Clutches, Clutches, Clutches!

newguy · July 09, 2004, 06:12:51 AM

Hi all,

I am in the semi final stages of building my mill. I still have not decided what to use to disengage power to the band. I am considering a centrifugal clutch, electric clutch or a hand operated tensioner on the drive belts. Any good suggestions? What kind of luck have you all had with any of the above. If there are any electric clutch users out there. What brand of clutch are you using? My powerplant is a 27hp Kubota diesel so I would like to have something rated for 30hp or so. Thanks for any help.

Craig

slowzuki · July 09, 2004, 07:38:39 AM

I wouldn't recommend electric as they can be bloody expensive to replace! I'm gonna use the belt tensioner method as belts are relatively cheap.

Ken

newguy · July 09, 2004, 08:10:31 AM

Ken,

That is kind of the way I am leaning. I just haven't come up with a real good design to lock the tensioner in when the belt is engaged and brake the belt when it is disengaged. Maybe some of those WM guys out there could post some pics of how they do it. ;D

D._Frederick · July 09, 2004, 09:06:39 AM

Newguy,

My mill is an electric powered sit on the ground manual mill. To keep from killing the power to the motor between cuts, I use a belt tightener as a clutch. I have and arm that is hinged on one end and with an idler pulley on the other end. The flat face pulley comes up against the drive belt on the return side. To raise and lower the idler, I have a rod connected to it that is pulled by a lever that breaks over center. The rod is threaded so that I can adjust the belt tension. The lever is flipped back and forth to engage or disengage the drive to the band wheel. My mill uses Vee belt pulleys for band wheel with Vee belt for tires. With this set-up I don't need a break to stop the band wheel rotation.

newguy · July 09, 2004, 09:35:07 AM

D._Frederick,

Thanks. Isn't that kinda like the WM set-up? I'd love to see a pic if you have one. Do you just let the band speed run down after you have disengaged the drive belt?

I think that may be the way I will go. I am also using V-belt sheaves for my band wheels as well as drive wheel.

Craig

slowzuki · July 09, 2004, 11:52:30 AM

D F that sounds a little like how the lathes speed change system at school worked, they had flat leather belts though. The break over centre lever is the key.

I've been looking it it wrong I think, I was going to have the break over lever on the motor mount.
Ken

D._Frederick · July 09, 2004, 01:34:27 PM

Newguy,

When using Vee belt pulleys with Vee belts for tires for the band wheels, the band compresses the belt. On my mill it takes over 1/2 hp to run the band when not sawing. The energy to compress the belts is enough brake to stop the rotation.

The WM saws have the engine mount hinged, they have a lever that rocks the motor back and forth to tension the drive belts.

jimbo · July 09, 2004, 02:08:54 PM

just a though what about the same way the lown mower runs the blade, on them it would have to be cheaper . just a though

jimbo

Neil_B · July 09, 2004, 05:03:36 PM

Craig,
What diameter is the shaft on your Kubota? Also how many belts are you using to drive it? I have the 36hp Kubota and replaced my 2 groove, 5" centrifigul clutch with a bigger unit.
The one that was on it is actually rated for your hp. Will be willing to sell it if you can use it.
Neil

pinecone · July 10, 2004, 06:48:52 AM

Newguy

I am using a 4" BLM centrifugal clutch on my home made mill.
Here is the breakdown of power transfer.
13hp Honda engine, mounted with the 4" 2 V groove clutch, connected to 14" 2V groove drive pulley that is on a 1.5" shaft, on this same shaft is my 20" V groove(with belt) band wheel. I am using B belts as well.

This system works very well, when I was building my mill I too considered using the tensioner system. I used a friends mill for 3 days straight, I found that the pulling of the manual clutch arm was a bit of a pain. The cost of the BLM clutch was fairly reasonable. $235 CD shipped. Cost of making the manual clutch including parts and labour, welding and just plain figuring it out maybe 125.00 CD. The beauty of the clutch is that I could just put it on, match the belts and was going right away. Downside, I will have to buy replacement pads for the clutch someday. When going from full speed to idle the band stops within seconds. The only advice I can offer is to call BLM and talk to their tech. he can give you the spec's you will need to match your hp. I found they were quite knowledgable about bandsaw mills.

Sorry for the long post, and one last thing, I too am a newguy to milling and to this site. I enjoy reading and seeing what others are doing.

newguy · July 12, 2004, 05:56:09 AM

Hi Guys,

Sorry it took so long to respond, I was away this weekend. First of all, thanks for all the responses. As usual the forum has come through again. 8)

Neil,
I believe it is a 1-3/16" diameter shaft. I haven't put the mics to it yet, just checked it with a tape measure. The engine came from Japan so it may be metric. I am going to use 2 B section belts to drive it. The 5" diameter is just what I had planned to run. I would be very interested in your clutch.

D_Frederick,

Thanks for the info. That solves the braking questions I had.

Pinecone,

Thanks for the info. as well. I am always interested in how others are running their mills.

Neil_B · July 12, 2004, 09:38:51 AM

Aw shucks, 1 3/16"?
The bore on mine is 1 7/16" with a 3/8" keyway. If you think you can rig some kind of sleave on the shaft and can still use it then email me to let me know.

markct · January 04, 2005, 09:54:44 AM

i would measure it with a mike before ya go buying any pulley or clutch for it, if its metric it would most likely be 30mm which is 1.181 inch so ya would need a mike to tell the difference

Fla._Deadheader · January 04, 2005, 03:21:40 PM

We used the WM method, only, made ours work EZ. We have an adjustment, so we can keep tightening the belt as it stretches. I will take some pics of the mill and post 'em this weekend.

lamar · January 06, 2005, 06:46:45 PM

Good stuff,my mill is similar to wm. only 25hp kohler slides with clutch arm and over center link, It works good but would like to rig a simple brake so wheels will stop when idiling and clutch disingaed. ANY IDEAS, I keep thinking I would get more life out of bands plus bearing wear ect.Thanks

WV_hillbilly · January 06, 2005, 07:21:23 PM

Newguy

I just bought an American Bandsaw sawmill that has a NORAM centrifugal clutch on it . I like it cause when you throttle the motor down it automatically stops like lamar said . Plus I think it would have to save on the belt life cause there is no belt slippace when you make it engage the blade .

WV hilbilly

Fla._Deadheader · January 07, 2005, 02:03:20 PM

  Here's the pics of our Belt Tensioner.

  You push the handle in, toward the sawhead. That rocks the engine up and tightens the belt. The handle "snaps" over center and stays there, until tou pull it back, away from the sawhead. The travel is adjustable from "0" inches to 1½". That takes up quite a bit of slack. Takes, probably 20# of "Push". to snap it over center. No sore arms or shoulders.

  First one shows Handle in "Disengaged" position. The 2 round objects are "Hime" joints, for swivel action.

2nd photo shows Handle "Engaged". The handle hits the sawhead frame, so that is the stop for over-center.