[HELP] Generic Building Help Topic

[Hrafn]

16 minutes ago, Technic tango said:

I had the idea to make pivots after the black u frames. If I steered the entire bogie then it would drag the tires a lot and take up a lot of space when turned

Between https://www.bricklink.com/v2/catalog/catalogitem.page?P=87408&idColor=11#T=C&C=11 and the portal axle?  I would try that out and see if it is feasible before worrying about the placement of the servo - you are cramming a lot of complexity in there.

[Technic tango]

35 minutes ago, Hrafn said:

Between https://www.bricklink.com/v2/catalog/catalogitem.page?P=87408&idColor=11#T=C&C=11 and the portal axle?  I would try that out and see if it is feasible before worrying about the placement of the servo - you are cramming a lot of complexity in there.

Yeah that is my idea. That way I don’t pivot around the gears and it brings the pivot point closer to the wheel.

[whitepen]

@Technic tango Your from discord right? I remember seeing this in the tble server.

Edited May 6, 2022 by whitepen

[Technic tango]

3 hours ago, whitepen said:

@Technic tango Your from discord right? I remember seeing this in the tble server.

Yes I am

[Technic tango]

10 hours ago, Hrafn said:

Between https://www.bricklink.com/v2/catalog/catalogitem.page?P=87408&idColor=11#T=C&C=11 and the portal axle?  I would try that out and see if it is feasible before worrying about the placement of the servo - you are cramming a lot of complexity in there.

 

this is what i have so far, any critiques? it is only 1 stud wider than the previous version

[mdemerchant]

Isn't that going to come apart as soon as you push up on the wheel?  It's a bit hard to tell from the photo but it looks like both top and bottom steering joints are assembled in the same orientation so the portal hub assembly can just lift vertically off.

What's the benefit of the Tatra part of the suspension?  The swing arm is pretty short and you should already have tons of travel from the bogey arrangement.  I'm definitely not a suspension expert so that's not a critique, just curious.

Edited May 7, 2022 by mdemerchant

[Technic tango]

3 minutes ago, mdemerchant said:

Isn't that going to come apart as soon as you push up on the wheel?  It's a bit hard to tell from the photo but it looks like both top and bottom steering joints are assembled in the same orientation so the portal hub assembly can just lift vertically off.

What's the benefit of the Tatra part of the suspension?  The swing arm is pretty short and you should already have tons of travel from the bogey arrangement.  I'm definitely not a suspension expert so that's not a critique, just curious.

so for the first part, Thanks for pointing that out, I had the bottom part on backwards, and now the only way for it to come apart is if the red pins come out and there will be no force to push them out save for the entire black piece breaking. As for the second part, the bogey setup I have is able to be toggled between powered and neutral for the model to have the ability to lift itself up.  This required ALOT of bracing and a few gears so there is some resistance on the bogey itself.  The Tatra swing arms provide absorption of smaller bumps as well as increasing the ground clearance, since it is a fairly wide axle at this point.

[Technic tango]

On 5/6/2022 at 8:05 PM, Technic tango said:

 

I got the steering joints strong and connected, but I'm having a very hard time getting the steering to even remotely function.  If anyone can find a real-world example of a steered bogey,  I would love to see it.  Here is my progress: I have printed a 4L track rod so that making this thing steered is actually possible.  I was thinking something similar to the mechanism used in pushrod suspensions would work, but all of them begin to turn away before they make a large enough forward movement. here is my .io file for studio if anyone wants to take a look at it:https://www.mediafire.com/file/px5fq079ynwwdas/dog-e.io/file

[Jundis]

@Technic tango The steering rod should be place in the middle position, where the joint is placed. Otherwise, the suspension will actuate the steering.

[Technic tango]

5 hours ago, Jundis said:

@Technic tango The steering rod should be place in the middle position, where the joint is placed. Otherwise, the suspension will actuate the steering.

When you say middle, do you mean at the midpoint between the joints on the side? Because if you put it in the center it won’t turn at all.

[Carsten Svendsen]

In the middle like this

[Technic tango]

1 minute ago, Carsten Svendsen said:

In the middle like this

Ah ok that’s what I thought he meant

[mdemerchant]

On 5/8/2022 at 6:51 PM, Technic tango said:

If anyone can find a real-world example of a steered bogey,  I would love to see it.

The most common application (trains) just rotate the entire assembly.  Rover type vehicles just rotate the wheels directly with a motor, no conventional steering linkages.  Were you contemplating doing it with some sort of conventional type linkage to a steering rack?  Given the range of motion of your suspension I'm not sure that will be possible without having wheel turn somewhat as the suspension moves.  The sketch above solves the Tatra suspension motion but then you've got the right connection point that can move up and down vertically and slightly forwards/backwards relative to your steering rack.  The distance between that point and the steering rack will not remain constant.

[Technic tango]

3 hours ago, mdemerchant said:

The most common application (trains) just rotate the entire assembly.  Rover type vehicles just rotate the wheels directly with a motor, no conventional steering linkages.  Were you contemplating doing it with some sort of conventional type linkage to a steering rack?  Given the range of motion of your suspension I'm not sure that will be possible without having wheel turn somewhat as the suspension moves.  The sketch above solves the Tatra suspension motion but then you've got the right connection point that can move up and down vertically and slightly forwards/backwards relative to your steering rack.  The distance between that point and the steering rack will not remain constant.

I was thinking something like this:

 

[Gray Gear]

Can someone try for me if the new narrow 20t gear 

Can engage with the 16t Gear on the old style 6573 Differential? 

Thanks a lot in advance 

 

[Zerobricks]

15 hours ago, Gray Gear said:

Can someone try for me if the new narrow 20t gear

Can engage with the 16t Gear on the old style 6573 Differential? 

 

Thanks a lot in advance 

 

Yes

[Jundis]

Hi guys,

just a question for the builders with more experience than me in the field of electric components: What pairing of the motors is better? Green or yellow and why?

I'd say less components so it should be yellow, but then, on the green variant, the main axle could be supported in a better way...

 

[Hrafn]

@Jundis, neither.  I would use 12z double bevel gears instead - the knob wheels wear quickly and I have been told they are inefficient because they don’t mesh closely.

 

[Jurss]

1 hour ago, Jundis said:

on the green variant, the main axle could be supported in a better way

For me it also seems mechanically better option, as main axle will have 2x load. Electrically it is not critical.

And yes, as mentioned, knob gears are not good option

[Jundis]

@Hrafn @Jurss : Thanks guys! I always had the feeling the knob gears are for such heavy duty work :D

[Zerobricks]

@Jundis, I would use 28 tooth gears and 7x11 frames, nothing can slip there and you can support gears on outer and inner side.

[Jundis]

11 minutes ago, Zerobricks said:

@Jundis, I would use 28 tooth gears and 7x11 frames, nothing can slip there and you can support gears on outer and inner side.

Hmm there is not enough space for an outer casing. Also: Using 28 tooth gears put even more torque on one axle. I'd rather gear it down later ;-)

[Carsten Svendsen]

Honestly either configuration is fine, the motors are locked mechanically regardless. The only issue you might have is that in the yellow setup, you need the motors to run in opposite directions which needs a reverser switch. And yes, knob gears are not for load transmission, use bevel gears. You could use a differential, but you'll likely lose some power there.

[Carsten Svendsen]

Hi all, I'm looking for possible solutions to building this rotor in LEGO. It doesn't have to be technic specifically, as I hardly know any advanced pieces or techniques outside of technic.

Diameter = 7L, Length = 11L not including axle at the ends. It is for the currently white pieces rotating, I'd like to make the design better, but need ideas.

 

I'm also always stumped when I meet anything auger. What is the best way to make augers? These would be Length of 5L and Diameter of 3L

Edited May 26, 2022 by Carsten Svendsen

[Hrafn]

@Carsten Svendsen

my first thought would be to try 

https://www.bricklink.com/v2/catalog/catalogitem.page?P=44374#T=C

doubled up it gives you 6 blades, then you can align successive pairs on the same axle at 30 degrees offset between each pair.  But that gives you too much twist… hm.

 

For augers, I have seen other builders use flex axles twisted in a helix around an axle, to give a sense of the auger’s edge.