Upgrades to my band sharpener.

Delawhere Jack · March 28, 2017, 05:09:20 PM

Long time in coming, but finally done. I replaced the V-belt and pulleys with a serpentine belt. Made the pulleys on the lathe. MUCH smoother running now. Chucked the grinding wheel arbor in the lathe and trued up the face on the flange. Runs perfectly true now. New supports on the blade clamp make easier adjustment to keep tangential alignment with the rock. Finally, I replaced the turnbuckle used to adjust the depth of grind with something more appropriate. 5/16" x 28tpi heim joints and a shop made post. More than doubled the fineness of adjustment.
(Grind wheel guard removed for photos).

Now if I could just find a proper gear reduction motor to replace this feature......... (hand crank) :

Rickcnc · March 28, 2017, 05:36:56 PM

Very nice.. Do you have a video of this working..

fishfighter · March 28, 2017, 05:41:31 PM

Quote from: Rickcnc on March 28, 2017, 05:36:56 PM
Very nice.. Do you have a video of this working..

This. ;D

Delawhere Jack · March 28, 2017, 06:03:42 PM

Quote from: fishfighter on March 28, 2017, 05:41:31 PM
Quote from: Rickcnc on March 28, 2017, 05:36:56 PM
Very nice.. Do you have a video of this working..

This. ;D

Before the upgrades.
https://www.facebook.com/CollinsPortableMilling/videos/775003719272066/
https://www.facebook.com/CollinsPortableMilling/videos/775003719272066/

Ga Mtn Man · March 28, 2017, 09:04:15 PM

Nice upgrades DJ. I've been meaning to do some of those on my home-built machine. If you're looking for a fairly cheap way to get rid of the hand crank, I used a 12V gear motor from a car seat, a couple of pulleys, and a DC speed controller from ebay. There's a 12V battery connected to a charger that sits on the floor next the sharpener. I've sharpened hundreds of blades over the last three years and the little motor just keeps on chugin. Here's a video but the quality is really bad...I had the camera set on low resolution. Maybe you can see how it's set up. I really should shoot a new video.

https://youtu.be/mwkTNHJMNWY

fishfighter · March 29, 2017, 05:21:39 AM

Now y'all guys have me thinking again. :D been using a radial saw set up that is complete manual, but does a good job.

bandmiller2 · March 29, 2017, 06:57:35 AM

Jack, you are a clever rascal, how did you figure out the cam.?? You realize that's just begging to be mechanized. Good show. Frank C.

fishpharmer · March 29, 2017, 07:43:10 AM

Very clever!

Delawhere Jack · March 29, 2017, 08:14:23 AM

Quote from: bandmiller2 on March 29, 2017, 06:57:35 AM
Jack, you are a clever rascal, how did you figure out the cam.?? You realize that's just begging to be mechanized. Good show. Frank C.

Frank, I used a new band, a roughly profiled stone and a blank cam. Advance the cam 5 deg, let the stone sit on the band, hold the cam end of the pivot down and mark it's position on the blank. Repeat 72 times, cut out the resulting profile.

Delawhere Jack · March 29, 2017, 08:18:00 AM

Quote from: Ga Mtn Man on March 28, 2017, 09:04:15 PM
Nice upgrades DJ. I've been meaning to do some of those on my home-built machine. If you're looking for a fairly cheap way to get rid of the hand crank, I used a 12V gear motor from a car seat, a couple of pulleys, and a DC speed controller from ebay. There's a 12V battery connected to a charger that sits on the floor next the sharpener. I've sharpened hundreds of blades over the last three years and the little motor just keeps on chugin. Here's a video but the quality is really bad...I had the camera set on low resolution. Maybe you can see how it's set up. I really should shoot a new video.

https://youtu.be/mwkTNHJMNWY

Wow. That looks VERY familiar! ;) A car seat motor.... awesome. Never thought of that. Thanks!

Ga Mtn Man · March 29, 2017, 08:50:51 AM

It should. I was inspired to build it after seeing yours. Thanks for the original thread on your build and these new ideas for upgrades.

This should look even more familiar!

https://youtu.be/k_3KnCSDaBw

This was the very first time I tested it and I clearly didn't have the stone correctly shaped.

fishfighter · March 29, 2017, 09:36:10 AM

Now I really need more info.

brewdog · March 29, 2017, 02:17:41 PM

HOW do you know what to shape the stone to

Delawhere Jack · March 29, 2017, 04:56:28 PM

Quote from: fishfighter on March 29, 2017, 09:36:10 AM
Now I really need more info.

Not a ton of detail, but photos and description here:
https://forestryforum.com/board/index.php/topic,66417.msg997014.html#msg997014

Roghair (and others) also added some good ideas in the thread. He measured a new band at precise increments, entered the data into an Excel spreadsheet, and created a circular graph to use as a pattern for his cam.

Delawhere Jack · March 29, 2017, 04:57:51 PM

Quote from: brewdog on March 29, 2017, 02:17:41 PM
HOW do you know what to shape the stone to

I started out by dressing the stone so it was like a scaled down version of the tooth-gullet profile.

Delawhere Jack · March 29, 2017, 05:00:00 PM

Quote from: Ga Mtn Man on March 29, 2017, 08:50:51 AM
It should. I was inspired to build it after seeing yours. Thanks for the original thread on your build and these new ideas for upgrades.

This should look even more familiar!

https://youtu.be/k_3KnCSDaBw

This was the very first time I tested it and I clearly didn't have the stone correctly shaped.

Love the slow-motion part! :D

Ga Mtn Man · March 29, 2017, 07:37:46 PM

My first, second, third,...cams were made by measuring the tooth profile at small intervals and plotting it on a circle graph, but I never could get it to match the tooth profile correctly. You don't even want to know how much time I spent trying to make it work correctly. I finally gave up on it and used a pointer with v-notch mounted in place of the cam follower to mark the profile on a blank cam...advance the blade 1/16", lower the stone until it just touches the blade, make a dot in the v-notch onto the face of the cam, repeat. Not particularly precise but after some fine tuning it was good enough. It occurred to me several months later why the graphing method wasn't working- The push stroke isn't linear but I was graphing it as if it were. The blade is pushed fastest at the beginning of the stroke and slows to zero at the end of the stroke. It is a sinusoidal function. There was a time when I had the math skills to graph a non-linear function and with some remedial math work I think I could figure it out, but I decided what I had was good enough.

bandmiller2 · March 29, 2017, 08:09:24 PM

Mt Man, you done good even the cams you buy for the "store bought" grinders don't fit the gullets perfectly. After two or three grindings everything fits fine. Frank C.

fishfighter · March 30, 2017, 08:00:59 AM

Thanks Jack.

Delawhere Jack · March 30, 2017, 07:21:30 PM

Quote from: Ga Mtn Man on March 29, 2017, 07:37:46 PM
My first, second, third,...cams were made by measuring the tooth profile at small intervals and plotting it on a circle graph, but I never could get it to match the tooth profile correctly. You don't even want to know how much time I spent trying to make it work correctly. I finally gave up on it and used a pointer with v-notch mounted in place of the cam follower to mark the profile on a blank cam...advance the blade 1/16", lower the stone until it just touches the blade, make a dot in the v-notch onto the face of the cam, repeat. Not particularly precise but after some fine tuning it was good enough. It occurred to me several months later why the graphing method wasn't working- The push stroke isn't linear but I was graphing it as if it were. The blade is pushed fastest at the beginning of the stroke and slows to zero at the end of the stroke. It is a sinusoidal function. There was a time when I had the math skills to graph a non-linear function and with some remedial math work I think I could figure it out, but I decided what I had was good enough.

"sinusoidal" not sure what that word means, but it probably costs a good $300.

I tried the graphing method too...... ended up doing it the way you describe.