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AstroEQ for EQ mounts


Oily

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James,

I kind of  cheated on the brackets and ordered two along with the motors, That left me with just the mounting plate to mount the brackets to the "mount" itself.  My mount is a EQ5 type clone - came with my Messier Bresser 8 inch Reflector.  I wasn't sure if it would work but so far I'm pleased, I just need to check its pointing accuracy now.  I know what you mean about centering the motors, I had trouble making sure the spacing was correct so giving the correct tension.  The tension on the belt on my RA motor is still a bit too low so I need to tweak the mounting plate a wee bit.  All in all it's been quite an enjoyable project - I'm really looking forward to getting it up and running.

Jim

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Tom,

I made the change you suggested and checked the reverse motor option in the utility.  A quick try yesterday with CDC and the mount is now slewing in the directions expected.  I think part of my problem was unfamiliarity with CDC as well.  The only thing left to do is check the pointing accuracy, I'm not sure I have properly counted the teeth on my RA gear.  Rather than take the mount apart again I'm going to see if I can use the mount's setting circles and the manually input RA coordinates from the EQMOD utility.  If that doesn't work then it will be a simple enough thing, if a bit of a faff, to undo the mount and manually count the teeth again.  I also need to read up on how to set up EQMOD with regard to its home position, syncing and limits. So far all is looking good - you have supplied a great bit of kit.

Tom

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Jim,

Very neat job !

I have a similar mount (Celestron ASGT EQ5, for which there are no spare parts) and trying to complete my part list. Are your motors NEMA 14 or 17 and from which supplier ?

This project is quite exciting and I hope to give a second life to my mount.

Jan

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Hi Jan,  I got the motors from http://www.omc-stepperonline.com/.  While the web site is USA based theh motors came from China.  No complaints though they arrived by FedEx within 3 days of placing the order and were trackable all the way.  The price was good so I ordered both the NEma 14 and 17, in the end I fitted the 14.  Having taken advice from Tom is looked like  the Nema 17 would have drawn too much current.  It meant I had to do some work on the bracket though as these were designed specifically for the Nema 17.  

I think this is the NEMA 14 model I used.

http://www.omc-stepperonline.com/nema-14-high-torque-stepper-15a-40ncm567ozin-14hs201504s-p-59.html

Jim

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Well I made the changes as Tom suggested (selecting the reverse on the RA).  After a good hour of pointing at various targets using CDC I'm happy that the scope is being pointed in the correct direction in both RA and DEC.  I just need to do a bit of work to confirm the pointing accuracy, but I need a clear sky for that.  I have a feeling I may need to recount the RA teeth.  The belts also slip occasionally, the tension is too low, so I need to adjust the brackets.

I'm also finding using CDC to be a bit of  a learning curve - not as easy as Stellarium but I guess it provides more control.  I had to laugh, after being frustrated at where the scope was pointing I realised that  I hadn't set the date correctly - it was out by 2 months!  No wonder the scope wasn't finding the moon. :p

Other than that everything is looking good, just need to get a pier now - hopefully have it all set up for the winter.  Like Jan I'm looking for the Astro EQ to give new life to the mount and hopefully give me some time to save up for an NEQ6 at some stage in the future.

Thanks for all the help folks.

Jim

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Many thanks Jim.

I was hesitating between the NEMAs 17 an 14, between higher torque with higher Amps and lesser torque and Amps manageable by the stepper motor driver.

T

he NEMA 14 high Torque Stepper 1.5A 40Ncm 14HS20-1504S you mentioned is rated 1.5 A, is this a bit to high for the AstroEQ stepper motor driver ? Overheating ?

Concerning the brackets which look very nice ! Are these brackets for NEMA 17 which can also accommodate NEMA 14 ?

Very nice and clean motorized mount, I wish I can achieve the same !

Thanks gain for your time.

Jan

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Tom, thanks for the link to the forum.  I think I'm just abou there now, I'm confident I can get everything working correctly.  I just need some time and experience with CDC and EQMOD.  Thanks again for the help and quick replies - no doubt I'll visit you on the forum if any issues arise.

Tom

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Hi Jan, thanks for your comments.  Yes the brackets for the motors are really designed for the Nema 17, for some reason they do not supply a dedicated bracket for the smaller form factor Nema 14 motor.  I just had to drill new mounting holes into the bracket - the Nema 17 and 14 have the same size main boss on the motor face so it fitted perfectly onto the bracket.

The Nema 17 being  higher torque pulled a slightly higher current.  From what I remember, the motors draw current on two phases at anyone time.  So with two motors the potential current draw was a little bit higher than the Astro EQ motor drivers would like.  I'll see if I can find the post that discussed this , together with the data sheets that came with my motors.  

All that said, my NEMA 14s appear to have no difficulty in turning the mount.  I just need to tension my belts to stop them slipping.  It really is such a great mod and as you say brings a new life to an old mount - a stepping stone to a NEQ 6 perhaps.

Jim

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Hi Jim,


 


Thanks. Regarding the belts, I asked for a quote from http://www.beltingonline.com/, they asked me about the belt pitch.... I had no clue about that !


Perhaps you can enlighten me about that, perhaps it has something to do about slipping other than tensioning ?


 


My EQ5 Celestron mount was with brass gears and worked quite well with Cartes du Ciel through the hand controller.


Very easy procedure and I highly recommend CdC as being a kind of standard, straightforward and simple once you get use to it.


 


Celestron let me down completely with their inept spare parts policy.


 


I think stepper motors are better and less problematic than Celestron Servo motors (with encoders).


 


Regards,


Jan


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Jan, I used Beltsonline for my belts and wheels, no real complaints although maybe a wee bit slow, otherwise a good reliable service  For the lengths I found an online calculator into which you put details of gears - diameter, number teeth, and the pitch between the two gears.  It then calculated a suitable length.  I can't remember where I found it, it came from a general search.  

I think what they may mean by the belt pitch is the distance between the two wheels (motor wheel and the gear wheel).  It is either that or possibly the pitch to match the teeth pitch on your wheels. I'm sure if you dropped Beltsonline an email with the details of your wheels (diameter, no teeth, centre distance etc) they would be able to advise on a suitable length.  As a rough idea you could measure the length by wrapping a piece of string/thread around the wheel  then measure it. 

Jim

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The belt pitch is the distance between the teeth, which must match the gears you use.  MXL pulleys and belts have  pitch of just over 2mm.  The HTD belts and pulleys are a little heavier duty and have a 3mm pitch.

I bought my belts and gears from here: http://www.motionco.co.uk/timing-belts-timing-belts-c-25_38_27.html  They have a link to their calculator on that page.  I found it was useful because it would allow me to see what the centres would be for the pulleys with different belt sizes and I could then pick a set that would fit comfortably on my mount.

James

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Hello Jim and James,


Thanks to both for your contributions.


Now I know what is a pitch, shame on me  :smiley:




Tooth form: 3mm HTD

Belt width: 9mm

Working Tension: 100 N (22 lbs. )


instead of:


MXL Belt

Material:Nylon Covered, Fiberglass Reinforced, Neoprene

Belt width: 1/4" (6.35mm)

Working Tension: 4.5 lbs (20N) 


For James: what is your setup in #922; motors, gears etc. How good is the slewing speed? Thanks.


Regards to both,

Jan
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Both sets of gears are 16 teeth on the motor output and 48 teeth on the worm spindle, to give a 3:1 reduction ratio.  I'm using the MXL pulleys and belts as I can't see that there will be a massive load on them.  I was tempted to use a 12-tooth gear on the motor outputs, but I had to drill them out to 5mm to fit the motor output shaft and I was worried about the amount of metal that would be left if I'd chosen a smaller gear.

Slewing speed should be the full 800x supported by AstroEQ, though I haven't actually measured it to check.

James

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Hi all thought I would join in on this thread. I too have joined the AstroEQ owners club. Got a mate to knock me up a couple of brackets and everything goes together nicely, thanks to Tom and all his help. I then installed all the software and then started having problems I found out my laptops windows 7 wasn't SP1 so it wouldn't load. So on investigating why it hadn't updated I discovered that my display driver needed a later version before it would update. Did all that and after several days of running updates it allowed me to load the software. I ran the AstroEQ Firmware update utility and all seemed to be ok, it lets me update firmware and configure the mount settings, I then get failed to open EQMOD! is it installed. Which it is but on manually opening it I get "Run-time error 55 File already open". In AstroEQ I get mount programmed couldn't test with EQMOD. Any ideas as before EQMOD used to flash on and off before connecting AstroEQ. Off to bed now as got to be up early, will wait to see your replies tomorrow night.

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Use the eqmod toolbox app to delete the ini files - it looks as though one of them is "locked". New ini files with defaults assigned will be created when eqmod next runs.

Use the toolbox to verify connection to the mount. Unlike many other ASCOM clients the toolbox will not shut down eqmod if it fails to connect (the cause of the flashing) allowing you to see any error messages it may be displaying.

Chris.

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Hi All,

I've just joined the AstroEQ fraternity as it just arrived here in Thailand from Tom on Thursday. Would have been setting everything up as I speak but for my laptop to develop the "blue screen of death". So, spent the last couple days rebuilding the damn thing. Hopefully I can start setting everything up tomorrow.

If things don't go smoothly it's good to know that the experts are on hand here on this thread.

Anyway, I understand Tom flies out to the States on Monday so I'm sure all of us here wish him a safe journey and a successful time whilst he's over there. (Make sure you come back, Tom).

Cheers

Brian

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Not been on this thread for a while. Good to see its still going strong :) finally got Astro eq set up on a permanent setup and it's working perfectly. I'm amazed how accurate it is with cdc. Had a good scan round the other day and thought I'd try andromeda. After a slow slew there it was bang smack in the centre. Thought I'd have a go at imaging for the first time using AstroEQ, here is the result, only my third image so forgive the basic processing! Thanks everyone for all the help getting up and running :)

8a2408d98fb2bcbbf7be2ba8775c9958.jpg

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