Centre wheel for ball bearings

[SNIPE]

Hi,

Is there something which will fit in the middle of this wheel so that it makes contact with the red ball bearings?

You can move the bearings to different pin holes if needed.

Here is the LXF file.

it is for a robot and the yellow wheels will be vertical as shown and have heavy load on them, hence the need for bearings and hi-torque, thru-axle ev3 motors 

[Myers Lego Technic]

Here's an idea. 

https://bricksafe.com/files/Myers_Lego_Technic/misc.-/ex-02.lxf

 

 

(I marked the one pink piece so you know it should be placed like the others, it's just that LDD was being stubborn.)

Edited November 25, 2017 by Myers Lego Technic

[SNIPE]

Hi,

I have considered using turntables but don't think they will be smooth enough under extreme load.

Regards, Snipe

[Carsten Svendsen]

Give them a bit of grease on the inside. Not oil, but grease, that's gonna help it rotate much better

[SNIPE]

It would certainly help but I'm a bit of a Lego purist. Thanks anyway though.

Edited November 26, 2017 by SNIPE

[aminnich]

LEGO purist... ok, so take apart a PF motor and use the grease inside that 

[mocbuild101]

Maybe try putting a wheel rim between the bearings?

[doug72]

 

The Z60 turntable is very free running, suggest give it a try & test to see how much load it can take before rejecting them.
The Balkirk Wheel MOC use six Z60 turntables and worked OK.

 

If you are a Lego purists you don't have many other options !

 

Note: it is very hard to seperate the two halves of a Z60 turntable.

[SNIPE]

I'll give it a try.

[Erik Leppen]

A wheel rim sounds like the best option. If it needs to be thin, maybe a motorcycle wheel.

[rasikaa]

How about placing a couple of 8 tooth gears around the inside of the banana gears? They are good at giving high torque movement of the gears too. Rather than putting a high load at the center axle, it allows you to move the gear/the central hub much easily. Have used them in a GBC module to rotate two banana gear disks in tandem and works like a charm.

BTW, having run GBCs for a couple of years, I can also highly recommend the silicon grease to reduce wear and allow smoother operations. You will need to leave out your purist pride when it comes to practical use.

Rasika

[SNIPE]

Hi

I have decided to abandon using the turntables and bearings and am going for this setup:

The master motors (EV3) bear the load of:

• The PF motors (orange)
• The PF motor "back to back" mounting enclosures. (orange)
• The PF motors shared axle (green)
• The struts (pink)
• The spokes (red)
• The spoke center hub (Yellow)
• The wheel (blue)
• The battery boxes (white)

The inner motors (PF) bear the load of:

• The spokes (Red)
• The spoke center hub (yellow)
• The wheel (blue)
• The struts (pink)

Battery boxes (white) ill be mounted on the PF mounts to add a counter weight, else the PF motor outputs will be stationary and the motor housings will rotate instead

The reason is because the EV3 motors do not fit inside of the wheels so I had to use the next closest thing but with enough torque (hopefully)

Here is the LXF file, I have color coded each section according to the above lists.

Missing parts:

PF rechargeable battery box (substituted with PF AAA battery box)

PF pole reverser switch (substituted with PF extension cable)

Edited December 3, 2017 by SNIPE

[SNIPE]

Small update:

I have built half of the above and have decided to use 99009c01 or 18939c01 turntables in between the PF motors as the center hub is not likely to slide out of an EV3 motor where as with PF it does slide out. Since the turntables are almost impossible to separate this will keep everything tied together nicely  They don't need to also support the spokes though because that was very difficult due to lots of weird pin hole directions and obstructions.

Here is the build anyway: Note in the top pic the PF motors and enclosure is slouching down, even since this is half a model is still was not good enough.

Changes:

I am now using either a buwizz, or EV3 brick to control both the PF and EV3 motors.

I have also added bracing to the PF motor enclosure as the motors would twist white a bit.

I am using an NXT motor and slightly different struts, again this is only one half of the model as the rest of my yellow curved gear strips are in the other house.

Please note (I should have mentioned before) that the PF motors are only supported by the weight of the buwizz/EV3 brick + some extra weights if needed. It must always point down towards the ground, unless I use the toothed half of the turntable for driving the yellow rings and make some sort of custom upscaled axle out of beams which is connected to the gray half of the turntable.

The entire model in the LXF file will be replicated x19 and all connected together into one long tube with an EV3 motor on EACH end of the whole tube.

Edited December 3, 2017 by SNIPE

[SNIPE]

Here is an update:

 

If the light saber pieces fit into the pin holes then I cannot see any other problem with this version which means it is basically complete for now unless I can later improve it, the priority now is to work on a totally different section of the model.

Here are the images: 

Here is the LXF file

problem A: a non idler hub would tie itself to the XL motor support holes but would not allow the motor output to rotate.

problem B: an idler hub would not tie itself to the XL motor support holes but would allow the motor to rotate.

Solution: the spokes should be meshed to the EV3 motor output and the black half of the turntable I used a light saber handle piece for this because it has an axle hole instead of a pin hole.

The gray half of the turntable is only fixed onto the PF XL motor pinholes. and is not meshed with the PF XL motor output.

The turntable keeps everything tied together so axles or pins do not slip out of their holes under weight.

I will probably use a 60T turntable soon as I can put the EV3 wires thru the centre but still have room in the centre to replace the light saber handle piece if it does not fix

Edited December 4, 2017 by SNIPE

[1gor]

On 11/26/2017 at 3:22 AM, aminnich said:

LEGO purist... ok, so take apart a PF motor and use the grease inside that