What will it take to overheat A victor?

[Andy A.]

In many of my non FIRST related robotics projects I regularly remove the fan from the victor and operate normally without it. I do this to reduce overall hight, weight and most importantly noise. Some projects require up to 12 of the things, and those fans make a racket. My non-first stuff usually has to run for very long durations under continuous draw (albeit less then a typical FIRST 'bot). I have never, since they were debuted, found a Victor that failed due to overheating or experienced any odd behavior as a result.

Let's put it this way- If you manage to overheat a Victor, chances are the motor overheated and failed a long time ago.

I do however keep my victors well spaced and unobstructed, within reason. I do this not for any consideration of cooling but to keep wire runs clearly defined and easy to follow. I've seen some electronics boards, both in FIRST and outside of it, that are very compact but seem just about impossible to work on or troubleshoot. I usually favor ease of repair and understanding over tight packaging. I do agree with what Mike said though, if you aren't pushing the envelope, your not being competitive. It's a balancing act.

-Local

[popo308]

Originally Posted by Andy A.

In many of my non FIRST related robotics projects I regularly remove the fan from the victor and operate normally without it.

-Local

We recently made some off season mini-robots and we ran all the victors without fans on them. They worked fine, the victors never shut down or went up in smoke because of heat. I know that the victors are rated to handle much more voltage. (i believe up to 48 volts??) So at 12 volts its really not hard on the victor at all. It should have no problem running at 12 volts with not fan on.

[vivek16]

An arc welder would do the trick.

In all seriousness though, I/we really don't know, we have never had problems with them over heating... but then again we had them very well ventilated and did not run them longer than 5 min. at a time. (last year's robot consisted of a plywood box with a two wheel drive train... you get the picture)

-vivek

[Andy A.]

Originally Posted by popo308

We recently made some off season mini-robots and we ran all the victors without fans on them. They worked fine, the victors never shut down or went up in smoke because of heat. I know that the victors are rated to handle much more voltage. (i believe up to 48 volts??) So at 12 volts its really not hard on the victor at all. It should have no problem running at 12 volts with not fan on.

As far as I know, the Victor 883's and 884's are rated between 6 and 15 volts. In practice they don't seem to run well at all below 9 volts, and I've run one 883 up to 24 by accident once. It functioned fine for about 20 minutes before I noticed the error. I think, but am not certain, that the older 883's had a higher voltage rating but lower current rating. I still have a bucket of the things that are all over 5 years old and still working fine despite lots of varied use over their lives.

IF does, or has, made some variations of the Victor that operate at higher voltages, currents and/or with out reverse. These are aimed at the combat robot crowd for running big spinning weapons and very large drive motors.

I wouldn't recommend running the Victors with out the fans in FIRST, and I think it's actually illegal to do so. The added cooling probably does increase the Victors efficiency more then the small draw the fan reduces it. If I had the option I might consider removing the fans on Victors running low current motors, like the globe or seat motors. These motors just aren't capable of overheating a Victor, and I'd rather save the weight.

-Local

[Al Skierkiewicz]

Originally Posted by popo308

We recently made some off season mini-robots and we ran all the victors without fans on them. They worked fine, the victors never shut down or went up in smoke because of heat. I know that the victors are rated to handle much more voltage. (i believe up to 48 volts??) So at 12 volts its really not hard on the victor at all. It should have no problem running at 12 volts with not fan on.

Only the 885 is rated for 48 volts and this model is not available for use on FIRST robots. Although the controller may run at 24 volts, the internal voltage regulator may get too hot for continuous duty at this voltage. The 884 and it's predeccessor the 883, are rated for 12 volts continuous duty.

[Pavan Dave]

*wonders if the fans are required by FIRST rules*

[Al Skierkiewicz]

Originally Posted by Pavan

*wonders if the fans are required by FIRST rules*

Not specifically called out as such but... IFI lists the fan as an integral part of the Victor and as such, electrical parts provided in the KOP may not be modified.

[eshteyn]

Personally i have taken off the cooling fan and run 2 cim motors at 40 amps each off of the victor. The victor ran for about 15 minutes before the heat overwhelmed it.

[popo308]

Originally Posted by eshteyn

Personally i have taken off the cooling fan and run 2 cim motors at 40 amps each off of the victor. The victor ran for about 15 minutes before the heat overwhelmed it.

Were the sims stalling at all by chance??
40amps is quite a load

[Richard Wallace]

Originally Posted by popo308

Were the sims stalling at all by chance??
40amps is quite a load

40A is about 50% above the specified normal load for a CIM motor, per its data sheet. CIM motors can operate at 40A for quite a while before they will overheat -- much longer than a 2 minute FRC match. Stall current for a CIM is much higher, around 130A.

[Mike Betts]

To continue Richard's point, peak power on a CIM is at almost 70A. Most "competitive" teams will design so that the 70A point is reached several time in a match (maximum acceleration, et cetera).

[popo308]

On our 06' bot we had a basic 2 sim drive with omni wheels in the front and they went not much more than 6-8 min of constant driving before they were stalling out because of heat. In a actual match this wasn't an issue but in finals or practice they would overheat and cut out.

Are 07' bot had a 4 cim swerve drive and when we were in are low gear and were in a pushing match with another team the motors would sometimes stall out which was causing them to heat up very fast. At ARC we were very lucky that we got enough time between finals that they could cool down.

[popo308]

Originally Posted by Al Skierkiewicz

Only the 885 is rated for 48 volts and this model is not available for use on FIRST robots.

Ok, sorry i was thinking of the wrong model. I knew one of them was rated at 48 volts.

Originally Posted by Al Skierkiewicz

Not specifically called out as such but... IFI lists the fan as an integral part of the Victor and as such, electrical parts provided in the KOP may not be modified.

I would have to agree with Al hear. It does not just come out and say it but it is implied. I highly doubt you would make it through an inspection with no victor fan on.

All in all its not needed unless there is a lot of current draw i suppose. But FIRST does want them on. Its better to be safe then sorry with victors anyways considering they aren't exactly "cheap".