Hi Mike,
Great job !
Have you ever tried these covers in hot weather ??
Just wondering if the motor could heat up? with this cover.
But I really don't know if this type of motor really heat or not...
Another question : I have no 3D printer => I would buy it on line though 3D printers online. But when I open the .stl file, I can't see the units. Are the units in inch or mm ?
Thanks for your replies
Rapha?l

Nice cover Mike. I'm going to try one out.

BC

Have been meaning to post this in the group for a while now.

Designed this cover in TinkerCAD. I wanted to provide some protection for the ALT motor, but also decided to put one on the AZ motor.? Just slips over the motor.

The .stl file is downloadable from Thingiverse: https://www.thingiverse.com/thing:6117144

I feel the SC is pretty well protected - as mentioned, it sits in the bottom of the rocker box with only the front end exposed.?

I have just the rocker box in the workshop right now.? My plan is to put the SC in EasyTrack mode and let it run for a day with the original cables while keeping an eye on it.? If that fails, then start the cable-swapping exercise.

Thanks for the tips.? I'll post any enlightenments!

Werner:

Send an email to bill at servocat dot com.

BC

Mike,?

Super! Congrats and good job. Although in general the components absolutely should not be corroding there are differing environments that do indeed have much higher prolonged humidity. The cables and their contacts all use gold plated components. Also - do you have it with the cover in place? If not I'd suggest that had a compounding effect. Where is it stored generally??

As for testing for the problem. First the fact that the motor runs away when you remove the cable says nothing about anything! This is normal and expected. The cable, which carries the motor encoder signal is absolutely required - remove it and the motor by necessity will run away! This alone doesn't suggest anything. But - if the run away happens when the cable is plugged in it is, as noted previously, one of those 3 causes and the cable is the most likely. That stated it is still very rare to have any cable fail. But it happens. Based on your description of mold I'd say it has a higher likelihood - although the jack itself would then fall in to that suspect category as well.

Back to testing: the test I described is the best way to determine where the cause is. If by swapping cables the problem moves to the other motor then it is the ServoCAT - the original axis system internally. If it does not move then it is the original fault axis cable or board/encoder. You can further pin it down IF the cables are removable (or like in your case you can make another one up) and you can then try a different cable on that axis to determine, (assuming that the new cable itself is good) either the motor itself is bad or the original cable is bad. If the former the motor assembly would need to be removed and sent in for Bill to replace the motor encoder module. These are very reliable but do occasionally fail.?

Have a good weekend! Enjoy.

Gary Myers?

Hi Gary,

First - there is life!

I was referring to the internal power LED.? All switches are in the up position, and only the power was connected.

But there is life, so this is good!? Poking around with the multimeter I rechecked the fuse yet again - the fuse was good as before, but then the probe slipped into a position along the fuse holder and the fuse and presto - the internal power LED came on.?

Turns out the fuse and fuse holder were corroded - see the first photo.?? I cleaned those up nicely with DeOxit :) and I can now get back to the original issue.?

I've done as suggested - swapping AZ and ALT cables and checked slewing from the hand controller.? All works as expected.

I suspect the AZ encoder cable as well (especially since unplugging it causes the AZ motor to spin up). For whatever reason I get what I think is mildew or mold in and around the rocker box.? The cables, especially the grey ethernet cables, get black spots on them, which cleans off easily enough with cleaner on a rag.? When I inspect the RJ jacks on the SC, there's crud in them sometimes. ? See the second photo - that's the remote jack on the back of the SC and is not used, so it's exposed all the time.? Being in WI we have damp dewy nights a lot - I think I will need to start setting the scope on something rather than just in the grass.

The SC sits in the bottom of the rocker box, just the front pokes out on the back side of the box, so it's not overly exposed to the elements.

So I think I'm back in business.? I've cleaned the cables, but will probably just replace the AZ encoder cable (I have a supply of 4P4C ends, flat cable, and crimper).??

Is there any other testing to better confirm the source of the random free-running AZ motor?

Thanks!

Note additionally. I don't like it when people suggest things like "'de-oxy' the pins on all cables". It's not too unusual for issues to show when people do this. Unplug all cables to the ServoCAT leaving only the power. Try that.?

The issue you were seeing is ONLY going to be in the AZ motor encoder system itself. So the AZ motor encoder components on the board, the AZ motor encoder itself, or the AZ motor encoder cable. With the latter being most likely and the others not very likely. Once the led's are restored to normal - assuming you can get that to happen there - you can plug the ALT motor encoder set (its TWO cables) into the AZ motor inputs and vice versa. See if the ALT UP/DWN buttons properly control the AZ motor to accelerate/run/decelerate when pushed... and the AZ CW/CCW controlling the ALT motor (disengage both axes for this test, be sure to run at SLEW speed).?

g.

?

Mike,?

First it is highly unlikely you've damaged it - at least not to the "brick" state. IF there is anything going on it can be repaired.?

First - when you say the power led - are you talking about an internal one, one on the board itself? If not, if the front panel LED's... do you have the 2 outside switches on the front flipped up - the EStop and the LED? If you don't have this - do this and re-connect power.?

Next check the upgrade switch - is it on the NORM side, 'clicked' in that position??

Is the red daughter board plugged in all the way? Look at it from the side to confirm the pins are all the way seated. Don't mess with it if they're nearly out, get back if that is the case.?

Send that info - we can go from there. If it needs to be looked at and then repaired you'd end up sending it to Bill at BBAstro.?

Gary Myers

I think I killed my ServoCAT. ?I believe it's a Gen 3, purchased 02/2011. The power in is 13.2v, the fuse on the PCB is good, and the voltage reads 13.2v on both sides of the fuse. ?The power LED does not come on.?

I was investigating a runaway AZ issue (see long history description below) and I found that disconnecting the small cable (encoder?) from the SC would let the AZ motor spin up to high speed. ?It was suggested that I clean the cable ends and jacks with DeOxit (the small bottle with the brush). ?After putting everything back together there is no life. ?And I've checked and rechecked all connections.

Is there anything further I can test with a multimeter? ? Do I have a brick or is there a diagnosis that someone can do?

Thanks!

Now for the description that got me to where things are at today...

Last fall I had a few incidents where the aligned and tracking dob just started slewing clockwise in azimuth - max slew. ?Flipping the 'stop' switch did not help, I was able to disengage the AZ clutch and then turn off the power at the battery. ?After turning all was good - no slewing. ?I was able to re-align and keep observing.?

In a second occurrence, the dob started slewing for a couple of rotations and then stopped and behaved normally - no loss of alignment.?

A third time I had aligned the scope and did a goto. ?I disengaged the AZ clutch and then went away for about an hour to give a presentation. ?When I returned the battery was too low for the scope to operate.

No problem. You can power the ServoCAT off of 11 - 16V. NOTE however other accessories, that might be connected to the PGB Power distribution rail, might not be able to handle this voltage!?

Also note that the ServoCAT has 3 internal switch mode power supplies and actually the system will run slightly more efficiently at a higher voltage (say power - less current draw which means less I^R losses in the wires). The power supplies that I sold for years were rated at 15V.?

Gary Myers
StellarCAT

[and if you only needed to upgrade the firmware or download parameters with the ServoCAT separated from the scope you can actually power it to do this from a standard 9V battery!]

开云体育

I have a related question. ?Over time will these springs loose their tension?

Mike

Any problem running my ServoCAT from a 14.4v battery?

Thanks,

Eric

开云体育

Hi,

Ive a quick questions, I lost the altitude tension spring for my goto system.

Can I ask whats its length /specs?, so I can get another one off amazon maybe ?

This is for a 15" classic obsession.

?

Thanks,

Dave.

Please send an email to support at servocat dot com and we will provide a new cable.

Regards
Bill Conrad
BRC Astro LLC
ServoCAT

My club has a 30”Obsession scope. ?The altitude drive cable is frayed and needs to be replaced. ?What size and type of cable do we need?
thanks!