Renovating Circular saw mill / learning what i dont know

outlawpatriot · September 25, 2018, 11:50:29 AM

Hello I have been putting a circular saw mill back to operation and i realize how little i know. i picked up this sawmill at a presumed great price i have repaired all the components. The carriage has four air cylinders that operate the dogs which i replaced the seals now they do bite. the Carriage also has a gear driven forward advance system which i have replaced the motor. The Mandrel "if im using the term properly" was once driven by a PTO off a tractor. upon backing up my tractor to size the drive shaft i realized rotation was an issue. subsequently i decided to purchase a power unit for it "Detroit Diesel 371. it has a clutch system and belt drive. I am planning on mating them this week. it is looking like i am getting to the end of the line where it may be go time. i have one tooth on my blade that is missing i have determined that shank is a type F but am unable to determine the tooth type/size.
If there is anyone out there that has any pointers i would greatly appreciate any input and comments
few questions on Power unit should i belt drive it to adjust rpm at PU to rpm at saw blade? or put drive shaft on the unit?

outlawpatriot · September 25, 2018, 12:01:28 PM

Off-site photo link removed by Admin. here i set mill on mountain

Off-site photo link removed by Admin. here finished repairs and building deck this is where i figure rotation is contra to what i need. i go pwer unit shopping found a 371

Revival Sawmill · September 25, 2018, 12:17:04 PM

Belt drive seems safer/easier on the motor than a shaft... I'm sure you've already read about setting lead on the blade and have researched the rpm the blade was hammered for?

outlawpatriot · September 25, 2018, 12:26:27 PM

i was not sure of what the blade was hammered for? would there be a mark on the blade?

thanks for the opinion on the Belt V shaft

mike_belben · September 25, 2018, 02:11:35 PM

In general, belts transmit power with a slippage limitation that is its own sort of clutch, however that comes with a sideloading on the shaft and crank bearings to keep belt tension. And enough rigidity to maintain alignment to prevent a thrown belt is also necessary.

Shafts need a clutch mechanism installed if take off power must be fused to protect components. They dont need the alignment precision of belting and they distribute a more even load concentrically about the bearing races, but they do cost some money to buy and take more maintenance in terms of joint greasing and replacement, spline wear and so forth.

Either can obviously work to power the saw arbor, just need to choose which method youd rather put up with. Either is happy to remove digits for you so think safety screen.

outlawpatriot · September 25, 2018, 02:27:55 PM

If i understand overall; shaft drive is somewhat the better choice. the Power unit i have is a 371 Detroit Diesel with a Detroit Diesel Allison PTO it has a clutch, would this suffice my clutch requirement for a shaft drive. this engine has low idle at 625-650rpm i m thinking my blade speed should be around that is there any consideration there with that issue.

thanks for your time and Information

Bill

bandmiller2 · September 25, 2018, 07:53:36 PM

Bill, you will get little power from a 371 Detroit at what is idle speed. You will need belts and pulleys to run your engine at 1800 or so RPM's and around 600 at the arbor, a three to one ratio. Just starting out it would be best to have your saw tension checked and a new set of bits. Frank C.

Ron Wenrich · September 26, 2018, 06:36:51 AM

Most hand mills in my area run at 540 RPM. I worked in one mill where the owner wouldn't get his speed up to that and the diesel run at an idle. Very hard to cut any wood.

As for shanks, you should be able to get them from a sawmill supply shop. I don't know if there are any neighboring mills, but they might have a used one or two to give you. F style is pretty common.

Did you get a saw wrench to change your teeth?

mike_belben · September 26, 2018, 08:11:27 AM

My neighbor just gave me 3 rusty saw blades for decoration that are peculiar. They go on a pretty large 3 bolt hub and have slots into the main body with brazed carbide inserts that must create a planing or clearing action against the log face as they pass by. Ever seen those? Theyre a curious thing to stare at.

Crusarius · September 27, 2018, 03:57:04 PM

I see alot of ppl talking about powering circle sawmills with belts and shafts and getting the rpm's right has anyone ever just used a manual transmission with clutch coming straight off the engine? I would think it would be the best way to set speed. just have to have the right gear and the right rpm's then also be easy to disengage the drive and not have to shut the engine down

Revival Sawmill · September 27, 2018, 04:25:11 PM

Quote from: Crusarius on September 27, 2018, 03:57:04 PM
I see alot of ppl talking about powering circle sawmills with belts and shafts and getting the rpm's right has anyone ever just used a manual transmission with clutch coming straight off the engine? I would think it would be the best way to set speed. just have to have the right gear and the right rpm's then also be easy to disengage the drive and not have to shut the engine down

I've seen a few of those on YouTube.... but there's lots of things on YouTube.

moodnacreek · September 27, 2018, 05:42:10 PM

Quote from: mike_belben on September 26, 2018, 08:11:27 AM
My neighbor just gave me 3 rusty saw blades for decoration that are peculiar. They go on a pretty large 3 bolt hub and have slots into the main body with brazed carbide inserts that must create a planing or clearing action against the log face as they pass by. Ever seen those? Theyre a curious thing to stare at.

You don't mention the diameter but most edger saws have a big eye with 3 bolt holes. Slots in the rim are to give the rim room to expand if it gets warm.

bandmiller2 · September 27, 2018, 08:08:52 PM

Crusarius, driving a mill from an engine and transmission is very doable. I have seen an old Chevy truck with the rear end removed and the drive shaft hooked to the arbor. A weak link is needed be it belts shear bolt or slip clutch. The old boy with the truck drive had a warm cab to sit and have his lunch. Frank C.

Crusarius · September 30, 2018, 01:30:36 PM

never thought of the warm place for lunch and relax. that would be nice.

Slip clutch be real easy to put on there. My dad put one on his bush hog.

mike_belben · September 30, 2018, 01:39:33 PM

Quote from: moodnacreek on September 27, 2018, 05:42:10 PM
Quote from: mike_belben on September 26, 2018, 08:11:27 AM
My neighbor just gave me 3 rusty saw blades for decoration that are peculiar. They go on a pretty large 3 bolt hub and have slots into the main body with brazed carbide inserts that must create a planing or clearing action against the log face as they pass by. Ever seen those? Theyre a curious thing to stare at.
You don't mention the diameter but most edger saws have a big eye with 3 bolt holes. Slots in the rim are to give the rim room to expand if it gets warm.

That might be it. Ill get some pics when i go get em. Theyre all rusted. Probably just yard art.

HPPDRoss · September 30, 2018, 03:33:04 PM

I power my mill with a White single axle road tractor. 6-71 Detroit and 10 speed roadranger. I cut the frame off behind the cab and run the driveshaft to the driver pulley with is on a shaft with 2 pillow blocks cemented in the ground. So if the truck kicked the bucket, I can just disconnect the driveshaft, drag it out the way and put another one in its place. Works out pretty good for me.

Haleiwa · September 30, 2018, 06:40:56 PM

A 371 is on the small side for a mill of any size. If you use belts, a power band will work a lot better than a flat belt. To get the power you need, I think you should have a four valve head and big injectors at the least. Might get some help from a turbo, but they don't do as much as you might expect on those smaller units. You can get a little more if you run a straight exhaust, but run it high or you will lose your hearing. The best set up would be an over center clutch into a 3 to 1 reduction gearbox, then a driveshaft to the mill. There are lots of this type of units used by the Dutch in Pennsylvania. Look up Lancaster Farming. Lots of diesel shops advertise there that will have just what you need, including the experience to put it together. Remember, your Detroit needs to be running flat out to make power and be efficient.

BUGGUTZ · September 30, 2018, 09:53:50 PM

I run a Chevy 350 with a 4 spd manual. My arbor shaft has a shear pin. The engine has a belt drive governor. Put the trans in second, set the throttle lock and it gives me 600 rpm at the blade.

mike_belben · September 30, 2018, 10:05:52 PM

Any ideas? Note the flat carbide we are pointing at.

Trapper John · October 01, 2018, 02:03:16 AM

I am using an 8" flat belt to run my Belsaw M-24 because it allows me to run the engine in the opposite direction as the arbor (by putting a twist in the belt) and also allows me to locate the engine 20' away from the arbor which I had to do with the design I went with. I was wondering if I could do the same thing with a power band. Does a power band look like a flat belt but with v corrugations molded on the inside? The flat belt is the weak link in my system because of slippage but it works with enough corn syrup!

Haleiwa · October 01, 2018, 04:42:42 AM

A power band is really just a bunch of v belts connected to each other. You can't run one with a twist. If you need to reverse the rotation, you have a couple of options. A Detroit can easily be reversed by replacing the camshaft and starter. Any engine can be swapped end for end if it is driving a belt pulley. If there isn't space to move the engine to the other side of the drive axis, you can usually turn the engine around in its cradle and take the power off of the other end of the crankshaft. If the balancer is such that it won't accommodate a pulley, the simplest way to deal with it is to mount a jackshaft that runs from the rear of the engine to the front. A short set of belts drives the jackshaft,another set connects the jackshaft to the mandrel of the mill. One advantage of the jackshaft system is that it can be used as a step up or down to regulate output speed.

moodnacreek · October 01, 2018, 08:19:07 AM

Quote from: Haleiwa on September 30, 2018, 06:40:56 PM
A 371 is on the small side for a mill of any size. If you use belts, a power band will work a lot better than a flat belt. To get the power you need, I think you should have a four valve head and big injectors at the least. Might get some help from a turbo, but they don't do as much as you might expect on those smaller units. You can get a little more if you run a straight exhaust, but run it high or you will lose your hearing. The best set up would be an over center clutch into a 3 to 1 reduction gearbox, then a driveshaft to the mill. There are lots of this type of units used by the Dutch in Pennsylvania. Look up Lancaster Farming. Lots of diesel shops advertise there that will have just what you need, including the experience to put it together. Remember, your Detroit needs to be running flat out to make power and be efficient.

Not to many years back 3-71's where common on small commercial mills.

moodnacreek · October 01, 2018, 08:23:24 AM

Quote from: mike_belben on September 30, 2018, 10:05:52 PM

Any ideas? Note the flat carbide we are pointing at.
I think those are kerf cutters to allow more abuse and keep the plate cool.

moodnacreek · October 01, 2018, 08:28:35 AM

Quote from: Trapper John on October 01, 2018, 02:03:16 AM
I am using an 8" flat belt to run my Belsaw M-24 because it allows me to run the engine in the opposite direction as the arbor (by putting a twist in the belt) and also allows me to locate the engine 20' away from the arbor which I had to do with the design I went with. I was wondering if I could do the same thing with a power band. Does a power band look like a flat belt but with v corrugations molded on the inside? The flat belt is the weak link in my system because of slippage but it works with enough corn syrup!
Be careful, I bent the mandrel doing that [ tightened the belt too much]

bandmiller2 · October 01, 2018, 07:46:06 PM

Flat belts work but they are a poor way to transmit power to the arbor especially 1 7/8" arbors. From load to no load they flap and sail and that can't help but affect the arbor and saw. Even multiple Vee belts take a set when cold and need to be run a wile to smooth out. The best lashup for a Belsaw is the tractor PTO shaft with a slip clutch especially if the "U" joints are not angled too much. Frank C.