looking for groves for cable to set in on 1 inch shaft

[Mac88]

Tom, using Gene's lift design, you could probably fab up some kind of spring loaded tensioner, to force the cable wraps close together. It shouldn't take a lot of tension to accomplish that. Does your mill have some kind of lock to prevent the lift from moving while the saw is in use?

I commend your desire for accuracy.

 

[PhilB]

Tom,

Maybe a rod spaced close to the cable rap would prevent the cable from overwinding on itself. Just a thought. I don't know if it would work or not, but just another idea.

Phil

View attachment 280837

 

[lps8]

more pics better view

He seems to have the same problem as mine as far as wrap spacing. If you look at his pictures, the cable has gaps on the wraps. When I was young as a scraper on lathes and mills, the boss insisted that we strive for accuracy on every part so the combined error was as small as possible. This was to make up for bearing wear and operator error on precision parts. Once you learn that way, it is hard to let go, even if sometimes it would be smarter to just run with it.

There is a better view of how it works on post by TMAR.

http://www.arboristsite.com/milling-saw-mills/156857-6.htm

Looks wound pretty tight to me. I think it will be about as accurate as you can get unless you use threaded rods tied together by a chain. That is what I have on my chainsaw mill, but I am going to use this system when I build a band mill.

There are a lot of other factors that effect the accuracy of you cut. You start cutting wood, you can't measure it with a mic, the natural tension in a lot of logs will change what you get off your mill. That's where a planer comes in.

Just my 2cents.

Larry

 

[Mac88]

Tom,

Maybe a rod spaced close to the cable rap would prevent the cable from overwinding on itself. Just a thought. I don't know if it would work or not, but just another idea.

Phil

View attachment 280837

That's a good idea. It would at least take care of that part of the problem. Replicating the missing parts on Tom's mill would be the preferred fix but that would require some machining work.

Perhaps a sleeve of HDPE or similar over the guide, just touching the cable.

 

[lps8]

garage door cable drum

Here is a link to a site that has what it sounds like you are looking for.

Commercial 400-12 Cable Drum, Std. Lift [400-12S] - $11.95 : American Garage Door Supply, Commercial & Industrial Door Systems, Hardware and Related Products, Manufacturer and Distributor of Garage Doors, Door Openers, Stainless Steel Hinges and Magn

I could not find what size the bore was, but the shafts that they sell are 1". And they were cheap. Do you have a 1" tube or is it pipe that actually measures a little more than 1"?

Larry

 

[Mac88]

Here is a link to a site that has what it sounds like you are looking for.

Commercial 400-12 Cable Drum, Std. Lift [400-12S] - $11.95 : American Garage Door Supply, Commercial & Industrial Door Systems, Hardware and Related Products, Manufacturer and Distributor of Garage Doors, Door Openers, Stainless Steel Hinges and Magn

I could not find what size the bore was, but the shafts that they sell are 1". And they were cheap. Do you have a 1" tube or is it pipe that actually measures a little more than 1"?

Larry

That would probably work. The only problem I see is that, due to the diameter of the drum, the cable would move a long way with only minor rotation of the drum. There's probably a work-around to fix that.

 

[lps8]

door drum

That would probably work. The only problem I see is that, due to the diameter of the drum, the cable would move a long way with only minor rotation of the drum. There's probably a work-around to fix that.

I had the same thought. Gene's setup uses 3/4" pipe and 1 click on the winch is 1/16". You could calculate the movement based on that if you know the size of the drum. If it was a 1/4" per click, that would normally work for me.

On my csm, one full crank on the adjuster is 1/4", but I don't have to move it a full round if I want.

Larry

 

[Mac88]

Thanks Larry. We run an LT30 bandmill with power/manual lift on the head, infinitely adjustable, which is a whole different creature. I haven't really looked into how Gene's lift system is constructed. I guess I need to go back and read through that thread. If you're moving in fixed increments, 1/16, 1/8, 1/4 or whatever, that would simplify the mechanism somewhat. I'm assuming that Tom's mill has some sort of ratchet stop to keep the cut a uniform thickness. Phil's idea on the guide to keep the cable from over-wrapping sounds practical. My only other concern would be keeping a close wrap as the cable is winding on the shaft. If one side was closely wrapped and the other side not so close it would induce some error in one side of the lift. Of course, for me, visualizing a modification to a machine I can't actually touch or even see makes it all the more difficult. I think we can solve Tom's problem. It'll be interesting.

 

[Tom60]

Thanks Larry. We run an LT30 bandmill with power/manual lift on the head, infinitely adjustable, which is a whole different creature. I haven't really looked into how Gene's lift system is constructed. I guess I need to go back and read through that thread. If you're moving in fixed increments, 1/16, 1/8, 1/4 or whatever, that would simplify the mechanism somewhat. I'm assuming that Tom's mill has some sort of ratchet stop to keep the cut a uniform thickness. Phil's idea on the guide to keep the cable from over-wrapping sounds practical. My only other concern would be keeping a close wrap as the cable is winding on the shaft. If one side was closely wrapped and the other side not so close it would induce some error in one side of the lift. Of course, for me, visualizing a modification to a machine I can't actually touch or even see makes it all the more difficult. I think we can solve Tom's problem. It'll be interesting.

That is exactly what happens.

 

[lps8]

look what I found in my shop

View attachment 281133


I found this in my shop today. 1" shaft size and 3" od where the cable runs. If you used the same boat winch where 1 click with 3/4" pipe = 1/16, then according to my calcs 1 click with the 3" od cable spool would be almost 3/16 if my math is close. I guess that sounds right if the spool is 3 time as large as the pipe. Just something to think about.

Larry

 

[Tom60]

You are right. What I have decided to do is to use it for now, then, when it is not in a critical need time, heat a spring, make a jig, and weld it to the 1 inch shaft. The rise will still be 1/16 inch and I will install push pins in the uprights so that the cuts are accurate to standard plus anticipated drying shrinkage. When the size cut is not standard, I will clamp above and below the slides. Thank you everyone for you help and suggestions. You are an amazing group of people...

 

[lps8]

had you used this saw yet?

I was curious if you had used the mill before or just putting it together. I am building a bsm using Gene's instructions. Already have a csm. Want to see if bsm is better.

Larry

 

[Tom60]

update

This was a $300 basket case with frozen bearings, water filled engine, missing platten and rollers, frozen adjustment slides for the blades and an overall rustbucket. There were parts forced into threaded holes with the wrong threads, and when they were removed the aluminum threads came out too. The clutch fell apart when it was removed. The engine broke inside even after soaking in mystery oil for a week. Bolts that didn't break off had to be cut off. That was three weeks ago.
Three bolts to attach the new engine and weather over 50 degrees and it will be painted and ready to run. (I havent cleaned or repainted the fiberglass covers yet either) The rails will be installed on concrete pads with screw levelers. As soon as this flu runs it's course, It will happen. Thanks

 

[lps8]

head adjustment

Hello Tom,

I don't know whether you have look around at other systems, but I saw a Norwood the other day. I didn't look at it too closely, but it used cables to adjust the head, but the cable was wrapped around a pipe and the head was counterbalanced with a spring like a overhead door. I think they had a friction clutch that kept it from moving easily, but was loose enough to adjust with a crank. It was infinitely adjustable. Maybe someone with a Norwood could answer questions about their set up if you were interested.

Larry

 

[lps8]

height adjustment

Tom, got a good look at the Norwood today. It is set up just like an overhead door, with the spring and a cable drum on each end and the spring is to counterbalance. Height adjusts pretty easily and then lock it at the height and cut. Pretty neat.

LARRY