Altitude Slow Motion Control

[vindictive666 (John)]

gday all

i had an other crack at the problem yesterday without much success iam afraid

the plate that sits against the altitude bearing still moves against the surface of the bearing (the plate is made of wood) so unless iam prepared to remove the 2 bolts holding the bearing (no keen to do ) and shoving those thru the plate as well because that would mean (in my case 12 inch dobbie) removing the mirror assembly ect ect. (colimation again)

or screwing 3 or 4 self tappers thru the plate into the bearing surface however iam not sure if the bearing house is solid or hollow if you know what i mean so untill i can think of a another way this project is come to a halt and yes it was a project i wanted to try because i had all the gear needed.

however ive got some speaker magnets anyway so its not a real problem

what i liked about it was the fine adjustments you could make with the turn buckle which would have come in handy in my case

ps

i made 2 plates in which the short handle sat plus the handle(made of alluminum) itself moved as well but i fixed that by glueing 2 bits of (small) alluminum on iether side of the handle on opposite sides of the plates.

the plates are almost but not the same size as the hub.

i would post pics but thats hard to do with no camera

[ving (David)]

hmm... sounding rather complicated now vin...

[vindictive666 (John)]

yes ving

i wonder how that clutch knob works then maybe a 10 inch dob a lighter
it seems to work a litle on going down but slips moving it back up i figure to much weight that why you gotta anchor the plate
is a really shame.

[ving (David)]

what if you were to use a rubber washer as a "clutch" vin? itd prolly stop slippage

[vindictive666 (John)]

actually i might try that ving all i have todo is find some

[ving (David)]

god I am brilliant!!!
all bow down to me!

PRAY TO THE MIGHTY COW GOD!!!

:p

[vindictive666 (John)]

i think ill pass on that i dont cowtow

[ving (David)]

just call me "Cow Tse Tung!"

[vindictive666 (John)]

hiya ving iam back to let you know that rubber idea works so it a sucess!

i made it the same diameter as the plates i had a old mouse pad loafing around and made a plate out of that it works

[ving (David)]

sweet, on ya vin
congrats!

[slice of heaven]

Originally Posted by ving

hmm... sounding rather complicated now vin...

Extremely.

Now who would've thought of using rubber?

[ballaratdragons (Ken)]

My speaker magnets work a treat. Because I rubber backed them I slide them up and down the OTA for perfect balance. I also use both springs attached so when I change EP's the scope doesn't move.

Easy and cheap.

[mick pinner]

firstly let me say that l have only looked at dob mounts in passing and not closely but reading these comments on balancing etc, l must ask why can't you mount a worm drive electric motor on one side, this would give you control over the balance issue and also prevent the scope from moving up or down if it was bumped. one other thing l have wondered and l realise the idea of a dob to keep the price down but why are the ota's not held in a cradle so they can be slid one way or the other to off-set the addition of ep's etc.

[slice of heaven]

A cradle can be fitted Mick.
My 12" Parks has a plywood box clamp arrangement. To adjust the balance,it is as easy as releasing 2 clasps and sliding the OT to the required position.

The gs dobs are built around the optics.
The price dictates how the scopes are supplied.
A few cents for 2 plastic side bearings V A few $$$$ for an adjustable setup and sturdy usable base.