shackers

On 27/11/2018 at 22:26, Fish said:

My onstep journey

When my LXD 75 electronics died I was left with a problem. After asking in this forum it was suggested to go the diy route but initially I discounted it because I wanted a quick fix and after reading up on the options I decided I wasnt upto the task.
After a successful temporary repair of my mount electronics I decided to have a go at DIY.
Out of the two options , Astroeq and Onstep I decided to research the latter.
Here is the wiki.
https://groups.io/g/onstep/wiki/home

At first this reads like some foreign language but dont give up , register on the forum and read. Eventualy things will start to become a little bit clear. 
After a lot of reading I decided to go with the STM32 blue pill , it seems like a neat solution and I found that you can order a full kit from here .
https://baheyeldin.com/astronomy/onstep-telescope-controller-stm32-pcb-kits.html

Thanks to Khalid and Dave for making these kits available.
Im now waiting for my kit to arrive from Canada and because of their postal strikes Im not sure how long it will be.

My intention is to log my build on here so that anyone who has been down this path can advise when im straying off course and in the hope that it may help someone else.

The first thing now is to start to decide on motors and how to mount them on my LXD 75 which is just a standard EQ5 mount.

So it would seem that stepper motors come in loads of variations . Basically for an eq5 mount that has a worm ratio of 144:1 a 400 step motor would be better with a further gear ratio of 3 : 1 between the motor and  drive so decided to go with these motors .
Bipolar Nema 17 stepper motor with step angle 0.9deg and size 42x42x39mm. It has 4 wires, each phase draws current 0.9A.
To get a gear ratio of 3:1 I needed to order the timing belt drive pulleys, it seems the most common standard used is the GT2 type so I ordered 16 tooth for the motors and 48 for the drive to give me 3:1 ratio.
Need to sort out the mounting next.
 

Hi @Fish thanks for this, I have been looking at doing the same as you with an EQ5 mount (mine is a skywatcher so not sure if the gearing still applies?) How did you know what gearing to use? I've tried to use the onstep group but just find it a bit strange on how ot all works 🙈

I'd really like to build this but want to get everything ready first. It doesn't appear that you can purchase the pre manufactured PCB anymore which isn't too much of an issue as is a simple circuit layout really so will just make my own up.

Thanks in advance!

Hi all, I nearly took the plunge earlier with a purchase of a Bresser Messier Dobsonian 8. 
This was supposed to be a gift for my wife (and me) for our wedding anniversary. 
 

I was looking at doing photography with it however have been doing more reading and others on other forums have said it isn’t really suitable for deep space, nebula etc and that I’d be better off with something like a skywatcher explorer 130pds and an EQ5 pro mount. 
 

From what I was told about the Bresser, down the road I would be able to add that to an EQ Mount too but now I’m just getting very confused as to what to purchase.

so in short I want to:

be able to use just to view the night sky, with the option down the road to be able to do deep space photography. Oh and it’s ideally got to be in stock. 
budget around 400-500 for the scope and a stand (hence the dobo I was going to go for). 
can any one help guide me please?