#1  
Old 20-10-2019, 04:16 PM
astrochix (Sharon)
Registered User

astrochix is offline
 
Join Date: Feb 2013
Location: Canberra
Posts: 8
Wheels on Dob

Hi

I have a 16" dob and it's a bit cumbersome to get around. I'm thinking of attaching wheels to the base.

Now I'm not using it for photography so a little movement won't matter too much for observing. I'm just not sure how much movement there would be. Has anyone else done this?

sharon
Reply With Quote
  #2  
Old 20-10-2019, 04:54 PM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 5,990
Maybe just buy a low flatbed trolley with a handle from Bunnings or online supplier and sit it on that
If you sell it in the future it will have no holes etc... So like new when you originally bought it
Reply With Quote
  #3  
Old 21-10-2019, 08:23 PM
ngcles's Avatar
ngcles
The Observologist

ngcles is offline
 
Join Date: Dec 2006
Location: Billimari, NSW Central West
Posts: 1,664
Quote:
Originally Posted by astrochix View Post
Hi

I have a 16" dob and it's a bit cumbersome to get around. I'm thinking of attaching wheels to the base.

sharon
Hi Sharon,

This can work if the telescope is used manually, but won't work with any sort of digital setting circles because even minute movements of the ground-board will wreck your star alignments.

Best,

L.
Reply With Quote
  #4  
Old 22-10-2019, 09:30 AM
doug mc's Avatar
doug mc
Registered User

doug mc is offline
 
Join Date: Feb 2007
Location: Mt Tamborine
Posts: 587
Flatbed trolley. There not expensive.
Reply With Quote
  #5  
Old 22-10-2019, 09:44 AM
Suzy's Avatar
Suzy
Searching for Travolta...

Suzy is offline
 
Join Date: Jan 2010
Location: Brisbane, Australia.
Posts: 3,700
Hi Sharon,

I have a 10" dob with a wheel frame. 2 locking castor wheels at the front and 2 larger wheels at the back. Stays put for me, even at times when its on concrete I don't notice any movement.

I use the tension handle to pull it along.
Reply With Quote
  #6  
Old 31-10-2019, 12:42 PM
WynneP (Peter)
Registered User

WynneP is offline
 
Join Date: Apr 2014
Location: Scarborough 2515
Posts: 20
Wheels for dob

I made something similar to what is shown in the following in this link:
https://www.cloudynights.com/topic/1...125-dob-advice

It works well for my 12" dob. Easy to make and the cost is minimal - can use old lawnmower wheels.

Suggest it is better than a castor platform, because:
- bigger wheels can better traverse unpaved surface or grass
- wheels are not in contact with ground, except when moving. So it is much more stable.

Good luck, Peter
Reply With Quote
  #7  
Old 07-12-2019, 07:01 AM
Wavytone
Registered User

Wavytone is offline
 
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
Wheels are cheap at Bunnings. Two lengths of wood on either side of the rocker box could be used to lift it off the ground and wheeled like like a wheelbarrow.

Or you could make a base with lawn-mover wheels and the whole dob sits on that, pull it with a rope or handle.


Plenty of examples for inspiration can be found on CN.

As above big wide wheels work best.
Reply With Quote
  #8  
Old 07-12-2019, 07:40 AM
mental4astro's Avatar
mental4astro (Alexander)
kids+wife+scopes=happyman

mental4astro is offline
 
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,979
Wheel burrow handles are a great solution for a large dob. You need to be careful though with whatever solution you use that you do not introduce "slop" into the mount by way of the wheels. It can be like setting up on turf - you need to overcome the slop or play in the wheels before the scope even begins to move, meaning that you need to use more force to move the scope. And when you stop moving the scope, this slop will then manifest itself as backlash and the object in the FOV moves out of position. In effect, the scope becomes harder to move around, you have introduced backlash into the system, and what fine control you had with tracking at high magnification is compromised if not rendered impossible.

This is one reason why those stumpy little rubber stoppers seen under the ground board of mass produced dobs are useless when the scope is set up on turf - they just cannot reach through the grass so the ground board is resting on the turf, and the turf becomes an integral part of the dob's mount now, and the quality of action you once had goes out the window and you end up wrestling with the scope. Dobs with those stumpy rubber stops need to be set up on hard ground, not turf.

Flat bed trolleys, even those with locking wheels, still have play in the wheel mechanism, which can affect the quality of the scope's action. The play comes from the axle holding the wheel and the hinge that the wheel pivots around, and there's four sets of wheels. This is if you leave the scope set up on the trolley. Wheel burrow handle solution leaves out any possible influence of the wheels.

Which solution you chose of course is entirely up to you. But you need to be aware that there can be consequences with some solutions depending on how you end up choosing to use that solution. What you do not want to do is compromise the quality of action the scope has. Any weak point in the system will affect the quality of the action. What ever small play there there appears to be in a trolley (if the scope is left set up on a trolley), don't forget that this "small play" will be greatly magnified through the scope. It is all about eliminating possible problems being introduced.

Alex.
Reply With Quote
Reply

Bookmarks

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 05:56 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Bintel
Advertisement