Paramount MX bits?

[baileys2611]

Hi Everyone,

I know that there's a fair few Paramount MX owners on this forum so I thought I'd ask for some advice please.

I've had mine for about two years now - it's been a solid performer but I want to do some maintenance (replace grease, look at the belts etc) because my PE and tracking are starting to suffer. I'd like to ask if anyone knows where I might be able to get spares for the mount if I need to replace bits?

I have the grease coming from America but don't know where to look for belts. I figure those will be the first things to do, then test and see if I can get an improvement.

Thanks
Simon.

[PRejto]

Hi Simon,

Personally, unless you see material flaking off the belts I would not replace them. If you do have the original black belts you will most likely see this. The new belts are grey and should last a long time. Certainly feel for any looseness but also do not over tighten!! If you need belts I'd get them directly from Software Bisque. Seriously though I doubt you will need any parts.

There is a video on line showing how to replace the worm block. You need to remove it to properly clean and grease the ring gear. Be careful because the video skips an essential step in the reinstallation, namely adjustment of the 1/4-20 bolts. This is the the literature but not the video. If you don't do the 1/4-20 adjustment you cannot get a good reseating of the worm block into the ring gear.

Please post your before/after results re tracking and PEC. Good luck!

Peter

[Logieberra]

There is a wonderful OZ supplier for the MX's SDP brand belts, Small Parts & Bearings:

http://www.smallparts.com.au/

SDP part no.: SDP A 6B16 100 025060

[baileys2611]

Thanks for that Peter, Logan (Hi Logan, still very much enjoying the PMX).

There are no bits falling out of the housing so I'm guessing I won't need replacement belts - but, I'll open up the housing and check when the grease comes in and if I've got black belts then I'll get some replacements. Otherwise I'll give it a clean, get the old grease out and put new grease in, then clean the electronics and re-tension the belts, give it a wipe with a cloth and put it back together again.

Thanks for the tip on what was missed out in the video. I watched the video this morning. Chris makes it look easy!

Out of interest, I did do a PEC experiment around November of 2013 and ended up with the curve you see attached to this post. About the best tracking I've had is less than 1/2 pixel correction - but that was exceptional seeing and was in January 2014. It's held that solidly now for some time, but over the last 6 months has introduced more errors. Last session, I was getting over 3 pixel fluctuation fairly regularly and that makes me think I've got some backlash or dirt in the grease or something. Could also be the scope, but the mount needs a service anyway so I'll do that first and come back.

It will probably take a month for the grease to come to me, hopefully that will be good timing so I can do the cleaning (while the mount is warm so the grease spreads evenly) and another t-point run then PEC experiment in winter when we get better seeing here than other months.

[LewisM]

Also, the Super Lube recommended as THE grease is actually available in Australia - you don't need to import it from the USA.

http://www.mektronics.com.au/brands/super-lube.html

Although, I have found the Inox brand electronics grease with PTFE just as good and cheaper, and made here.

[frolinmod]

Superlube is not recommended by Software Bisque for use with their mounts.

[LewisM]

Yes, you are right.

I recall one mount manufacturer recommended Super Lube though - I thought it was Bisque.

Anyhow, the Lubriplate recommended by Bisque IS available here too without issue.

[Paul Haese]

Simon, might I suggest you use prempro for doing your PE. I found using the PE software in the SkyX, give very inconsistent results and could be causing your results.

[Logieberra]

Exactly. They recommend Lubriplate Motor Oil Assembly Grease...

[baileys2611]

Actually that's a good idea Paul - I was relying on TheSKyX but was skeptical when the PE curve showed such a small amount of error. I know the mount is good but was expecting somewhere around 5, not 2.5 - 3. I think I also need to improve my focus - although looking at your latest image post here you're setting the bar very very high! I've been using Nebulosity and trying to manually guage sharpness. I think I'll try @Focus2 for a bit - but have some other questions which will no doubt require a post outside of this equipment discussion forum. I know you use FocusMax with MaximDL.

So, PemPro will get a workout soon I think.

Logan - you're using an AP1600 now!?! Decided again a ME II?

[baileys2611]

Yes, specifically Lubriplate 105, which has things in it like Zinc Oxide and rare-earth albino baby seal blubber giving magical anti-ceasing properties. Ahem, that last bit isn't strictly true but finding that brand in Australia hasn't been easy! Here's where I started (http://www.kennysholdenspares.com.au/shop/viewitem.php?productid=358) and they didn't have any (despite advertising it). I went for the easiest option (ebay).

[PRejto]

Let me second what Paul has said re PEMpro. I personally think TSX is busted for use in the Southern Hemisphere and I could never get any improvement in PEC using it for either my MX or MEII. But, with PEMpro I got my MX to go from 3 arc-sec error to around .6 arc-sec. I wouldn't be at all surprised if your uncorrected PEC was around 3-4 arc-sec. With a good correction you can do very well.

Actually you might want to use PEMpro before doing any maintenance at all. When you did your last PEC what was/is your correction using the curve you posted? I don't think looking at guiding corrections is a reliable way to tell if PEC is working or not given that guiding can often compensate for PE. Your guiding errors could be due to any combination of factors such as seeing, aggressiveness, exposure length, guider resolution, etc. I think PEC needs to be measured with guiding off.

Peter

[gregbradley]

Maintenance is fine but I would not necessarily assume PE has worsened because of dirt, grease or grit.

I think an indicator of grit would be a PE spike where the guide corrections suddenly jump very high.

I think its more likely your Polar Alignment has deteriorated.

Even when mounted on a permanent pier, soils can change with different climatic environments. The mount can be bumped numerous times throwing things off.

I would do a 40 point recalibration of your TPoint model and do a super model and read the polar alignment report to see how accurate that is.

Also things like balance greatly affect guide accuracy. How well balanced is your scope at the angles you often image at (not horizontal)?

I did have some grit in one of my PMX worms and it caused a repeating spike every few minutes.

By the way your PEC curve looks remarkably like the one I just recently did on my PMX using Pempro.

Are you using direct guide or a guide cable?

Greg.

[Logieberra]

Same. I was unable to source it locally. Flebay. Mr Braddley ended up with mine :)(http://www.iceinspace.com.au/forum/showthread.php?t=123627&highlight=lubriplate) as AP recommend AeroShell No.33 Synthetic Universal Airframe Grease! This hobby is nuts...

[Logieberra]

Yeah.. No, I definitely didn't decide against the ME2. I was all for it, but I was really curious about the APs. I actually intended on getting a 900GTO from the beginning, even before I got the MX, but was notified that the 900 and 1200s were being phased out, so I went with SB. Fast forward a few years, and with news of the updated 1100 and 1600s, I gave them a shot! I'd buy another SB without hesitation. People are getting some wonderful results with the MyT. Would love one :)

[baileys2611]

All excellent suggestions Greg, thanks. I'll definitely re-do the calibration though. The report when I last did (about two years ago) it said 1 minute out on both axis (good enough but not excellent) so it's fitting that I do a re-calibration. In my case things may have slipped more than soil moving - otherwise the entire water tank might be sliding towards the house and heaven help me if that's the case! But metal bits might have moved over time so your advice is definitely timely.

I'm using direct guide on my setup - I found that while pulse guiding worked ok for ... forgotten the name now, that software you can use for guiding! Umm...I think it's PHD, anyway, it worked ok but I was getting better results using direct guide.

And that's an odd coincidence that you have the same curve...of course nothing is a coincidence so it's curious...

[baileys2611]

Whaa?!!? If I could see anything like that as a correction after applying a curve I think I'd do a highland jig. However, I will definitely give it a go with PEMpro ... when I get a break from the darn clouds to give it a go!

I share the sentiment about it being busted for southern hemisphere. I've read many of the posts on SBs forums and they don't seem to be able to directly answer questions about PEC for the south. Lots of questions answered about the north. Us poor cousins.

[baileys2611]

Update on this. My grease hasn't arrived yet, but the GSO RC12" has! So, I haven't forgotten about posting PEC results post maintenance - but will do after maintenance + commissioning the RC with adapters, camera, OAG etc etc etc. This hobby is nuts!

[Paul Haese]

LOL, the pain has only just begun. ;)

[baileys2611]

The thread on the back is 117mm x 1mm right? Has anyone come up with a set of adapters for these to mate the takahashi collimating scope on the back? Or a moonlite?

[Paul Haese]

I actually don't know the thread size but Precise Parts makes adapters up for all those pieces of it. I have an adapter from the atlas to the Tak collimation scope. Works a treat.

[baileys2611]

Yeh, thanks for that Paul. I hear you were partly responsible for the RC12" rear cell redesign. I also heard why ;-)

Here's what I think I'll use: Moonlite AT RC 10 flange -> Moonlite -> 2" Nosepiece (yes, it's not threaded but what can you do with a 2" moonlite?) with T-thread adapter -> Precise Parts T-thread to tak collimating scope.

( ! ! ! )

Unless I've got the wrong idea and the collimating scope should just go straight on to the rear cell with a Precise Parts RC 12 flange -> tak collimating scope attachment?

[Paul Haese]

I did have a small hand in the redesign as it turns out, putting that much weight on the back of the scope lead to errors showing up.

You should definitely have everything in place up to and including the focusor. So you are on the right track.

You would need to get a threaded draw tube on your Moonlite to run a thread off that to the imaging train. Possible but it depends on your need for a threaded assembly. If you camera is light then it might not be necessary at this stage.

[Logieberra]

I use a non-threaded standard 2" setup on my 12"RC. Optec TCF-Si. To connect my Tak Collimation Scope, I simply thread it into part no. 13 in the attached pic. Works for me, and infinitely cheaper than a PreciseParts adapter.

[baileys2611]

Hmm...I could have done that. I got excited (impatient?) and ordered my bit from precise parts.

I also managed to find some time to service my PMX. In the end it wasn't that hard! For those interested there are some shots and what not here. (http://www.skyslab.info/paramount-mx-maintenance/)

[Logieberra]

Nice page. Good info there.

PreciseParts... in US dollars... we really need an Australian equivalent. Might look into it...

[baileys2611]

I managed to get some time to put the GSO 12" RCA on my Paramount MX. Still no PEC test - but the 1st step has been done. If any are interested: http://www.skyslab.info/guan-sheng-optical-12%E2%80%B3-carbon-fibre-truss-tube-ritchey-chretien-part-two/

[Paul Haese]

Your link reminded me about a shroud. I bought one today as a result of your link. So that worked for me.

[baileys2611]

Thanks Paul. Paul, Logan I have a question about the rear cell of the RC.

Bintel recommends an attachment to square the focuser for both collimation and photos (http://www.bintel.com.au/Accessories/Collimation/GSO-RC-Collimation-Ring--RC10-RC12-/1729/productview.aspx) but the rear cell of the RC looks like it has something like this already in place: https://farm9.staticflickr.com/8757/17151406128_b2101c47b4_c.jpg (https://flic.kr/p/s8BruL)

Do you know if this is the same thing or something different?

Thanks
Simon.

[Paul Haese]

Your new RC12 already has the collimating ring as well as the primary collimating on the actual back plate. This was part of the development that I had a hand in last year. The website has not been updated I suspect.

[baileys2611]

Awesome! Thanks Paul.

[baileys2611]

I finally got enough time and clear weather to put everything together, do some Tpoint runs, correct and do that again, then re-do PEC. Funny, no change in the result - although there is a change in the curve.

I need to see if I can get PEMPro working, which at the moment I'm having problems getting to communicate with the mount. It starts up ok, I can get past calculating the pixels/arc second but cannot get past trying calculating angle, rotation and direction. Something weird going on there. I've got 60 days to figure it out because at the moment, I don't want to pay $ for some software that will not do what I need.

Here are the results using TheSkyX: http://www.skyslab.info/theskyx-tpoint-and-periodic-error-corrections/

[Paul Haese]

HI Simon, don't bother with the SkyX PEC. It is garbage and does not work correctly. Use Pempro. Your values will be correct then and you will see real results.

[SpaceNoob]

+1 For this, Pempro is king. Both my MX and ME are flat lines on guide history after using Pempro. With native SkyX PEC, there was inconsistency and it just wasn't quite right.

[baileys2611]

It's a terrible night for it tonight, the high level cloud keeps on blowing in and away again, but I'm going to give it a shot. I know when measuring you turn off PEC corrections in TheSkyX, but do you also turn off pro-track?

[PRejto]

I hope I'm not misquoting Patrick Wallace, but I believe he has said on the SB Forum that it ought to not make any difference if Protrack is on or off. The advantage of on is that the star will stay in the guide box window longer. With PEMPro I don't think it really matters as PEMPro will just follow the star anyway.

I probably said this before as well, but PPEMPro has been the only way I could correct PEC in both my MX and MEII. I never could get TSX to work properly (and I have tried a zilion+ times).

Peter

[baileys2611]

Fair enough. I tried it the other night - just before it clouded up and now need to wait for a clear night to see if it made any difference or if I need to invert the curve. I think I'm getting a bit more relaxed about this though, given the way a curve seems to be applied and then you can re-apply a different curve, the worst that can happen is the curve is inverted incorrectly which will double the error and you re-do the PEC to compensate, which then corrects the error and so on. Sounds simple!

[baileys2611]

I finally managed to get PEMpro sort of working with my Paramount the other night and gave a shot at recording and setting PEC. I'm not sure I'm getting this right at all.

After 45 minutes of recording, about 10 or 11 cycles, I created a graph and it now tells me I'm correcting at +-0.1 error. After applying the graph, I get slightly better guiding through TSX, but certainly not phenomenal guiding which you would think was the case at +-0.1

I was as close to 0 Dec that I could get, was on a magnitude 6.8 star, told PEMpro I was in the southern hemisphere and was west of the meridian. About the only thing I couldn't do was calibrate fully in PEMPro because a)TSX is not ASCOM compliant, b) I am using the main camera for PEC which does not have a guider relay port for moving the mount and c) do not know what 'other' means when telling PEMPro how to move the mount about during calibration.

Am I missing something here? Any ideas why PEMPro would be saying such a small error?

Like I said, +-0.1 was the final curve but only a slight improvement in tracking once the curve was applied. My resolution is about .65 arcsec/pixel.

[Logieberra]

Hi
If you haven't calibrated fully in Pempro, I would not trust the results you got. I connect to my cameras in Pempro via CCDSoft (the STi and Atik). I'm also using a plug-in from the ASCOM site,
"CCDSoft™ ASCOM Camera Plug-In for CCDSoft" which lets CCDSoft control my ASCOM camera directly (the Atik - but I've also used a QHY to collect PEM data before).
Otherwise, try using only your SBIG STi. Calibration will be tougher on that small chip - but it can be done. I've calibrated Pempro and collected PEM and PA data via STi and MMOAG in the past! Not ideal, but it can be done.

[Paul Haese]

A question here is whether you had the camera at 0 degrees? If not then you need to do a full calibration in Pempro. You only need to be a few degrees out and your results will be affected.

[baileys2611]

This is messy business. To be honest the PEC correction using TSX software seems to be better than the results I'm getting with PEMpro - which is a worry because I let the program go through it's paces and applied it correctly afterwards and have a feeling I could have put the money to better use.

I've tried it a couple of times and am not getting consistent results. Sometimes the correction is large, sometimes small but every time the X error in the TSX Graph is large and the Y error tiny.

Sometimes it's coming back with a tiny amount of error and other times it's large.

Tracking hasn't improved any from applying a PEC correction resulting from PEMPro.

Any advice or is this about as good as it gets?

[baileys2611]

Finally sorted it. After experimenting with TSX, DirectDrive guiding, pulse guiding, PEC and PHD I can confidently say that the curve produced by PEMPro is the same as the curve produced by TSX - not exactly but it dips and rises in the same places.

What causes my guiding to go out is the calibration. Because the calibration results can vary, it changes the way that the mount is guided. When I used PHD, the calibration process includes measuring backlash, pulse guiding using the relays, flexure and can build a picture of all this and start guiding accurately.

If I then 'fiddle' around with the calibration results on TSX, I can add compensation for backlash, play with the calibration angle and length and eventually it performs just as well as PHD.

Same process can be used for direct drive, fiddle about with the settings a bit and the result is better.