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Messages - khobar

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1
DIY AstroEQ / First light
« on: August 13, 2019, 15:36:56 »
Finally, the clouds went away and I got my first chance to try out my DIY AstroEQ on real targets. I used my "light" ES80 80mm APO w/Nikon D5300.

PA: Sharpcap Pro 3.2
Guiding: ASI120mm and PHD2
Image capture: Nikon D5300 via BackYardNikon
Mount: LX70 w/AstroEQ EQMOD Stellarium


I had some issues with GOTO's. Initial GOTO the moon was pretty accurate, but M31 was not. I believe this is my unfamiliarity with EQMOD.

Guiding was interesting once I figured out EQMOD RA and DEC guide rates. Once the mount settled it seemed to guide okay especially since I discovered the DEC belt was actually loose. I'll check the RA belt today as it's under a cover presently.

Slewing is so much quieter than my wife's "coffee grinder" 5 but not as quiet as my CEM25p, but it's pleasant.

Focus - OMG last night was a challenge even with the Bahtinov mask.

I did find M31 manually - this is a single 60s ISO200 exposure:
 

2
DIY AstroEQ / Re: RA rotates same direction/autoreverses
« on: August 08, 2019, 14:34:52 »
Yesterday evening, I ran Stellarium in "real time" and pointed the mount at perhaps six targets including Saturn, Jupiter, and the moon. The mount slewed to them fine (as verified from our patio).



3
DIY AstroEQ / Re: RA rotates same direction/autoreverses
« on: August 08, 2019, 00:10:04 »
Small update.

It seems my joy is short-lived. Electrically, the mount moves smoothly and quite quickly, but pointing doesn't seem to be working as I had thought. After having left the mount powered up in park for about an hour, I tried to slew to Saturn again and it pointed roughly WSW.

I'll keep at it. I must be overlooking something.


4
DIY AstroEQ / Re: RA rotates same direction/autoreverses
« on: August 07, 2019, 20:26:11 »
Pins 2&4 on M1 (DEC) driver board were shorted. Unfortunately, I don't know what I did to clear the short. Maybe it's gone for good, maybe not. But it's gone for now. ;)

As a result, I was able to slew both axes at full speed (800) simultaneously. That's a big difference already.

DEC was reversed.

Mount now slews in general direction of Saturn in Cartes du Ciel! I'm sure it will do likewise in Stellarium. That makes me very happy indeed!

Thanks very much, Tom. I am so looking forward to clear skies to give it a go outside.




5
DIY AstroEQ / Re: RA rotates same direction/autoreverses
« on: August 07, 2019, 15:48:30 »
Some additional info:

Physically slewing DEC 90 degrees only shows about 45 degrees in EQMOD.


6
DIY AstroEQ / Re: RA rotates same direction/autoreverses
« on: August 07, 2019, 15:13:34 »
Thanks Tom.

Even eyeballing RA before coffee this morning, I can tell it's tracking fast, and a rough measurement confirms - it makes one revolution in about 222 seconds. That's not right, or is it?  :o

From jslight in another thread: "The EQ5 mount has a 144:1 worm gear ratio for both axes.  360 / 144 = 2.5, the angle of mount movement with one revolution of the shaft.  If you are using the 40 and 15 tooth pulleys from the FAQ (with the 40 tooth pulley on the mount shaft), then 2.5 / 2.6666667 = ~0.9375, the angle of mount movement with one revolution of the stepper.

Sidereal rate ≈ 1 / 4min.  So it should take about 3 minutes and 45 seconds for a full stepper revolution at sidereal rate."


I have manually counted the teeth both on the 15T and 40T gears.

The motors are: STEPPERONLINE Nema 14 Bipolar Motor Stepper 7.5V 0.5A 32.6oz.in/23Ncm 4 Leads 1.8 deg

As for direction, at the moment I have the mount pointed North, and while tracking, RA rotates West. This is consistent with the direction buttons in EQMOD, and with slewing within CdC and Stellarium. I *think* that's right.

7
DIY AstroEQ / Re: RA rotates same direction/autoreverses
« on: August 07, 2019, 03:13:55 »
I'm getting there!

I am now stumped, however. I'm taking advantage of our monsoon season by bench testing indoors, and while it seemed like everything was slewing nice and smooth, there's something amiss.

I have the LX70 (CG5) mount pointed north. Input all the correct information regarding location, time, date, etc. I tell Stellarium or Cartes du Ciel to slew to Saturn and while the program(s) think the scope is doing its thing, the scope actually overshoots by a huge margin.

My config is 1.8, 2.666666667, 144, 550 for RA, and 1.8, 2.666666667, 144, 550 for DEC. 16uSteps, Enabled. Click "Update" and the RA and DEC fields are the same (see attached). I can set RA to 800 (824) fine, but DEC doesn't seem to like to go that high. 550 works fine.

I have tried disabling ustepping, and changing the value, and it just seems to affect the speed at which things go wrong.

Any thoughts?

Cheers!

8
DIY AstroEQ / Re: RA rotates same direction/autoreverses
« on: August 06, 2019, 02:55:41 »
Upon closer inspection of the driver boards on the AstroEQ, I found what appeared to be a cold solder joint. I touched up that and any suspect pins and, so far, the problem seems resolved. Fingers crossed.

 

9
DIY AstroEQ / Re: Before first power up question
« on: August 03, 2019, 00:47:59 »
Hi Tom.

I was thinking the gears themselves rather than the values plugged into the configuration utility.

I just got my "final" gears: 15T and 40T.

10
DIY AstroEQ / RA rotates same direction/autoreverses
« on: August 03, 2019, 00:02:23 »
My final gears arrived today and I'm bench-testing the mount (LX70) inside. At first it was working as expected - very smooth, very quiet. But after 10 minutes or so I noticed the RA motor turning in the same direction no matter what I commanded in EQMOD. This followed a DEC motor "stall".

Any ideas why my RA motor would suddenly start rotating same direction/autoreverse?


Thanks.

11
DIY AstroEQ / Re: finished build inc 3D printed housing.
« on: July 12, 2019, 23:40:16 »
I don't know if the OP is still active, but I thought I'd say THANK YOU just in case. I printed one of these and it really is very nice. Very pleased.

I have heat sinks but I went ahead and soldered the driver boards to the AstroEQ pcb. I'm probably asking for trouble, but there you go.

12
DIY AstroEQ / Re: Before first power up question
« on: July 12, 2019, 23:35:48 »
Thanks Tom!

I'm a bit excited. I have the system running on the bench currently with Stellarium.

As for the blank fields, I have saved things to a config file so no worries. One thing I am puzzled/curious about and that's gear ratio - I'm using 2:1 (30T15T). Obviously, I can change this to 3:1, 4:1, etc. What determines what's best?


13
DIY AstroEQ / Re: Before first power up question
« on: July 12, 2019, 15:22:14 »
Okay, so I had my wife go over my work and she approved.

Powered it up and was able to update/configure.

Had downloaded the wrong piece of EQMOD. Now have something called EQASCOM, and once I configured the com port, AstroEQ now brings up EQMOD.

When I click on N, the stepper motor kicks like one step. When I click multiple times the motor moves but it is rough, like hitting with a hammer.

***update***
The motors were wired incorrectly. I thought it was 1A/2A and 1B/2B but it's actually 1A/1B and 2A/2B.

I noticed every time I open AstroEQ it leaves a lot of stuff blank even after it reads from the device (motor step angle, gear ratios, etc.).

***update2***
I guess the config stuff doesn't matter because I have things running with Stellarium on the bench.



14
DIY AstroEQ / Before first power up question
« on: July 11, 2019, 16:33:23 »
Hi folks,

I'm just about ready to power up my AstroEQ for the first time and am wondering if there's anything I should be aware of before I do. Also, assuming I've done things right and nothing smokes, then what?

Thanks.

15
Mount Support / Pulleys, ratios, EQ5 (CG5) just to be sure
« on: June 12, 2019, 16:47:28 »
Hello!

I've now got all the parts to assemble my AstroEQ board.

I have a brand new manual Meade LX70 as the intended mount to GT.

From reading here, the worm gear ratio is 144:1, but that's something for the config file.

I am awaiting 2x 3M30 and 2x 3M15 pulleys, 10mm width.

Also awaiting 2x 3M 10mm width 111mm length belts.

If I read the other thread correctly, this is a simple 2:1 ratio. But someone else used 40:20 for the same ratio. Does it matter? ***edit 40:20? Must have read that wrong as that's still 2:1***

And the 111mm belt - does the length matter much with it? ***edit length matters because the motors are non-adjustable. 111mm is too short***

Thanks!

Khobar

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