Old School Sawmill Edger

[Brian Rupnow]

This afternoon seen the first assembly of the two overhead shafts, gears, and pulleys. I think I'm going to end up putting a bolt on gusset plate on the tower coming off the gear reducer, because right now things are more flexible than I am comfortable with. Tomorrows job will be to build the gusset plate and put set-screws into all of the pulleys.

 

[ddmckee54]

Brian:

It takes a special kind of crazy to go through this much trouble just to rip paint sticks to width.

That being said, it's looking very impressive.

Don

 

[Brian Rupnow]

Don--I am a special kind of crazy, and I love it. I've been this kind of crazy for the last 70 years or so.

 

[LorenOtto]

Don--I am a special kind of crazy, and I love it. I've been this kind of crazy for the last 70 years or so.

You go Brian! Keep it up, I enjoy every new addition to your build.

 

[Brian Rupnow]

So, I have arrived at the point where there really isn't much left to do except buy a bunch of O-rings for drive belts and "free up" all of the shafts which run in bushings. This picture shows my 1750 rpm motor "running in" the top two shafts and bearings. There is also one o-ring belt driving the saw arbor. I will keep lots of oil on the bushings and let it run that way for an hour.

 

[Brian Rupnow]

For all intents and purposes, the project is finished. My next challenge is going to be getting the correct size and length of O-rings for drive belts. there is a local o-ring company that doesn't sell to the public, but who have helped me out before. There is also a seller in Toronto who I will contact on Monday. I am quite excited to see this edger working.--Brian

 

[Brian Rupnow]

Just for the heck of it--Here is a picture of "running in" the textured rollers. There wasn't a lot of resistance there, but even a brand new piece of roller chain will loosen up considerably when "ran in" for an hour with lots of oil on the chain and the bearings which support the textured rollers. The spring loaded pressure rollers are tied up with a piece of string to keep them from being "imprinted" by the textured rollers while they are being run in. On full size edgers I am sure that there must be an adjustable stop to keep the pressure rollers from riding up against the face of the textured rollers

 

[Brian Rupnow]

I received a quote yesterday for the eleven O-rings I want to use on this project. $55--Ouch. Still cheaper than buying one timing belt pulley. Remember--I'm not in USA. Everything up here costs roughly 30% more than south of the border.

 

[Brian Rupnow]

I've decide to use one of my side-shaft engines for the edger project. This is not a hit and miss engine, but is a throttle governed engine. The governor mechanism senses when the engine begins to slow down from a load, and consequently opens the throttle wider to compensate for the load and bring the engine up to it's pre-set "no load rpm". I know this engine has more than enough power to drive my sawmill, so I am hoping it will have no problem driving the edger.

 

[CFLBob]

Count me as anxiously waiting for video, as I'm sure many folks are.

 

[Brian Rupnow]

This falls into the category of "wild ass ideas" but---On many of the small machines I make to run off my engines, I use o-ring drive belts. They work just fine. However, in order for them not to slip on the smooth surface of the aluminum pulleys, they have to be stretched very tight. The fact of "being stretched really tight" is hard on the bearings of both my engines and the machines they run. What can I do to alleviate this problem?---Well, what about the idea of giving some texture to the smooth surface of the pulley grooves?
I have a dedicated cutting tool which I ground to cut the pulley grooves. I know the geometry of the tool tip and consequently, the grooves it cuts. If I were to make a round cutter from 01 steel, which had the same geometry as the cutting tool, then drilled a series of holes around the thing and hardened it, it would leave the shape shown. If I then had a hole in the center for an axle and a holder, I could mount it in a holder in my quick change toolpost, and after lining it up with the pulley groove, crank it in far enough that it was giving some pressure. The pulley would be rotated by my lathe, and as it turned the new cutter would "imprint" a pattern in the smooth pulley groove. Remember, I'm not trying to remove material here, just imprint a pattern. Unless I got into one of those situations where the pulley groove was exactly a multiple of the cutter pitch diameter, it should not repeat the pattern in the same place on each rotation. I like the idea. I have enough material on hand to make something like this. What do you think?

 

[werowance]

sounds interesting. steel against aluminum should imprint easily - at least to a point of giving you some traction. only thing I'm thinking about is burs or something similar to a knurl that might cause the oring to cut or grind away rapidly maybe?

 

[Brian Rupnow]

Werowance--It's one of those "Try it and see what happens" kind of things. If I don't need it, I won't do it. If I decide that I do need it, I'll make one and it should last me for the next hundred years.

 

[Charles Lamont]

I received a quote yesterday for the eleven O-rings I want to use on this project. $55--Ouch. Still cheaper than buying one timing belt pulley. Remember--I'm not in USA. Everything up here costs roughly 30% more than south of the border.

Why not try the round polyurethane belting? It is dirt cheap, you can easily make it up at any length you require, and being made for the purpose, which O-rings are not, it works better.

 

[Brian Rupnow]

Charles--I didn't use round polyurethane belting because up to now I've never used anything but O-rings for drive belts. I do have a link that someone sent me to a place that sells polyurethane belting and connectors for it.

 

[dsage]

How about a rubber pulley (hard but sticky) with an aluminum hub.
Rubber is easily turned on the lather when frozen. (pre-frozen or use freeze mist on the fly).
Perhaps just a slightly concave aluminum pulley (to keep the belt tracking) and a glued on layer of thin inner tube rubber.
I'm thinking any sort of texturing would just wear the belt.
Perhaps a bit late now but large pulleys would give more circumference and more grip.

 

[dsage]

Another thought.
How about a leather belt. Strips are easily cut and if the two ends are gradually beveled they are easily glued together - just like they used to do it - and fitting for your project.

 

[Brian Rupnow]

I've had a rather lazy, non machining week and I've rather enjoyed it. I called the o-ring vender in Toronto, and they have my O-rings ready to ship on Monday. They were supposed to ship this week but something got screwed up with their supplier and they couldn't make it this week. I did get rather excited about the link posted by Jason, as it shows polyurethane cut-to length belting and a multi jointed mechanical connector, but more reading showed me that minimum diameter is 3/8", too large for my use. I actually did contact Fenner Drives to enquire about 1/8" polyurethane drive belts and a "splicing kit". It is winter here now, and since I don't have any heat out in my main garage, I will probably set the edger, clutch, and engine up on a piece of 3/4" plywood on my reference desk beside my computer for the actual running.

 

[Brian Rupnow]

So now we are going to see about old dogs and new tricks. I have always used black rubber O-rings as drive belts for the array of "Things to drive with my engines". That was mainly based on the fact that Hercules O-rings have a distribution warehouse in Barrie, and if I went over there and begged enough, they would give me what O-rings I needed. Time has moved on, and all of the personnel over there has changed so I doubt that my begging routine would do much good. The newest bunch of O-rings I am planning to use on my sawmill edger have been ordered from a Global O-rings in Toronto, and by the time I pay for the O-rings, the tax, and the shipping, I'm going to be looking at $75 or $80 which is a bit much. I have contacted a distributor of polyurethane Fenner drive belts (which are sold in 100 foot rolls, and a "welding kit" for joining the ends. According to people who seem to know, this round polyurethane belting is far less apt to slip on an aluminum pulley than an o-ring. I will post what I am quoted and also post what the O-rings I have on order end up costing, and let you know.---Brian

 

[Brian Rupnow]

dsage--I'm not ignoring you. It's just the fact that my aluminum pulleys are already made. Leather belting works in some applications, but I'm not really a leather worker.---Brian