Curved Gear Strip Bearing ideas?

[SNIPE]

Hi,

Does anybody have any ideas on how to vertically support rings which are made up of 4 curved gear strips, putting gears inside of them would not be smooth enough.

I have tried putting different types of pulleys and Lego system 2x2 tile round with centre hole in the channel on each side of the gear strips but the spacing is imperfect and there is no bricks thin and small enough to fill this spacing. and it would also offset a big proportion of the whole model.

If not, I could always just use NXT/EV3 motors as they have a strong output hub which is supported by the motor enclosure anyhow, but this will be expensive and noisy.

I need something that will allow for the curved gear racks to spin smoothly because they are used as wheels.

here are the pictures of what I have tried:

https://imgur.com/a/H5Wfq

https://imgur.com/CpFwpwO

https://imgur.com/2q4308j

 

Edited November 15, 2017 by SNIPE

[Imanol BB]

Hi, have you tried placing 1x1 round tiles?, they offer an smooth movement and great support, here is a video showing it:

I hope this can help you.

[SNIPE]

Hi,

I did consider it but the problem is my turntable is on its side as shown in the pictures so there is nothing to clamp the two halves together. also the spacing between the two halves are an unconventional amount, which is hard to build around.

I tried normal technic 60T turntables but they are not smooth enough.

Edited November 15, 2017 by SNIPE

[doug72]

Take a look at how I supported a gear ring vertically from inside using gears and wedge wheels.
It might work for what you require.

 

Edited November 15, 2017 by Doug72

[SNIPE]

I think gears would be too rough. There is a lot of load on the yellow rings so If bearings dont work ill have to add more motors.

Regards, snipe.

[doug72]

3 minutes ago, SNIPE said:

I think gears would be too rough. There is a lot of load on the yellow rings so If bearings dont work ill have to add more motors.

Regards, snipe.

Check out the video on page 2, it runs very smoothly using gears for support & drive, with wedge wheels to keep the gear ring in place. Slow rotation is because It is worm gear driven but should be able to be speeded up.

Edited November 15, 2017 by Doug72

[doug72]

4 hours ago, SNIPE said:

Hi,

Does anybody have any ideas on how to vertically support rings which are made up of 4 curved gear strips, putting gears inside of them would not be smooth enough.

Is this any use - its an idea I was working on recently for a GBC module.

 

Edited November 15, 2017 by Doug72

[SNIPE]

Ill give it a try thanks.

[RohanBeckett]

on a related note.. I'm in the middle of making a GBC using Hailfire wheels.. and found using the newish 1L beam works very nicely as bearing, when placed on a pin, or axle

add a tiny squirt of silicon spray, if you're running it for a long time...

[doug72]

22 hours ago, SNIPE said:

Does anybody have any ideas on how to vertically support rings which are made up of 4 curved gear strips, putting gears inside of them would not be smooth enough.

 

Can you give more info what will be attached to the gear ring ?

10 hours ago, RohanBeckett said:

on a related note.. I'm in the middle of making a GBC using Hailfire wheels.. and found using the newish 1L beam works very nicely as bearing, when placed on a pin, or axle

add a tiny squirt of silicon spray, if you're running it for a long time...

Good idea, tried it and a gear ring runs very smoothly. 
See image of a couple of solutions - the left one with 5 x 7 frame supports and guides OK and has clearance for 2L axles connecting the segments without snagging.

The right  would need 1L pins to connect segments  to prevent snagging.

Idea using all eight 1L roller guides.

 

Using wedge wheels

Edited November 16, 2017 by Doug72
added more images

[SNIPE]

Hi

I unfortunately cannot have anything supporting the yellow rings from the outside as they will have the rubber 2L beams on the outside to mimic a car tire.

I think I will just use motors rather than bearings but the problem is that the NXT/Ev3 motors are too long and stick out beyond the yellow rings. So I'm back to square one again now

I'll put some more images of the idea when I get home.

Edited November 16, 2017 by SNIPE

[doug72]

22 minutes ago, SNIPE said:

I unfortunately cannot have anything supporting the yellow rings from the outside as they will have the rubber 2L beams on the outside to mimic a car tire.

This should meet your requirement and allow rubber tread to be added on edge of rings.
If only a single width of rings required just reduce distance between the two 5 x 7 frames.

PS this is just what I need for a projected GBC idea.
 

Edited November 16, 2017 by Doug72

[SNIPE]

Hi, this looks good, can it go inside of the rings instead though? it cannot go on the outside. Imagine the rings are wheel hubs basically so the small rubber parts would go on the outside of the rings. Images coming soon.

[doug72]

11 minutes ago, SNIPE said:

Hi, this looks good, can it go inside of the rings instead though? it cannot go on the outside. Imagine the rings are wheel hubs basically so the small rubber parts would go on the outside of the rings. Images coming soon.

I,ll see what I can come up with tomorrow,

Doug

[SNIPE]

I will try and put something together as soon as I get home.

I like the self induced pivoting of the bevel gears and I think if they are at a 45 degree angle and there is 4 per side it will also reduce the load and friction a bit on the bevel gears. should be able to reroute the wheel spokes on the outer edges of the bevel gears. will need non idler bevel gears for the holes on the wheel to not be obstructed but should be fine.

[doug72]

I have tried to come up with supporting the rings inside using the shallow groove using 12T single bevel gears but none successful .



This is the set up I used for my Bucket Wheel Trencher which provides good support and is very free running.
Ample space to attach your rubber pads and still not obstruct the gears. Can be driven via any one of the gears.

Note the  uneven spacing of gears to get best teeth engagement without slackness.


One pair has 9L spacing - the other pair has 11L spacing.

The grey wedge wheels insure the gears stay on the gear.

Centre turntable can be for support if required.

Two gear rings possible by using longer axles to connect the 20T gears to get desired width.

 

PS I ony have enough curved gear racks to make one ring at the moment as my TC12 entry used alot !

Edited November 17, 2017 by Doug72

[SNIPE]

I'll try your last idea soon. The half bevel gears are too small so the yellow ring  wobbles.

[doug72]

2 hours ago, SNIPE said:

I'll try your last idea soon. The half bevel gears are too small so the yellow ring  wobbles.

Yes that what I found.

Note, the turntable as shown if 0.5 L off center,. It can be fixed by cross blocks 2 x 2 split (twin axle/pin).

Edited November 18, 2017 by Doug72

[SNIPE]

2 hours ago, Doug72 said:

It can be fixed by cross blocks 2 x 2 split (twin axle/pin).

What part is that again?

[doug72]

30 minutes ago, SNIPE said:

What part is that again?

https://www.brickowl.com/catalog/lego-technic-cross-block-2-x-2-split-axle-twin-pin-41678

You need four plus two 6L axles to connect to the turntable.

I,ll  add a photo tomorrow.

[doug72]

After re-tying all gear sizes found this is still the best solution using 20T double bevel gears:
Support frame for gears made made stiffer using 4L x 1L angle beams & 3 x 3 Tee Beams

Two versions: with a 60T turntable and without.

If you need two gear rings connect them with beams and axles.
To get rotation centre point two methods are used to centre turntable and and without T/T which can be seen in images.

 

Edited November 19, 2017 by Doug72

[SNIPE]

Right, Thanks for the ideas, I have tested them and unfortunatley still require too much effort to turn.

(the geared half of the turntable is for driving it and the gray half is is fixed onto the support structure. Since the turntable is in the centre.

The nxt/ev3 motors have a super strong, multi hole output rather than an XL motor which only has a single 1L axle hole for the output.

The nxt/ev3motor housings can easily support the load but they would hit off the ground since the yellow wheels are smaller than the motor.

There will be around 19 yellow wheels each consisting of 4 curved gear racks.

Back to the drawing board I go!.

[doug72]

4 hours ago, SNIPE said:

 

There will be around 19 yellow wheels each consisting of 4 curved gear racks.

Back to the drawing board I go!.

Difficult to understand what you are trying to build, can you post same images, preferably embedded photos not links.

Doug

[Carsten Svendsen]

I reckon that there's too much friction between the bevel gears and the ring for the entire thing to turn properly. 

I think you should skip the idea of rotating the ring by the gears on it, and instead use the turntable to turn it with.

Then you could make a simple 4-point connection from the ring to the turntable.

However, don't use the gears of the turntable to spin the wheel, connect the EV3 motor directly to the attachment points on the turntable it self.

[doug72]

Friction is the problem and drive gearing.

On my bucket wheel trencher which has the same gear frame set up, the gear ring with 8 buckets is rotated using only a single M motor only BUT via a 24:1 worm gear reduction engaging with the curved gear rack teeth for increased torque and runs very smoothly. 

 

Edited November 21, 2017 by Doug72