efferman

Axle Collection Thread

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23 minutes ago, I_Igor said:

@Mechbuilds

Steering could be done with help of 5L steering arms...

I've made thing physically irl. There is an issue on the gears skipping teeth.. So i made out a quick sketch up in LDD for two different mechanisms that allow you to have tatra swing axles without the axle riding the driveshaft:

0x0dPpfl.png

Both of these have issues. 

The U joint one is not as durable but it's much simpler to make with less parts. 
The gear version is much more complicated but much sturdier. 

I wonder if there are other solutions to this? I wonder which one i should go for? 
This type of axle can't be made for tank steering i think. 
I just can't fit two drive shafts in the middle without making the thing extremely wide. It's already very wide as it is. 
So using the 7 wide beam in the middle is the maximum width i can give this. (preferably i'd do 5 wide in the middle but there simply is no room.)



As for using the 5 long steering arms, i didn't really think of using those. 
It could quite possibly work! Just need to figure out a little bit more complicated steering rack assembly but worth the shot.



EDIT:
hVA3WHkl.png
Third option gives me half a stud more room in the middle. 

Edited by Mechbuilds

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@Mechbuilds because of skipping teeth I have made a prototype with gear 36 tooth double bevel; all smaller (in my case even 28 tooth double bevel) had that issue, but I'm struggling with shocks (they are mounted to high for my project)...steering idea for my model is a kind of copy of 42099 steering system...

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3 hours ago, I_Igor said:

@Mechbuilds because of skipping teeth I have made a prototype with gear 36 tooth double bevel; all smaller (in my case even 28 tooth double bevel) had that issue, but I'm struggling with shocks (they are mounted to high for my project)...steering idea for my model is a kind of copy of 42099 steering system...

The issue is geometry. 

If i have the steering link attached to the top, the steering link would need to compress as the suspension moves. 
I need to move the steering arm lower so it's at the same height as the pivot point that lets the tyre rotate up and down. 

But the issue with that is that the whole axle assembly will hit it. So i would need to make the steering arm much much longer so it clears the assembly. 
When i do that, the steering arm is very far from the wheel itself. So i'll have to use ackerman geometry. But when doing that, the 5 long steering ball cup arm is too close to the center.. 

There are soooo many variables with it. That's why making functional steering for tatra axles is extremely difficult. 
If the geometry is even slightly off, the wheels will steer as they move up and down from the suspension. 

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HD7Cqs0l.png

This is one way i thought about doing the steering system.. Anyone else got any better solutions in mind? 
I can give the LDD if anyone wants trough PM. 


EDIT:
After building it physically, yep doesn't work either.. 

Edited by Mechbuilds

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Perhaps you should look at @Madoca 1977 's Tatra 813 8 x 8; it uses similar portal axle setup. I'm trying to make stronger setup for my MOCs, but only after I finish current project (parts will arrive at end of next week and I hope that I do not need extra parts)

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13 studs wide drift steering:

oLWi0zdl.png

Just remember to brace everything well and you'll have insane steering angles. 
Works for RWD only. You can also make a suspension for this axle but the suspension travel needs to be minimal.


EDIT:

hQcCCevl.png
Got it even more compact.. Only issue with it is that if you decide to make a suspension for it, it's entirely possible to attach springs to the lower control arms. 
But since the upper control arm is only attached to a single black pin, the whole axle will bend forwards when the suspension is compressed. 
Attaching both control arms to a frame and eliminating the whole suspension will fix the issue. Depends which one you need more, function or rigidity. 


Steering works fine and you get pretty great steering angle. Great for a drift machine. 
This width will work with the 42111 charger and cars that size. 

Edited by Mechbuilds

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4wd drift front axle 21 studs.

eQE95l6l.png
(17 studs with smaller tyres.)
Has a strong chassis that can withstand front crashes without doing any damage to the axle. 
Extremely steep steering angles and a tough U joint build that can handle torque. 
Doesn't flex when pushed because of the top bracing. 
You can also use smaller tyres without interference issues.. Also 1 stud of ground clearance using smaller tyres. 1.5 stud clearance with these tyres. 

Edited by Mechbuilds

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I couldn't find many solutions on how to make use of buggy motors in an axle. 
So here i present to you: 

Modular drag axle.LXF

feFVl9wl.pngc0DqwYil.png

You can use the short stubby hub for 5 stud clearance between tires for a smaller moc that needs to have the tires inside the bodywork. (Sleeper cars)
Or you can use the portal hub version with 3 different gearing options. Uses the faster spinning gear from the buggy motor. (Drag cars)

Very compact and simple. 

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3 hours ago, Mechbuilds said:

I couldn't find many solutions on how to make use of buggy motors in an axle. 
So here i present to you: 

Modular drag axle.LXF

You can use the short stubby hub for 5 stud clearance between tires for a smaller moc that needs to have the tires inside the bodywork. (Sleeper cars)
Or you can use the portal hub version with 3 different gearing options. Uses the faster spinning gear from the buggy motor. (Drag cars)

Very compact and simple. 

Good idea. I would just add a few beams across it on the top and bottom to keep it from sliding apart.

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39 minutes ago, Zerobricks said:

Good idea. I would just add a few beams across it on the top and bottom to keep it from sliding apart.

Good thing the axle is easy to modify. But pretty much gives you the idea how to use two buggy motors combined with those drag slicks and show you how much room you have to work with. 
Already saw a couple of ways to improve it. Matched the top side with 15 long beams with the bottom side. 

At the time making the LXF i was trying to figure out how to incorporate a wheelie bar so i used those L beams for connection points. 
But yeah it's a simple solution. People can use it as a base to start modifying and optimizing it better.

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On 10/15/2020 at 7:12 PM, Mechbuilds said:

I couldn't find many solutions on how to make use of buggy motors in an axle. 

 

Interesting, thanks!

I ordered a couple of buggy motors, and was thinking of connecting each one to a front wheel directly, and making a forward-wheel drive where the motors themselves rotate with the steering. (They haven't arrived yet.) I wonder if you have any thoughts on this sort of axle.

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2 hours ago, Ami Tavory said:

Interesting, thanks!

I ordered a couple of buggy motors, and was thinking of connecting each one to a front wheel directly, and making a forward-wheel drive where the motors themselves rotate with the steering. (They haven't arrived yet.) I wonder if you have any thoughts on this sort of axle.

It would be easier to build steering for the wheels only but the CV or U joints used would be a weak link considering the raw power the buggy motors have. 
Rotating both buggy motors with the front wheels is going to be tricky. You'd probably need a some sort of virtual pivot linkage and build a frame around the buggy motors to accept it. Not to mention if you want suspension for it, it'll be even harder. 

But it all depends on how much space do you have in your use? 

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On 10/17/2020 at 10:34 PM, Mechbuilds said:


But it all depends on how much space do you have in your use? 

Yes, your points make a lot of sense, thanks. I'll play around with them when they arrive  and see :-)

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3 hours ago, Mechbuilds said:

I wonder if lego has fixed this planetary hub so it doesn't disintegrate when used on mud and dirt. 

Uh oh... This is the first I have heard of this issue. Is there a discussion about it somewhere?

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11 hours ago, 2GodBDGlory said:

Uh oh... This is the first I have heard of this issue. Is there a discussion about it somewhere?

Me to, hope it's nothing.

11 hours ago, Mechbuilds said:

Here!

Oh... :sceptic:

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Hi,

In build instructions step 21, there are 2 yellow 3 long axels, are they right length? or should I trim then to 2.5 length?

 

S:J

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