Meade ETX 90 - stripped azimuth drive gear

[Wayneman]

Hi everyone - I recently dusted off my wife's Meade ETX 90 PE. After successfully replacing the broken base mount for the SmartFinder (yay, me), we ran into problems with aligning...which resulted in a broken gear in the azimuth drive mechanism (see red arrow in pic, below).

Does anyone know of a gear manufacturer/seller who can provide a replacement?

BTW - Dimensions for the gear are as follows:

Diameter - 13mm

Height - 4mm, including bottom spacer

Bore - 3mm

Teeth height - 1.5mm

 

[Alfian]

Oops, know anybody with a 3d printer?

[Wayneman]

I know. That Celestron with smartphone adapter is calling to me. 🤣😂

 

When we were trying to align the Meade scope, it kept trying to turn against the hard stop, when finding north. We eventually figured it out and did some stargazing. However. By the end of the night, the scope stopped turning in either direction along the azimuth. After loosening the worm gear, then diagnosing back through the drive mechanism, I found the missing tooth on the bottom of the 4th gear combo.

 

I don't know anyone with a 3D printer. I did find a "reasonable" 3D printing shop to do the base mount for the SmartFinder. 

 

 

[lenscap]

Hi Wayneman,

Looks like you need something like this   https://www.beltingonline.com/24-tooth-delrin-500-0-5-mod-type-b-spur-gear-ds05-24b-6496?zenid=ugjfua4bhg01ld9qg7dt354025

Try googling      "  24 tooth mod 0.5 nylon plastic spur gear " and see if you come up with a stockist in your area.

Good luck.

[RT65CB-SWL]

Hi @Wayneman and welcome to SGL. 

Oh gosh! 😱 ...another ETX with the 'infamous' gear issue.

If you cannot get hold of the replacement drive gears, you can give the ETX90 a new lease of life. The OTA can be remved from the fork arms with patience and some brute force, then you can attach a Vixen type dovetail on the underside, but don't overtighten, otherwise you risk the mounting points becoming loose in the ABS plastic flip-mirror housing. Though it does mean sourcing another mount and tripod, which is easier to obtain.

Below are a few past and present images of my ETX105, before and after a 're-mod'...

    

  

 

and video showing removal of an ETX from the fork arms...

 

Edited August 17, 2020 by Philip R

[Wayneman]

Lenscap - thx for your response. I'm trying to locate a company in the US. I appreciate your giving me the language to discuss my requirement 🙏🏽🙏🏽🙏🏽🙏🏽

[Wayneman]

Phillip R - nice job with that conversion. Unfortunately, I'm still a novice, who needs help navigating the skies...so, I need Autostar to show me the way