Author Topic: Old School Sawmill Edger  (Read 9995 times)

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #90 on: November 16, 2019, 10:07:52 PM »
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
« Last Edit: November 16, 2019, 10:10:53 PM by Brian Rupnow »

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #91 on: November 17, 2019, 04:05:12 PM »
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.

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #92 on: November 17, 2019, 06:25:43 PM »
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.

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #93 on: November 20, 2019, 05:19:51 PM »
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?

Offline doubletop

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Re: Old School Sawmill Edger
« Reply #94 on: November 20, 2019, 06:57:37 PM »
Brian

I've been away so I'm a bit late to the party but rather than use O rings, which will most likely slip under load, have you considered the alternatives?

https://www.beltingonline.com/

The toothed polyurethane timing belts are small enough to scale down to our model sizes.

Pete
?To achieve anything in this game, you must be prepared to dabble on the boundary of disaster.? - Stirling Moss

Online Jasonb

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Re: Old School Sawmill Edger
« Reply #95 on: November 20, 2019, 07:31:10 PM »
Or if you want to stay with round then get some of the lengths of belting and make up your own, the green has a textured surface and will grip the pulley better than any O ring will.

http://www.fennerdrives.com/eagle/

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #96 on: November 20, 2019, 07:47:03 PM »
Pete--I hadn't considered that type of belting. Jason--I really like the stuff you have provided the link to. My o-rings are currently somewhere on the road to my house. I will definitely check out the product and connector which you gave the link to.--Thank you.

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #97 on: November 22, 2019, 03:46:21 PM »
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.

Online Jasonb

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Re: Old School Sawmill Edger
« Reply #98 on: November 22, 2019, 03:51:02 PM »
It was more the belting I was directing you to than the joiner, flame and a bit of thin metal is all you need to heat weld then and  a 3mm a lighter would do. Failing that stick the ends with superglue.

They are a different density and make up than O rings so far more grippy and also have a bit more stretch which O rings were never designed to.

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #99 on: November 22, 2019, 05:34:56 PM »
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

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #100 on: November 25, 2019, 03:23:44 PM »
I'm still waiting for O-rings, but in the meantime, the brain never rests. I'm still thinking of a pattern embossed on the aluminum pulley in the area where it connects with the o-ring. The o-ring gets squeezed into a v-shaped slot with a flat bottom. If the sides of the v-shaped slots have an embossed pattern, I can imagine it tearing up the rubber O-rings fairly quickly. However, if the pattern was embossed only on the flat in the bottom of the groove, it would supply a lot of traction ensuring that the O-rings would be far less apt to slip, yet not tear up the O-rings. This makes the roller easier to fabricate. I can do a heavy knurl on the outside diameter of a 1" diameter piece of 01 steel, then part of a slice .075" wide and harden it. After heat treating it, put it in a handle as shown, mount the aluminum pulley on a mandrel and drive the pulley with my lathe. With the knurled piece held in my Q.C.toolpost lined up with the flat in the bottom of the pulley, then just crank the cross feed  down tight and let the pulley make a few revolutions. I have never seen this done, but it seems like a good idea.

Offline mike mott

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Re: Old School Sawmill Edger
« Reply #101 on: November 25, 2019, 03:52:36 PM »
That is an interesting solution Brian.

Mike
If you can imagine it you can build it

Offline RayW

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Re: Old School Sawmill Edger
« Reply #102 on: November 25, 2019, 03:59:19 PM »
Hi Brian,

When I was restoring my 1/2HP Stuart engine, I needed a small diameter round (4mm) section belt for the drive to the flyball governor. I found a product from Fenner Transmissions called Poly Cord, and they made up some endless belts for me to my dimensions.
As Jason has said, you can just buy the belting, cut it to length, and superglue the ends together, but superglue joints are non-flexible and my experience is that belting joined that way breaks easily when bent. The only effective way is to heat weld as he suggests.
Poly Cord is pretty grippy and may be just what you need.
Ray

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #103 on: November 25, 2019, 04:13:15 PM »
I am currently waiting for a quote from Fenner for a 100 foot roll of 1/8" polyurethane round material and a kit for heating and welding the ends.---Brian

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #104 on: November 25, 2019, 04:29:41 PM »
I just happened to have a short piece of 01 steel 1" diameter. It wasn't a big deal to knurl the outer diameter, ream a hole in the center, part it off, then heat treat it. I will heat soak it in my wife's kitchen oven at 350 degrees for a couple of hours to draw the hardness back a bit. Not sure if I will need it, but it didn't cost anything to make and I think it's fairly innovative. The knurled pattern came out very well, and I'm sure it will imprint the aluminum with no difficulty.