78 replies to this topic

[dougspeterson]

I have an optical tube and drivebase, once separated because of an intermittent drive issue. Owner no longer with us.

 

See 4 pics.

 

Missing are the six attachment screws, are they custom or generic? Lengths, threads?

 

Missing is the bottom plate. I know little about the DC drive, I know I am missing the hand paddle.

 

For those experienced, what are the pitfalls?

 

 

Attached Thumbnails

• 

Edited by dougspeterson, 08 June 2019 - 10:59 PM.

[dougspeterson]

2 of 4

Attached Thumbnails

• 

[dougspeterson]

3 of 4

Attached Thumbnails

• 

[dougspeterson]

4 of 4

Attached Thumbnails

• 

[Optics Patent]

Screws are all easy. Will provide specs when I can

Baseplate is a big challenge. It’s a PG1 model that has special cutouts and a milled our area. Unless you can luck out and get an old one it’s virtually unworkable. I suggest converting back to normal AC drive. That’s inexpensive even with factory parts.

Will post more later.

[dougspeterson]

The six screws are reputedly standard threads but those heads look like custom flathead hex

[sgorton99]

If you call Questar they will sell you replacement screws pretty cheaply. I have ordered some in the past.

[Optics Patent]

Screws are #3-56 1/4" stainless allen screws.  Easy to find on Ebay.  If you're ordering another part like a bare baseplate and an AC motor (don't forget base plate screws) then they will toss them in.  I have a good supply.  The original Bristol screws are a rarity, and I have a small supply. 

 

I suspect you don't know the serial number of the scope, because it's recorded only on the base plate.  The optics have code numbers, but that requires disassembly, and then the factory can look up the number.

 

A new base plate is about $25 from the factory, and an AC motor might be pricier new, or they may sell you a take-out from a PG conversion.

 

I'm a fan of the PG-1 you have because it's the only Questar to track without a cord dangling from the base.  Even without the controller it still tracks as well as the AC motor.  I have three of these and vastly prefer them.

 

If you are unable to acquire a PG-1 base plate with its special cutouts and milled pocket, I'd be interested in the PG-1 parts for my repair bin.  Maybe I can help you get fully set up and assembled with AC if that makes sense. 

[dougspeterson]

Thanks for the help. I will start by talking to Questar tomorrow. Looking to keep this low cost, even if the sensible thing would be to have them upgrade to PG-2. The main thing is to get the tube mounted, so six screws.  Then, the drive works, so even wo a baseplate the components could be velcroed into the void. Doubt lightening will strike but if they have a boneyard and could get a PG-1 plate and hand control, dream come true. However no dec motor, but basic tracking.  To be honest the 20 years I owned a Standard, I rarely used the drive, the manual motions are so sexy.

[Erik Bakker]

[...]  To be honest the 20 years I owned a Standard, I rarely used the drive, the manual motions are so sexy.

Found a similar thing with my Questar 7, gorgeous manual motions to support relaxed and quiet observing of the sky at 180x-235x, sometimes even at 375x, although that's were the RA drive definitely has it's advantages.

[Kevin Barker]

Thanks for the help. I will start by talking to Questar tomorrow. Looking to keep this low cost, even if the sensible thing would be to have them upgrade to PG-2. The main thing is to get the tube mounted, so six screws.  Then, the drive works, so even wo a baseplate the components could be velcroed into the void. Doubt lightening will strike but if they have a boneyard and could get a PG-1 plate and hand control, dream come true. However no dec motor, but basic tracking.  To be honest the 20 years I owned a Standard, I rarely used the drive, the manual motions are so sexy.

Questar will not likely let you upgrade to a PG 2 as they may not have the parts.

PG 3 Yes. I found this out when I tried I converted my Field into a Duplex. I got hold of an old mount which had a dysfunctional PG1 and faulty dec slow motion function.

Whilst I am happy with my PG 3 conversion......

PG 3 conversion is quite expensive and the hand controller is quite large. Batteries do not last long with PG 3 either. 

 

As Ben has suggested the cheapest option might be AC.

[dougspeterson]

Ok no need to upgrade.

 

Remember pic 4 of 4 I have a functioning PG—1. I love DC. How to mount or hide inside is the question. Lacking a used PG-1 base plate, getting an AC version or blank baseplate, and machining the holes for the PG-1 hardware intrigues me.

 

I have a friend with quite the shop. How thick is the plate? I have assumed thin aluminum.  I might take on using a Dremel myself.

 

Personally w apologies to Tom Edison but I dislike AC, but will revert if that becomes the answer.

Edited by dougspeterson, 09 June 2019 - 09:26 PM.

[cbwerner]

Having a functioning DC version, I would never "downgrade" to AC - too much convenience and usability lost. But as always, YMMV.

[Matt Looby]

I rarely use my drive as well- too much hassle.

[Optics Patent]

The PG 1 is the best. It’s a project but a machinist could easily cut the openings and mill the recess. Most wouldn’t do it but it’s the best choice if you can.

My only suggestion is to make a spare or two.

[dougspeterson]

Aluminum or steel?

thickness approx?

[Optics Patent]

0.062” hard anodized brushed aluminum.

[Optics Patent]

Doug, I actually have a PG-2 that needs a home, so don't commit to buying new for $600+ when you can get it for half that.  Also, PM me your address, and I can have the six screws out in the mail before Questar picks up the phone.

 

If you do go with PG2 know that it's presently the last minute to get in on a group buy for a custom Pelican case that fits the large baseplate, posted in another thread. 

 

Dating your scope for fun:

• PG1 could have been an add-on, but presumably original 1990-95 era.
• Purple tube suggests 1992 or earlier.
• Arms are brushed not polished - consistent with date.  Same for flat leg hole plug (your legs should be threaded and have fat tips).
• If your declination knob has a groove encircling it to divide the knurling into two paths, then I'd guess 1990 or 91, and if it's ungrooved it's probably a 92.  Broadband coatings predominated in this period so I'd guess that.

When you get the six screws, you can unscrew the motor from the base and be fully operational for unguided viewing.

[BillHarris]

I went the AC route with my dead PG. Installed an AC synchronous motor and got an ORION lithium battery pack/inverter combo. Works like a dream.

[dougspeterson]

I received the fork today.

The slo motions work fine .

the knob on the fork opposite the fine motion appears frozen, is that not a lock? If so it is locked open. I don't want to force it till I talk to you guys.

See pic of inside engagement 

Attached Thumbnails

• 

Edited by dougspeterson, 11 June 2019 - 07:38 PM.

[Optics Patent]

It’s the declination brake and its rotation is backwards from normal intuition. Turn to the right to unlock it. But be sure the knob is solidly tight to the screw before applying much torque. Maybe 1/2 turn is the range of motion.

[JamesMStephens]

If you go with the AC drive you can't get much more convenient that this https://tinyurl.com/Orion-AC-power

[dougspeterson]

Sadly the knob will move in neither direction. There is a tiny set screw, perhaps I should remove the knob.

[Optics Patent]

If you’re confident the set screw is on the flat of the screw then just crank it down. To get confidence you may need to remove the knob, note screw orientation, and replace the knob. Look carefully because there may be two set screws.

Removing the knob and using two nuts locked together is one option.

[dougspeterson]

There is some sort of ancient label  remains opp the azimuth knob (you can see the brownish residue in the photo 3 of 4 above). It doesn't come off with water. Decided to get guidance from the experts: what solvent do you recommend that won't damage the finish?