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51 minutes ago, keymaker said:

A while ago I looked for reliable solution for narrow live front axle for my Kraz 255 model. I end up with below solution. It should be useful for small scale models. Building instructions included.

-SNIP-

I'm going to stop you right there.. The suspension.. The springs are mounted wrongly because when you compress the suspension from the side, the spring will twist in a breaking way.. 
You should add lego-technic-hole-with-pin-15100-27.jpgthese parts so you can mount the springs sideways so they can turn while compressing. 

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9 minutes ago, Mechbuilds said:

I'm going to stop you right there.. The suspension.. The springs are mounted wrongly because when you compress the suspension from the side, the spring will twist in a breaking way.. 
You should add lego-technic-hole-with-pin-15100-27.jpgthese parts so you can mount the springs sideways so they can turn while compressing. 

Yes, I am aware of that. After fast check the change you are proposing is possible, but it also has a couple of drewbacks:

- it will change geomatry of the front suspension quite a lot - springs mounted closer to ther center, more movement of the axle, in the result tires touching the fenders in maximum positions

- less robust connection of the axle and springs

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It's compact yes.. But it doesn't look very tough. The axle for the motor is off center which means either offcenter balance or added gears.. Also the steering can't move 90 degrees which requires additional parts for the servo in order it to move the full 90 degrees. 

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Good point about using a servo ...  if you turn it any more then 45 degree you will pop out the cv joint..   I'll use a m mtor any way.. my servo has expired !! :( 

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Just now, sirslayer said:

[...] my servo has expired !! :( [...]

:wall: Damn!

How long did it last and how much did you use it in that timeframe? I'm not looking forward to the day my servos go the way of the dinosaurs.

 

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I had for a year and It was abused in every technic way..  I got myself a few Lego Powered up motors to go with my 2 port hub.. I know you can program the m motors to act like a servo.. Im learning on using the software right now .    

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9 hours ago, suffocation said:

:wall: Damn!

How long did it last and how much did you use it in that timeframe? I'm not looking forward to the day my servos go the way of the dinosaurs.

 

My servo works after 4 tears of ignorence so I do not want to break my head with it. Question is how will new system perform if you need multiple steering modes?

...not to mention that my mobile phone has to much apps it can normally handle already...

...about dinosaurs; you can here them every day singing in the trees :thumbup:

Edited by I_Igor
Writing error

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Does anybody have a 6x6 rear axle design? I think it's called oscillating axle or something.. 
You know, lift one wheel and other goes down. 

13 studs between tyres so compact but needs to be sturdy. 

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15 minutes ago, Mechbuilds said:

Does anybody have a 6x6 rear axle design? I think it's called oscillating axle or something.. 
You know, lift one wheel and other goes down. 

13 studs between tyres so compact but needs to be sturdy. 

This is 15 studs but it can be adjusted to 13. Includes pneumatic diff lock.

800x450.jpg

800x450.jpg

800x450.jpg

800x450.jpg

 

 

Edited by suffocation

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No i was talking about 6x6 axles.. You know, the 4 tyres mounted to the chassis and they're linked to eachother so if a wheel goes up, the other must go down.. Oscillating bogie or what ever it was called? There is no name for that system that i know of.

I wonder if i should go for a tatra style rear axle for my truck.. I've been stuck with the rear axle for so long that i might just ditch the idea and have it a 4x6 instead.  
But this time it will need diffs as the front wheels steer and have no drive. 

Edited by Mechbuilds

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I think this is 13 studs? Designed for a daf YA-328 moc that never really got off the ground.

thumb.php?api=SYNO.PhotoStation.Thumb&me

thumb.php?api=SYNO.PhotoStation.Thumb&me

I'm not too happy with it. The worm gear drive requires motorization to work at all which I'm not sure if I've got the room for, and since the connection between the two sides is an axle it sags all kinds of wrong. My solution for the front axle (not pictured) is even worse.

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Quote

I think this is 13 studs? Designed for a daf YA-328 moc that never really got off the ground.

thumb.php?api=SYNO.PhotoStation.Thumb&me

thumb.php?api=SYNO.PhotoStation.Thumb&me

I'm not too happy with it. The worm gear drive requires motorization to work at all which I'm not sure if I've got the room for, and since the connection between the two sides is an axle it sags all kinds of wrong. My solution for the front axle (not pictured) is even worse.

The u joints and cv joints are a weak point in that. 
But it's an interesting design for sure.

Edited by Mechbuilds

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I've gotta ask and i think this might be the appropriate thread to ask. 

If i make a crawler that will be used 99% of the time just crawling obstacles, do i need diffs on front and rear axles or should i be perma-locked?

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11 minutes ago, Mechbuilds said:

I've gotta ask and i think this might be the appropriate thread to ask. 

If i make a crawler that will be used 99% of the time just crawling obstacles, do i need diffs on front and rear axles or should i be perma-locked?

I would put a diff between the front and rear axles, but otherwise it'd be permalocked between wheels

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Just now, letsbuild said:

I would put a diff between the front and rear axles, but otherwise it'd be permalocked between wheels

Thanks!

I could make it so it's 2 motors, one for each axle.. That way i'd have more control on climbing.

Edited by Mechbuilds

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36 minutes ago, letsbuild said:

I would put a diff between the front and rear axles, but otherwise it'd be permalocked between wheels

I'd do the opposite, put open diffs on each axle, but no center one.

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Has anybody made heavy duty axles with lots of ground clearance for CLAAS tyres? 

I'm looking for 5-6 studs of ground clearance with claas tyres. Probably independent suspension can handle this ground clearance and still be reliable for a heavier moc. 

Here is what i've been working on:
jd2klzQl.jpg

The width is correct. 15 studs between pivot points. The ground clearance is also over 5 studs. 
And with the help of U joints, you can get proper amount of steering while still keeping the 4x4 drive. 

But how about the middle part? The diff (lockable if it could fit) in the middle.. Also XL motor drive.. 
Where and how to connect the links that are connected to the 5x7 frame.. 

Can somebody help me out with this axle?

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@Mechbuilds perhaps you should use 2 frames 5 x 7, one in front and other behind suspension arms, so you can put differential between frames 

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1 hour ago, I_Igor said:

@Mechbuilds perhaps you should use 2 frames 5 x 7, one in front and other behind suspension arms, so you can put differential between frames 

I changed the suspension arms to the beam version instead. Now the hard part is figuring out how to make it steer.

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