[WIP] MAN TGS 10x8 Effer 2655

[pagicence]

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Edited June 5 by pagicence

[M_longer]

29 minutes ago, pagicence said:

If you are not satisfied with the color of 3L axle with stop, you can use 3L axle with knob and then put a round tile (1x1 or 2x2, or what ever else you want) over it in the color you desire.

You are talking about that axle that holds bevel gear that drives differential?

[1gor]

18 minutes ago, M_longer said:

You are talking about that axle that holds bevel gear that drives differential?

No, the one that holds tile 2 X 2 round on outer part of the wheel 

[Beck]

3 hours ago, pagicence said:

If you are not satisfied with the color of 3L axle with stop, you can use 3L axle with knob and then put a round tile (1x1 or 2x2, or what ever else you want) over it in the color you desire.

Good idea, but with the 1x1 round tile will protrude too much from the face of the wheel. The brown axles are acceptable.

 

[ludov]

On 8/8/2018 at 6:23 PM, Beck said:

I would still need the metal washer for this gap

Can you use the steering rack from 8479 Barcode Truck? See step 14 of the instructions. Then the gear rack only needs one stud, and you get Ackermann steering geometry for free.

Nice to see the real build getting started. Looks good 

[Beck]

On 8/9/2018 at 12:28 PM, Ludo Visser said:

Can you use the steering rack from 8479 Barcode Truck? See step 14 of the instructions. Then the gear rack only needs one stud, and you get Ackermann steering geometry for free.

Interesting idea. Here's what I came up with:

 

Problem: I need the gearrack to be held up, but 1 plate wont work.

 

 

Besides, my steering mechanism is off-centered because of the driveline, so I wouldn't be able to achieve full right steering lock. It's a neat idea, but unfeasible.

I'm going to stick with the bevel gear and washer. 

 

[1gor]

I think it would be better to use solution similar to 42082 set for "Ackerman" type of steering. I have tried to use gear rack like yours in my Unimog to make front axle as narrow as possible but even if you use tiles / plates gear is slipping over gear rack because it is designed to be used with Technic bricks and not liftarms 

Sorry for disappointment, but I know how long it takes to correct something like this; I needed half a year...

[ludov]

I thought the solution with the 8z gear would work. It’s the same distance as you’d have with bricks. I’ll check later, out of curiousness. 

[1gor]

1 hour ago, Ludo Visser said:

I thought the solution with the 8z gear would work. It’s the same distance as you’d have with bricks. I’ll check later, out of curiousness. 

Ludo, here is the same thing that did not work under moderate weight...

...but I'll be more than happy if you could solve this problem 

[brickless_kiwi]

I can see your limited in height due to your Chassis, however could you have the 8:24 reduction before the final drive, http://www.brickshelf.com/cgi-bin/gallery.cgi?f=548971 pipasseyoyo has a very good model using the same principles as you want. After a lot of playing around with a axle I have used you could mod to fit what you want .lxf is on my bricksafe page.

 

 

Edited August 11, 2018 by brickless_kiwi

[ludov]

@Beck The 8z fits on the 5x7 frame; not sure why LDD doesn't allow it (this is a 8M gear rack on a 1x8 plate):

But the restricted steering lock is a valid issue. Maybe linkage-based solution would be better, but I guess you made your design decision, so let's see how it works out 

@I_Igor Is that RC? I only build manual models, so I don't have experience loads that can take stuff apart. But the 8z on the frame seems a fairly tight fit. If you turn the supporting beam 90 degrees, it seems even a tighter fit (on account of the beams not being square), but it doesn't jam:

 

[1gor]

26 minutes ago, Ludo Visser said:

@Beck

@I_Igor Is that RC? I only build manual models, so I don't have experience loads that can take stuff apart. But the 8z on the frame seems a fairly tight fit. If you turn the supporting beam 90 degrees, it seems even a tighter fit (on account of the beams not being square), but it doesn't jam:

 

 

It is not RC, it is manual; but (probably based of higher front weight) it slips ?

Perhaps I should redesign it when I finished reparations in house...

Thanks , the only problem is that I do not have plate 1 X 8 so I have to think about something...

[Beck]

@brickless_kiwi Thanks for the ideas. I specifically designed the axles with gear reduction to lessen the stress on the UV joins (I have broken soooo many). I actually tried a design like yours three years ago just after coming out of a mini-dark age. The major flaw associated with that design is it's nearly impossible to connect the drive and steering without interfering with each other or using a linkage steering system (I've tried it and don't like it). I appreciate your ideas!

@Ludo Visser I will look into it.

Update 5:

 

 

 

Looks like the rack doesn't need much range to achieve maximum lock. (+/- 1 stud)

 

 

Edited August 14, 2018 by Beck

[Beck]

Update 6:

 

Finally, some actual progress! Before building the cab I had to fit the air tank and compressor in a 3 stud wide gap between the chassis and respective wheel arch while ensuring that they did not interfere with the "suspension" and servomotors. I also began work on the outriggers and connected the [pneumatic cylinder] rotation mechanism to a single axle. I also tested the 10l gear rack design for the front axle; however, the links between the wheel hubs and gear rack were quite weak.

 

 

 

[1gor]

It looks nice, but perhaps you could change arches in mudguards from dark gray to dark bluish gray one day. I know what problem is when you need one specific part and it is not available in dark or light bluish gray color... 

[Beck]

Update 7:

After much deliberation, I decided to remove all of the universal joints in the drivetrain and steering and opt for 2L axle connectors. In my previous chassis designs I have broken numerous universal joints (even the older variants) while driving outside. Surprisingly, the axles retain all of their travel even though they didn't have much to begin with (+/- 2 plates). I was also quite relieved to have chosen a springless suspension system as the model was already quite heavy even without the crane and rear outriggers.

 

The 5th axle was quite a challenge, but nothing in comparison to the outriggers. The challenge was to achieve a small steering angle without significant backlash. First, I tried to use a linkage mechanism in conjunction with a worm drive, but the backlash affected the entire steering lock. This left rack and pinion as the only remaining option in my mind, but this system necessitated a universal joint. 

Below is my solution to a rack and pinion steering system without using a universal joint. The entire axle assembly rotates along the axis parallel to the wheel axles, perpendicular to the 12z gear between the the two 9L beams. Having tested the system, I can say that it works perfectly without any backlash or bump steer.

 

 

Here's the completed frontal outrigger system.

\

 

The next steps are:

1. add further support to the wheel arches

2. design a rear outrigger system

3. design a slewing mechanism

 

Edited January 7, 2019 by Beck

[1gor]

It is nice that you find time to continue to work on your project. Interesting combination with technic bricks 

[Beck]

Update 8: 

After an entire year, it's about time that I updated this thread. I mounted the rear steered axle and the rear wheel arches. Next I tested the central outrigger system and decided that I couldn't make the assembly sturdy enough without enlarging it beyond scale. So I scrapped the motorized piston rotation mechanism and designed a more compact and robust outrigger assembly. After examining some reference photos, I noticed that the crane was mounted slightly off center from the chassis. This presented an issue; the turntable had to be secured to the chassis without considerably increasing its height or unbalancing the chassis. Many hours later I found a solution of which I will render later. Then I completed the crane's first stage and began work on the second; however, I'm unsure whether I want to have the second stage extension be driven mechanically or pneumatically. Lastly I adapted the central outrigger assembly for the rear and mounted it on the chassis.

 

 

 

 

Up next:

- finish the second stage and design the third stage 

- connect the pneumatics 

- build the loading box on the rear.

- probably some other stuff I'm forgetting at the moment