Satnogs - All Metal "Box Mountable" Rotator

That’s exactly why we decided to organize a group order at a manufacturer for the machined parts

The part list is kind of simple, two RV030 worm gear reducer, two NEMA23 stepper motor, and then the machined parts and some screws.

EDIT : More precisely in the mechanical size :

It’s true that It could be a good idea to write a wiki page to sum up the information about it

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What about electronics?

I am o.k. with the price you projected, plus shipping.

Bill
W2WHC

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@DL4PD for the electronics, it exactly the same as for the Satnogs Rotator, 2 Stepper controller, sized for the stepper you buy, an Arduino connected to your raspberry pi, and two optical, or mechanical endstop.
You maybe missed this link in the thread, which permit to see the full design https://a360.co/2CAJL9K

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Cool project! Thanks for sharing. Have you got any trouble with the RV030 in terms of outdoor use or are they well enough encased? I can’t seem to find a IP rating for them.

Greetings, Alex

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Hi @raaptormet !
Thanks for your interest !
The structure of the RV030 is in aluminium, then for the gears they are in an oil bath and therefore totally isolated from the outside by several joints, however it seems that the part that drives the axle rust a little on the surface, but by brushing a little bit the rust disappears.

This is before brushing


And after

And for the moment, the RV030 are the parts of the rotator that have caused the least number of problems (0)

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Thanks for the quick respond @Yohan_Hadji !
Have you had any other problems with your current station iteration?

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My only current problems are a usb cable that has a false contact and a raspberry pi that programs 2 observations at the same time, so mechanically speaking, everything works great !

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Hi @Yohan_Hadji ,

@raaptormet continued your developments on this project https://community.libre.space/t/outdoorproof-and-powerful-rotator/6690, and since we are moving forward with another rotator design, we would like to publish our current status for this project on our TUDSaT GitLab account https://gitlab.com/tudsat-cubesat to preserve it. Unfortunately there still is no License file on your GitHub repository https://github.com/YohanHadji/Yohan-s-Rotator-/, do you want to add one there or are we allowed to choose one on our own?

Hi @milenko and @raaptormet,

The project is on pause on my side for external reasons. However, here is a new repo with few more information, the latest files, pictures, links, and a license.

Thanks again for your interest !

Yohan H

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The new upgraded version is coming to life… more soon !

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That looks pretty beefy!!!

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Thanks! Indeed it was designed for!
One of the last parts, the bracket is also validated since this morning, I’m now just waiting for the very last part to publish more information about it.

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Hi all!

I am very happy to present you the latest version of SuperAntennaz, with all the new machined parts, perfectly functional!

  • The current rotation speed is about 20°/s. (and as you can see on the video at the bottom of this post the noise is very low.)

  • The estimated (extreme minimum) torque is 60 N/m on both axes.

  • The azimuth axis is now supported by a plate ball bearing to support several tens of kilos of antennas

  • The rotator weighs 5.5kg.

  • All mechanical parts are either made of aluminum or stainless steel and are therefore corrosion resistant.

  • The motors are waterproof IP65

  • 3D Files will be soon updated on the github

Feel free to ask me any questions you have!

Yoyo

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Awesome job and it looks amazing for the smaller Yagi Antenna setup… Keep me posted please I’d like to get my hands on one or the parts to put one together for testing it in my location and cold climate which was -43c over night and the Yaesu G-5500 doesn’t like that temperature one bit.

Keep up the great work and thanks for sharing with the community.

Regards
Karl. (Station:1920)

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Hi Karl!
Thanks for your interest!

I would also be interested to see how the rotator resist to really hard climate, the main concern will be to see how the wormgearbox react to really cold temperature.
The gears are in an oil bath, so if it’s not warmed up a bit I think it might solidify at this temperature and block the rotator. However, the advantage with the use of stepper motors is that they can also be considered as heating element! So it’s possible that they will be hot enough to allow the oil in the gearbox to remain liquid enough even at -40°C, but this remains to be tested!

Best Regards,

Yoyo

The latest version of the design (V0.5) have been published on the github, this is the first, “tested and operational” version :

The first version of the mechanical assembly instructions is also available there : https://drive.google.com/file/d/1CX67OoED31l0qCKSzgDJZNf59-uH2FNJ/view?usp=sharing

(Please note that it’s only the first version, and few things might need some modifications and or verifications)

A second manual for the electronic part is also being written, it will be published as soon as possible.

Yoyo

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Hi Yoyo.

Good to know about the oil in the gear boxes and yes for sure it would need some testing and maybe replacing with a 0W20 synthetic oil.

Thanks
Karl.

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Kits n°002 and n°003 are ready to be sent to their future owners very soon!!

(Note that some screws are missing on the pictures, but all necessary screws ARE INCLUDED in each kit)

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Hey @Yohan_Hadji very nice work. Recently we got, i think, your first kit. It works nice and smooth. We make indoors tests (as station-200 needs to update photo :wink: ) and when we have time we will put it in Athens hackerspace rooftop.

The antenna that is used is a dish at 2.4GHz. We will add Counterweight for Antenna.

Some comments:

  • The u-clamp of elevation mast it has collision with cable of end-stop.
    To resolve it, we added an additional cable tie.

  • The stepper motor drives are tuned at 4.9A(peak current) as a result after two days with 5-8 observation the elevation axis stop working due to over temperature. After a power cycle of stepper drive it works again. For the same reason the cables are hot. To resolve it we reduce the current to 3.8A(peak current) but the elevation is rotated harder than before. I just read that the SW4 of driver is used to set motor idle current percentage at 50% when is OFF position, i need to check. Also @Yohan_Hadji do you have any suggestion or reference about the current setting(rated/peak/RMS) vs microstepping for this set-up?

  • This comment is related with specs. The worm gear box it has static efficiency ηs = ~0.4, that means if the stepper motor has torque (stall/holding) 1.2Nm the output shaft (stall/holding) torque could be 1.2Nm*50(gear ratio)*0.4(static efficiency) = 24Nm

  • It is unclear which is the firmware that the arduino uno runs, that would confuse a contributor :wink:

  • It would be nice to add your design in SatNOGS - wiki, i can help you!!

:rocket:

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