Go Back   IceInSpace > Equipment > ATM and DIY Projects

Reply
 
Thread Tools Rate Thread
  #21  
Old 22-05-2019, 09:13 AM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
I knew I m not the only one
Reply With Quote
  #22  
Old 22-05-2019, 11:42 AM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,973
The table was antique before my parents got it sometime in the late 1960's, it is just like crashing and repairing a race car. A couple of decades later it is just another bit of it's history.
Reply With Quote
  #23  
Old 23-05-2019, 08:09 AM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
What nice stories you have, once I had a motorcycle engine on the table in the bedroom. I need some thinking of what I could do with it.

http://www.astrofriend.eu/vehicles/m.../minibike.html

But now the problem are of smaller physical size.

Today I have found shims washers of steel, m40 ID 50 OD, 0.1 and 0.2 mm thickness. I don't trust these plastic shims, the old are deformed by the pressure. It will come photos later. I will keep one plastic shim on top to have it act as a spring when length of shafts changes because of temperature.

I wrote to the university where I studied once, thay had a terrific workshop. But they didn't have it anymore, I must look for a lathe somewhere else.

Everything are in progress now and I can't see any problem that I can't fix.

Lars
Reply With Quote
  #24  
Old 23-05-2019, 08:14 AM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
Quote:
Originally Posted by Astrofriend View Post
...Everthing are in progress now and I can't see any problem that I can't fix.
Lars

That is good
Reply With Quote
  #25  
Old 24-05-2019, 11:30 AM
Sunfish (Ray)
Registered User

Sunfish is offline
 
Join Date: Mar 2018
Location: Wollongong
Posts: 451
Sounds familiar.

My dad used to repair the Kombi motor on the kitchen table. In those days there was no garage with a workbench I suppose.

Must run in the family as when I came home from school my brother had his triumph Bonneville in parts on newspaper in the lounge room.

I like the sound of onstep for the EQ6/EQ5 with belt drive. . I should try that next , having tried it on the fork. Just need to get the wireless module to work.


Quote:
Originally Posted by The_bluester View Post
You sound like my dad bojan.

It was before I was born but my mum's Fiat 500 apparently used to do a head gasket with some regularity and he had replacing it down to a fine art, doing it on the dining table. A table which we still have and that half a century later still has marks on it to prove it where oil went in to the oak and marked out the corner of where the head was sitting one time, among other things like a clear imprint of a ball bearing.
Reply With Quote
  #26  
Old 17-06-2019, 05:19 AM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
It's always so much to do, but this weekend I got some time to work on my EQ6 mount.

I have removed the paint on the surfaces of the lids that cover the worm gear.

You can follow the work here:
http://www.astrofriend.eu/astronomy/...ebuilding.html

To my surpise one of the surfaces was not milled, anyone else that have found that too ?

/Lars
Reply With Quote
  #27  
Old 17-06-2019, 05:29 AM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
Whenever I have situation like this, I use a large enough sheet of sandpaper on flat surface.
This way the final result is close to what it would be if the paint was removed on milling machine.
Reply With Quote
  #28  
Old 17-06-2019, 07:56 AM
mswhin63's Avatar
mswhin63 (Malcolm)
Registered User

mswhin63 is offline
 
Join Date: May 2009
Location: Bertram, Western Australia
Posts: 3,327
Quote:
Originally Posted by bojan View Post
Whenever I have situation like this, I use a large enough sheet of sandpaper on flat surface.
This way the final result is close to what it would be if the paint was removed on milling machine.
Have to agree, I have a marble cutting board that is never used as a cutting board and place a large sheet of emery paper of varying grits to get an excellent finish. Not much use for protrusions but can be manipulated to get in some tight places.
Reply With Quote
  #29  
Old 17-06-2019, 03:27 PM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
Yes I thought about that, but then I need to find a flat surface with a hole to let the RA shaft through. But even better with a lathe, then I get the surface orthogonal to the RA shaft also.

Lars
Reply With Quote
  #30  
Old 20-08-2019, 12:48 AM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
Now it's time for an update of my timing belt project.

From the beginning I was not convinced that I should modify my EQ6 mount and replacing the spur gears with timing belts. But I do now.

I needed some tools and machines.

I looked for a used desktop lathe but couldn't find any and the time goes on. Later a new friend offer to me to use his lathe, perfect, maybe I can be finished in time and some test later when the darkness comes back.

You can read here what I have done, also added a lot of photos to make it easier to follow:

http://www.astrofriend.eu/astronomy/...ebuilding.html

I can not recommend any to do this, better to buy a ready made kit that is just to mount. I feel it's more exiting to do things myself, maybe a sickness.

It will be very interesting to see if I get any advanteges of using a wider 6 mm belt for more stiffness and the GT2 profile pulleys that they use in 3D printers to reduce the backlash.

/Lars

Last edited by Astrofriend; 20-08-2019 at 08:14 PM.
Reply With Quote
  #31  
Old 20-08-2019, 08:10 AM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
You did a very good job, I would say.
Yes, generally kits are easier to install (but as we know, anything can (and will) go wrong), but they are also much more expensive.. and they are (probably) using the same sources for components... so why not try to DIY, it is always fun.
Reply With Quote
  #32  
Old 20-08-2019, 08:17 PM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
Hi Bojan,
Thanks for the coment.

I have a question for you, you looks to be a big DIY. Do you have any experience of 3D-printing, and maybe Carbon fiber filament?

/Lars
Reply With Quote
  #33  
Old 20-08-2019, 09:48 PM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
I have used PLA at the beginning, and ABS ever since. Never tried Carbon filament.
Reply With Quote
  #34  
Old 20-08-2019, 10:12 PM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
Hi Bojan,
I'm on the move to buy a 3D printer, just need to collect more information what's important.

I setup a new page with 3D related links, the last link is an info page about 3D printing and carbon fiber.

http://www.astrofriend.eu/links/link...-printing.html

See also the spectrograph, very interesting.

There must be many parts that I could 3D print and use in my telescope and others.

I start a new thread later when I have something more to tell about 3D printing and what I do. Lots of ideas in my head for the moment.

The 3D printer I'm interesting in is this one:
https://www.anycubic.com/collections/kossel-series

Maybe more safe to buy a traditional XYZ printer.

/Lars
Reply With Quote
  #35  
Old 21-08-2019, 07:22 AM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
Yes, there are many thngs you can 3D print.. however you always have to keep in your mind the limitations:
- structural strength is always lower compared to injection moulding of the same material
- dimensional tolerances are usually > +/-0.15mm or even more

I usually apply post-printing machining where needed... of course that means the model must be appropriatelly dimensioned (by 0.5mm or so on surfaces to be machined)

The printer you linked is OK (price is certainly attractive)... judging by reports from some of my friends who also use similar concept (my printer is DIY, cartesian type. Firmware is Repetier, which also support Delta geometry, which is potentially capable of moves Cartesian printer cannot do ).
Reply With Quote
  #36  
Old 26-08-2019, 04:03 AM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
I found a lot of interesting information about 3D printers. One link is about parametric CAD model of pulleys.

All links are collected here, this link is the second last:

http://www.astrofriend.eu/links/link...-printing.html

If I can 3D print pulleys with enough accuracy it's fantastic. I can then print odd dimension and teeth numbers. If it not possiblie today it will be soon.

Next time I need a gearbox or timing belt drive I will give it a try.

/Lars
Reply With Quote
  #37  
Old 26-08-2019, 07:26 AM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
I was printing pulleys and gears, see here, here and here.
Parametric designs (using OpenSCAD) are a good way to go, especially because it is easy to taka care of details like tolerances where needed... And printer settings are also VERY important... Once I even needed to alter the design to get desired outcome on my printer.

Last edited by bojan; 28-08-2019 at 07:47 AM.
Reply With Quote
  #38  
Old 28-08-2019, 07:46 AM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
BTW, this guy published VERY useful parametric designs for all sorts of gears.. I used one of them for my dobson encoder (large helicoidal sector).

Also, I used this design for my timing pulley (for encoder).. However, there was an error (IMO) in the design, the timing belt thickness was not treated in calculations as it should have, resulting in wrong teeth pitch (2.4% smaller.. I notified the author about this, and it is easy to correct the design to the pulley turns out OK).
Reply With Quote
  #39  
Old 29-08-2019, 08:05 PM
Astrofriend's Avatar
Astrofriend (Lars)
Registered User

Astrofriend is offline
 
Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 206
Hi Bojan,
Thanks for the links, I added them to my link list about 3D printers: http://www.astrofriend.eu/links/link...-printing.html

What filament (material) have you found that works best when printing pulleys and gears?

I have no experience yet but have read that carbon fiber filament are strong but give a rough surface. PETG I have seen recommended for this purpose.

I got the printer delivered yesterday, now I assembling it. Looks to be of very high quality, but not better then I found some small details to improve. I will setup a page about it later when I'm finished.

/Lars
Reply With Quote
  #40  
Old 29-08-2019, 08:46 PM
bojan's Avatar
bojan
amateur

bojan is online now
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,859
I was using ABS for everything.. it is strong enough, but you need to know what and why you are doing.
When you need strength, you should use metal.
Carbon fibre is OK (so I am told) but it is ver abrasive, it wears nozzle (there are nozzles made of ruby for that)
Reply With Quote
Reply

Bookmarks

Tags
dismantling, eq6, mount, timing belt

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 01:11 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Lunatico Astronomical
Advertisement
SkyWatcher Australia
Advertisement
Meade Australia
Advertisement
Bintel
Advertisement
Celestron Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
NexDome Observatories
Advertisement
Astronomy and Electronics Centre
Advertisement