# How to determine DC servo motor voltage

• posted

I have this Troyke CNC rotary table with a DC servo motor.

The nameplate is missing.

Thus, I do not know what is the nominal voltage of this motor.

How would I measure that voltage?

My own plan was, to take the motor off the rotary table, apply increasing voltage, and watch the RPM. When RPM reaches 2,000 RPM, (or some other speed that should be safe for any imaginable servo motor of ths kind) write down the voltage and consider it the nominal motor voltage.

This way I will probably be safe, right?

Any idea how to find out max amps?

i
• posted

I guess I would go about it the opposite way. I would power up the motor with a variable voltage supply. Then starting at 12 volts, judge if the table is rotating at the speed I want. Then if not, raise the voltage somewhat and repeat the test. Continue up to not beyond 32 volts. The motor should not heat up enough to be detectable to the back of your hand. Most of your table use will be short term movement, minutes, not hours.

Paul

• posted

The motor does get about as hot as my body temperature (I would say

100 degrees F) when run at 30 or so volts. That is not too hot in my book. The table, then, turns at a visually acceptable rate. I am not looking to build a crazy Ed Huntress type rapid production facility, with red hot chips flying all over my garage, so I would guess that stopping at 30-40 volts will give a perfectly acceptable result. i
• posted

Why not simply call Troyke?

11294 Orchard St., Cincinnati, Ohio 45241 p: 513.769.4242 ? f: 513.769.6362

Beepboobbeeeepbooop

Simple really.....

Gunner

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

• posted

2000 RPM is a good conservative number. Small, high performance servo motors are usually rated around 6000 RPM. Perhaps a bit more for brushless motors, less for brushed.

Continuous current is generally limited by winding insulation and heat dissipation; peak current by the magnet material. The peak current for motors with inexpensive magnets is typically 2 or 3x continuous. The ratio for fancy motors with magnets that are more resistant to demagnetization may be 7:1 or greater. The motor's proportions and construction may be the best clues.

• posted

They have no info on this table. I called them twice.

i
• posted

• posted

OK, good to know that 2,000 RPM is generally safe. This is a very plain looking brushed servo motor.

OK. Interesting. I ran this motor for 15-20 minutes yesterday, turning the rotary table at 30 or so volts (I do not remember if it was 30 or

20).

The current was 3.something amps. I tend to explain this by the fact that the worm is preloaded and thus hard to turn. I will take the table apart to find out more to see if there is anything blocking movement.

Anyway, three times that is 10 amps.

My guess is that this is a 10 A, 80v motor. I will measure it better tonight when I take off the encoder cover.

i
• posted

Really?????

Thats rather odd. Someone bought Troyke tables and modded them then.

Interesting

Gunner

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

• posted

Sorry..must have missed that post.

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

• posted

I personally do not think so. The nameplate is Troyke's.

i
• posted

Yes the nameplate on OmniTurn CNC lathes collet closers say Dunham as well.

Though Dunham doesnt have a clue about OmniTurn lathes.

Troyke has been in business for a very long time. Its odd that they dont have any info on their own tables, if they did the conversion.

But..shrug..it is possible.

Gunner

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

• posted

They acknowledged the model and serial, but could not find anything.

i
• posted

I assume that you mean max continuous amps. That is a matter of the insulation class of the motor. The most conservative common class has a rating of 100 degree C over ambient, IIRC. You can Google it.

So to determine the max current, you lock the rotor and apply increasing amounts of current until a steady state 100 degree C increase is found. The temperature is determined by measuring the resistance and using the R(T) function. You can Google that too.

Bob

• posted

I wonder if it is a case of after a point in time, they just don't want to deal with it.

For example.

Those files were on their website years ago. I looked recently and there was nothing. The site seemed fairly broomed of older stuff.

That is my table, big and heavy, an inch or two higher than rotary tables today and it doesn't mount right angle. I'm still waiting to use it. The day will come eventually.

Wes

• posted

nothing. The

I wish I had these manuals (esp. the first) a year and a half ago.

I have not used one either up until now, but I think that I will use it, once I set it up for 4th axis. Just doing hex ends and stuff would be good.

i
• posted

Possibly, but that's a poor policy since maintaining an "obsolete documentation" section in their support area uses very little resources and provides good word of mouth promotion.

Kohler of engine, toilet and golf resort fame (yep, really) seems particularly good at support of old stuff. I emailed them about the engine in my old lawn mower at about 3pm one afternoon and about 9:15am the next morning I got an email back with links to the full pdf owners, service and parts manuals for this 32 year old engine.

• posted

deal with it.

nothing. The

This is a manual table.

W
• posted

deal with it.

Yup. If, as a struggling whatever, you find some support on the way up, when you make it into the big leagues, you will have a favorable opinion of the firm. That often equals sale\$.

Clausing for example, still supports their older stuff and will sell you a print if the item is something they no longer stock.

Wes

• posted

The old Kohlers were made so well, they are just now starting to need parts.

Karl

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