HELP: NEQ6 Dec Worm Adjustment

[Peje]

Hi All,

I'm aware there are MANY topics on this but I can't quite find what I'm looking for. I recently had someone locally belt-mod my NEQ6, all seemed well until a couple of nights ago I noticed the dec motor binding. I had a play with it tonight & it was a little odd, it seemed to work ok then after a few minutes of rotation it would bind up.

I started fiddling with the adjustment but wasn't not getting anywhere with fixing it by minor adjustments, then I got frustrated and went for large adjustments so now I need to start afresh in terms of their adjustment as I have no clue where it's at.

Looking at guides it seems the best approach is to start with the casing (and axis) pushed upwards, giving the least engagement possible and gradually work downwards (loosening top screw, tightening lower screw. Does anyone know if this is the correct procedure? 

At the highest point, should there be any engagement at all?

Thanks in advance,
Pete

[david_taurus83]

Have you followed this procedure:

 

http://www.astro-baby.com/EQ6 rebuild guide/EQ6 worm alignment.htm

 

Its pretty much the go to procedure and works well. Are you sure it's not a lack of voltage? I've adjusted my RA axis before and you have to rotate the axis fully in each direction after each adjustment. If your satisfied you think you've nailed it then rotate both axis fully at full speed at the same time to make sure your PSU is providing enough volts. I found this out myself. If power is too low then one or both motors will let you know their upset!

[Peje]

1 hour ago, david_taurus83 said:

Have you followed this procedure:

http://www.astro-baby.com/EQ6 rebuild guide/EQ6 worm alignment.htm

Its pretty much the go to procedure and works well. Are you sure it's not a lack of voltage? I've adjusted my RA axis before and you have to rotate the axis fully in each direction after each adjustment. If your satisfied you think you've nailed it then rotate both axis fully at full speed at the same time to make sure your PSU is providing enough volts. I found this out myself. If power is too low then one or both motors will let you know their upset!

That's the one I'm looking at, it seems to be starting with the cover down at the bottom and working up towards some free play. I'll maybe try that first, head is pretty pickled trying to figure out what way to sort it.

You're comment on power is very valid, I'm using a 10a 13.8v block so I should be OK.

One bit I wondered about was loosening the worm end float adjuster, mine is tight from when the belt-mod was done. Should this be loosened before adjustment? If yes, will this mess up the spacing between the casing and the belt pulley? I guess it could be that these are too tight and causing the mount to bind

Edited July 17, 2019 by Peje

[spillage]

Yes undo the screw nearest the worm and wind the screw furthest from the worm out. to disengage the worm and in to engage. From memory you wind in the top grub until you start to take the play out of the up and down movement of the casing. tighten up the four allen key bolts and bottom screw run it 360 and wind it in some more. You will get to a point where it will bind. Mine did in one spot. wind the screw out 1/8 of a turn and test again. I would suggest you attach you scope when slewing to ensure it is not binding under weight.

 

Leave the float adjusters alone for now if tight.

 

If I recall once the worm is near enough it can be a balancing act between the worm and float adjustment. I am sure mine is not 100% but I do average 0.6-0.7 and have had it down to 0.4 when guiding.

Edited July 17, 2019 by spillage

[Peje]

6 hours ago, spillage said:

Yes undo the screw nearest the worm and wind the screw furthest from the worm out. to disengage the worm and in to engage. From memory you wind in the top grub until you start to take the play out of the up and down movement of the casing. tighten up the four allen key bolts and bottom screw run it 360 and wind it in some more. You will get to a point where it will bind. Mine did in one spot. wind the screw out 1/8 of a turn and test again. I would suggest you attach you scope when slewing to ensure it is not binding under weight.

Leave the float adjusters alone for now if tight.

If I recall once the worm is near enough it can be a balancing act between the worm and float adjustment. I am sure mine is not 100% but I do average 0.6-0.7 and have had it down to 0.4 when guiding.

OK, I will forget about the float adjustment for now. Having one thing to adjust is certainly preferable. Something that keeps coming back to me is that it seemed to bind up in different adjustment places, I need to try again and get better data. It would be good if this binding was the float but don't want to go changing too many things at the start.

I've also heard people talking about adjusting the tension of the belts but it don't see any reference to this in the rowan guide.

[spillage]

The belt tension just involves slackening off the bolts that hold the motor in place and using a bar or screwdriver to lever the motors to add tension then just nipping up the bolts. You undo the four panel screws and undo the dec and ra electrical connectors to remove the panel to gain access to the motors.

[Peje]

13 minutes ago, spillage said:

The belt tension just involves slackening off the bolts that hold the motor in place and using a bar or screwdriver to lever the motors to add tension then just nipping up the bolts. You undo the four panel screws and undo the dec and ra electrical connectors to remove the panel to gain access to the motors.

Thanks, my main concern is how to know how tight the belt is / should be when I have no access to it.

[Starflyer]

Not too much, not too little. Slacken the bolts and then push the motor so it takes up the slack in the belt and then push it a tiny bit more, nip the bolts up again.

[Peje]

Thanks. I'm going to have a play with the mesh and see how I get on, I have a feeling that I got binding when fully loaded in numerous mesh positions so this might point at one of the other two factors.

Have ordered a little USB endoscope to see if that helps me see belt tension

[Peje]

Took some time this evening to completely slackened the worm mesh and redo from scratch. Left it with a little more backlash that I wanted but it seem to not bind anywhere.

Only took it for a quick spin around the sky so will need more testing to be sure.

[spillage]

10 hours ago, Starflyer said:

Not too much, not too little. Slacken the bolts and then push the motor so it takes up the slack in the belt and then push it a tiny bit more, nip the bolts up again.

+1

[Starflyer]

15 hours ago, Peje said:

Took some time this evening to completely slackened the worm mesh and redo from scratch. Left it with a little more backlash that I wanted but it seem to not bind anywhere.

Only took it for a quick spin around the sky so will need more testing to be sure.

Great news, sounds like you're getting there.

Remember, in the winter, when things contract a little you'll have more backlash than at summer temperatures.  If backlash is a problem in the autumn / winter months then it may need a slight tweak again.

 

[Peje]

1 hour ago, Starflyer said:

Great news, sounds like you're getting there.

Remember, in the winter, when things contract a little you'll have more backlash than at summer temperatures.  If backlash is a problem in the autumn / winter months then it may need a slight tweak again.

 

I hadn't considered the temperature, it has been much warmer the last month or so. I wonder if when I previously adjusted for no backlash it was fine because the temp was around 10C cooler.

[sloz1664]

On 19/07/2019 at 15:19, Peje said:

I hadn't considered the temperature, it has been much warmer the last month or so. I wonder if when I previously adjusted for no backlash it was fine because the temp was around 10C cooler.

When I had my NEQ6; I belt modded & super tuned it. I adjusted it to within limits that were unknown to man  I'd adjust it so that it would turn 180 degrees without stalling, on both axis and thinking that was it. Then over time the temperature dropped and the motors stalled and they needed to be fine tuned again. So yes, to gain the fine precision needed to make the EQ6 an excellent mount, you will need to tweak it from time to time.

Steve