Atlas 618 Treadmill Motor Install

[mattthemuppet2]

Hi all,

this is a summary of my recent project to install a treadmill motor on my Atlas 618 (see http://www.hobby-machinist.com/threads/wiring-up-a-treadmill-motor-i-know-i-know.37159/ for the full experience!). It got a bit lost in that thread and Nels thought it would be worth posting it here so it was a little easier to find.

I have (had?) a perfectly nice 1/3hp reversible motor on my 618 but I found myself wishing for on the fly variable speed, especially when facing large disks or dealing with chatter. A long story short involving me, a thrown out treadmill, my wife and Jake from East Texas and I had an Icon 1hp motor and MC68 (update of the MC60?) controller.

I chose to remove the flywheel as I didn't want to figure out a way of dealing with it unscrewing when I reversed the motor (1/2-13 LH threads), so I adapted a rather nice 120mm PC fan instead by making a hub that was a slip fit onto the shaft with a set screw to hold it in place

bored out a 2" pulley to fit the shaft (17mm from memory) and then trued up the V. Actually, I did this twice - once on my 3 jaw chuck with runout (doh!) and then again on my 4 jaw with no runout.

I now remember why PC fans have shrouds - without them, most of the air goes out sideways, which isn't what you want. So I cut up the original shroud and mounted it to a piece of wood that was then mounted to the motor with an adapter plate


works waaaay better now!

drilled some holes in the motor flange to reduce backpressure

wooden mount. I ended up taking the base off, but I might need to put it back on again - still fiddling with vibration isolation (the motor also resonates a bit, which = whine through the bench) vs. belt tension
controller adapted to a BUD industries box that I got off Amazon


the KEY to defeating the "return dial to zero so you don't kill yourself when restarting the treadmill" feature. Cut the resistor that is directly connected to the white rheostat terminal (the center "wiper"), called R19 and/ or RPS3. Now the motor will restart at the same speed you stopped it at.

lick of paint
making a lexan cover for the control box, so I could see the status lights on the controller board. Bit of the PITA and I won't be doing it for the next one on my drill press


cover populated with tach display, speed dial, forward/ reverse DPDT switch and on/off SPST switch (both 15A). Annoyingly I deleted the pic that showed how to wire the forward/ reverse switch. Basically, the motor wires from the controller go to the two central terminals on the switch. You then connect the diagonally opposite outer terminals (ie an X shape) and then connect the wires to the motor to one set of outer terminals. Switching from one side through off to the other side will reverse the polarity of the current to the motor and make it reverse direction. If you get it wired the wrong way round like I did, just reverse the connections on the controller board!

power cable and 15A fuse

wired up! This was before I discovered that I'd wired the reversing switch the wrong way round Space is tight in there - if you can find 1/4" right angle connectors, I strongly recommend it!

here you can sort of see how the reversing switch is wired up, as well as the power wires to the 9VDC wallwart that powers the tach

 

[mattthemuppet2]

alright, last few pics. I still need to tape up those motor wires


motor is on that side instead of under the countershaft because the fan pushes air when spun CCW, which I completely didn't think of when I put it on there. That 1/2" belt really struggles to get around that 2" pulley and the join (you can see it on the top pulley) causes a rhythmic thumping - I'll be replacing it with some 1/2" link belt when my wife has a chance to go to HF.

pick up for the take. I'll make a permanent mount at some point, but this works and I have plenty of other things to do first!

I've been using it over the last couple of days to re-true a 4" cast iron backplate and it's working pretty well. You can hear it slow down a bit with a decent DOC but it's easy to fiddle with the speed to get it right. The motor belt was slipping a lot as there's too much give in the rubber isolation mounts, so I need to work on that, but the motor didn't get hotter than I could comfortably touch after 30min to an hours use (ambient ~25C).

A few more tweaks and it'll be perfect! Hopefully the one for the drill press will take a lot less time than this one!

 

[kd4gij]

nice job

 

[mattthemuppet2]

thanks! It's pretty to have finally finished and I learned an awful lot in the process

 

[brino]

Thanks Matt,

That is much easier to read and scroll thru in one clean long post.
I appreciate the great pictures!

-brino

 

[mattthemuppet2]

you're welcome Brino! I'll do the same for the drill press once I get to it.

 

[jpfabricator]

Looks awesome Matt. We will of course expect a write-up on the drill press.

Sent from somewhere in east Texas!

 

[mattthemuppet2]

thanks again Jake, it wouldn't have happened without you! I have all the stuff for the drill press bar the link belt which I'm trying to order from HF right now (won't accept my 20% coupons, grr), the key is finding the time. Semester starts tomorrow and it's going to be full on crazy. Not as crazy as last semester, but crazy enough

 

[Ulma Doctor]

A job well done!!!

 

[mattthemuppet2]

thanks Mike! I still haven't taped up those wires either.

Funny thing in the pics that I just noticed - look at the chuck and spindle in the 1st "live" pic vs. the second. When I wired up the controller I initially had the lathe running backwards and the chuck started to unscrew itself! Thankfully I stopped playing around with it before it did, but whenever I need to reverse the motor I think I'll dial the speed to 0 first before starting it back up again.