Backlash

matt · #1 17-07-2006, 09:09 PM

Can someone please give me an explanation of exactly what this is, in terms of how it applies to a mount such as an EQ6???

Why is it necessary to adjust it?

Why might it need adjusting?

Any tips on what I should be aiming for when making these adjustments?

Thanks

ballaratdragons (Ken) · #2 18-07-2006, 12:43 AM

Matt,

Backlash is movement in drive gears or worms. If a gear or a wormdrive is not a good fit it will have some backlash, which means it can move (although tiny, it is huge at the EP).

Focusers get backlash as well.

Picture this: You have just made a slight movement on your RA, Dec, or focuser and when you stop movement it jumps back a fraction, making centreing hard. That's backlash.

Quote:

Originally Posted by Matt

Any tips on what I should be aiming for when making these adjustments?

Just make sure all gears are meshed properly.

Astroman (Andrew Wall) · #3 18-07-2006, 01:20 AM

Another way to put it is if you move in one direction RA or Dec, then stop then go to move in the opposite direction the mount does not move straight away, until the gears take up the slack and start moving, this pause is the backlash. Almost every mount will have this. the Backlash settings on your mount are so the motors spin in the opposite direction a little bit, just to take up that slack.

Its not really necessary to adjust this if most of your movements are in one direction, but it can cause GOTO's to become less precise the more you movethe mount from one direction to the other.

Most backlash settings are corrected at the time of manufacture so each mount is factory set.

If its not a major problem I wouldnt bother adjusting it until you feel comfortable with doing so. You can make your gotos worse if the backlash settings are incorrect.

Hope this helps a little.

Striker (Tony) · #4 18-07-2006, 10:59 AM

Andrew has pretty well explained it well.

I wouldn't be too concerned..Like I said in another post I have got backlash in my mount and as long as it's minimal their is not a problem.

You also run the risk if you adjust the worms to tight you will get bad PE and your gears can jam so a little backlash is pretty well optimal.

matt · #5 18-07-2006, 11:03 AM

OK

Thanks guys.

Am getting down to the nitty gritty with this EQ6 and SynScan (V2.05a) and looking to get the most out of its performance.

Might just be getting a little ahead of myself now that I'm about to start drift aligning and PEC training.

Will worry about backlash later.

Cheers

Astroman (Andrew Wall) · #6 18-07-2006, 11:10 AM

Once you get the PEC and Drift aligning done you should forget about the backlash

and just enjoy using the mount.

matt · #7 18-07-2006, 11:14 AM

Yeah. That's what I thought Andrew.

Although there does appear to be a degree of "play" in the RA.

How much that affects my "enjoyment"?... time will tell.

It might be an issue when I move on to longer exposures on DSOs.

Like I said, I'll cross that bridge when I come to it.

asimov (John) · #8 18-07-2006, 12:57 PM

I'm about to get more fussy with the backlash on my EQ5...Drives me crazy!

matt · #9 18-07-2006, 12:58 PM

Just enjoy your mount John

asimov (John) · #10 18-07-2006, 01:06 PM

Well, I have been 'enjoying' it for 12 months like it is...but all good things must come to an end eventually...In this case I will be doubling my enjoyment real soon.

Enjoy!

matt · #11 18-07-2006, 01:13 PM

nightsky · #12 18-07-2006, 01:42 PM

Quote:

Originally Posted by matt

Can someone please give me an explanation of exactly what this is, in terms of how it applies to a mount such as an EQ6???

Why is it necessary to adjust it?

Why might it need adjusting?

Any tips on what I should be aiming for when making these adjustments?

Thanks

G'Day Matt,
Not sure if this will help you but there is a bloke I think he's from Newcastle who has a programe for $9 that stops the "Back Lash" on computer scopes.
Cheers
NightSky
I can send you the web address if you like

matt · #13 18-07-2006, 01:44 PM

Thanks Arthur

Hopefully I'll be able to track that down.

Someone's likely to come forward with a link.

Cheers

ballaratdragons (Ken) · #14 18-07-2006, 01:53 PM

Matt,

because the comment about the $9 program is buried in this thread it might be worth starting a 'Wanted' thread in the Buy/Sell section. Then it will be noticed

I'm sure others may be interested too.

nightsky · #15 18-07-2006, 01:55 PM

Quote:

Originally Posted by matt

Thanks Arthur

Hopefully I'll be able to track that down.

Someone's likely to come forward with a link.

Cheers

G'Day Matt,
Here you go
http://cgi.ebay.com.au/Meade-Autostar-Telescope-Active-Backlash-Utility_W0QQitemZ190007499698QQihZ0 09QQcategoryZ3636QQssPageNameZWDVWQ QrdZ1QQcmdZViewItem
Cheers

matt · #16 18-07-2006, 01:58 PM

Ken

It's not a wanted at this stage.

Arthur's offering a suggestion and has now been kind enough to provide a link, as requested.

But feel free to start your own thread

ballaratdragons (Ken) · #17 18-07-2006, 02:02 PM

I have no need for the program, but thanks anyway

matt · #18 18-07-2006, 03:27 PM

But feel free to follow through on your great advice/idea... for the benefit of other members, if you feel that strongly enough about it to make such a great suggestion