DIY powerfeed

[Skidoojustin]

Hey all, I need some help. Im building a power feed on my lt15 using a wheelchair motor and a drum and cable, much the same as the rope feed and crank it originally came with. The motor is off a jazzy 1120 power chair and is a fairly large motor. Running on 12v. 
The problem I'm having is the saw head only starts to move a 90-95% and is wide open at 100% which is making the saw head hard to control. 100% is much to fast. I'm using a 10-55v 60amp PWM. Is it because I'm running 12v instead of 24v or is something wrong with the PWM. Most videos of power feed builds, the saw head will start moving at 30% or so on the PWM. Any help much appreciated.

[barbender]

Was the Jazzy motor designed for 12v or 24v?

[Skidoojustin]

The power chair was 24v. The motor itself doesn't say. Model number on the motor is E675

[ladylake]

  If its going way to fast try gearing it down.  Steve

[Magicman]

Before trying to otherwise control the motor speed, I would match the motor to the correct voltage.

[fluidpowerpro]

This guy used a jazzy wheel chair motor.

https://youtu.be/AMGNQrd_yXw?si=nwW8BcTbEn-6mWZu

[jpassardi]

I made the same setup for my LT15 and it works well. Jazzy motor (not sure if same model)  running on 12V and the 60 amp PWM. The drive pulley is about 4". I can slow it down more than enough. What size pulley or sprocket are you using?

BTW: I had to replace the cheap rocker switches that the PWM comes with.

I use a dump truck tarp gear motor and a PWM to run my up/down.

[Skidoojustin]

I'm very interested in seeing your setup. Im hoping to spend some time this weekend trying to figure this out. The motor is running plenty fast on 12v at 100% the return is about right. Just having trouble controlling it with the pwm. The motor is a drvmotr1116 hi-speed. Model # E675. When I turn the pot the motor only starts turning at about 90-95%. I'd love to see pictures of your setup.

[never finished]

I set mine up to saw in reverse and gig back in forward. They tend to reverse slower.

[ktm250rider]

I have a similar issue running my motor at 12v.  Im wondering if its the motor age as it was purchased used through Ebay.  Im also running a reclaimed from the dump battery which doesnt hold a charge for too long.  If i hook my jump box the motor seems to have more control.
I did just learn about 12-24v up converters that i need to wire in and see if that helps.

[fluidpowerpro]

I was watching a u tube video this morning of a guy that used the wheel chair motor for his power feed. In it he comments that "it worked a lot better" after he went to 24V. He didnt elaborate any on the "better" part. He pointed to a 12-24v step up boost unit he had installed. I did a search on ebay and saw what looked like the unit he used. Its a unit intended for use on golf carts. Its only rated for 10 amps which in my mind would be suitable for charging, but it seems small for a drive. Its only $18.00.

Sorry.. going off board a little here, the reason is that my mill will come into the shop shortly for winter upgrades. 
This year one of the items on my list is to add power feed. 
Reading this thread has given me concern that although some people have had success running on 12v, I think 24v would be better. I suspect thats why some arent getting much range of speed adjustment that is desired. For that reason I think Ill use a 12-24 v boost unit. 

These are the 2 voltage booster units noted above. 

The cheaper one that the U tube guy used.

https://www.ebay.com/itm/146042169822

The one I plan to use.

https://www.ebay.com/itm/176063233068

After some time using my mill I have found that although I can get something to work, it becomes a matter of how long. 
Although I do saw for hire, I'm not hardcore like others. I put about 100hrs a season (May thru October) on my mill. Even at that, I have found reliability of components can be an issue so I will spend a little more on a heavier duty unit, even if I have found the lighter duty will work.

One example is the PWM units. For my raise / lower winch, I started by using a unit rated for 30 amp continuous / 60 amp intermittent, and it works fine, but not very long. I found I would have to replace them after about 30 hrs of use. I have since switched to one rated for 60/100 and so far it has lasted a year with no issues. 

Thats my plan for the power feed.
I would welcome any comments from others that have experience in this area.

[jpassardi]

Here is how I did mine:
Not sure which used Jazzy motor it is but I have a couple hundred hours on it run by the 60 Amp PWM & 12 Volts. No issues other than replaced the cheap rocker switches it comes with.
I kept the original rope/pulley setup the LT15 crank used. At some point I plan to upgrade to chain/sprocket drive because it can slip if rope is wet.
I used a PVC electric box and made the front label in AutoCAD and laminated it.
As I noted above, the up/down I made uses a dump truck tarp motor also run off a 60 Amp PWM and 12 Volts.
Both work very well and adjustability in speed is key.

Edit: Forgot to mention I placed limit switches on the carriage to stop it at max travel distance going forward and in reverse.

[ktm250rider]

I got the cheap one, still in the box waiting to install.

[fluidpowerpro]

I'm anxious to hear how it works.

[jpassardi]

Like I said, the only issue for me was the rocker switches failed so I replaced them with HD toggle switches.
One annoying thing with those PWM's is that they use tiny wiring to the switches so a pain to terminate and are fragile.

[ktm250rider]

Like I said, the only issue for me was the rocker switches failed so I replaced them with HD toggle switches.
One annoying thing with those PWM's is that they use tiny wiring to the switches so a pain to terminate and are fragile.

yeah, my master switch just broke this weekend! 

[fluidpowerpro]

Have you ever found that the ability to slip is a good thing?

One thing I have concern about is what happens if the mill hits an obstruction. When I'm pushing the mill by hand I feel it and can stop to see what the issue is.
With power feed I wont be able to feel it and worry that bad things could happen.
Im planning on including something in my design to sense an obstruction before any damage is done. One idea is to mount the idler sprockets in some sort of swivel set up that is spring loaded. If the mill hits something the chain tightens and the idler swivels and then trips a switch.

[jpassardi]

FPP: You're on the right track - Yes, I have found that useful. That's one of the reasons I haven't yet gone to a sprocket/chain setup. Though, you should be right near the controls when feeding anyway.
Mine will slip if I run into something like a barnacle I need to trim which is good. The downside is it sometimes will tear up the elastic band I super glued to the pulley for rope traction. Not a big deal, happens rarely, scrape it and glue another on quick but it is a short delay.
What you're proposing could be done with one of the same limit switches wired to the feed side of the PWM. The key will be getting the right spring rate.

[rusticretreater]

I was watching a u tube video this morning of a guy that used the wheel chair motor for his power feed. In it he comments that "it worked a lot better" after he went to 24V. He didnt elaborate any on the "better" part.

A motor can operate at both 12 and 24 volts by being designed with an internal winding configuration that allows it to adjust its current draw based on the applied voltage, meaning the motor can handle different voltage levels without damage. Running at a higher voltage will generally result in increased speed and power output.

[doc henderson]

Mine drives a chain and sprocket with a hydraulic motor.  if it hits an obstruction like a loading arm up to high, it pulls the motor a bit and bypasses at the valve. so, I hear it and stop.  it does not wreck anything on the mill.