I can report that Bodine 0866 (0865 should work as well - albeit requires a crimper) works well in the grinder. DIP Switch settings are 3,4,5 on.

Did anyone else ever try the Bodine controller on the Bodine motor? http://www.bodine-electric.com/Asp/Prod ... Sort=11399

Edit: Wow. I can actually get the grinder to start grinding with the grind chamber full. The DC motor torque is pretty amazing when driven hard. I am beginning to REALLY like the 0866.

Note: Stalling the motor and starting at full load is not a recommended practice. I was playing with the torque safety setting when I went too far and stalled the motor (current limit kicked in), upping the torque (current) high enough had it started again when it was still half full (about 3A current in). I did not expect it to start and theoretically I could have burnt the motor winding.

Note 2: More interesting is the fact that it didn't slip. I expect it to slip. The old driver board would slip. This one doesn't. Hmm. I'll keep an eye open for slipping.

Note 3: Just ground at 350RPM. No slipping. Light roast. I saw it try to slip twice. But it recovered. I bought the 0866 so I could grind low speed and assumed I'd need the toothed belt. Not so sure anymore...

Just tried grinding at ~100 RPM. It was too slow for the current limit I had set. So it stalled. But it didn't slip. So I upped the set speed. The pulley did a "stop-n-go" and the grinder started again and finished the dose.

I think the belt cannot slip with a speed regulated controller:
When the belt slips, the speed increases.
Back EMF goes up so the controller drops the voltage (to reduce the speed).
Belt reengages, some serious torque is applied, current increases and back EMF drops again.
Controller ups the voltage (remember current is high) and belt tries to slip again.

This cycle happens until it engages, at which point current drops and grinder functions perfectly. This is really cool.

This is a highly recommended upgrade to anyone who owns a Versalab.

BTW - It would make an interesting exercise to profile the safe operating range for this. The controller can do 2.1A (~260W) continuous and peak at a whopping 5A (~650W!), the motor is rated for 1A (but Bodine warn that it as capable of 2.4A - not sure why). So there is a speed under which the current will increase (as the back EMF decreases at low speeds) above the safe value for the motor - one has to be careful to not to go below that speed. A default safe value would be the 550RPM or so set by Versalab during manufacture. Going below this setting is of course risky, and would benefit from measuring the current profile. Of course, this would also depend on continuous vs. intermittent operation.

AssaFL,

I don't own a Versalab so I probably don't fully understand the significance of what your tests have revealed using this controller, but it sounds like it could be a relatively simple enhancement to help with the slippage and stalling problems many have experienced, is this correct?

Do you have any photos of the install? After it has been installed, how do you run the controller?

Thanks for sharing this!!!

Just adding my 2c since there's not a lot out there about these grinders other than some not so positive feedbacks.

For the record I've had my M3 as daily driver going on two years now basically without issue; I've never had stalls, belt slipping, bent wiper... In the past 15 or so years I've owned all sorts of home and full on commercial grinders and really other than some small quirks am happy with the device.

Yes the pop corning is the first major flaw though I simply cut up a plastic lid to fix. And I wish the funnel had at least 2cm more clearance.

AssafL wrote:This post had me take out the Bodine 0866 controller and test it for use in the M3 and this is what I have for now:
1. It fits perfectly inside the Versalab. My hunch is that during the design the 0866 was used instead of the aftermarket board.
2. It has speed control via a potentiometer: it regulates speed almost perfectly (based on the back EMF of the motor), and the level of regulation is also adjustable.
3. It has torque (current) limiting built in:
a. It will stop the motor if a rock falls in.
b. Setting is done with a potentiometer and a set of dip switches.
4. It has some additional features which I don't find useful for the application: Min and max speed, acceleration and deceleration.
5. It is an expensive board (hence Versalab had an OEM make one for them) but they are available on eBay for less than half price ~40$ used to 70$ new.

With the Bodine (if I make it work) it will make the belt safe and speed can go down to 200 or so RPM.

Cool to hear. Would be interested to see pics.

Although if sticking with the stock belt, is there any benefit to upgrading?
As as Versalab board can also do RPM adjustments.

The main advantage with a stock belt is no more slipping even at lower speeds & increased torque. The RPM regulator doesn't allow the belt to slip at any speed. It also fits perfectly in the Versalab.

Also, the torque is tremendous. (If concerned about the motor over heating, remember that the over torque happens randomly during the grind, also, you can set the maximum current with the control). Yes - torque is higher while slipping is lower (boggling - I know).

It is an easy install - 2 powerful Velcro affix the controller inside the grinder body and 6 wires into screw terminals (+ 2 ground wires to the body of the grinder).

It makes sense to me that when John Bicht designed the M3 he used the 0865/0866 as it is stock Bodine. Ordered with the motor.

It was a perfect grinder them (even sans the grooved pulley). Cost issues had him replace the $150 or so controller with a cheaper OEM non regulated driver.

110/220V support, 4 output SCRs,regulation within 1% of RPM by measuring the back EMF of the motor.

Seems like my order of pulleys and belt ( when it arrives) will be put on eBay...

I'll post pics - when I get a chance later.

Administrator - I think the discussion about modifying the Versalab might be better catalogued in a new thread in the grinder section.

Ok - here are the requested pictures. On the right is the Bodine 0866. The screw terminal is at the bottom of the board. The potentiometers are (from bottom) acceleration, deceleration, min speed, max speed, maximum torque (ie. max current), DIP switches for the max torque range and a regulation potentiometer. Switches 3,4,5 are on. There is also a 110/220v jumper near the transformer on the board. See wiring diagram below pictures.

On the left is a previous mod (Automating the Versalab M3). The mod works perfectly with the replacement controller. Apologize for the rats nest wiring...





I didn't take a picture of the wiring so here is the relevant wiring from the 0866/0865 manual (The 0866 has a convenient pluggable terminal block, the 0865 has quick connect lugs). To get the proper rotating direction, the Black motor wire should be connected to A1 and the White to A2.

Wiring list:

• A1 - Motor (Black)
  A2 - Motor (White)
  L1 - 110/220V (Black)
  L2 - 110/220V (White)
  S3 - Potentiometer
  S2 - Potentiometer Wiper
  S1 - Potentiometer
  H2 - Switch (Green)
  H1 - Switch (Green)

Remember to set DIP switches 3,4,5 to ON (the rest should be OFF); Set the 110/220v jumper to the proper voltage. DO NOT touch the regulation potentiometer (or at least mark the preset position of the wiper). It is preset at the factory to regulate Bodine motors accurately.

http://www.bodine-electric.com/Asp/PutS ... 400205.pdf

nickw wrote:Cool to hear. Would be interested to see pics.

Although if sticking with the stock belt, is there any benefit to upgrading?
As as Versalab board can also do RPM adjustments.

After cogitating a bit as to why this works (seems counterintuitive that torque is higher but slips less) - I was reminded of high school physics. Basically - coefficients of friction (remember Sears Zemansky?) - Static (higher) and dynamic (lower) coefficients. When the belt slips, the dynamic coefficient between the cog sets in and the cog spins (hence it accelerates with the non regulated controller). But with a regulator, the controller drops the voltage which tries to stall the motor (as the friction increases) - current goes up, motor stutters, and belt picks up. This will happen until the offending bean relents and the motor picks up and finishes grinding.

To get back OT, I really like the grinder. It does have faults, and it is expensive - but I think it is a great single dose design.