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Lifter gearboxes.
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marto
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Lifter gearboxes.

For last few years we have been just using winch gearboxes for lifters, grabbers, etc however they are now getting up to $100+ don't include the relays to control it and they really are stupidly heavy and a bit fragile. They need quite a few mods to use and most people are now putting brushless motors on em anyway.

I was wondering if anyone had any alternatives which can provide a similar reduction in a not necessarily cheaper but more user friendly package?

Steve
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Post Sun Oct 25, 2015 2:35 pm 
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MikeNCR



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For Nyx's lifter I run a DeWut in low gear with an extra 9:1 reduction going to a 23" arm. Rough numbers say that at the 50A current limit I use it should be able to lift 45lbs at the tip. It's worked quite well so far.

Post Sun Oct 25, 2015 2:41 pm 
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Nick
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A Dewut gearbox & 18V motor is $223 USD + exchange rate + shipping, so its around $300 landed here. It's a well made and light option but more than most people want to pay.

Perhaps we could search around Alibaba for a group buy of winches?
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Post Sun Oct 25, 2015 3:47 pm 
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Valen
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I wonder about a hypocycloid box attached after a single planetary stage, should get heaps of reduction in a compact package without worrying too much about the high speed limitations of the hypocycloid on the input.

You could go harmonic but DIYing that is left as an exercise for the reader
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Post Sun Oct 25, 2015 3:49 pm 
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Nick
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Would laser or waterjet cutting be smooth enough for the rotor in hypocycloid garrbox, or would it need to be CNCed? The rest seems fairly straightforward to make.
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Post Sun Oct 25, 2015 4:21 pm 
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Rob Team Rotwang



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This is a drill motor with a clutch modded onto a manual car seat adjuster. Found in a falcon I think.
available at wrecker yards plentiful.
its almost free hypocycloid box rescued from a scrap car.
they're strong enough to hold up people while the cars accelerating, should push a robot over.
they dont free spin due to how they're designed, but go around easily once the center is turned.
the outer diameter goes up and down like a wave, about 5-10mm when rotated due to the way the gear inside pushes the outer gear around. so that needs to be considered for the design.



Here it is pulled apart a bit
can see it here before being cut down with the black handle as you would use in a car to wind a seat down


used a drill with lock nuts
drill uses the clutch that it comes with
if u dont use the clutch the drill will get to the end and burn out
clutch should still allow to lift 30 pounds before ratcheting
ordinary socket on the end
welded on a long piece of square thread, car jack.
makes an extra long linear actuator for bulldoze



bulldozes bucket must weigh about the same as a feather weight


dads got the same system in our feather lifter





Electric car seat linear actuator slow lifting


some people like george i think have used an electric car seat linear actuator in their robots, i think he welded on or made an adapter for a larger worm shaft with a bearing race. that sped it up somewhat.


have a look through George's thread here.

He used the linear actuator effectively in Pincher the robot in this picture.

http://robowars.org/forum/album_pic.php?pic_id=263
https://www.youtube.com/watch?v=8gnB1oqZbHA
http://www.robowars.org/forum/viewtopic.php?t=110&highlight=pincher

There are some commercially available linear actuators
motion dynamics have got a lot of them
got one in Ref Bot for the lifting arm shown here

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Post Sun Oct 25, 2015 8:15 pm 
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Ellis



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Big drill + chain/belt stage. Get the biggest multiple speed drill you can find, an extra stage (or two if long like Nyx' arm) and you're golden.

An bin-scavenged AEG two-speed monster with a further 3:1 can chuck featherweights around (T2/the old feather - pic missing sewer snake style top part of the lifter):


And an oldschool Dewalt + 3:1 properly throws them in Tormenta 3. It just murdered the belts until given more wrap. Torque is plentiful.


These are both more flippers than lifters, but even with the relatively low reduction (120:1 or so) they can shift a full featherweight at the end of the top bars ~35cm long.
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Post Sun Oct 25, 2015 10:28 pm 
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Cpnwolfe



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that bulldozer is beautiful can I have some more info on it please?
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Post Mon Oct 26, 2015 5:54 am 
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Valen
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I think for the way we use it laser/water should probably do the job for hypocycloid , I mean ideally they would be induction hardened and all sorts but for a lifter you want seconds of operation tops, and you have plenty of power to throw away.
Perhaps even run it first with some abrasive to knock off any rough edges, then grease it up good
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Post Mon Oct 26, 2015 7:58 am 
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Knightrous
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Waterjet / Laser is not good enough for hypocycloid designs, CNC is a much better method for doing the cams as you need a dead flat face on them or they will bind.

I have designed two gearboxes for the 2016 version of Farmboy which utilises the hypocycloid design. The first is a 12:1 single stage gearbox to suit a low to medium kv brushless motor within a 50x50x41 package.





The second gearbox is a 100:1 two stage hypocycloid gearbox which I will post images of tonight.

Both designs I'm looking to get CNC'd in China, if people are interested, I can get additional units made.
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Post Mon Oct 26, 2015 8:18 am 
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Rob Team Rotwang



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Sure Harley

Dont have a build thread or any video on Bulldoze.
There was a few updates and pictures of him on this thread while we were discussing heavyweights.
http://www.robowars.org/forum/viewtopic.php?t=519&postdays=0&postorder=asc&highlight=bulldoze&start=0

Was one of the first robots built by Gary in 2000

Plan was to compete with bulldoze if a heavyweight competition came along. We didnt know at the time what direction things would go. Turned out the feathers were favored but bulldoze was still built to drive around and articulate its front scoop also a rear lifter for modular weapons.

crewed by cocoa the furby he never saw much action, no fight history. Sad


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Post Mon Oct 26, 2015 6:54 pm 
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Glen
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Am i too late to join in on this thead? D:

I still think the compressor + 5/2 valve + small pneumatic ram would be the strongest way as its completely decoupling the motor from the lifter itself. You lose some ability for control like say aussie battler has, but most lifters of the winch variety seem to be very fast anyways.

Also has the advantage of being able to use 100% off the shelf parts with no mods, and easy speed control as no limit switches are required.

Would be keen to try it myself sometime with maybe a 40mm bore ram.
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Post Wed Oct 28, 2015 2:17 pm 
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Cpnwolfe



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thankyou!
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Post Sat Oct 31, 2015 9:18 am 
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Philip
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Re: Lifter gearboxes.

quote:
Originally posted by marto:
I was wondering if anyone had any alternatives which can provide a similar reduction in a not necessarily cheaper but more user friendly package?

Steve
This guy has an encoder for the BB 220 gear box. It might be of interest to you. http://www.andymark.com/product-p/am-2885.htm
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Post Sun Nov 01, 2015 8:08 am 
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Nick
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quote:
Originally posted by Knightrous:


I have designed two gearboxes for the 2016 version of Farmboy which utilises the hypocycloid design. The first is a 12:1 single stage gearbox to suit a low to medium kv brushless motor within a 50x50x41 package.


Were these designed for drive or as a winch replacement and how much torque do you think they are good for? Is there any chance of scaling them up or increasing the single stage gearing a bit?
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Post Sun Nov 01, 2015 9:32 am 
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