EQ6 Supertune problems

[Astro_Baby]

OO-err - Astro Baby stuck with an EQ6 hassle - surely not.

OK heres a shout for help/advice from me.

I have an EQ6 with me thats being tuned and I have run into an oddball problem - which may not be a problem it may be common to early model EQ6s - this one is quite old.

When running in a fast slew with both motors either manually or when in its aligning process the power light tends to flicker a lot when running off of a battery. Its fine when connected to a main supply and has no problems at all.

When running from a battery the mounts LED flickers in time to the motor pulses. Now I know people are going to jump in and say 'well the battery is at fault' - it isn't. I have tried three brand new batterys with it and they all show the same result. My HEQ5 and my own EQ6 work perfectly from the same batteries, leads and handset.

Now the LED flickers when the mount is in perfect tune - ie no play in any axis. If I slacked the DEC axis a bit so some play creeps in the LED stays stable which seems to suggest the motor may be straining but I am at a loss to see why. Set-up and tune is perfect, the mount is silky smooth in to feel and with zero play. Theres no untoward gear grinding or anything.

I havent tested this in a fielkd yet so I have no way of knowing if the mount is flickering just out of an oddity or whether its genuinely in distress and an alignment would be flawed in the field.

Its possible that the LED is wired straight across the same circuitry as the motors so as the motors pull power the LED suffers (I have seen this in another system of gears years ago due to bad circuit design) or it could mean somethings amiss.

Anyone out there with an older EQ6 that may exhibit this problem ?

[Skylook123]

I don't know the time frame on your "older" EQ6, but my Atlas is over six years of age so I'll just toss up some comments.

I believe that you'll need some small relaxation in the gear train or you get binding and extra force required to move. The flashing light on the mount is an indication of insufficient input power available. This usually happens in the field as a battery gets depleted, or is actually at the end of its life. The current draw of the LED is miniscule. FLickering means not enough power available, either from excessive friction internal to the mount or inadequate power supply. The fact that you are getting a steady light off the mains input says that the battery is insufficient for the job either due to age, charge level, or binding in the gear trains.

The worm clearances and backlashes of EQ6 family of mounts are notoriously tricky to adjust. The Yahoo! EQ6 Users' Group has instructions that involve using a thin piece of paper to set the clearances to prevent binding or excessive backlash.

Mine is over six years old, is used 5-10 times each month, and never has needed to be touched internally. It isn't broken, so I shall not try to fix it. But many are in need of fine tuning, thus the helps on the Yahoo! site.

Good Luck!

[Astro_Baby]

well it cant be the battery - two of them are brand new and one is an 85 A/h job. One of te batteries used for testing went on to power an HEQ5 for hours of observing straight after testing last night so I can be sure its not the battery so its obviously excessive stress on the gears which is weird because this mount is so well set-up.

Unfortunately its owner wants it running of batteries, its original problem was excessive slack and backlash.

Yes I know how awkward the EQ6 is - this is the 5th one I have tuned (maybe the 6th cos I lost count) but this one has been a complete cow from the off.

It looks like I will have to strip the DEC gear down again and redo it from the top.

[jam1e1]

Mel, got an EQ6 also, welcome to try that to compare?

not tried off battery, would expect this to happen though - its like when a car stereo is used with a powerful bass speaker - the leds dip on that too - just drawing a lot of power and is perfectly normal. Thats why they need big capacitors.

Expect in eq6 the power circuitry may not have big enough capacitors to smooth the current therefore see dip. With a mains much more power can be drawn therefore wouldnt be as noticable.

Hope that helps

[m.tweedy]

mel my new NEQ6 pro did the same when attached to the battery. I think it was some strain being put on the power lead that attaches to the mount. so I attached a clip onto the mount that the power lead gets attached to and no strain is put on the connection into the mount now.

[Astro_Baby]

Hmm - thats what I thought Jamie - might be that the circuitry is a bit naff so any sligh power pull dims the LED. On top end gear the LED would run off its own supply off say a 5v rail with a cap and not be connected directly in stream with the power.

Problem is none of the other EQ6s I have done have had this problem. I am minded to do another strip and see what the cause can be. I suspect as Skylook suggests something is just too tight. I cant see how right at the moment but the DEC motor may just need a bit more spacing between it and the worm assembly. That would fit in with another problem the mount seems to have which is when the worm carrier hex nut nearest the motor is tightened the mount can start to play up even though up to that point its been fine with the tune. I compensated for that in the worm tuning stage but perhaps theres something deeper amiss.

pooh ! thats going to take some time to fix for sure - I hate EQ6s - the HEQ5 is much sweeter all round I think.

I have noticed that this old EQ6 (and I assume its about 5 years old but its third hand so no one really knows) also has a really nasty vibration/resonance through its mount legs when on full power slewing - if you touch a mount leg you get a real rumble through it - thats something else that needs a bit of tuning as well.

[jam1e1]

hmm tight barings would cause excess load on motor hence dimmed Led. My only suggestion is elimination - i.e. disconnect any other barings and take motors out and run on their own - that way with no load you should have idea if circuitry has issue or more likely tight barings.

When i stripped an EQ6 you could take out motors, try them without load. From circuitry point of view you do get boards with some duff components hence one possibility that can be tested with unloaded motors. If only happens with loaded motors then you have the most likely answer

Like any electronic testing the only way is experiment and play

If only clear skies were that easy so summon and test..................

[Astro_Baby]

Yes, the problem disappears with the worm gear loosened off so my suspicion that its loading seems correct. Thanks to all, i now have a strip down on my hands.

[Skylook123]

Good Luck! I've never opened mine in six years. For all I know a strong little man is in there wit a very precise clock and a tiny table of catalogs.

Stories I've heard about the gear train slack remind me of very old autos that took a feeler gage to set the ignition points, then when you tightened the screw, the dwell changed and now time to start over.

[MG1]

Mel are you any further with this? just curious how things turn out is all.

[Astro_Baby]

I'll be taking tge DEC to bits this weekend,,,,,,,dont worry I'll post up once I have found the problem and will add notes to my guide as well.

[kookoo_gr]

i am also interested in the result since my heq5 pro has the same problem from day one when i connected it to a battery. i don't have major issues in guiding but i have noticed that some days the LED will be always on and most of the times the LED will flicker