Rebuilt drag type sharpener

pineywoods · December 29, 2014, 09:08:24 PM

I have a 20 year old woodmizer drag type sharpener that came with my mill. Over the years it has been abused and not well cared for. It had become a big pile of rusty parts and grinder dust. I took it all apart, cleaned as well as i could, then dumped all the parts in a tub filled with vinegar. 4 days later, it came out all clean and shiney, then got a coat of rust proof paint. A weak point of this sharpener is the small 12 volt grinder motor. That got replaced with a 1/3 hp 110 volt ac motor, fitted with a new hub. here's the finished job

Next major problem was the profile cam. 20 years ago, the blade profile of choice was a 13 degree, with a flat bottomed gullet. That's what came with the sharpener. MY blade of choice is 10 degree double hard from woodmizer. Sssooooo, I mounted a junk blade and attacked the cam with a hand held grinder. About 2 hours of trial and error resulted in a cam that grinds a pretty close copy of a 10 degree profile.

Close enough ????

drobertson · December 29, 2014, 09:16:12 PM

I like that gullet, looks like it gives good support to the tooth at the gullet transition,, nice work, I have a small 12v motor, it is getting week as well, thanks for the idea!

JB Griffin · December 29, 2014, 09:31:12 PM

Looks good Piney. 8)

paul case · December 29, 2014, 11:01:31 PM

I use 1 just like that, except mine is still in the somewhat rusty and covered with grinder dust and slightly dilapidated state of abuse. Sharpens 4 to 8 blades a day though. 110 volt motor on mine just got replaced last month. Drag motor is getting weak.

PC

YellowHammer · December 30, 2014, 12:06:54 AM

Looks like it has another 20 years of life left in it. 8). Do you think there is a big difference drag grinding with a bath on the blade as opposed to dry, like my CatsClaw? Can you take a deeper cut without burning? Does it sling lube and make a bug mess or is it pretty clean? Is it cutting oil?
thanks
YH

Chuck White · December 30, 2014, 07:41:31 AM

Nice job on refurbishing and upgrading your sharpener, Piney!

bandmiller2 · December 30, 2014, 08:11:02 AM

Hammer, I have always ground bands dry it kinda keeps you honest as you don't hog off a lot of material. The CBN wheels require it for their longevity. Time is money commercially, sharpening services use coolant to speed things up. I have considered going half way and using misting equipment as used in machine shops. Frank C.

LeeB · December 30, 2014, 08:42:42 AM

I wonder if forced air cooled would be of any help?

drobertson · December 30, 2014, 08:51:57 AM

we have used forced air in the past on other types of cutting actions, we added an inline oiler that throws a mist of whatever is the choice of coolant. Only down fall if you can call it that, is it can become a mess if not cleaned up regularly. The plus side is a regulator controls the amount of pressure as well as coolant flow.

pineywoods · December 30, 2014, 10:36:14 AM

I use water for a coolant, but I mix a small amount of water soluble cutting oil (machine shop stuff) mixed in. The biggest plus from the oil is it cuts down on the rust problem a bunch. Blades don't rust either. When I use up my supply of oil, I'm gonna try veggie oil. One neighbor sawyer ran his dry for a while when the water pump failed. Appeared to work ok, but found out the hard way the heat buildup took some of the hardness out of the hardened teeth so they definitely dulled sooner. One worthwhile tip from Bibby, put a good stout magnet in a ziploc bag and suspend that in the coolant pan. It will collect most of the filings and you can re-use the coolant..
I lucked up on the replacement motor. Needs to be 3600 rpm and physically small. Mine came off a discarded hospital patient lift.

bandmiller2 · December 30, 2014, 09:02:24 PM

Piney, many years ago we used a water soluble oil called Rustlick, steel parts would not rust and it even had a pleasant minty smell. The old automotive water pump lube you added to the radiator is also soluble oil. Frank C.

customsawyer · December 31, 2014, 03:09:44 AM

If you need to touch up a cam I find a belt type sander works a little better. Sometimes you have to make do with what you have too.

pineywoods · December 31, 2014, 09:46:33 AM

Quote from: customsawyer on December 31, 2014, 03:09:44 AM
If you need to touch up a cam I find a belt type sander works a little better. Sometimes you have to make do with what you have too.

Yeah, make do with what I have is a way of life for me ;D The belt sander works fine for final touch-up, but I had to take off a bunch of metal to get deep enough gullet. I may tackle making a new cam from scratch to use a full profile wheel..