Dob Bearing Plates

[Wombat_In_Space]

Hi guys I have been woking on inproving the center bearing on my dob here is the finished drawing for what I am about to make for my 12" for those of you with smaller Dobs remove the 3mm step on the treaded bearing plate.:thumbsup:

[mick pinner]

nice idea Wombat

[Wombat_In_Space]

Mick I am also thinking up a version for use with encoders where the bolt will be able to rotate.

[mick pinner]

keep me informed, l'm having a new type of dob mount being built at the moment and might be able to incorporate your idea if your interested.

[ballaratdragons]

?????? WELL, DO TELL ????

[slice of heaven]

Top stuff Darren
Good to see people looking past the supplied setup.

[Wombat_In_Space]

Well here it is the other version of the plates for a rotating bolt, replace the upper bearing with a solid brass or bronze press fit bush in bearing plate and bolt.:thumbsup:

[Wombat_In_Space]

Ok here is the third drawing in this series it is for use with encoders the only dimensions not on this drawing is the mounting holes for the encoders as there are to many different ones to warrant the dimensions being included in the drawing I hope these will help.:D

[davidpretorius]

I think i know where this goes.

So instead of the centre shaft we get supplied, this recesses into the centre of the bottom circular base?

I was looking at some trailer assembly parts yesterday and there were sort of similiar bearings there.

I have added 4 roller bearings around the outside of the bottom base, will this negate the need for these?

I am going to be adding a 560mm 1.2mm aluminium sheet to the underside of the base for the current bearings to run on and also for a stepper motor to drive the base on. Driving from the outer edge gives extra reduction, how do you see your bearing incoporated with the following?

http://www.bbastrodesigns.com/cot/rollerdriveaz.jpg


Any idea on a cost, i am going to post a summary sheet of where I believe things are at re motorizing a dob, dob buggies, your bearing, els focusser etc I can then add your cost, micks buggy, etc etc

thanks

[Wombat_In_Space]

Providing a smooth and accurate rotational point for either manual or motorised operation and an accurate mounting point for digital encoders, as to the cost I will need to work out the machining time and materials that it will take to make them. Right now I am trying to find someone I know that has a lathe so I can make a set up for my 12”.

[davidpretorius]

the guy that fixes all our generators here has a lathe, do you want him to give it a go?. He loves to tinker around?

[Wombat_In_Space]

Well get him to make you a set for you Dob at lest that way when you get all the motorising done for yours you at least know it is going to go around in a perfect circle.

[davidpretorius]

is this similiar

http://www.skf.com/portal/skf/home/products?paf_dm=shared&maincatalogue=1&lang=en&newlink=2_12_1

and then choose design b
7225(00) flanged housings can be supplied for end shaft arrangements (design A, fig (javascript:openPopup('1','en','IMA GES','600','500','/skf/productcatalogue/jsp/viewers/imageViewer.jsp?image=051_0411.gif&file=2_12_1'))) or for through shaft arrangements (design B, fig (javascript:openPopup('1','en','IMA GES','600','500','/skf/productcatalogue/jsp/viewers/imageViewer.jsp?image=039_0411.gif&file=2_12_1'))).

[Wombat_In_Space]

Very similar but the outer diameter might not be concentric with the bearing so you would need to align it all before bolting it in place.