From scrap metal to mount #celestron


tjoeki@...
 

Hi all

first of all thank you Howard for your efforts. 

also to all others I see here across the boards giving advice sharing knowledge. What good is knowledge if you don’t share it.

i want to give special thanks to a friend of mine who, like you guys, is gifted with technical skills a brilliant mind and perseverance.

because of personal problems I had to sell my equipement a couple years back. All that remained was a CGEM, shorted control board crappy DC motors and a tolerance  in its gears, it look more on a shakerdeck from Parker Schnabel then a mount.
it was its weight worth in aluminum. 


but Patrick my friend likes a challenge. So after spending €100,- in parts and stepper motors, a begin was made. a lot of time invested by Patrick his agreeable spous, the result is awesome. 

the setup is a CGEM OnStep KD mount. (Kastelijns-Dutton 🤓) 


Mike Ahner
 

That's really great! You're friend did a very good job it seems, especially since the mount was non-functional.

I like these kinds of projects that salvage items and restore the usefulness. For many people it's hard for them to see the hidden valley in broken items like this & even if they see it, people often don't have the skills or patience for such a project. You're very fortunate to have such a good, skillful friend!

I hope you have many, many enjoyable hours under the stars.


Khalid Baheyeldin
 

Nice project!
It is in the showcase page now.


Chris Vaughan
 

Very nice. What gear ratio have you used? I've got 48:15 in mine but thinking of changing to 60:15. It's just a bit of a squeeze to fit in the larger pulley

Chris


Patrick Kastelijn
 

Yes,
I used 60/15 ratio and 0.9 stepangle steppers.
The 60 t pulley was made a little thinner on the lathe and I had to mill out the housing to make enough room so the 172t belt would not bind.
To get better acces to the belt and for easier assembly I bored some acces holes and 3d printed some plus to cover them.


Mike Ahner
 

On Sat, Aug 1, 2020 at 06:11 PM, Chris Vaughan wrote:
Very nice. What gear ratio have you used? I've got 48:15 in mine but thinking of changing to 60:15. It's just a bit of a squeeze to fit in the larger pulley
Chris, you might try these 12t pulleys with your 48t. That gives the same 4:1 without having to use a larger pulley. I've ordered from them earlier this year but of course it's anybody's guess about shipping these days. I don't really remember how long it took before but they did arrive. These have 4mm & 5 mm bore.
https://www.aliexpress.com/item/32871142006.html?spm=2114.12010612.8148356.14.fe7d6a79UUV513




Mike Ahner
 

On Tue, Aug 11, 2020 at 09:46 AM, Mike Ahner wrote:
Chris, you might try these 12t pulleys with your 48t. That gives the same 4:1 without having to use a larger pulley.
Here's a source in the US that has flangeless pulleys. However they are quite a bit more expensive than pulleys from China.

https://www.sdp-si.com/products/GT-Timing-Belts-and-Pulleys.php

Here are 60t pulleys without flanges, that makes them somewhat smaller than usual.
http://shop.sdp-si.com/catalog/?cid=p346&filter=a0%3A2%3A2%20mm%20(GT2)%3Ba6%3A2%3A60.0%3Ba20%3A2%3A6.0%3Ba15%3A2%3ANo%20Flange%2FFairloc%20Hub%3ANo%20Flange%2FWith%20Hub&sort=a25&view=table


Curly
 

Most of the flanged gt2 pulleys have removable flanges. They are pressed on and will come off with a pair of pliers. 

Curly

On Tue, 11 Aug 2020 at 16:29, Mike Ahner <mahner@...> wrote:
On Tue, Aug 11, 2020 at 09:46 AM, Mike Ahner wrote:
Chris, you might try these 12t pulleys with your 48t. That gives the same 4:1 without having to use a larger pulley.
Here's a source in the US that has flangeless pulleys. However they are quite a bit more expensive than pulleys from China.

https://www.sdp-si.com/products/GT-Timing-Belts-and-Pulleys.php

Here are 60t pulleys without flanges, that makes them somewhat smaller than usual.
http://shop.sdp-si.com/catalog/?cid=p346&filter=a0%3A2%3A2%20mm%20(GT2)%3Ba6%3A2%3A60.0%3Ba20%3A2%3A6.0%3Ba15%3A2%3ANo%20Flange%2FFairloc%20Hub%3ANo%20Flange%2FWith%20Hub&sort=a25&view=table


Drew 🔭📷🚴‍♂️
 

On Tue, Aug 11, 2020 at 10:46 AM, Mike Ahner wrote:
These have 4mm & 5 mm bore.
https://www.aliexpress.com/item/32871142006.html?spm=2114.12010612.8148356.14.fe7d6a79UUV513
That same vendor also has these excellent diaphragm type couplings that I have been searching for:

https://www.aliexpress.com/item/32923775926.html?spm=2114.12010612.8148356.4.abe2398dSNdwAi

These are the best type for direct coupling and are usually hard to find and much more expensive.