Author Topic: DIY Worm Gear Based Heliostat Design  (Read 13713 times)

Gabriel

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Re: DIY Worm Gear Based Heliostat Design
« Reply #15 on: October 28, 2014, 10:17:49 AM »
That looks promising. It's really not a bad deal considering that it comes with the stepper motors. Thanks for sharing!


abhijitrathi

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Re: DIY Worm Gear Based Heliostat Design
« Reply #16 on: January 24, 2016, 01:27:15 AM »
Hello Gabriel,
Can I request you for a pdf of the worm gear equipped Heliostat set up please?

Many thanks,
Abhijit


Gabriel

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Re: DIY Worm Gear Based Heliostat Design
« Reply #17 on: January 24, 2016, 06:17:49 AM »
Hi Abhijit,

I don't have a pdf for this heliostat, but if you go to the first post you will see that there is a Sketchup file that you can download. Sketchup is a free (for individuals) CAD program that you can download and view or modify the design file. I have sort of abandoned this design and am trying to build more out of metal this time around, but it would definitely be cool to see someone finish it.

Hope that helps,
Gabriel

luiklodwig

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Re: DIY Worm Gear Based Heliostat Design
« Reply #18 on: November 27, 2017, 04:14:56 AM »
I started a new try on a heliostat, I finished the initial design, some things need to be tweaked and rebuild and a decend mirror will be obtained in the future! I used car wiper gears. Gear ratio is about 1:55
I hope to get this machine electrified and programmed as soon as possible, can't wait to see if it works.
e: unfortunately I can't buy the shield but I'm trying to do put it together somehow
« Last Edit: November 28, 2017, 09:08:25 AM by luiklodwig »

Gabriel

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Re: DIY Worm Gear Based Heliostat Design
« Reply #19 on: December 07, 2017, 03:01:14 PM »
Looks good!


Silverbrewer

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Re: DIY Worm Gear Based Heliostat Design
« Reply #20 on: December 18, 2017, 01:05:44 PM »
I'm sure you will have sorted your gears by now, but as a heads up, the automobile scrap yards are full of geared motors, so find a common car and then find something you can use and there is your endless cheap supply.
Power seats have flexible drives, acme screw drives and helical drives (and that is just a Range Rover seat)
Windscreen wiper motors, electric window motors are good foe helical.
Tailgate lift motorised struts are linear etc etc
Some of the power handbrake/ emergency brake mechanisms have really powerful leadscrew systems
Most will lend themselves to having the motor replaced with a stepper.

Teghan

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Re: DIY Worm Gear Based Heliostat Design
« Reply #21 on: January 07, 2018, 03:50:10 AM »
Great tip regarding the scrap auto motors. I hadn't thought of that either. Does it matter which manufacturer at all?

Silverbrewer

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Re: DIY Worm Gear Based Heliostat Design
« Reply #22 on: January 14, 2018, 07:03:56 AM »
I am just starting out on my experiments, and so far am looking at using the gearboxes on front windshield wiper motors.
Just pick a common make that is cheap. Most all will be steel worm and plastic worm wheel nowadays, though if you find one with full metal construction then even better. Both of mine have the motor shaft running through a ball bearing race.
I have taken them both apart, and cut off the motor armature and removed the commutator segments. This gives me an 8 mm dia shaft about 12 mm long going into the 61:1 ratio gearbox. Using ebay flexible shaft couplings, it is my intention to first try a nema 17motor, which is small enough to mount to the shaft stub, and be able to re fit the original motor cover, and if that proves too feeble, I will fabricate a motor mounting plate that allows me to fit a nema 23, and bin the motor cover.

It surprises me that this worm gearbox can be rotated by hand on the output shaft, as I was expecting it to lock against back driving forces. Perhaps I will go through two gearboxes in series if back driving is a problem.

Most stepper motors can be had with integral planetary gearboxes, but they are a tad pricey. Good planetary gearboxes can be had from cordless drills, but then you have to come up with a connection method for the input drive. not impossible though. First, lets see what sort of gear reduction ratio best suits our needs.
In a week or so I will cobble together a crappy video and post it on YouTube so this verbal ramble makes sense.


Silverbrewer

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Re: DIY Worm Gear Based Heliostat Design
« Reply #23 on: January 14, 2018, 07:36:56 AM »
Well shiver my Timbers!!!! How the hell did I miss Luiklodwig's post about 3" above this one???
He has already done exactly what  am going on about.
Luiklodwig, could you post a video showing its max speed and enlighten us on how you think it will cope when bigger, and out in the elements.

luiklodwig

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Re: DIY Worm Gear Based Heliostat Design
« Reply #24 on: January 17, 2018, 03:13:41 PM »
Hi Silverbrewer, sorry for the late reply.

I'm currently rewiring the whole thing to have just one cable from heliostat to arduino-control and finalising the mechanical aspects as good as I can, so I can't really do a video right now because it just not in a working state right now. I should add maybe that I am not planning on a sort of permanent installation of my heliostat so weatherproofing and the likes are not my top priority. I think that the gears should hold up rather well since they are made to be used in  harsh conditions I guess, but the waterproofing of the motors would be essential. Maybe a mechanical solution were the electronics and drive system is protected in a single case would be easier to be made fit for real weather.. Concerning speed and scaleability. I was surprised how fast the system goes.. when I last tried, i set my motors to 60rpm and it felt  too fast for me so I set them back to 20rpm for the testing time beeing :) The power of the motors in combination whith those gears which give something like 1:55 is also quite impressive, so I think that it is safe to say that a glass mirror of 50cm in diagonal would be no problem if the bearing is good and you could probably go larger if you would use an acrylic mirror or sth.

I can try to post a video once I get the thing were I want it to be, but I think I'll just need a few days do get it done now..
« Last Edit: January 19, 2018, 01:31:55 AM by luiklodwig »

luiklodwig

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Re: DIY Worm Gear Based Heliostat Design
« Reply #25 on: January 30, 2018, 02:21:37 PM »
I made a timelapse of my heliostat, I'm very happy with the precision, but It's my first working heliostat ...

Distance between target and heliostat was about 6-7m
https://vimeo.com/253500405
(Password: heliostat)

Thank you so much Gabriel for your wonderful work!
« Last Edit: January 30, 2018, 02:33:53 PM by luiklodwig »

Gabriel

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Re: DIY Worm Gear Based Heliostat Design
« Reply #26 on: January 30, 2018, 05:38:16 PM »
Wow! That is really accurate. That's the hardest part it seems is making the machine be precise.

I'm glad you got it working. :)

luiklodwig

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Re: DIY Worm Gear Based Heliostat Design
« Reply #27 on: February 01, 2018, 01:29:43 AM »
Thanks! I tired my best to make the machine as mechanically accurate as I managed.. it turned out that the base is not exactly parallel to the fork where the mirror is mounted but when you play around with a level for a while it still get's sort of straight ;)

another video showing speed with motors @20RPM
https://vimeo.com/253754632
PW: speed