Problem: Motors shutting down

Thank you for your messages. I got the new motors and they are huge compared to those VW wiper motors. I guess that the problem was just a combination of weak wiper motor and Moto Monster's inability to provide them enough (over)power before some protection kicked in. Maybe with different driver those VW wiper motors would have worked. Or Moto Monster with stronger motors.

But your messages are still very relevant, because I think my next problem will be if Moto Monster can provide enough power for those big worm gear motors. They are classified as 12V 23A motors, but I guess I wouldn't have to drive them so hard. Those VW wiper motors would have had pretty much enough power without that problem. But they probably wouldn't have lasted long.

I guess I will first try new motors with single Moto Monster with low PWM. I don't know with how low current those new motors can work with, but I try if it is enough. If it isn't then I will try Pit's way of using Moto Monsters parallel (thank you for that link!) which should be enough. And I already ordered cheap IBT-2 H-bridges for next test if Moto Monsters wouldn't do the job, but I doubt it.

I will report in when I get those new motors installed. Maybe I should have started a project thread, but I guess I will do a "showroom" later. But I'm not sure if my ball rods are strong enough for new motors. I already bent one but I know it would have been stronger if I had adjusted it differently. Would somebody know some good and cheap ball rods from Europe's ebay for example?

Do not to forget to mount any coolers + ventilators onto the Monster Moto. I used for best results Artic Silver Thermal Adhesive. Otherwise you will burn it. I can run my winches at full speed PWMmax and kp at 500. This is not the problem. The weight is the problem which will lifted by the crank. The more weight you want to lift, the more power the motors need to move. So you must stress the motors later by raising the weight by pressing down the crank lever.

To be honest but this is b***s*** . One channel can handle up to 25A continuous, in a dual parallel channel mode the Monster Moto can handle up to 50A.

with Cooling and dual parallel setup at 12 Volt,

MonsterMoto - 50A (2 x monstermoto - $140)
VNH5019 - 120A ($100)

18v25 - 240A ($100)

Still MonsterMoto is more expensive and the weakest of all in any kind of setup.
Also my previous calculations were based on manufacturers specs, and using any product continuously for a long period of time beyond its rated capacity is meant to fail.

I have read that post on using monster moto as a single motor driver a while ago, I wonder why you want to go in to that much trouble when you can simply buy a card that can handle more power, less wires, less connections, less space, cheaper, efficient and less trouble ?

You can get Monster Moto copy really cheap from Aliexpress or Ebay, around 15$. That's why many use them over others. And you won't lose much if you are testing something new and it fails.

Some info copied from the Pololu site (http://www.pololu.com/product/2502) that may be of use...
(Note: the VNH2SP30 drivers are used on the moto monster boards and the JRK12v12 boards)

Quote:
The current-related values in the table below (i.e. the entries to which footnote 3 applies) are the results of tests on only one or two of each driver version, so they do not capture potential unit-to-unit variation, and they were performed using the single driver versions, not the dual carriers. As such, the values should be treated as rough estimates of performance, not as performance guarantees. While these tests seem to indicate that the VNH2SP30 runs a bit cooler—and hence can deliver more continuous current—than the VNH5019, it is important to note that the three driver versions were tested at different times under potentially different conditions, so the results are not necessarily accurate indications of relative performance.

In our tests, we noticed that the thermal protection on the VNH5019 was activating at a lower temperature (153°C) than on the VNH2SP30 (170°C), which could partially account for the shorter VNH5019 overheating times. However, we also observed that the VNH5019 was reaching slightly higher temperatures than the VNH2SP30 when used under the same conditions: the VNH5019 reached a temperature of 85°C after 3 minutes at 10 A while the VNH2SP30 reached a temperature of 80°C.

The following table offers a comparison of the single-carrier versions of all three drivers:

Code:

                                    VNH3SP30        VNH2SP30        VNH5019
Operating voltage: (1)              5.5 – 16 V (2)  5.5 – 16 V      5.5 – 24 V
MOSFET on-resistance (per leg):     34 mΩ typ.      19 mΩ max.      18 mΩ typ.
Max PWM frequency                   10 kHz          20 kHz          20 kHz
Current sense                       n/a             0.13 V/A typ.   0.14 V/A typ.
Over-voltage shutoff                36 V min. (2)   16 V min.       24 V min. 
                                    43 V typ.       19 V typ.       27 V typ.
Logic input high threshold          3.25 V min.     3.25 V min.     2.1 V min.
Time to overheat at 20 A (3)        8 s             35 s            20 s
Time to overheat at 15 A (3)        30 s            150 s           90 s
Current for infinite run time (3)   9 A             14 A            12 A

1 The VNH3SP30 can survive input voltages up to 40 V, and the VNH2SP30 and VNH5019 can survive input voltages up to 41 V, but the over-voltage shutoff will kick in at lower voltages.
2 While VNH3SP30’s over-voltage shutoff doesn’t activate until 36 V, in our experience, shoot-through currents make PWM operation impractical above 16 V.
3 Typical results using the Pololu motor driver carrier boards with 100% duty cycle at room temperature (with no forced airflow or heat sinking beyond the carrier PCB).

Well I think i have to explain my experience, because i've used both Pololu Dual VHN 5019 and Monster motor.

Factory specs:

Yes. monster moto says 14A, but they use the 2SP30. A board with 2 of these, is supossed to handle 28A constant.

Yes, Pololu dual 5019 says 30A, 60 peak. If you look they are very similar specs between both.

Pololu dual 5019 is 60€ at home ( here )
Monster moto from sparkfun is 70€, YES, more expensive and almost the same.

But, the chinesse monster moto is about 25€ incl shipping, has the SAME chip on it, the 2SP30.

My tests:

Burned 3x Pololu 5019. ( this makes about 180€ wasted on it) 1 direction stopped working, other worked. Proper heasink, fan on it. NO HEAT, SMC3 code, PWMmax 120.

Maybe the code nor the pololu is wrong, since the monstermoto works the same way ( 1PWM 2 Dir pins /motor) I think there is a lack of something on the pololu.

I've tried the Chinesse monster moto., 25 €.

WITH CHINESE MM:
Same config on SMC3 util, got more reversing power, no fail on any direction on 5 minutes of use

For now, I think the chinese mm are way way stronger than the pololu dual 5019's.

More tests soon. My first actuator is almost ready.

PS: my motors are the ZYT-90 -155, rated at 23A constant 48 peak, and use a 70A psu.

I cannot affirm that the MM are weak. Since months they are driving my winches and they need very very much power (only for reminding: specs max 120A, normal working conditions current 40A = 480w!!). If I would (and perhaps will) build a 6DOF, I would do it using Arduinos and MMs again. What I confirm as well: the reaction time is insanely fast. There is absolutely no delay. It would be nice if we can come to an end within this discussion and stop persist in saying the MM are weak (and expensive...).

I will prove that with MM. Acually, im building a 6dof with full heave with these....

As i'm a scientific and my mind works like this, I do understand that someone say monster motos are expensive ( if they dont know the chinese one, and numbers say 2 amps less than 5019's for 10 $ more) But I do not understand it, if the chinese one exists, and it is as robust as people has proven here.

I have not very much experience, but the poor experience i have, It seems that mm are way stronger that 5019, and I dont know at what level 5019's are.

It is also hard for me to see the JRK 12v12 pushing more than 30Amps, but if people here do it, why not?

At first I though the chisese mm was not worth. I was WRONG. Not much more to say. But they work nice ( 1 motor /mm )

Jyma, did you solve your issues with the power supplies shutting down? I predicted the exact same problem and used the following item to fix it:

http://www.protoplant.com/power
Look for this item: Power Supply Multiplier with Back EMF Clamp for Single Supply (24-80VDC @15A)

Of course, I am running 24v. Hope that helps somebody!

Pololu and Sparkfun rated specs should be considered second to the specs rated by the chip manufacturer STMicroelectronics.

According to ST, VNH2SP can handle high currents longer than 5019. For some unknown reason Sparkfun have rated MM at half its actual capacity. JRK also uses the same Chip but since it is a single bridge, the board can perform slightly better because the board only needs to handle heat from 1 chip.

@John Hien Nguyen Actually my power supply stayed on when I had this problem. It was the Moto Monster that cut the power. I installed new motors and new Moto Monsters with Pit's setup and added also another PSU. Everything has been working pretty well after it. It's hard to say the real cause because I changed pretty much everything but I think that those wiper motors were mainly just too weak for my build.

I have written about the finished build here: http://www.xsimulator.net/community/threads/2dof-motion-base-for-playseat.5976/