Vixen Polaris RA Drive question
Posted 03 July 2013 - 08:01 AM
Posted 03 July 2013 - 09:14 AM
Posted 03 July 2013 - 09:59 AM
Posted 04 July 2013 - 04:07 PM
I machined an aluminum block to accept an Orion #7832 True Track R.A. motor drive to an SP.
My opinion is the drive is adequate vs cost even if the dec. drive is never used.
Someday I'll fabricate the dec. motor as well.
I've built a few for others and sent the dimensions to a few to build their own. The feedback was positive.
The cost of the True Track dual axis is less than other alternatives investigated.
Posted 04 July 2013 - 04:33 PM
Posted 04 July 2013 - 06:50 PM
Posted 04 July 2013 - 07:28 PM
I know the Dec mounting is completely different, and from the pictures and manuals I have seen, so is the RA. There is no position to mount the motor on the mount below the worm, the only motor mount has to connect with the shaft extending away from the mount.
Posted 04 July 2013 - 07:39 PM
I wonder if there is a Pot you can tweek the speed?? havent checked that far.
I hope you find a drive.
Posted 05 July 2013 - 08:28 AM
My apologies for misreading the original post.
The Orion#7829 EQ-3M Single axis bolts right to a Vixen Polaris mount.
The Vixen MD-5 that were original to the mount will interface fine to the Orion motor. The Orion controller interfaces with the Vixen motor as well.
That said, there is a DC voltage step up with a MD-5 of 3 volts DC. The Orion # 7829 is 6 volts DC.
I will confirm sidereal.
The drive systems appear to mount identically although the Vixen bracket is slightly heavier gauge metal and the motor has (in my opinion) a smoother pulse.
The motors are offset from the EQ mount by a significant amount. I have installed a counterweight (dummy shaft) that is attached on the opposite side of the mount on the worm shaft. This eliminates a slight imbalance on the mount.
Posted 05 July 2013 - 09:29 AM
Posted 05 July 2013 - 10:07 AM
Posted 05 July 2013 - 10:24 AM
Posted 05 July 2013 - 11:31 AM
I would guess a small DC transformer or resistor would work.
Sorry, that's not much help!
Surprisingly, the Orion battery pack with soft case and strap hangs conveniently between the Polaris tray and the leg on the attachment and just stays there.
The Polaris mount is the grab and go for about 4 different OTAs.
Consequently, It is used almost every clear night so it stays setup in the family room.
I get many many hours out of the battery pack and just use rechargeable D cells.
Posted 05 July 2013 - 05:30 PM
Posted 05 July 2013 - 05:37 PM
Posted 05 July 2013 - 05:42 PM
Posted 06 July 2013 - 02:03 AM
I use a car audio converter, it can select 12, 9, 6 or 3 volts output. It plugs into a cigar socket and has various output plugs, cost about £5 iirc.
I found mine in Maplins (UK), I imagine Radio shack would have them?
Posted 06 July 2013 - 07:36 AM
Posted 06 July 2013 - 10:31 AM
Posted 07 July 2013 - 10:06 PM
Posted 08 July 2013 - 08:53 AM
Posted 08 July 2013 - 08:58 AM
Posted 08 July 2013 - 11:13 AM
This drive is used on grab n go scopes. I should have stated that I have noticed this.
Quite honestly,it never bothered me enough to find where the error existed and place a quantitative percentage on the error.
I'm a lazy amateur!
The other slight anomaly is at high power 300+ range on planetary viewing, I will notice at times (new batteries) the pulse count from the motor effecting fine planetary details.
The procrastinator just uses the pause on the controller then slews over. My bad!
This was all acceptable from having RA drive vs no RA drive.
Thanks for filling me in on the mod.!