9700 replies to this topic

[andylsun]

Figuring this out…

 

It’s I assume a variable rate AC drive for the Parks Optical 10” superior telescope and mount I just picked up. Other pictures of the item I picked up are cluttering up the classifields thread (https://www.cloudyni...cope-ads/page-5)

 

AC input power cable  and 1/4” stereo jack connector that goes to the RA motor drive.

 

has an optional 12V DC input that is also a 1/4 inch stereo jack.

 

not impressed by the speaker wire used for 120V AC input.

 

two transformers on top step down 120V AC to 9V AC.

 

cant find any pictures of anything like it online and I guess it’s home built from a kit.

 

ill take the bottom off and then cautiously power up from 12v DC and probably delete the AC cable.

 

I’ve not checked the drive motors on the mount but they are hopefully 12v AC.

 

ill put an oscilloscope on the motor output to see what’s going on there.

 

Here's the rest of the find! Thanks to glittledale

 

Attached Thumbnails

• 

Edited by andylsun, 06 September 2024 - 01:17 PM.

[andylsun]

Looks pretty much home made.

Attached Thumbnails

• 
• 

[deSitter]

Voltage regulator and 2 amplifier transistors plus an oscillator - probably 2 axis motor control? Made from a canned circuit in Sky and Tel during the 80s (date code on chip).

 

-drl

Edited by deSitter, 06 September 2024 - 01:17 PM.

[andylsun]

Voltage regulator and 2 amplifier transistors plus an oscillator - probably 2 axis motor control? Made from a canned circuit in Sky and Tel during the 80s (date code on chip).

 

-drl

 

yeah, with a 555 keeping timing and allowing for adjustments. Pretty textbook I guess. The telescope has a RA motor and a DEC tangent motor. I'll dig into the motors themselves. Hopefully there's a manufacturing date and serial number inside the RA motor housing.

[Kasmos]

Figuring this out…

 

It’s I assume a variable rate AC drive for the Parks Optical 10” superior telescope and mount I just picked up. Other pictures of the item I picked up are cluttering up the classifields thread (https://www.cloudyni...cope-ads/page-5)

 

AC input power cable  and 1/4” stereo jack connector that goes to the RA motor drive.

 

has an optional 12V DC input that is also a 1/4 inch stereo jack.

 

not impressed by the speaker wire used for 120V AC input.

 

two transformers on top step down 120V AC to 9V AC.

 

cant find any pictures of anything like it online and I guess it’s home built from a kit.

 

ill take the bottom off and then cautiously power up from 12v DC and probably delete the AC cable.

 

I’ve not checked the drive motors on the mount but they are hopefully 12v AC.

 

ill put an oscilloscope on the motor output to see what’s going on there.

 

Here's the rest of the find! Thanks to glittledale

 

 

Strike 2!  

 

Unless you're showing or writing what you did to it, it belongs in the finds thread or maybe even create it's own thread for the restoration.

[andylsun]

Sure! I can start a separate restoration thread no problem.

 

edit: done.

Edited by andylsun, 06 September 2024 - 02:20 PM.

[Bomber Bob]

Keep It Simple!  Converting my Carton ZO-65x101 Spotter from this:

 

 

to RFT is gonna be easier than I thought:

 

 

The Prism & Eyepiece Assembly threads onto the body with a standard M64x0.75 thread.  I was 99.9% sure that I had at least one such ring out in the shed, from back when I was finding ways to upgrade my Classic MIZAR / TAK refractors to 2" with Baader ClickLock adapters.   As I found out years ago, ALL of these scopes have the male 64mm thread on the main focuser tube, so only female rings will fit.  Naturally, I forgot that little detail...

 

Luckily, Agena & other vendors sell the Baader M64x0.75 2" CL.  Gotta love it...  One Ring to Rule Them All... and, with Zero / None / Nada irreversible mods to this oddball.  

[clamchip]

I removed the weight from the top of my Dynamax tube and left the paper towel in place to keep

the bugs out. I'm giving the RTV seven days to out gas before the corrector goes back in.

In the mean time I have a new project to keep my mind off the Dynamax.

A friend was in need of a metal cutting lathe so I gave him my Atlas 6 inch and $100 in trade

for his Starsplitter 8 inch tube type dob. I get to do some wood working because the Starsplitter

is missing it's ground board and azimuth bearing. I'll make the ground board and while the

varnish is drying the Dynamax should be ready for assembly and the great sky show!

Robert

 

IMG_2649.JPG

I made my ground board today.

In 24 hrs. another coat of varnish. I made the 3 plywood feet replaceable, that's why the 6 screws on top.

I'm going to use John Dobson's phonograph record and furniture glides idea, and oddly enough the record

with the best stiction behavior is from 1971, I'm not sure why. 

It took the better part of a day to make this part and now its done. It won't be too much longer and I'll be

lookin thru the eyepiece at the big sky show.

Robert 

 

[clamchip]

It's been 7 days, plenty of time for my Dynamax RTV Silicone tube bonding job to cure.

I assembled the scope this morning and had a look see around the valley.

Perforated thingy, no problem easily resolved, like it should be for an 8 inch.

How do you like my blue finder cover, courtesy of Planters Peanuts.

Collimation seems at least in the ballpark, amazing considering the major surgery

this poor thing went thru.

The drive works fine, manual controls for up down left right are very nice. Oh and when

you uncork the visual back you get a whiff of phenolic, what a treat.

Its interesting the 5-40 fasteners used on this telescope, that's an old school size

not found in hardware stores anymore, I love little touches like that.

I have some more cleaning to do on the tripod and then I will need a really good night

to collimate, and then come the big test. Will it be an A, maybe a B, or perhaps a C, I hope it's not

a D, this scope is too cool for a D.

Robert

 

Edited by clamchip, 09 September 2024 - 01:25 PM.

[deSitter]

If anyone deserves to find That One, it's you! Fingers crossed!

 

-drl

[deSitter]

I made my ground board today.

In 24 hrs. another coat of varnish. I made the 3 plywood feet replaceable, that's why the 6 screws on top.

I'm going to use John Dobson's phonograph record and furniture glides idea, and oddly enough the record

with the best stiction behavior is from 1971, I'm not sure why. 

It took the better part of a day to make this part and now its done. It won't be too much longer and I'll be

lookin thru the eyepiece at the big sky show.

Robert 

 

IMG_2660.JPG

IMG_2656.JPG

Oboe, harpsichord, and harp - what is this?

 

-drl

[clamchip]

Oboe, harpsichord, and harp - what is this?

 

-drl

It's an old record from my 'too good to throw out' stock.

I think it might have come from a old dob if I remember right because the hole has been enlarged

to half inch, too big to listen to but just what I needed for my Starsplitter.

I thought it interesting out of the records I tested this one performed the best. My test was to use

the furniture glide and note the resistance to motion from static, this one did it best or I should say

least resistance. I don't know if its the type of vinyl or the depth of the grooves, I don't know.

 

Robert 

Edited by clamchip, 09 September 2024 - 01:44 PM.

[tim53]

the 3 DX8s I have all have very nice controls.  The focus knobs are nice and big and smooth.  I've gee whizzed with two of the scopes (the other isn't complete), and I see no image shift while focusing.  

 

Still, I predict you'll give it a C at best.  Them correctors are just too rough for a higher grade.

 

-Tim.

[Bomber Bob]

Now & ZEN & my Carton 101 conversion:  Nabbed a dual Male 64 / 42 threaded adapter ring last night, so I'm psyched-up.  I'll be able attach any standard F42 accessory to it, including extension tubes and/or a helical focuser.  And, this RFT can ride on any of my mounts -- a "native" fit on my 1968 Tak S-1; or, with the Tasco cradle + dovetail, my VersaGo or Mizar EQs.

 

Can't wait to surf the Winter Milky Way with it.  All that's left is a lightweight dewshield.

[clamchip]

I applied the last coat of varnish on my Starsplitter ground board today.

While that's drying I'm cleaning up the telescope.

Starsplitter tube dobs have full rotating tubes, that should get the attention of you gals and guys.

See the closet door rollers and Teflon pads on both ends of the tube cradle to rotate the tube.

A familiar looking old school primary cell only rubbers instead of springs.

The mirror is unknown, anyone recognize it? ground back with 48 in pencil. It looks like cast

Pyrex. I would say from the mid to late 1990's. Starsplitter telescopes can have a mirror from

many sources, Discovery, NOVA, Swayze, Zambuto, Galaxy, Pegasus, to name a few. Or you

could also buy the telescope without mirrors. I'm just hoping someone might recognize the

penciled on focal length in the center of the back as it's only identification.

Robert

 

[deSitter]

I applied the last coat of varnish on my Starsplitter ground board today.

While that's drying I'm cleaning up the telescope.

Starsplitter tube dobs have full rotating tubes, that should get the attention of you gals and guys.

See the closet door rollers and Teflon pads on both ends of the tube cradle to rotate the tube.

A familiar looking old school primary cell only rubbers instead of springs.

The mirror is unknown, anyone recognize it? ground back with 48 in pencil. It looks like cast

Pyrex. I would say from the mid to late 1990's. Starsplitter telescopes can have a mirror from

many sources, Discovery, NOVA, Swayze, Zambuto, Galaxy, Pegasus, to name a few. Or you

could also buy the telescope without mirrors. I'm just hoping someone might recognize the

penciled on focal length in the center of the back as it's only identification.

Robert

 

IMG_2676.JPG

IMG_2678.JPG

IMG_2680.JPG

IMG_2681.JPG

IMG_2673.JPG

Someone just mentioned that they have mirrors by Nova Optical.

 

-drl

[CHASLX200]

Someone just mentioned that they have mirrors by Nova Optical.

 

-drl

Ya don't remind me of my 18" F/5.

[clamchip]

Here's the ID tag on my new Dynamax. Easy to remember because that serial number is what happened to

my waist size, 36, 38, and touching 40 sometimes after a Costco shop and a gallon of the most delicious Kirkland Super Premium vanilla ice cream.

Robert

 

Edited by clamchip, 10 September 2024 - 11:47 PM.

[clamchip]

I made my ground board today.

I'm going to use John Dobson's phonograph record and furniture glides idea, and oddly enough the record

with the best stiction behavior is from 1971, I'm not sure why. 

 

1974 and the oil shortage did change vinyl records.

Before 1974 records were made from high quality raw materials.

1974 on brought about less quality and fillers to try and stretch the the vinyl in short supply. 

 

Robert

[jragsdale]

I wanted to make a lightweight grab and go mount that I could roll out of the garage easily or even pick up one-handed if needed. Mainly to use with small refractors. I decided to go with a tall pedestal style mount based around the SVBONY SV225 Alt-Az mount that has dual axis slow-motion, locks and a handle, similar to the Twilight and Porta mounts.

 

Got a 4' chunk of 3" OD aluminum pipe at a local scrap yard and 3D printed a tube adapter in PETG that has a captive 3/8-16 hex bolt for the mount and then (3) 1/4-20 brass threaded inserts I press fit with a soldering iron into the the sides of the 3D printed adapter with matching holes drilled in the tube.

 

 

For the feet I ordered (3) 12" x 8" heavy duty shelf L brackets and 3" locking casters. Then 3D printed a mounting plate for the brackets so it can go from flat to round and have good surface contact. This was printed in PETG Carbon Fiber, then drilled and threaded 3 holes in the metal tube for each bracket with #10-32.

 

 

Turned out very nice. Perfect height for me, smooth rolling and relatively stable for small scopes. 

 

 

I plan to fill the tube with rubber mulch to help with low frequency vibration dampening and then sand for the bottom foot or so for extra weight in the base to discourage any tipping (sand also helps with higher frequency vibration dampening).

 

Price for the pedestal: $87.32

$54.39 - tube (3" x 4', 1/8" wall)

$5 - fasteners

$12.11 - Heavy Duty Brackets (12"x8")

$12.82 - Casters (3" locking)

$3 - 3D filament

 

It's perfect for the newest addition to my collection, a 1920s Alvan Clark Type T (3" f/10 aluminum), shown here with 3D printed rings, dovetail and lens cap. Next up printing a small shelf to hold eyepieces while viewing. Kind of like the Sears 6336 pedestal.

 

Edited by jragsdale, 11 September 2024 - 07:50 PM.

[norvegicus]

Nicely done, Eagle Man.  That's very similar to my grab and go pillar, which I leave outside with a cover over the mount.  I found wheels to be a not necessary complication since I can pick the thing up easily to move it around.

 

Are you happy with the SVBony mount?  How does it compare to a Porta II?

[jragsdale]

Nicely done, Eagle Man.  That's very similar to my grab and go pillar, which I leave outside with a cover over the mount.  I found wheels to be a not necessary complication since I can pick the thing up easily to move it around.

 

Are you happy with the SVBony mount?  How does it compare to a Porta II?

I haven't used the Porta II so nothing to compare to, but so far it's pretty nice only issue is you can lock the alt and az locks in certain angles as it collides with itself. That's a big oversight, but once locked the slow motions work well with minimal backlash.

[deSitter]

I wanted to make a lightweight grab and go mount that I could roll out of the garage easily or even pick up one-handed if needed. Mainly to use with small refractors. I decided to go with a tall pedestal style mount based around the SVBONY SV225 Alt-Az mount that has dual axis slow-motion, locks and a handle, similar to the Twilight and Porta mounts.

 

Got a 4' chunk of 3" OD aluminum pipe at a local scrap yard and 3D printed a tube adapter in PETG that has a captive 3/8-16 hex bolt for the mount and then (3) 1/4-20 brass threaded inserts I press fit with a soldering iron into the the sides of the 3D printed adapter with matching holes drilled in the tube.

 

20240911_115205_copy_489x753.jpg

 

For the feet I ordered (3) 12" x 8" heavy duty shelf L brackets and 3" locking casters. Then 3D printed a mounting plate for the brackets so it can go from flat to round and have good surface contact. This was printed in PETG Carbon Fiber, then drilled and threaded 3 holes in the metal tube for each bracket with #10-32.

 

20240911_114620_copy_554x866.jpg

 

Turned out very nice. Perfect height for me, smooth rolling and relatively stable for small scopes. 

 

20240911_114550_copy_406x783.jpg

 

I plan to fill the tube with rubber mulch to help with low frequency vibration dampening and then sand for the bottom foot or so for extra weight in the base to discourage any tipping (sand also helps with higher frequency vibration dampening).

 

Price for the pedestal: $87.32

$54.39 - tube (3" x 4', 1/8" wall)

$5 - fasteners

$12.11 - Heavy Duty Brackets (12"x8")

$12.82 - Casters (3" locking)

$3 - 3D filament

 

It's perfect for the newest addition to my collection, a 1920s Alvan Clark Type T (3" f/10 aluminum), shown here with 3D printed rings, dovetail and lens cap. Next up printing a small shelf to hold eyepieces while viewing. Kind of like the Sears 6336 pedestal.

 

20240911_114902_copy_421x740.jpg

So you trust this plastic to not depolymerize and crack under the stress?

 

-drl

[norvegicus]

I haven't used the Porta II so nothing to compare to, but so far it's pretty nice only issue is you can lock the alt and az locks in certain angles as it collides with itself. That's a big oversight, but once locked the slow motions work well with minimal backlash.

Do you believe the 10kg capacity?  A Porta II can handle about 5kg at most, and then only if it's a short scope.  I can overload it easily with an FC-100 just by adding a few heavy accessories.

 

I'd like an inexpensive alt-az mount with slo-mo and more capacity than the Porta II....  so far everything suitable is too expensive to leave outside.

Edited by norvegicus, 12 September 2024 - 06:36 AM.

[norvegicus]

So you trust this plastic to not depolymerize and crack under the stress?

 

-drl

PETG is water bottle plastic and is UV and water stable.  His leg brackets are PETG with carbon fiber reinforcement, so extra stiff and strong.

 

The stresses here are mostly compression.  Steel bolts and the aluminum tube are doing all the shear and tension work.

 

I have printed probably dozens of astronomy related brackets and accessories and so far the only issue I've had is with stuff like a dovetail to be secured by a set screw;  plastic is too soft for that application.  Otherwise everything has proven stronger and more reliable than necessary.

 

The exception stress wise is the tube to mount adapter.  I assume that it's through-bolted with a big washer on the bottom, but the body of the adapter is bearing some torque.  However, it is big and monolithic and the stresses are spread across its surface contact with the tube and mount.  But, if it wasn't through bolted with a big washer it could suffer a layer adhesion failure at the junction.  I have made several of these and have not been able to break them, applying huge test loads way in excess of anything they see in use.  Mine all have big bolts going through them, with big washers to spread the load.

 

My pillar tube to mount adapter has been left outdoors and used often through two Upper Michigan winters so far with no issues.  It has 50% honeycomb infill and 5 perimeters, so 2mm thick walls, but is made of PLA, which can be heat and UV unstable.  It has a three big bolts with big washers going through it.

Edited by norvegicus, 12 September 2024 - 07:41 AM.