Peje

3 minutes ago, StarDodger said:

The Shaft on the motor does have a good flat already on it, so that should be good as long as at least one screw is against that...it the other end that will be the issue..

Damn, I was hoping it was too much of a coincidence that this was loose.

If it's not slipping, what would have caused the pulley to get jammed on the motor shaft?

Just now, tooth_dr said:

No the Dec cog that attaches to the worm gear shaft. To see if it moves independently of the shaft.  

You're too quick lol

No, haven't tried that. Will give it a whirl but I doubt I'll be able to move it as it only slips under heavy load

16 minutes ago, tooth_dr said:

Can you spin/move the Dec cog inside the mount with your finger?

Do you mean the idler?

EDIT: Oh, do you mean can I turn the dec pulley on the worm shaft? I doubt I'd be able to move it as the slip only happens under big load

Checked belt and it wasn't loose to I pulled out the motor and discovered one grub screw completely loose and the other seemed tight. (Image attached)

I removed both screws in an effort to remove the pulley to see underneath but it won't come off. It'll move about 1mm, I put it in the vice (wrapped in kitchen roll) and was able to move it around 10mm but decided not to push my luck so pressed (hard) to get it back on.

I'm guessing that this supports the slipping theory as it has probably gouged a lip into the shaft and this is stopping the pulley coming off.

Rain has stopped any further work at the mount tonight (I have a small roll off shed), I'm wondering if I should get some locktight onto the screws tomorrow??

Thanks. 

My slight struggle with doing it on the pier is that its outside so light isnt an readily available but I can figure that out. 

The guy got back to me, he didn't file a flat into either motor, maybe this is the problem.

Did you both file the flat?

Pete

Top marks for sorting it out mid-session!! TBH I wasn't sure what was wrong and with me being a bit bullish, I figured it was best to just leave it be.

Looking at the options I can see three potential causes:

(1) Dec Belt too loose
    > This should be easy to check without removing the mount from the pier, tighten it a little and see if the problem changes. If the problem gets worse then it points to item (2) or (3).
    > This could explain the 'hopping', mount moves but belt jumps a tooth, then it moves again, and so on.
    > This would be the happy path but it feels quite unlikely.

(2) 47 Tooth pulley (Worm shaft) grub screws loose
    > Not much else I can do other than strip the Dec to bits, ensure everything is solid and rebuild.

(3) 12 tooth pulley (Dec motor) grub screws loose.
    > I notice in the guide it say to file a flat on the motor, have asked the guy who modded mine if he did this.
    > This one could be easier checked that (2) but rebuild involves what I'm told is the hardest part, getting the motor back in with engagement on the belt. Any advice on how best to do this?

Thanks again for the great information.

Pete

Thanks. The logic in my head right now is that the only places for the 'slip' to occur would be the belt side or the worm mesh side.

If the worm mesh adjustment was so far out that it was skipping I think it would be very noticeable, in terms of noise and play in the axis.

I think the pulley at the motor would be most likely, I'd just like to figure out the best way to attack it without risking making a mess of it. It looks like there are 3 bolts that need to be removed to take out the dec motor, doesn't seem like a complete nightmare other than how to know if the belt is engaged with the motor without being able to see it

Hmmn... now that's something I hadn't thought of. Is it common for them to be not tightened enough? I guess tightening the belt would probably be the first thing to try as it involves less stripping.

I'm now wondering if the motor can be removed (to get at the grub screw) without stripping the rest of the dec assembly to bits? EDIT: Looking through the belt mod instructions, it seems like this should be OK (fiddly, but OK)

As title,

I had my NEQ6 Pro belt modded by a friend and initially all seemed well, I had some minor niggles with worm gear mesh adjustment but got over that hurtle after some advice on SGL.

What I am now seeing is that the Dec axis sometimes isn't moving, the motor is running fine (no stalled noise) but no movement. I *think* I can provoke this behaviour by unbalancing the mount, even just a little. I first noticed it this evening when I put my dew shield on and the dec wouldn't move, remove the shield and it seemed happy. This is causing me other issues to do with plate solving but I think they will go away once this issue is cured.

Something else I do see from time to time is the scope 'hops' as the dec is slewing at full speed, rather than a smooth movement it is quite jerky, there are no unusual sounds when this happens.

My current best theory is that the tension on the dec belt is too loose, once the belt is loaded up then it is slipping. Before I start fiddling about I wanted to check if anyone here had any better ideas or had seen this before??

Any feedback would be greatly appreciated.

Pete

1 hour ago, pablotwa said:

I'm having the same problem. I changed from and SBIG ST-I camera with big pixels to an asi 120 mini and now the image is drifting ,by the way using an OAG with a Celestron C-14 Edge HD....could it be oversampling due to the small pixels?

Mine ended up being differential flexure. After a while each night it resolved itself. 

I tightened everything up and it seemed to reduce the issue dramatically. Eventually I moved to a permanent setup which tracks outside temperature so I haven't seen the issue for a long time. 

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.

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.

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

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.

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.

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

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

I'm also having this problem, no idea what's wrong. My guiding performance seems pretty good but the images drift slowly

I have to unfollow this topic, as a hardware engineer I'm ashamed to say I just bought the Moonlite version and didn't even try making my own :(

On 05/03/2016 at 17:19, richardcav said:

Thanks Chris, this worked for me, perfect advice being used years after you gave it :-)

And again!!

For all a couple of bags of sand will cost I suppose it's worth doing. Why would it rot? surely if no water is getting in it'll stay fairly dry, due to the mass it should be fairly resistant to temperature change also..though I'm not sure how helpful this will be

On 28/01/2016 at 21:12, carastro said:

I have the Skyshed pier and have no problems with it at all using an NEQ6, I like the design, it's is easy to install.

I did have a bit of problem when I previously had a CG5 GT on the pier as being smaller I could not see through the polarscope as the top pier plate was right where my chin needed to go, but once I swapped that for an NEQ6 that problem went away.  

Works better with a piggy backed guidescope than a side by side arrangement as less risk of scopes clashing with the pier plate.  

Contrary to what has been said about not needing the pier level, I did accidentally "slightly unlevel my top plate" once when removing the mount for Astro camp (this is because the top plate needed to be removed in order to get the central rod out).  I had not realised I had done this and it took me quite a long time to fathom out why I could not get a decent polar alignment or do an alignment procedure properly.  I also could not do a polar alignment using Alignmaster until I levelled that top plate.  

I don't remove the mount any more and no further problems.

 

A quick question, did you use the standard center bolt to attach the EQ6? I'd like to not use this (given the huge length) so was wondering what length of bolt I need? I'd like to order it before I take the head off my current tripod as I am sure the second my kit is out of action we shall see an unprecedented number of clear nights and celestial marvels!!

On 06/03/2016 at 12:29, pyrasanth said:

I use a similar type of pier, albeit a different model http://www.altairastro.com/altair-skyshed-8-observatory-pier.html, & it happily supports my Paramount MX+ & a fully loaded Celestron C11 Edge. My T-point model gives me a SKY RMS & PSD of under 12 & if there was anything wrong with the pier I would know about it. My pier sits on a modest 30" of embedded concrete & I filled the hollow tube with bags of sand for extra dampening.

The design makes polar alignment a breeze. I made a graduated degree scale & added that to the pier so its easy now to fine tune alignment although I've not done this for a year which proves its a solid mount. If I had any doubts I would have got rid of the pier very quickly so all is good.

I quite like the rats cage type configuration as it is fairly straight forward to level the top & I've not had any perceived problem with vibration or movement. This also makes a useful space to put power supplies & other small items under the mount. I have a four port cigar type lighter adapter & various power supplies under the mount.

All in all a worthy additional to your observing happiness.

On 08/03/2016 at 13:29, Andrew INT said:

Thanks Pyrasanth; that's good to know! I think it looks like our two piers are the same. I'm pleased that it certainly feels pretty solid. I haven't filled mine with sand bags simply because I had originally intended to run all my cables through the centre. However, the pre-drilled holes are pretty small ( a USB lead wouldn't pass through). I think I would also be a bit nervous about having electrical power leads out of sight on the inside of a metal tube!

Did adding the sand make a noticeable difference to the dampening? I've only really just started work on my observatory (  http://andrewrichens.wix.com/astro-nerd#!observatory/c5dt ) but now the pier is in place I can at least start doing a little bit of observing and imaging...provided this rain stops...and the clouds go....and the council sorts out a street light....and I don't run out of money...

I'd also be interested in knowing if the sand is actually necessary, I just got the Altair 8" pier

Left him a message earlier and haven't heard anything back so I'll just fire him an email directly. Wanted to get some advice from him on some of the different cameras he offers for sale.

Fine Tuning Ring on the  FLO website

http://www.firstlightoptics.com/baader-planetarium/baader-hyperion-finetuning-ring.html