PST40 motor focuser

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Bastelhannes
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PST40 motor focuser

Post by Bastelhannes »

Hi folks,

just wanted to show my idea of a PST40 mod 1 focuser.

Just a NEMA14 stepper controlled by Bob Browns MyfocuserPro2. Printed with PLA.

Works pretty nice and smooth.

Next steps:
- add a motor for the etalon adjustment
- add a second pcb for the second motor
- print a GT2 belt of TPU (to replace the rubber ring of the etalon for the GT2 belt)

Updates are coming soon.


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Bastelhannes
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Re: PST40 motor focuser

Post by Bastelhannes »

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Re: PST40 motor focuser

Post by marktownley »

Cool mod!


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Re: PST40 motor focuser

Post by Rusted »

Neat job. Well done! :bow

The PST's textured rubber ring provides plenty of grip for a GT2 belt.
[I used a "Skywatcher" DC focuser motor.]
However, it doesn't offer repeatable indexing for a stepper motor drive.


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Baader 160mm D-ERF, iStar 150/10 H-alpha, PST etalon with rubber band tilter, Baader 35nm H-a, Beloptik KG3, Lunt B1200S2, Assorted T-S GPCs, ZWO ASI174.
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Re: PST40 motor focuser

Post by Bastelhannes »

Thank you.

I was thinking about using the original rubber ring of the etalon. But hey, I have a printer here, so why not using it? Hopefully I am going to have it built until Monday.

The only disadvantage so far: the pentaprism shifts while focusing. I am going to tear the black box open again. Last time i adjusted the pentaprism, because it had have an angle of about 15. It was not possible to rotate it over the edge so it would come into the desired position. I just cut it off and heated it together again (I was lacking of silicone glue).

Not good for flat frame making...


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Re: PST40 motor focuser

Post by MapleRidge »

Great addition to the scope...well done !!!

Brian


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Re: PST40 motor focuser

Post by Bastelhannes »

And... modified it:

- two motors (unfortunately two PCB myFocuser2Pro are necessary, attached to each side)
- used now high impact PLA (the green body) and carbon fibre PETG (the motor holders)
- for the moment I used TPU for the teeht ring (Etalon) and the belt itself...

Now waiting for the sun...
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Re: PST40 motor focuser

Post by Bastelhannes »

By the way, if anyone needs the .stl or Fusioon360 files.. just drop a message. I am glad to share...


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