry with the tension.

Hopefully some of that helps. I'd start by checking your lead, winding up your tractor RPM quite high (if you're not already) and going from there.

[Plankton]

I dont have any real knowledge to share on the matter but one thing we did on a chase I helped saw lumber on a while to sort out some weird issues we were having was got this hand held tach and put the reflective stickers on the pulleys. Really handy, we were able to find out the tach on the engine was off and we were running 200 rpm off. Turns out after all the saw was hammered to a different speed then we were told anyways so thats what fixed it.

[moodnacreek]

If you are just starting to learn don't mess around with hardwood or any long not straight logs. Removing part of the log from one side can cause the log to bow and that is confusing to the novice. Try to start with an 8 foot pine say 14" diameter . Protect your eyes and head and try to see the kerf being sawn. When you back out and go back in you should not be starting a new path if so go to above posts.

[Gearbox]

.To much lead will pull . To set the lead you back off the guides and mark 1 tooth measure from that tooth to the bunk roll the saw to the other side and measure to the same bunk . 1/16 to 1/8 should do it

[Fearski]

Thanks for all help I had collar machined at same place as hammering was done very reputable shop in Minnesota. I have since tighten all knee gears and slides as they were sloppy that helped a lot but still pulling on log checked lead it looked good but that will be next move. Checked shaft speed with hand held tachometer was running slow but now am up to speed. Have sawn only 1 small log since all adjusting don't feel blade is getting hot. Will check though I have a hand held temp check tool.Thanks again for advise 70 but not too old to learn!

[Ron Wenrich]

You might want to change teeth to make sure it isn't in the sharpening.  If it still digs in, then its time to check the lead.

[Fearski]

Blade has fresh set of teeth very sharp

[moodnacreek]

It is almost impossible to diagnose a sawmill without being there. Everything suggested here has merit. It can be just one little thing but that is more likely on a mill that has been sawing. Your problem can be a combination of things not set up right. If it is the saw laying in [it may not be] you have to see it happen and no where or when. An example: as soon as the log enters the saw or when the log passes the collars or at the splitter. In general the saw goes where the teeth take it. At the point of the undogging can you stop and remove the board or slab without disturbing the log?

[Woodside Kai]

Any chance your track is deflecting when you have a heavier log on the carriage?

[moodnacreek]

Is the spreader a disk or a knife? On the disc it could be cocked so that the sawn face would pass the very edge but then press on the cant.  With the knife style the log would likely hit it and not travel farther.

[Fearski]

Am still having problems after all I have done blade seems to wobble or flutter on arbor at out edge moves good 1/4th inch when at speed have had blade rechecked it not bent collars are good could I have a bent arbor ? How would I. Check it

[beenthere]

Have you taken the sawblade to a saw Doc? Or have you run dial indicators on the arbor? Maybe need both.

[dgdrls]

Well.  it sounds like you still have an alignment problem.

Not clear what you have actually checked based on your last post.

Let us know,  lots of really talented circle millers here that can help.

D

[Ron Wenrich]

How tight is your arbor nut?  It shouldn't be so tight that you smash your collar. 

I used to check the saw by using a series of "+","o", & "-" on the saw blade to check things out. The procedure is to loosen the saw guides so the saw isn't rubbing them as you rotate the saw.  Find a starting tooth that is in the neutral position and mark with a "o".  I used a lumber crayon.

As you rotate the saw, mark each tooth.  If it goes towards the log side saw guide, mark with a "+".  The closer it comes to the guide, add more "+" marks.  When it goes to the board side, mark with a "-".  You now have a map of the saw.

Rotate the saw and see if the "+" and "-" match.  If they don't then it could be in the arbor.  If you rotate just the collar and they don't match, it could be in the collar. 

To check how well your collars are, put chalk or something that will give you a mark, on the outside of the collars.  Put the collars back on.  Remove and see how well your collars are working.  There should be a consistent mark all the way around.  If not, your collars need turned.

You should check your RPM.  On a new mill, I was told it was running at 650.  When checked it was 710.  Your saw may be hammered at a different speed than your saw.  Check the RPM before you get it hammered.

[DanielW]

It might be your arbor. But the inner (fast/fixed) collar would have been machined on the arbor as one-piece (I hope so, anyway), so I'd think your machine shop that did the collars would have checked/noticed if the arbor was sprung. But it's still definitely worth putting a dial on the fast collar face and on the mid-span of the arbor between bearings to see what it does.

Are the bearings good with no slop? Run at the right speed? Lots of things it could be. Definitely time for a dial-gauge, piano wire, and hand-held tach to come out if they haven't already.

[Fearski]

I'm still at it . I have now put modern roller bearings on my mill. I think old babit bearings and armor were worn too much about 50 thousands near fixed collar rebuilt don't laugh but used JB weld and turned down on lathe . Runs smother had to adjust plumb of blade .first run today léad needs to be done tuned first it went in then after adjusting is going out getting closer though been a long haul thanks

[fluidpowerpro]

JB Weld has saved my ash many times. Great stuff.

[Fearski]

Ok after all I have done could not make it saw kept sawing I to log I got a blade off a working mill a 40 inch versus my 46 saws perfectly is it possible to have a bad blade?? If that the case where to look for a good one ? Left hand  540 rpm would like to stay in 46 inch range . Can a guy find good used? 

[Ron Wenrich]

I ran a left handed mill for decades.  I would have problems with used saws that were from right handed mills, but dished for a left handed mill.  It seems that the saw has memory from the original manufacturing and wants to go back to the original shape.  He always had problems with switching the dishing.  We ended up going with new blades and that solved the problem.

Have you had a saw doc look at your blade?  There may be a crack in the saw, and that will mean its good to use as a sign. I had that happen on one of my saws, and it was fairly new.  A saw doc should be able to point you to any used saws that are out there in your area. 

[Fearski]

Have had saw doc look at it 3 times. It was a right hand blade for first 90 years of its life I had doc switch it . Could be the problem.not sure thanks

[cutterboy]

It was a right hand blade for first 90 years of its life

Good God!! How long do those blades last?

[Ron Wenrich]

I've had guys tell me they have had blades that last for decades.  A lot depends on how much abuse a blade is subject to.  Metal strikes are really hard on sockets.  It stretches them out of shape.  It also bends socket tips out of shape.  Eventually shanks won't stay in the sockets, even the oversized ones.  Heat is also a destroyer of blades.  Hanging a blade stretches steel. 

Generally speaking, its how many million feet of lumber you can put through a blade.  I circulated blades at about every 1-2 MMbf.  I was cutting grade hardwood.  When I circulated, we put new shanks in and had the saws hammered.  Generally, it was done before winter set in and you need really good shanks.  A set of teeth lasted about 75 Mbf.  When you get a good saw, you'll know it.

[DanielW]

I can't add much more to my first post, but one thing you said is rather concerning:

You said you put a 40" saw on and it ran fine. How did this work with the existing guides? I assume you had to modify the bracket and move them further in? If you're using the same guide position on a 40" saw as a 46" something must be awry. You want your guides to be just below the shanks. Guide location for a 40" saw would be far too close to the mandrel for a 46" saw, and running the larger saw with the guides that far in would be a little concerning, and possibly part of your issue.

It could very well be a bad/worn saw, but your saw doctor really should be able to tell that (if they're experienced in inserted tooth saws). A smaller saw will mask a lot of problems, however, so don't immediately assume the old saw is the culprit.

Can you post some pictures of the original saw and the mill? What's your lead set at? What style of tooth? Are the bearings keepered so they don't slip/deflect? Have you put a tach on to verify the RPM? Pictures & videos might tell a lot.