Lakeside focuser getting hot

[Gorr_77]

Hi Everyone,

Recently i've linked lakeside focuser to ML, and after few hr of work, the heat on the motor is quite high. Just wondering if this is normal or i have a problem with power supply...

Regards

[MarkAR]

You could try just running it from the control box to see if there's a difference.

[Gorr_77]

Thanks. i will. I forgot to mention it is running through HiTechAstro V4 box on Hitec cable...

[Skipper Billy]

I would suggest that it's not normal - mine runs stone cold.

[Gorr_77]

3 minutes ago, Skipper Billy said:

I would suggest that it's not normal - mine runs stone cold.

Thank you SB

I thought not... is not like it has to do max out several times or so.... the spacing is good and it has only few steps to adjust...

I shouldn't  left  big  candle lit next to it... t!!!!

[symmetal]

There is possibly an option in the driver to power the motor continuously or only when you want to move it. As the lakeside focusers are well geared down it's normal to only power them when they move. If you use microstepping on the motor then continuous power is needed but the normal detent torque when unpowered is sufficient to stop them slipping. If continuous power is applied they will get warm or quite hot if the driving current is high.

Alan 

[Gorr_77]

You might be on it.....in the V4 menu they are options to run continuously or m-step, and last night i've left it on continuously....hmmm

[Gorr_77]

Hmmm. weird.. running it max in a max out for last 20 min - and is cold.

[TerryMcK]

Mine, like Billy’s, runs cold. When you say you linked lakeside focuser to ML what is ML?

[Gorr_77]

sorry - Moonlight  Focuser 

[Gorr_77]

Last night I've used original control box and no problems at all. 

I will re-connect it today to Hitecastro V4 and will set for continues setting - we will see.

Edited May 15, 2020 by Gorr_77

[symmetal]

2 hours ago, Gorr_77 said:

Last night I've used original control box and no problems at all. 

I will re-connect it today to Hitecastro V4 and will set for continues setting - we will see.

The Hitecastro controller looks to be a generic controller and isn't tailored to specific motors. Stepping motors are intended to work with an optimum current to give the best turning torque without overheating. The controller should vary the voltage applied to the motor to maintain that current. When turning the motor generates back EMF which opposes the force trying to turn it so the voltage applied to the motor is increased to counteract this. Some controllers will also reduce the current through the motor when it detects the motor isn't turning, either by no step pulses applied or no back emf generated, to maintain the holding torque without overheating the motor. If you aren't using microstepping then the holding torque is not usually necessary to keep the motor stationary and the detent torque (resistance to turning when no power is applied) is sufficient to hold the focuser in place.

The lakeside controller doesn't use microstepping as the gearing down is sufficient to give good stepper resolution, so doesn't use continuous power mode and relies on detent torque to hold it in place which is sufficient.

If your driver doesn't have the option so set the current through the motor than some motors will run hotter than others dependant on the motor winding resistance.

In your situation I would disable the continuous mode operation in the driver and things should stay nice and cold. It's likely that it doesn't reduce the current in continuous mode operation when the motor is stationary. 

Difference between detent torque and holding torque

Alan

Edited May 15, 2020 by symmetal

[Gorr_77]

2 minutes ago, symmetal said:

In your situation I would disable the continuous mode operation in the driver and things should stay nice and cold. It's likely that it doesn't reduce the current in continuous mode operation when the motor is stationary. 

thank you Al,

I do intend to use step...i was just curious why the Lakeside mtor was hot that particular night.

[sloz1664]

The continuous power mode is used in the likelihood that you have focus slippage issues and helps "lock" the motor in position to prevent slippage. With your Lakeside having a high torque gearbox & a ML focuser you don't need to have the focus motor energised constantly.

Having built three autofocusing units I came across this issue and upgrading to higher quality focusers eliminated the need to have the auto focuser permanently energised. 

Steve

[Gorr_77]

....so.... last night i've put the focuser - through the HT V4 - in the cont mode, after starting the sequence : focus on start : it started to focusing out.... few minutes later - it overheated. maxted out and focused in . I've restarted the HT V4 (power, exit) and it started saved settings, step mode - all back to normal.