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1950's Circle Mill Trouble Shooting

Started by jemmy, August 29, 2018, 11:14:40 AM

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jemmy

When I purchased this mill the previous owner had a 56" blade mounted. I don't want to mess up that blade in my learning curve so I swapped it out for a 48" blade. The issue is that I need to move the blade guide back and situate it on the 48" blade. How far onto the blade should the wooden guides be? I imagine the distance between the teeth and the pegs is the most important factor. If anyone can point me in the right direction that would be grand and glorious. Thank you for helping!

Don't worry, I will end up posting many more photos/videos once the weather is frigid but for now I will just be posting trouble shooting photo's. 
 



 
Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

Jeff

Guidepins should just clear your shanks.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

CCCLLC

Exactly like Jeff has said. Just under shanks at first available smooth surface. Control that cutting edge as close as possible.

jemmy

Awesome! Thank you Jeff and CCCLLC for the help!
Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

dgdrls

Jemmy,  good evening.

Just a though, you're gonna want to know what the arbor RPM is geared at.
The saw speed (surface feet per minute) is going to change with the smaller saw
 and will probably not saw as well as it could unless you pick up the arbor RPM speed.

Let us know how u do,

best
D


jemmy

Ok, I was able to break the bolts that secured the guide pins, allowing me to move the pins to what I believe is the correct position for the new 48" blade. I have posted updated photos of the updated positioning. If you all could tell me what else needs to be address with the pins that would be great! My primary concern now is how plum the pins are and whether or not the distance (currently about 1/8" on each side), if there is even suppose to be any, between the pins and blade are appropriate. And despite these photos, I got the cable system hooked up and taught. So there is only two things left before testing the saw. These pins and I have a leak in the radiator :( ... But this has been two years in the making so I am pretty ecstatic, just need to figure these couple of issues. In regards to rim speed, I really have no idea how to calculate it. The power source is a 3-71 Detroit diesel with a standard transmission. The directions for cutting from the previous owner was "slam it into 2nd and bring it up until you hear the Detroit hum" hahaha, so not the most scientific fashion of distinguishing feed rates, rim speed etc. Any ideas on how to approach?  


 



 

 

Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

Ron Wenrich

Things may change with the distance on your guides when you start things up.  I always adjusted my pins on a running saw, but I wouldn't suggest that to someone without a bunch of experience around a running saw.  I'd loosen the pins up to see how the saw stands when its running.  Then shut it off and adjust until you get to where you can see daylight around the guides.  It may take a little bit of playing around with them to get them right.  

Get a digital tach to check your RPM.  They aren't very expensive.  There as some that are contact type.  Those you hold on the center of the shaft.  Others are non contact and are checked with a laser on a piece of reflective tape.  No need to get close to the spinning shafts.  Both will fit your needs.  The laser type are about $10 on Ebay.

Most mills of that era ran about 540 RPM.  When I was running diesels, they had a tach on them, and the throttle was set that it ran at a certain RPM.  These were industrial Detroits and didn't have a transmission.  
Never under estimate the power of stupid people in large groups.

moodnacreek

If you bring the engine speed up from idle, with the blade spinning, and at say half speed the saw starts to wobble, and slowly keep increasing speed until the saw runs flat, that is the hammered speed.    While sawing you cannot go below this speed. If you had the tach  described above, you could know this rpm when making this test.    What make is this sawmill?

jemmy

Alrighty, well I will be doing some shopping on ebay for a tachometer. And in terms of RPMs is there such a thing as too fast? Obviously there is too fast for the Detroit. But once you exceed the hammered speed does the outside pin have the responsibility of keeping the blade from bowing too far outward? This mill is an American Mill that has been set on a 6" H beam frame. 
Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

Ron Wenrich

Guide pins is sort of a misnomer.  They don't really guide the saw, but protect it from knot dodge and other sorts of things when the cut goes off line.  

The last mill I ran, I was running 700 RPM.  That's what the mill was set up for, and that's what the saws were hammered for.  If you run too fast, your saw just won't perform very well.  Fast running saws are harder for maintenance.  Your teeth have to be in good shape.  The angle has to be good and there can't be any corners off on the teeth.  The saw collars also have to be in good shape.  There isn't that much of an advantage on an older mill to run that fast.  Most of them ran around 540 RPM.  

If you go too fast for what the saw has been hammered, it will bow out, which will also effect your lead, especially if you are holding it back with the guide pins.  You'll also get heat in the rim, and that will twist the saw.  You'll also be burning up your guide pins.  
Never under estimate the power of stupid people in large groups.

Gearbox

I like to run my saws about 25 RPM over the stand up speed . the way I do it is back your guides off so you have a 1/8 on the log side . increase the speed as you will hear the saw banging the guides . keep increasing speed until the banging stops.  
A bunch of chainsaws a BT6870 processer , TC 5 International track skidder and not near enough time

moodnacreek

Quote from: Gearbox on October 20, 2018, 09:03:59 PM
I like to run my saws about 25 RPM over the stand up speed . the way I do it is back your guides off so you have a 1/8 on the log side . increase the speed as you will hear the saw banging the guides . keep increasing speed until the banging stops.  
Me too, or even 50 rpm over depending on how the governor takes ahold.

DMcCoy

Just a fwiw.  Hopefully the rusty blade in the picture is your old blade.  I have those same bits and shanks and they are no longer available. 

Ron Wenrich

I remember my saw doc saying that you can go +/- 25 RPM from how the saw was hammered without too many problems.  I couldn't do that at the higher RPM that I ran.  
Never under estimate the power of stupid people in large groups.

moodnacreek

Quote from: DMcCoy on October 21, 2018, 10:18:15 AM
Just a fwiw.  Hopefully the rusty blade in the picture is your old blade.  I have those same bits and shanks and they are no longer available.
Are they style 3 or something larger?

jemmy

Yep, that's my old blade, I got a nice 56" blade being stored inside that will act as my primary soon, just want to get through the learning curve on this one, I ordered a laser RPM tachometer and chrome paint. I'm going to get the radiator problem hashed out tomorrow hopefully, and will be making my couple of passes. The capable system is hooked up, the blade is pretty well secured, just need to tidy a few things up with black tape, zip ties, a few minutes with the cut off wheel, and 1 run to TSC or Home depot and I'll have my first couple of boards. Pretty exciting to be this close, practically been two years since I dropped the down payment for this mill. Got what seems like an eternally long knock out list of knick-nacky projects, after the already mentioned problems are solved (radiator, etc) Ive got to set up the throttle, but Im, thinking I will be able to rig something for the mean time hehe. I've got practically all day tomorrow to work on it, so I should have things tidied up and ready for testing by tomorrow night, all things going exactly to plan and what not..... I will keep you all up to date, I'm probably going to start a separate thread for this build, I have hours and hours of video that I took of the extraction of the mill, building of the form, and what not, I have practically the entire project captured on my go pro, just need to condense it. These are my current problems though, so I don't see this thread disappearing anytime soon. Thank you all for the help so far and for the future help and interest. These past two years have been quite a trip, and I know things are just beginning. Got practically an endless amount of knowledge to acquire, I'm just a young buck trying to cut some great lumber!
Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

Ron Wenrich

Mounting the blade.  Put the saw on the arbor, and pull back on the shear pins before tightening.  If you don't, you might snap your shear pins on the first cut.  Snapping shear pins is nasty.  Also, when you tighten, you can overtighten and smash your collars.  The way I tightened up the nut was to snug it up with the wrench, then kick the end of the wrench 3-4 times.  That's tight enough.  
Never under estimate the power of stupid people in large groups.

jemmy

Well, I have the guide pins off of the blade by 1/8th inch and secured well. In terms of the shear pins, I put the blade on and how I thought it went together then tightened down the nut with a 36" pipe wrench no kicking, just the force of 250lbs giving a few pulls (not me my big friend), there were two pins that were inserted into the collar, then were inserted into the mill through the blade before the tightening of the nut.  I hope this makes sense, I've had the saw up to rpms and everything seemed to be good in terms of the the securing of the blade. I really did not understand your explanation of what to do with the shear pins, and from what you described as the consequence I don't fancy having my shear pins break on my first cut. If you or someone could put it into other terms or explain differently this technique that would be grand and glorious. 
Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

Ron Wenrich

I was describing what to do when you have the shear pins and collar on the saw.  You pull back on the saw while you snug up the nut.  Chances are you won't shear the pins.  But, it has been know to happen.
Never under estimate the power of stupid people in large groups.

moodnacreek

Those pins are a big deal. What Ron is telling you is that the saw pin holes must be touching the pins in the direction of force when the saw is in the log. They are not shear pins, they are drive pins. They do not have to fit tight and should be smooth. The saw needs to be able to 'oil can' in the collars so dents in the pins are not good.  Never stall or jam the saw in the log as this can dent the pins or worse and over tighten the nut and damage the collars and even bend the threaded end.  When learning to saw there is a lot to keep tract of.  It took me a long time to teach myself to saw and many years to trouble shoot well enough that I can saw every day.

bandmiller2

Jemmy, your doing the right thing going slow and asking questions. Being a sawyer on a circular mill is like learning to ride a bicycle, you just have to do it, a toss or two are to be expected. It seems strange that such large heavy machinery requires such exact adjustment. Really check your lead and be sure no slivers of wood or bark rub the saw plate and heat it. Learn to file straight, best to copy the profile of a new bit. I'm sure their is science involved but handset mill are more of a seat of your pants operation that will become second nature with practice. Frank C.
A man armed with common sense is packing a big piece

jemmy

SUCCESS! hahaha, got everything set up and went for it. The pins seemed to be in good condition and went into the saw in a somewhat loose fashion but once the nut was spun on tightened there seemed to be a solid connection. First cut is a very little piece that I'm going to put on a shelf, didnt figure out the radiator yet, just kept filling it with water then drained it at the end of the day. Gonna get some fittings tomorrow to hopefully solve the issue. Got the chrome spray paint for the PTO to use in conjunction with the laser tachometer, and a game plan for the throttle, thank you all for the help! Got a lot of tweaking, and little punch list things to do/monitor, feels like I just met my first child haha, hes got a little attitude, but seems to be working pretty good. 






 

 
Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

jemmy

OKKKK, so I was attempting to cut up some 4x6s for the track extensions for the sawmill and lost some teeth. When I was cutting my RPMs dropped a few times, I didn't stall the motor, but it did throw the blade into a wobble. After a couple of cuts I noticed I was missing teeth, so I shut the mill down to inspect. What I saw was 2 teeth and their inserts entirely missing and 1 tooth was sheared off  :'( ... to make matters worse I noticed was what looked like hair line fractures in the blade that start in the center and stretch outward like sun-rays (picture below). Now when I bought this mill, the previous owner was not using this blade, something should have triggered my brain then. I have a 56" blade that I believe is in good condition. My question is, did I do this to this blade by having the RPMs drop? Or were these cracks probably there before I started cutting, and I couldn't see them until I started cutting and the cracks re-surfaced. If I did do this to my blade, I do not wish to do the same thing to the 56" blade. And on a separate note, do you NEED the guide pins to run the saw? Or are they there just to insure a straight cut through variable conditions? (like knots and what not) I only cut about 30 bdft before these issues arose. 

 
Plan for the worst, hope for the best, and take what comes with a grin. - Grandpa Chuck

Ron Wenrich

Looks to me like you cleaned the surface rust off the saw when you made a few passes.  Judging from the cracks, I am surprised it stood at all.  There is rust in the cracks, so, it isn't something that you did.  

As for missing teeth, I've done that on numerous occasions.  There were holes in the roof to prove it.  It comes from the shanks being too loose in the sockets.  Sockets can get stretched over time.  You would need an oversized shank to correct it, or you could stretch it by peening the inside of the shank.  I have also tapped on the shoulder of the saw to put it back into place as a fix.  

Do you need guide pins?   You won't be able to control your saw and you will saw into something that will ruin your saw, like a headblock or the like.  Those will rip shoulders off the saw.  There's a lot of things that can pull your saw off line.  They include dull teeth, a chipped tooth, the grain of the log, knots, nails, insulators and a multitude of other things.  Your saw will get hot when it goes off line, and possibly bend.  Then you'll need to get it hammered.  

If nothing else, look at guide pins as an insurance policy.  
Never under estimate the power of stupid people in large groups.

moodnacreek

If everything was perfect that cracked saw wouldn't clean up unless you sawed watery wood but in this case it showed you what was there. That saw is scrap. Somebody ran that saw to destruction.

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