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Old 20-10-2019, 04:16 PM
astrochix (Sharon)
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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
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Old 20-10-2019, 04:54 PM
Startrek (Martin)
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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
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Old 21-10-2019, 08:23 PM
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ngcles
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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.
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Old 22-10-2019, 09:30 AM
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Flatbed trolley. There not expensive.
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Old 22-10-2019, 09:44 AM
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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.
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Old 31-10-2019, 12:42 PM
WynneP (Peter)
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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
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Old 07-12-2019, 07:01 AM
Wavytone
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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.
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Old 07-12-2019, 07:40 AM
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mental4astro (Alexander)
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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.
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