Saving an old mount.

[xelasnave]

I have a Meade lxd 55 goto mount and a dud paddle.
I sneaked it into a repair job with other "normal" items for repair with a guy who fixes tvs.
I dont hold much hope of repair and I wont buy another if indeed you can find one...however my thought is..wire the motor direct with a "volume" control"☺ er potentcheometer I think however its spelt☺ such that I can dial in the ra to track ...polar aligned well would see this unit, with the dec assembly removed and a fitting to hold the camera a handy thing... I made one with another mount which is not goto but am having motor problem due to its hand paddle...a pre goto sold as a eq5 ... way before the newer ones...
Anyways can I do what seems like a possibility.
Alex

[xelasnave]

Here is the one that I am working on, not the meade, but you can get the idea of removing the dec assembly...the camera moves thru dec and fixed for the target. Neither mount was flash but should by ok for wide field.
I like wide field and it would be nice to have something like this running while you are out there for a specific yarget with the main scope...or for those nights where you dont feel like a long set up as hopefully it will handle up to 200 mm fl...and I am making another bracket so I can mount two dslrs...anyways it would be nice to get them functional.
Alex

[bojan]

Originally Posted by xelasnave

I have a Meade lxd 55 goto mount and a dud paddle.
I sneaked it into a repair job with other "normal" items for repair with a guy who fixes tvs.
I dont hold much hope of repair and I wont buy another if indeed you can find one...however my thought is..wire the motor direct with a "volume" control"☺ er potentcheometer ....
Alex

Alex, not likely :-)

Motors are steppers and they can't be wired to "volume control pot" just like that...

If your friend can't help, I may be able to.

[xelasnave]

The above mount I pulled down ..even the gear box on the motor and cleaned it lub with olive oil and it is rather reasonable so far.
Alex

[bojan]

Originally Posted by xelasnave

Here is the one that I am working on, not the meade, but you can get the idea of removing the dec assembly...the camera moves thru dec and fixed for the target. Neither mount was flash but should by ok for wide field.
I like wide field and it would be nice to have something like this running while you are out there for a specific yarget with the main scope...or for those nights where you dont feel like a long set up as hopefully it will handle up to 200 mm fl...and I am making another bracket so I can mount two dslrs...anyways it would be nice to get them functional.
Alex

You need something like this...

[bojan]

Originally Posted by xelasnave

The above mount I pulled down ..even the gear box on the motor and cleaned it lub with olive oil and it is rather reasonable so far.
Alex

Surely not olive oil????
Use green Lithium grease for that.

[xelasnave]

Originally Posted by bojan

Alex, not likely :-)

Motors are steppers and they can't be wired to "volume control pot" just like that...

If your friend can't help, I may be able to.

Thanks Bojan.
He is also looking at the paddle for the non goto.
It seems to me that the problem is with the on/off switch....ot ran for hours but when I yried later I had to jiggle the switch until finally no responce..I was going to solder the switch out by putting a wire on the board side...and use the power plig as switch on..it only has to run in ra...one speed..no need for controls.
Thanks again.
Ot will be interesting to see if this guy can fix it...I am hopeful of using this set up on m31. ...30 second captures approaxh.
Alex

[xelasnave]

Originally Posted by bojan

You need something like this...

Yes. Great you know what I am about.
It is a shame that these mounts sit around and two cameras...if I can combine images from the old canon and the new nukon I will have two eyes in my draggon fly.
Should buy that modded cam and dedicate it to ha...
Alex

[xelasnave]

Originally Posted by bojan

Surely not olive oil????
Use green Lithium grease for that.

Yes but I cant find it...however it will do the job until next pull down.
I like using oil over grease anyways.
Alex

[RyanJones]

Originally Posted by bojan

Alex, not likely :-)

Motors are steppers and they can't be wired to "volume control pot" just like that...

If your friend can't help, I may be able to.

I'm going to add to this because one thing that generally frustrates me is when people say that things can't be done but not why. ( no disrespect intended Bojan )

They use stepper motors because they require a given number of pulses to complete a rotation. These pulses can then be measured over time to give a correct slew rate. A potentiometer ( volume control ) is effectively a variable resistor. For this to stay accurate you would need to supply the exact same voltage and current and have no change in the load on the motor. Almost impossible to do accurately enough without a whole lot of extra electronics.

Good luck with the resurrection of the mount Alex

[bojan]

Originally Posted by RyanJones

.... can't be done but not why. ( no disrespect intended Bojan )...

Alex and I are good mates for a long time (I hope this feeling is reciprocated).... so I felt I do not have go too deep into technicalities at this instance, instead I offered direct hands-on help with this.
I even have spare electronic circuits (the same as described in the link I provided), which I can give him (gratis of course) if he chooses to accept my offer.

So.... no worries.

[RyanJones]

Originally Posted by bojan

Alex and I are good mates for a long time (I hope this feeling is reciprocated).... so I felt I do not have go too deep into technicalities at this instance, instead I offered direct hands-on help with this.
I even have spare electronic circuits (the same as described in the link I provided), which I can give him (gratis of course) if he chooses to accept my offer.

So.... no worries.

I totally understand Bojan and as I said, I was in no way being disrespectful. I just think it is handy for anybody else reading the threads to be able to understand why. I'm sorry if I have butted in where I shouldn't have but I guess this is just the first thread where I've voiced this opinion.

[xelasnave]

Originally Posted by RyanJones

I'm going to add to this because one thing that generally frustrates me is when people say that things can't be done but not why. ( no disrespect intended Bojan )

They use stepper motors because they require a given number of pulses to complete a rotation. These pulses can then be measured over time to give a correct slew rate. A potentiometer ( volume control ) is effectively a variable resistor. For this to stay accurate you would need to supply the exact same voltage and current and have no change in the load on the motor. Almost impossible to do accurately enough without a whole lot of extra electronics.

Good luck with the resurrection of the mount Alex

Thanks Ryan.
I thought what you said would be the case as I figured these circuits were there for a reason.

I think you may be able to do it with a volume control but you would have to in effect manually guide it...which is a pain and not easy to get right...but Bojan has my back I am happy and grateful to say.
First I wiat to see what if anything can be fixed ..it only need one mount..each requure a different approach and will cross that bridge when I come to it.

But I really have been thinking of adding at least the second camera as I went outcearlier and the trees are closing me out here I think less than an hour on a target☺
Alex

[xelasnave]

Originally Posted by bojan

Alex and I are good mates for a long time (I hope this feeling is reciprocated).... so I felt I do not have go too deep into technicalities at this instance, instead I offered direct hands-on help with this.
I even have spare electronic circuits (the same as described in the link I provided), which I can give him (gratis of course) if he chooses to accept my offer.

So.... no worries.

Yes mates and yet to have that beer.
The experience had me actually looking at the circuit and yrying to work out what was going on...I was almost going to try and replace the switch that required soldering ... something I once did on big stuff ...new to new relatively...learning new stuff...
And you wont believe..I purchased a little dingy which I am converting to a camper sailer to keep busy☺
Alex

[Paullus (Paul)]

Hi Alex,

I've had a slightly similar issue with my LXD75. A few years after purchase the motors clapped out (probably the circuitry more likely). Long story short I purchased a Skywatcher EQ5 dual axis drive kit (no goto) for just under $250 AUD at the time from 365Astronomy. You're probably looking for a cheaper fix but this is a viable option to consider. I used it for the first time last month on Fraser Is with guiding for widefield; worked well.

If you're interested I have the LXD75 motor units and the directional controller/paddle sitting a box taking up space. The motor units I wouldn't trust (no/uncontrollable slewing at times) but the paddle should be ok. PM me if you'd like me to send any/all of it your way.

Cheers

[xelasnave]

Originally Posted by Paullus

Hi Alex,

I've had a slightly similar issue with my LXD75. A few years after purchase the motors clapped out (probably the circuitry more likely). Long story short I purchased a Skywatcher EQ5 dual axis drive kit (no goto) for just under $250 AUD at the time from 365Astronomy. You're probably looking for a cheaper fix but this is a viable option to consider. I used it for the first time last month on Fraser Is with guiding for widefield; worked well.

If you're interested I have the LXD75 motor units and the directional controller/paddle sitting a box taking up space. The motor units I wouldn't trust (no/uncontrollable slewing at times) but the paddle should be ok. PM me if you'd like me to send any/all of it your way.

Cheers

Thanks I really appreciate your post and kind offer.
First step is to determine if the fix it guy can fix it.
He hasnt rung and I will give him a littlevmore time before I ask if he has looked at it...anyways its cooking ... have to wait for the next decision gate.

I sure appreciate everyones input..I dont feel like its a problem now but just something that will become useful with a little more effort.
The prospect of using this set up for two or more cameras has really had me thinking given there is a program that can marry photos from different cameras...what was it ? Must get it and try it out.
Alex

[xelasnave]

Well its back.
He claimed that he fixed it but I think I have paid $40 for the priveldge of being conned as it does not seem to work....in fact I very much doubt he even opened it.
I was going to go back but I think I would be in for more of the same.
The loss has been taken and I wont add getting upset or worse by going back.

I have decided not to worry about the Meade mount.

However Bojan I plan to send you a PM to investigate what could be done.☺
I put a photo here as I dont think pms carry photos.
Alex

[bojan]

Originally Posted by xelasnave

Well its back.
He claimed that he fixed it but I think I have paid $40 for the priveldge of being conned as it does not seem to work....in fact I very much doubt he even opened it.
I was going to go back but I think I would be in for more of the same.
The loss has been taken and I wont add getting upset or worse by going back.

I have decided not to worry about the Meade mount.

However Bojan I plan to send you a PM to investigate what could be done.☺
I put a photo here as I dont think pms carry photos.
Alex

Hi Alex,

Yes, by all means please do - just post it to me.

I will try to fix it for you (of course, depending on root cause of problem and availabity of parts - and gratis as I mentoined earlier).

[bojan]

Alex,

After very careful look at your handpad, I have not so good news for you - it is the processor that behaves erratically, upon power-up sometimes it starts properly but more often it doesn't - usually it just hangs, which (again sometimes) results in high current (basically short) through stepper driver transistors. I checked the reset circuit (which was my prime supect after initial look) but it works OK, all supply voltages are OK... so basically that's it.
(This handpaddle has no protection from overvoltage - no voltage regulator - so theoretically processor could be damaged by applying higher (12V) voltage... any chance of that happening in the past?)

Motor you send me is OK.

My next step with this will be to try to read processor's firmware and program the new one (I have couple of them from previous projects), but I don't put much hope in the positive outcome of this as it may be unreadable due to damage and besides, usually processors are protected from reading by manufacturer, in which case the only way would be to find the same hand paddle with working processor as replacement.

I may have another solution for you as well - I was planning to totally overhaul my LXD75 (new electronics, new motors), so I will be ending with surplus of those.
I haven't finished that 100% yet (as is visible here, I am still using the same hand paddle with processor clock multiplied by 5 to match the added belt transmission) but reversing the mods back to original and giving it to you would promt me to fully implement OnSTEP controller, new motors etc. However it may take me some time to undo the mods.

Another option for you would be to do the same, of course. Again, it will take time.

So.. let me know your thoughts

[xelasnave]

Well first of all thanks for looking at it Bojan.
Although its possible I connected 12 vlt I doubt it.
It sounds as though it really is not worth the effort you need to put in.
Perhaps set it aside and we can think about it but all I can see at this stage is to throw out the box and you keep the motor for one of your projects.
Alex