Date   

Connecting to telescope. MKS Gen-L

alekstad46@...
 
Edited

Hi to all.
I recently made a project using MKS Gen-L and Onstep v:2.22. When running through an android application, everything works well.
Reinstalled ASCOM Platform and The STABLE OnStep ASCOM driver (version 1.44). I connect it through com5 and ASCOM Platform sees the com5 port in the list of available ports. Trying to connect to the planetarium I get an error. Yes, I forgot to add - I use a USB cable with a cut +5v line.
What's wrong?
 

 

 


Re: My OnStep setup.

Gilles Gagnon
 

Sorry, I just attached 1 photo. 


My OnStep setup.

Gilles Gagnon
 

Here are 2 photographs of my OnStep setup. It consists of:

An OnStep modified Astro-Physics AP400 mount, with a MiniPCB V1.274, a Teensy 4.0 (replacing a 3.2) and TMC5160 drivers, driving NEMA 14 motors;
An ODROID N2 computer running Ubuntu, KStars, EKOS and Indi server;
A RPI running as a hotspot;
A ZWO ASI1600 camera and Zagyl filter wheel;
A Pegasus Astro DFMC focuser and Power Box;
All this on a home made telescope cart (missing a wheel :-) ) that will allow me to roll it out of the garage and get ready for observing/astrophoto within minutes. 

The OnStep controller is the grey box mounted on a small plexiglass sheet, attached to the tripod leg. The cart design was an adaptation of one, presented by the BBC Sky at Night Magazine (https://www.skyatnightmagazine.com/advice/build-a-rolling-telescope-dolly/).

Enjoy!


N.I.N.A. focus control

pfloyd36069@...
 
Edited

Hello,

I recently finished adding a focuser motor to my OnStep rig. I am having some issues though using it to autofocus in N.I.N.A. Sometimes when it commands the focuser to go to a certain position, -11995 for example, it will not go to that position but will continually bounce between -11994 and -11996. Once it starts doing this during autofocus or backlash measurement, I am unable to stop it unless I disconnect from the focuser in N.I.N.A. I have tried various backlash settings including setting both N.I.N.A. and the OnFocus driver to zero backlash. I do not know if it is the driver, the OnStep controller, or N.I.N.A. causing the issues. Has anyone else had any similar problems?

Thanks,
Bryan  


Re: Onstep converted EQ3-2

pfloyd36069@...
 

I have not tried readjusting yet. I have used it a few times in the past week and things seem to be working great! I do need to refine my alignment and polar alignment skills though. 


Re: Onstep converted EQ3-2

julianporter5@...
 

How did you get on with the adjustment? Have you persevered with this mount?


Newly built MaxPCB mock-up

Dan
 

About a month ago I bought a MaxPCB pc board from the classifieds on Cloudy Nights. The plan is to use it to control a 10” dob that I’m building but I accumulating parts and soldering it together just as a knitting project.  When I had it basically together I hooked up a couple of stepper motors and ran it on the bench just to see the motors turn.   It mostly just worked out-of-the-box, and I was so pleased that I wanted to see it do something more realistic, so I zip-tied my tetrad and a finder scope to a board and made a mock-up of a dobsonian telescope.


This is a really crude model that is screwed together out of some salvaged plywood, odds and ends,from the junk bin, and about $30 worth of stuff I had to buy on Amazon.  It’s cloudy in Seattle tonight (what were the odds?!) so I set it up on my workbench, pointed it about where Polaris ought to be, and fired up SkySafari.  In this youtube video I arbitrarily picked out Mirfak in Persius, hit goto, and the scope slewed east and a bit south about as it should.  I need clear skies to see just how accurate it is, but in rough terms it all seems to work as expected.
 

This mail duplicates the start of this thread on Cloudy Nights, where I will post any follow-up content:








Re: OnStep version 3

Howard Dutton
 

Glad you guys are liking the changes.

Once we start building out a Wiki page with more detail about the settings and add links to that in the new Config.h file it'll become even better.


Re: New Dob Owner

T.K
 

Obviously you need off-center screws to hold it. It can't be fixed just with the friction of that small contact surface, and the centre bolt alone will not provide enough force to increase the friction to the required level.
Along with your solution, you can also build a structure using mount legs screws to keep the pulley fixed. That's avoid more drilling in the mount.


Considering selling my CG11 with Onstep Max

John Scherer
 

As always Howard, if this post is a problem, just let me know and I'll remove it:

I've been lamenting over this for a few months now and I think I'd like to test the waters.  What I've got:

  • Celestron/Losmandy CG11 mount converted to Onstep.  400 steps/r motors on RA/DEC  Encoder mounted on RA for PEC  It still has some bugs to work out but I suspect that won't be too hard to figure out.  Mostly software at this point I suspect.
  • Upgraded One Piece Worm block and worm
  • Upgraded Losmandy G-11 SPDV saddle plate. Accepts both D and V series dovetail plates.
  • Losmandy Ra Extension kit which allows for meridan flip.
  • Onstep MaxPCB assembled and functional and enclosed in the enclosure recommended in the WIKI, along with 3d printed front and rear covers. TMC2130 on RA/DEC
  • A built SHC but no enclosure as of yet.
I'm not excited about selling this.  I think the work Howard and others here have accomplished are truly spectacular.  But my wife and I are traveling around the USA in our 40' motorhome, and try as I might but not having a workshop and bench space or the time to work on this project, has proven to be quite frustrating.  Also, I'm not interested in shipping this setup, just too much risk,  but we will be back in the San Diego area on November 14th, so if you live in an area within reasonable distance to me, that would be ideal.  If you have any interest, let me know..  We are currently traveling along the Oregon coast and presently in Garibaldi until Friday, at which point we head to Newport for 7 days.  So if your in the area and have and interest, reach out.


Re: New Dob Owner

John K.
 

I have updated the design of the base pulley again, and I will use PETG this time to print it..  The main reason is that it was slipping and turning freely.  I tighened up the the nut, but it kept on happening.  I have never printed nylon before.  If I have any problems with the PETG, I will give it a try.

The new design has a larger footprint that mates up to the lower base, and I also added 4 bolts around the center that will keep it in solidly in place.  I will add some pictures when I have printed it.

I also went through several designs for the Alt stepper mount.  I think I have one that will work well.  I am printing that now. 

I have also printed the Az stepper mount in PETG.

One of the great things about 3D printing is the ability to rapidly update designs.


Re: New Dob Owner

Ant No
 

Sorry, should have said force over area means if you divide the force by the number if teeth the higher number of teeth in a larger wheel means less force per tooth.

In a similar way I wonder about the area of the nut embedded in the pulley. Will the print around it be ample to handle the force per area or would a lager plate, drilled and tapped, be useful to allow a greater area of plastic to divide the force over? I have no idea of the loads and forces involved.


On 14 Oct 2019 03:00, wrote:

The larger the pulley the less the torque per tooth is. The larger circumference has a larger area for the given force to be divided over. Force over area.


On 14 Oct 2019 02:51, "Ant No" <cmpaqp1100@...> wrote:

I would have suggested nylon, which has a long history as durable plastic gear teeth. It is strong and will resist breaking much more than PLA. POM (Delrin, Acetal) is even stronger and lathe users have turned bar sections into half nuts for the lead screw in small metalworking lathes with great success

I have heard good things about PETG but I suspect the other two are even stronger.

Anthony


On 12 Oct 2019 22:10, "John K. via Groups.Io" <tj_slice=yahoo.com@groups.io> wrote:
Don't you want to use a clutch on this axis?
Not at first.  That will be a project for a later date.  I know next to nothing about them, so I will have to do some research.  I am open to ideas.

The stepper brackets are adjustable for the tension.  I am going to use some wing nuts that I can loosen to relieve the tension on the belts for now.


Re: New Dob Owner

Ant No
 

The larger the pulley the less the torque per tooth is. The larger circumference has a larger area for the given force to be divided over. Force over area.


On 14 Oct 2019 02:51, "Ant No" <cmpaqp1100@...> wrote:

I would have suggested nylon, which has a long history as durable plastic gear teeth. It is strong and will resist breaking much more than PLA. POM (Delrin, Acetal) is even stronger and lathe users have turned bar sections into half nuts for the lead screw in small metalworking lathes with great success

I have heard good things about PETG but I suspect the other two are even stronger.

Anthony


On 12 Oct 2019 22:10, "John K. via Groups.Io" <tj_slice=yahoo.com@groups.io> wrote:
Don't you want to use a clutch on this axis?
Not at first.  That will be a project for a later date.  I know next to nothing about them, so I will have to do some research.  I am open to ideas.

The stepper brackets are adjustable for the tension.  I am going to use some wing nuts that I can loosen to relieve the tension on the belts for now.


Re: New Dob Owner

Ant No
 

I would have suggested nylon, which has a long history as durable plastic gear teeth. It is strong and will resist breaking much more than PLA. POM (Delrin, Acetal) is even stronger and lathe users have turned bar sections into half nuts for the lead screw in small metalworking lathes with great success

I have heard good things about PETG but I suspect the other two are even stronger.

Anthony


On 12 Oct 2019 22:10, "John K. via Groups.Io" <tj_slice=yahoo.com@groups.io> wrote:
Don't you want to use a clutch on this axis?
Not at first.  That will be a project for a later date.  I know next to nothing about them, so I will have to do some research.  I am open to ideas.

The stepper brackets are adjustable for the tension.  I am going to use some wing nuts that I can loosen to relieve the tension on the belts for now.


Re: 3d printed cycloidal/harmonic reducer accuracy

Ant No
 

Good luck. Keep us informed so that we can learn from what happens. It's interesting.


On 13 Oct 2019 19:56, "T.K" <regulus.mj94@...> wrote:
I talked with Dave Schwartz and designer of that YouTube link harmonic drive. I think i will use timing belt as flex spline.
 Now I'm preparing a 3d model of a 25:1 drive based on a 50 tooth HTD 3M belt for test.
 I changed some parameters from original design (YouTube link) and think it should have better output torque. positional accuracy need to be tested.


Re: OnStep version 3

Khalid Baheyeldin
 

On Sun, Oct 13, 2019 at 02:53 PM, Pete wrote:
Howard,  I am just loving this.  A single config.h file.  Yeah, sure it was a shock the first time I saw it and of course I tripped over the wiring file but, WOW, this makes the whole design much cleaner.
Same here: this is a quantum leap for OnStep!
No more a separate config file for each board.
Same parameters for all boards.
Intuitive and descriptive names for parameters.
No need for an online configuration generator anymore.

And under the hood, there are tons of changes too making it easier for Howard to maintain going forward:
Cleaner code separating validation by driver and by board.

I have it on both my controllers (the one in the mount, and another for testing), and V3 works well.

Thanks again Howard ...


Re: 3d printed cycloidal/harmonic reducer accuracy

T.K
 

I talked with Dave Schwartz and designer of that YouTube link harmonic drive. I think i will use timing belt as flex spline.
 Now I'm preparing a 3d model of a 25:1 drive based on a 50 tooth HTD 3M belt for test.
 I changed some parameters from original design (YouTube link) and think it should have better output torque. positional accuracy need to be tested.


Re: OnStep version 3

Pete
 

Howard,  I am just loving this.  A single config.h file.  Yeah, sure it was a shock the first time I saw it and of course I tripped over the wiring file but, WOW, this makes the whole design much cleaner.

I have just received my S109 drivers and I put them up using OnStep V3 on my bench test rig.  They worked fine.  I am just waiting for a new motor from China and I will put V3, S109s and the new motor onto one of my scopes.

Thank you once again.


Re: 3d printed cycloidal/harmonic reducer accuracy

Ant No
 

Regarding precision and backlash, that depends on your printer. Mine (in theory) is good for 0.1mm. I've toyed with the same idea you have. The truth is I don't know if that precision would be useful. I do know the available materials are up to it if you can work with them to sufficient precision.

Maybe someone else could comment on what precision would be useful.


On 13 Oct 2019 16:53, "Ant No via Groups.Io" <cmpaqp1100=gmail.com@groups.io> wrote:

PETG has been used in working models for the flex drive. Not tested under load. TPU might be or might be too soft, don't know. The timing belt should work.

Nylon or POM (Delrin, Acetal) are durable for non flexing gear teeth. Carbon fibre might be but I have no experience with it and am cautious because it's still PLA and suspect the fibers can't be that long to work in the printer.


On 3 Oct 2019 22:10, "T.K" <regulus.mj94@...> wrote:
On Thu, Oct 3, 2019 at 11:16 PM, Khalid Baheyeldin wrote:
If you mean that this is the total gear reduction (without the motor steps/rotation and microsteps), then it should be sufficient.
Use the spreadsheet and enter your parameters.
Yes, this is the total mechanical reduction. I have an arduino mega 2560 with ramps 1.4 ,two a4988s (which may be replaced by lv8729 after tests) and two 1.3A 200 step NEMA 17 motors. They are tested without load on them and work fine at 0.8A.

P.S. Check here for more info on harmonic drives (eBay used, not 3D printed), and see the results.
I'm not new to OnStep. I almost follow the project for near 2 years and planned to make one last year for mars opposition (which ruined by martian dust storm), but it's stalled due to my lack of knowledge in electrical and manufacturing processes.
I saw that beautiful design and images taken by it. but I can't also buy from ebay or amazon because they don't have shipping to Iran. My options are limited and I should deal with them. So a working 3d printed harmonic drive will make my work easy.


Re: 3d printed cycloidal/harmonic reducer accuracy

Ant No
 

PETG has been used in working models for the flex drive. Not tested under load. TPU might be or might be too soft, don't know. The timing belt should work.

Nylon or POM (Delrin, Acetal) are durable for non flexing gear teeth. Carbon fibre might be but I have no experience with it and am cautious because it's still PLA and suspect the fibers can't be that long to work in the printer.


On 3 Oct 2019 22:10, "T.K" <regulus.mj94@...> wrote:
On Thu, Oct 3, 2019 at 11:16 PM, Khalid Baheyeldin wrote:
If you mean that this is the total gear reduction (without the motor steps/rotation and microsteps), then it should be sufficient.
Use the spreadsheet and enter your parameters.
Yes, this is the total mechanical reduction. I have an arduino mega 2560 with ramps 1.4 ,two a4988s (which may be replaced by lv8729 after tests) and two 1.3A 200 step NEMA 17 motors. They are tested without load on them and work fine at 0.8A.

P.S. Check here for more info on harmonic drives (eBay used, not 3D printed), and see the results.
I'm not new to OnStep. I almost follow the project for near 2 years and planned to make one last year for mars opposition (which ruined by martian dust storm), but it's stalled due to my lack of knowledge in electrical and manufacturing processes.
I saw that beautiful design and images taken by it. but I can't also buy from ebay or amazon because they don't have shipping to Iran. My options are limited and I should deal with them. So a working 3d printed harmonic drive will make my work easy.