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Split Ring / Horse shoe Mount construction gets under way.


Graham
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Well I have decided to make use of this awful weather and get down to designing my new mount.


After a lot of reading up on the different types I have decided to go for a variation on the  Split Ring / Horse shoe mount.


 


By moving the Dec axis pivot point down the frame it makes driving it an easier set up.


It also means I can mount a larger scope with out having to increase the size of the ring / Horse shoe.


 


The RA will be direct drive.


 


Motors will be Nema 23 steppers so power and torque will never be a problem.


 


If I can get it work I should be able to control and guide this mount using Maxim.


 


All steel construction.


Frame - 100mm x 50mm Box section.


The Ring / Horse shoe will be plasma cut from 3mm plate and then backed with 25mm marine ply to allow for the drive to be fitted.


 


These drawings are to scale .


The test scope will be my Helios 200 newt as in the drawings.


 


The idea behind this is if the test go to plan the 200 newt can be replaced with a 16 inch newt.


 


SPLIT%20RING%20MOUNT.jpg


 


View from the rear.


 


SPLIT%20RING%20MOUNT%201.jpg


 


Front view.


 


SPLIT%20RING%20MOUNT2.jpg


 


Top View.


 


SPLIT%20RING%20MOUNT5.jpg


 


Dec Axis drive.


 


SPLIT%20RING%20MOUNT4.jpg


 


RA Axis drive.


 


 


Now all I have to do is build it. :lol: :lol: :lol:


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A bit like this one ?


 


http://www.considine.net/aplanatic/fork/fork_mount001.htm


 


I've been looking something more in line with my wood working skills (Not Hot)


 


http://steve-bell.home.comcast.net/~steve-bell/atm/atm.html which is more of a yoke. I guess  mine will be more like a joke !


Edited by stash
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Thanks folks.


 


I will try to remember to do a step by step photo  journal of the build.


 


Peter - should be portable enough as it will break down into manageable bits.


 


Leigh - I have the breakout boards ect here from when I built a CNC milling machine. Hopefully I can get Maxim to talk to it.

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Thanks folks.

 

I will try to remember to do a step by step photo  journal of the build.

 

Peter - should be portable enough as it will break down into manageable bits.

 

Leigh - I have the breakout boards ect here from when I built a CNC milling machine. Hopefully I can get Maxim to talk to it.

That is even better if it strips down for easier transport.

 

Looking forward to seeing more on this Graham :)

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Fantastic project.

 

Does It works basically the same a EQ Platform, the axis is angled at your latitude and the motors drive it at the desired speed?

 

Hi Doc

Yes it works exactly as an EQ mount does but has the advantage of no counter weights required.

The mount is pola aligned the same as an EQ mount using a pola scope mounted through the Ring / Horse shoe. ( forgot to draw that bit ) :facepalm:

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Great project Graham.


When you mount the 16 inch your going to need lots of counterweight at the mirror end to keep the CoG low enough for the tube bottom to pass through the horseshoe?


 


Welded steel and portable!


Edited by fwm891
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Update on progress.


 


Drives are all sorted.


RA and dec drives will work on a 1 - 900 Ratio.


 


Will be using one of these :- ARDUINO MEGA2560 REV3, BOARD


This will be driven through EQMOD using :- http://www.astroeq.co.uk/downloads.php - written by a very clever chap called Tom (TCWORLD) on Astronomy Shed.


 


This means the mount will work with the full EQMOD functions.


 


Now got to get down to making it.


 


Will keep the updates coming.


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Nice one Graham. I've got an interest in Arduino, I've built a couple of things with it myself. Does it really need a MEGA? I'm guessing you need the extra PWM pins along the way?

 

Leigh I have absolutely no idea what you just said :lol: :lol: :lol:

 

I have some driver boards here from a CNC Milling machine I built years ago, so I sent some photos over to Tom to see if I could use them.

The Arduino board was his recommendation as I will be using 20 volts to drive the stepper motors.

 

Quote

" The Mega board is fully supported by the AstroEQ firmware so using that wouldn't be a problem. You would need to basically connect six wires (plus GND) from the mega board (Step, Dir, En, for each axis) and plug them in to your driver boards."

 

I hope he is right as I am totally useless at this electronics lark. :facepalm: :facepalm: :facepalm:

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All the best with it. There is something very satisfying about getting your own kit made and working. :)

 

Thanks I will let you know if you are right.

The mount I have no problems with building as engineering is what I do :)  but the electronics :facepalm::wallbash:

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