Cheers Curt. I finally got to try it last night for the first time and I am very happy with how it is performing. I've been capturing pec curves and have +/- 5 arc second average PE according to PECPrep. I've also tried some 15 minute guided subs and have no noticable trailing - the best I could get previously was 2 mins.
Fantastic. 15-minute subs is what hypertuning an Atlas is all about. I heard similar numbers reported from folks on the yahoo group, and their testimonials were what persuaded me to give it a try.
I know its all your fault that this weather is upon us, Peter.
+/- 0.005 arc second PEC and 95 hour subs doesn't cut it when its cloudy.......... Grrrrrrrrr.
Maybe we should take your mount out into a deep dark and lonely place and fill its bearings with sand and Vegemite so that the rest of us can get back to fumbling in the dark.
Glad to see that your efforts have paid off so well. Have to measure the PE of mine sometime when this cloud goes away... But I said that before
Great work peter.. I'm thinking of acquiring on of these kits myself very shortly.
Did you get a chance to measure the PE prior to the work over?
Some have mentioned the Atlas/EQG-EQpro mounts having a +/-30 PP ?
I'm not sure I would recommend buying the whole kit as the tools are pretty basic and the spare parts are readilly available. The instructional DVD's are quite good however there is an error in the DEC re-assembly bit.
I didn't measure the pre workover PE as there were some more fundamental issues with the mount I was trying to address. I was interested in the post PE to see if I'd done a reasonable job putting it all together more than anything.
I reckon it'd be extremely useful to make a post here about the best place to get the different parts instead of the kit. Like, if you had to do it all again, how would you do it and where would you get the stuff, links to the websites etc.
The basic kit only contains the spacers. You have to pay (quite a lot) more for the ceramic hybrid worm bearings. The bearings can be bought from VXB.com and the spacers are available from one of the members on the Yahoo EQ6 group. The kit doesn't contain a worm gear and you should n't need to replace this. The best part of the kit is the DVD's in my opinion.
It is a pity you did not determine which component was contributing the most..
In my case it was transfer gears (47 peaks 2-3 arcsec in one period) and gearbox (last stage, 1:3, ~5arcsec pp).
Total it was ~35srcsec pp, after tuning (mesh) it is 23 arcsec pp.
Just 15 minutes exposure using 1000mm lens with slightly mis-aligned mount. Then I analysed the image pixel by pixel (tedious job ! )
I did not use the K3CCD then, unfortunately.
The images are after and before tuning (and replacement of motors and gearboxes)
I reckon it'd be extremely useful to make a post here about the best place to get the different parts instead of the kit. Like, if you had to do it all again, how would you do it and where would you get the stuff, links to the websites etc.
OK Troy here goes:
Spacer kit - join the Yahoo EQ6 group and find the post from Doug - he sells Delrin EQ6 spacer kits for US$13 including post to Aus.
Worm Bearings (2 on each axis) - These are 608 deep groove ball bearings. The standard ones are steel but the recommendation is to get some hybrid ceramics. I got mine (ABEC7 ceramic hybrid low friction in a set of 8 for US$70) from VXB.com although I've seen posts where people got the same ones on ebay for less. http://www.vxb.com/page/bearings/PROD/Kit8344
There are quite a few different ceramic hybrid bearings to choose from apart from these - key is to get some good ones. I was told to go for ABEC 7 or ABEC 9 by someone I trust.
Grease - I got Superlube synthetic grease (3oz - 85g) from a local locksmith http://www.toplock.com/
I chose to replace the main bearings also although some say this is not necessary. I decided upon SKF bearings as follows:
6008-2RS1 - 6 in the mount although you can choose to re-use the original 2 DEC ring gear bearings as these don't rotate when the DEC clutch is locked
30206 J2/Q - 1 required
32208 J2/Q - 1 required
You need the following tools:
a set of metric allen keys
a set of phillips head and straight screw drivers
a shifter
some needle nose pliers to remove the worm shaft covers and to adjust the wom thrust ring.
possibly some vice grips if the locking rings are done up really tight.
some fine wet and dry sand paper.
a craft knife for scraping paint off the mating surfaces.
a small length of 6mm ID tubing to rotate the worm shaft by hand.
Finally - a lot of patience when you adjust the worm mesh.
Peter
Last edited by peter_4059; 17-02-2010 at 06:25 AM.
It is a pity you did not determine which component was contributing the most..
Based on my post tuneup PE curves, most of the PE is coming from the transfer gear and the worm (about 50% each). The transfer gear has an o-ring either side of the gear as a bearing and this is obviously not quite right. Luckily this is easy to adjust without pulling the mount apart again. There are also a number of modification options that can be looked at to replace the o-rings with spacers, or proper bearings. I just haven't got there yet.
Based on my post tuneup PE curves, most of the PE is coming from the transfer gear and the worm (about 50% each). The transfer gear has an o-ring either side of the gear as a bearing and this is obviously not quite right. Luckily this is easy to adjust without pulling the mount apart again. There are also a number of modification options that can be looked at to replace the o-rings with spacers, or proper bearings. I just haven't got there yet.
Yep, this was my conclusion also, and it is quite visible on images above..
The transfer gears contribution can not be tuned out - I wanted to replace the gears with timing belts, everything is ready for the task but I do not have time...
PS: my mount is classic, with gearboxes (yours has only 200 s/r motors and transfer gears)
I was referring to two 47-teeth gears - one is on the worm, another one is on the output shaft of the gear box of my classic EQ6 (gearbox with 131 reduction).
Also, I mentioned the last stage of the reduction in the gearbox that is 1:3, and the effect of this is visible as 3x higher frequency un the PE photos..
The Synscan EQ6 mount has slightly different reduction: 200s/rev motor, 12 (or 20?) teeth gear on motor shaft, then there is middle-size transfer gear (with rubber spacers?) and finally larger gear on the worm shaft. The reduction ratio is determined by gears on motor and worm axle [middle gear size (transfer gear) is irrelevant]
Pete, thanks for posting all of that info. It appears I will be following in your footsteps in the near future. Your thorough documenting of the hypertune is truly inspiring.
