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Motor Drive Question

Discussion in 'Beginner's Corner' started by Seer, Jan 7, 2019.

Motor Drive Question

Started by Seer on Jan 7, 2019 at 6:19 AM

29 Replies 10894 Views 0 Likes

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  1. Seer

    Seer Well-Known Member

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    Would it be worth getting a motor drive for my Meade Polaris Telescope?
     
  2. Gabby76

    Gabby76 Well-Known Member

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    A tracking motor is always handy when using higher powers with an EQ mount.
     
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  3. Ed D

    Ed D Well-Known Member

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    Only you can determine if it's worth it based on what you want to accomplish, finances, etc. RA motor drives are available on eBay for about $35-40 shipped. They come with a mounting bracket and hardware, use a 9V battery, and are pretty easy to install and use.

    I mounted a Celestron branded motor on my CG-4 years ago and it works as well, if not better than the day I installed it. Because of the side I mounted it on, the motor direction switch is set to South instead of North to get the correct rotation. No big deal.

    I made two mods to mine. Early on I found the 9V batteries varied speed as the night progressed. My solution was to solder a long 22ga twisted pair wire with a 9V battery snap on the end. I use a six AA battery holder that has 9V terminals. With the added capacity (amps) the motor speed is stable and the cells last for months with frequent use. The other mod I recently made was to the speed control shaft. It's skinny and somewhat hard at times to dial in the motor speed. I found a small grommet that I slipped on the shaft, and with the increased diameter I can dial in the tracking speed very precisely. I didn't feel a need for the larger diameter until I got into imaging deep space.

    You can see the motor on the mount, as well as the battery holder held on the spreader tray with a Velcro strap.

    Ed D

    IMG_20190101_210102.jpg
     
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  4. Seer

    Seer Well-Known Member

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    I got my motor drive yesterday. Reading the User Guide and running some scenario sorties I think I may have uncovered a major discrepancy in the instructions. The User Guide says.

    "3. The N/S switch is used to control direction of motor tracking. Use the "S" setting for observing in the southern hemisphere. Users in the northern hemisphere should set the setting to "N"."

    According to these instructions it is base on the observers location north or south of the equator. I think that this only partially correct and slight at that and that it leads to much confusion.
    My scenario sorties indicate that the switch would have more to do with whether I am observing north or south of MY ZENITH.

    Ed I like what you did with your battery pack. I am wondering how I could get that done with mine.
     
  5. Seer

    Seer Well-Known Member

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    Check out what this guy did.
    I was thinking wouldn't it be way easier to just put a knob with an indicator on the stem. The knob might hinder battery changes that is unless it was rigged with an external battery pack like yours Ed. Doesn't that knob seem like something Bob's Knobs should have?
     
  6. Gabby76

    Gabby76 Well-Known Member

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    The N/S switch only needs to be set once. It is not dependent on your local zenith but hemisphere once aligned to the N or S celestial pole.

    I use one of these and converted a multi voltage regulator to be plugged into my 12v battery pack but run at 9v.
     
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  7. Seer

    Seer Well-Known Member

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    I have had my 80mm EQ for a very long time but haven't really started using it yet. If the EQ mount preforms some kind of flip between viewing north to south you will be right. If you sit in a swiveling chair and face south you need to track stars from left to right. When you swivel your chair and face north you need to track stars from right to left. I know that most if not all of you know this but hopefully it will be something that I will be finding out for myself soon.
     
  8. Gabby76

    Gabby76 Well-Known Member

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    You will figure it out easily enough :)
     
  9. Leonard

    Leonard Well-Known Member

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  10. Leonard

    Leonard Well-Known Member

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    I think the N and S are for the hemisphere. If ur in the North hemisphere, u set that to N.

    The moter is attached to the RA shaft. Once u polar allign ur mount, that drive will keep an object in the FOV of an eyepiece.

    If you polar allign your EQ mount, once you center an object in an eyepiece you should be able to tract it by twisting the slow mo controls. The moter will do the “twisting” for you.
     
    Last edited: Feb 7, 2019
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  11. Leonard

    Leonard Well-Known Member

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    I have a moter that I seldomed used. With a slow mo control for me, it was just as easy to track manually. But that’s me. The fact is I seldom polar align my scopes. Even with an EQ mount. I know that’s terrible for an amateur to admit there failure, but it’s true.
     
  12. Gabby76

    Gabby76 Well-Known Member

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    Not really a “failure” depending on the type of viewing you are planning.
    For general viewing it will work for a time but if sketching or trying to concentrate on detail viewing, polar aligning makes the session much easier.
     
  13. Leonard

    Leonard Well-Known Member

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    Yep. I was being a bit sarcastic, and unsuccessfully so. But as to why I seldom polar align the 114 on the EQ1 or for that matter any EQ mount, 114mm combo, that’s a longer story.

    After a few years in the hobby I purchased an 8” DOB to replace the 114 as my primary scope. I decided to use the 114mm as a grab and go. And the scope performed well in that capacity. Cool down under 15 minutes with enough apperature for good views. However the EQ1 was a bit lacking in support especially when not polar aligned.

    So, I decided to purchase a Vixon Porta mount 2 to support the 114. To be sure the mount would work well with the 114mn I gave a Vixon Tech that scope’s specs, weight and length, etc right from the manual. However the Vixon mount didn’t do the job as the scope suffered from excessive vibrations while focusing.

    After a year long struggle with Vixon, they refused to refund my purchase or exchange it for another porta mount. I told them if your sure this mount can adequately support this scope there must be something wrong with the mount I purchased. If there is nothing wrong with the mount, then the tech made a mistake assuring me it would support the scope. They disagreed, (and I don’t know how) so I found myself looking for either another mount for the 114, or a scope for the porta mount. I researched this decision for a good bit, while waiting to save enough money for the purchase. I finally decided the scope was an easier more economic way to go, so I got the Orion 80MM.

    I was lucky, Orion had a sale on their scope/mount combos, I bought their package deal, the 80MM F7.5 ED APO, on their SkyView pro EQ 5 mount. When my purchase arrived, I placed The 114 on the SkyView Pro mount and the 80MM on the Vixon. So, both scopes have a good mount.

    Yet, I seldom use the SkyView Pro/114mm combo because that mount is a handful to use. Its not the weigh of the mount nor is there a problem with supporting the scope. The problem is in the general construction of the mount. It has long spider-like legs which causes the scope and obviously the focuser to sit high above the ground. It’s just uncomfortable to use.

    On the other hand, the Orion APO/Vixon combo is much easier to use. In fact, the 80MM APO and the Vixon mount are an almost perfect combo. The mount easily supports the 80mm while the entire setup is very lightweight. Finally, the APO can easily handle mags up to 200x.

    In the end, the 80mm gets almost all the grab and go work and the poor 114 seldom sees the night sky.
     
    Last edited: Feb 8, 2019
  14. Gabby76

    Gabby76 Well-Known Member

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    Surprising that the Porta mount had issues with the 114mm. Good to hear that you managed to find a good combination though.
    The Skyview is a good EQ mount (EQ-4 though not a 5) but then I prefer EQ mounts when viewing.
    Everybody has a style that suits them and gets them out viewing.
    With the 114mm on the EQ is it a situation of the eyepiece ending up in a odd location?
     
  15. Seer

    Seer Well-Known Member

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    I just mounted the drive motor on my telescope. My question is (and it seems like it might be important) does it matter if the Right Ascension clutch/lock is set or not when running the motor? If it is tightened down will it keep the scope from tracking and or damage the motor?
     
  16. Gabby76

    Gabby76 Well-Known Member

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    The clutch needs to be snugged up, if it is loose the motor will not be able to turn the gear.
     
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  17. Leonard

    Leonard Well-Known Member

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    That’s what Vixen Tech said, but they finally came to the conclusion that the combination of that aperture plus the length of the scope was too much for the mount. Of course, this was after I purchased the mount.

    After about 18 months of misery, I noticed the lower, slow mo gear seemed to slip. So, I took that gear box apart and discovered a large deep scar running around the entire gear. I thought this might be problem. The mount had just been returned to me from Vixon. I had sent it to them in a hope they would discover the problem. They didn’t, but I thought I did. I took several pics and sent them off to Vixon.

    Instead of being pleasantly surprised, I was told: 1) that could not be the cause of my alleged issues. 2) I had voided the warranty by taking the mount apart.

    Think about that response! They didn’t find the problem, but I was wrong for doing what they failed to do. If I hadn’t opened that box, that defect would have not been discovered. I actually think they felt I had damaged that gear.

    At any rate, I asked got them to send me another gear and we will call it even. They said OK. I replaced the gear and it did have a positive effect on the use of the 114, but not by enough to enable smooth use with the 114. However it handles the 80mm with ease.



    The SkyView Mount is easy to polar allign, but due to the long legs, the eyepiece often placed too high for me to observe in comfort.
     
  18. Seer

    Seer Well-Known Member

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    Is there a reason you can't adjust the length of the tripod legs?
     
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  19. Gabby76

    Gabby76 Well-Known Member

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    You can also make some rings to turn the reflector quite cheaply which would easily let you move the focuser to a comfortable position.
    Another “trick” is to place the focuser pointing up instead of to the side.
    Most times the focuser will be better placed for viewing.
     
  20. Leonard

    Leonard Well-Known Member

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    I have them withdrawn as far as possible. I would estimate the mount is 3 foot off the ground, while the focuser of the 114mm is a little higher than 5 foot above the ground.
     

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