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Author Topic: Bresser exos 2 mount  (Read 1032 times)

David

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Bresser exos 2 mount
« on: November 22, 2017, 14:51:10 »

Hello,

Has somebody tried to adapt stepper motor and astroeq on a Exos 2 Bresser mount. As far as, I read, this mount is very similar (or identical) to a Meade Lx 75.
 suppose the worm gear ratio should be 144:1 ?

Thanks.
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TCWORLD

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Re: Bresser exos 2 mount
« Reply #1 on: November 22, 2017, 16:57:16 »

Appears to be an EQ5, so yes, should be 144:1.
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Tom Carpenter (AstroEQ)

doramason

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Re: Bresser exos 2 mount
« Reply #2 on: November 22, 2017, 19:23:49 »

Hello,

Has somebody tried to adapt stepper motor and astroeq on a Exos 2 Bresser mount. As far as, I read, this mount is very similar (or identical) to a Meade Lx 75.
 suppose the worm gear ratio should be 144:1 ?

Thanks.

I have done and yes it is the same.
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David

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Re: Bresser exos 2 mount
« Reply #3 on: November 23, 2017, 07:59:52 »

Thank you.

@ Doramason, did you use Tom's recommendation about type of motors, pulley,... I would be very interesting in having more info on the way you did it.

Regards
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doramason

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Re: Bresser exos 2 mount
« Reply #4 on: November 25, 2017, 23:38:46 »

Thank you.

@ Doramason, did you use Tom's recommendation about type of motors, pulley,... I would be very interesting in having more info on the way you did it.

Regards

it is the same mount as an eq5 so you don't have to change anything. don't buy low voltage motors, they miss steps. I have used 1.8 degree Nema17 motors and 4:1 pulley ratio. Probably it gives more resolution than I need. Thoughest part is attaching motors to the the mount, I have used standard nema17 brackets and pieces of aluminum bar.   
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David

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Re: Bresser exos 2 mount
« Reply #5 on: November 27, 2017, 09:13:35 »

I plan to use the Nema 14 type proposed by Tom on the website. Are they similar to the one you used (voltage and torque) ?
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doramason

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Re: Bresser exos 2 mount
« Reply #6 on: November 27, 2017, 13:42:10 »

I plan to use the Nema 14 type proposed by Tom on the website. Are they similar to the one you used (voltage and torque) ?

https://www.pololu.com/product/1200

this is the motor I have used. But even with this the missing steps was an issue hence I had to do the fast decay mod on the DRV8825 driver. So maybe an even higher voltage motor would be better than this. But if it is too high it might stall in high speeds. It is a bit of trial and error. Or you can check other threads on the forum maybe someone had used a motor which didn't miss steps and stall. If you are going to do a DIY board you can also add diodes in to the circuit or use a different driver to solve the missing step issue.
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David

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Re: Bresser exos 2 mount
« Reply #7 on: November 28, 2017, 10:39:52 »

Has somebody some recommendations on "motor which didn't miss steps and stall" ?
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David

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Re: Bresser exos 2 mount
« Reply #8 on: November 28, 2017, 14:32:21 »

I found these ones. They seems to be Ok (?).
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David

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Re: Bresser exos 2 mount
« Reply #9 on: May 02, 2018, 14:04:27 »

Hi,

For those who are interested, here are some data about the motor I used and the associated drawings for their support to the mount.
It works well. I can now take picture of 60 sec without guiding and with quite good results.
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