1x30 Variable Speed Grinder - Treadmill - WIP

Joined
Feb 5, 2014
Messages
93
Hello everyone !!
I have been making knives for approximately 18 months and produced 28 knives all on my
20 yr old Sears 1x30” 1/3hp sander. Like most new knife makers, we are on a VERY limited budget
and not all of us can afford that awesome KMG 2x72. For the last 4 months, I have been researching
on how to make my own 2x72. Watched many videos and read more forums that I care to
admit to. In many cases, I have seen these made from treadmills. Has everything you need;
bigger motor, bearings, variable speed, etc.

I have talked to many sources lately and have warned me about using a treadmill setup for my
2x72. The motors, bearings, and belts are all different. I was also told that since it was an
open motor, shaving and debris would ruin the motor quickly. OK, I believe all of that.

But because of all the research that I have done on this treadmill setup, I decided until I could
afford to build that 2x72, that I would soup up my 1x30 and make a variable speed unit so I
could slow everything down from my normal 3450rpms. (a finger and steel burning maching)

Everything I found and read was strictly about the 72 and not many modifications about 1x30.
Here is a WIP that I did to hopefully help the new makers out there, on a budget, make something
until they can move up to the bigger machines.

Here is my current setup that I have been using for all my knife making including handles:


I then went to craigslist and watch it for about a month looking for the best deal and the
biggest motor. This guy just wanted it out of his garage. He wanted $125 for a month and
no takers. I called him up and offered him $30 to haul it away. He accepted.
[URL=http://s901.photobucket.com/user/Poolqs/media/IMG_1927.jpg.html]
[IMG]http://i901.photobucket.com/albums/ac213/Poolqs/IMG_1927.jpg[/URL][/IMG]

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Next thing I had to do is undo the tracking and pull out the long bearing units that the mat
ran on. Found out that the pulley system was totally different than I expected. Wasn't a flat
belt or a V. Opps... now what...hmmm. I tried to disassemble the bearing unit to get the pulley
off but somehow it was fixed to the long bearing bar. I waited awhile and disassembled the 1x30:
[URL=http://s901.photobucket.com/user/Poolqs/media/photo%2014.jpg.html]
[IMG]http://i901.photobucket.com/albums/ac213/Poolqs/photo%2014.jpg[/URL][/IMG]

I wasn't able to get the bearing unit off so I decided just how to get the pulley assemble off.
I was locked into the bearing and epoxied in. After some choice words, I was able to get it off.
It just left me with an 8 thread round rubber piece with a 2.5" hole in it. How was I going to
but that on a 13/32" shaft. I came up with this. I made a wood circle to act like the bearing
unit. I also added 2 pieces of aluminum rods into both to make sure that neither would spin
under pressure. All of it was epoxied together.
photo%2015.jpg
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After cleaning all that up and making sure it was true, I attached it to my grinder. I then pulled
the motor out and the control boards to see how I would line everything back up.
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Next trick was how to bolt everything down and be able to make tension on the belt. I cut out
the motor housing out of the treadmill and used it as my anchor. I then cut out an angle
piece and attached it so I could thread bolts on top to adjust the belt pressure.
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I took the control box out of the treadmill and cut it down in size. Moved the solenoid and the
grounding wires and used my bandsaw to cut away the excess. I mounted it on the wall to
keep it out of the way and until I will build a new box for it.
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Now the final stage, the variable speed unit. I took the whole unit off the treadmill and hooked
everything back up just to make sure everything was still working. All good !! I knew that I
didn't want the "handlebars" and sure didn't need the heart monitor. I took them apart and then
cut away the excess of the panel to only the part that I wanted to use.
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I mounted it on the wall in front of me for easy access.
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Now to wire everything back together and make sure that it still fires up. Hopefully NOT go up in fire. It works :rockon:
 
Now for the maiden voyage, putting steel to it and really press down hard to see if everything
stays together and doesn't bog down.

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SPARKS !!! I could not bog it down with even 2 hands. That is hardened Aldo 1084 at 58rc.
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I turned down the rpms to low and tried some wood out. Oh my... no burning anymore wood !!

I really hope this helps out some new knife makes out there. This entire setup cost me $30
and used all bolts, iron, screws, etc from that one treadmill. As stated earlier, I will be making
a new box for the control panel and shield all the wiring. I have NO prior experience in electrical
or mechanical areas. This is all from a lot of reading and knife forums.
Thanks for reading my WIP and if anyone has further knowledge of areas I can improve on this,
I would love to hear them and incorporate them in this design.
Troy
 
Hey Troy,
Great wip. With that type of ingenuity you'll be throwing together a real 2x72 before long with a couple skate boards and that same motor. Thanks for taking the time to do this. Best of luck and have fun. Oh and watch those thumbs!
 
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