[TC8] [WIP] GSK55 Grove Trailer Crane

[aminnich]

Ok so from what people are commenting, I'm going skip the idea of a driveable trailer. This will also bypass the problem of crab steering. I can focus on the regular steering and have more receiver channels to use for more functions :)

[aminnich]

I want everyone's advice...

Usually outriggers are in the very back and somewhere around 2/3 from the back. The picture below shows a LDD drawing of the number of axle im putting on the fixed trailer (the angles will b different on the real thing)

Now i want your advice on where i should put my outriggers, keep in mind, they are going to be 2x the size they were in the first set of pictures. I believe it was Milan who once said, those outriggers are too small (not exact words). so anyway, where do you think i should place the outriggers, Thanks

EDIT; just so you know that is basically as good as my LDDs will ever be, not so great at it....

This is what i meant by self driving trailer @ 30 secs

Edited September 22, 2015 by aminnich

[Milan]

What type of outriggers would you like to install? Extending, like on original build? Star type? Or upright, like on the video?

On six alxe cranes, they are placed at the very back and between 2nd and 3rd axle, but since you dont have carrier's cabin and carrier's engine (with their weight, they influence where the outriggers will be), you can place them just anywhere.

I would suggest putting them at equal distance from your turntable. Probably best at the very ends, so they dont interfere with the steering setup.

[aminnich]

I think that would be the best idea, to put them on the ends. The outriggers in the back are going to to be much closer than the front one but that's ok. I don't want to move the turntable any closer front than it already it.

As for outrigger design, they will b extendable, like a crane boom.

[aminnich]

5 days to build.... 30 mins to take apart....

[aminnich]

Sorry for all of my little messages, but here is a small steering update/ problem

From the pictures below you can see that i just extended the beam length by one for each axle, starting from 3 in the back to 6 closer to the front. These all work fine, but i want to add 2 more steerable axles, but if i continue with how i did the others, the wheels don't clear the turning beams (7L and 8L). So again im a bit stuck.

As others have mentioned, i could gear up or down a motor to get the desired turning angle, the problem is that a servo wont be able to handle all of those gears and i want to use a servo for the return to center feature. I could add another servo, but im not sure it will be able to handle it.

So here are some pictures of a new steering set-up...

comment or ideas are welcomed. The second picture is bugger, so you can see the steering arm lengths.

[__________________________]

What's the 2-week rule?

[MaxSupercars]

Aminnich...

You can change wheels turning angle either with your method or you can use gears to change the angle ratio between 2 parts of long middle axle... So if you continue then do not connect new part of the long middle axle directly but you have to put the continuous axle to the side, for ex. 2 holes and use gears to change the angle ratio... You can make it more times to avoid your 5,6,7,8 long beams... I have used max. 4L...

Look at my picture... on the right side ends the central long axle for steering with tan 20 teeth bevel gear and then continues via 12 teeth gear to the most front 2 wheels... The only small problem is that the continuos axle is half tooth rotated so the wheels will not be perfect straight aligned but it's not so visible... If you want it perfect you can add one more gearing with the two same gears, for ex. two 16 teeth gears and go back to the middle...

So you become this:

- Central axle ends with 20t gear

- continues on the side with 12t gear at the start and 16t on the end

- continues back in centre with 16t gear

My picture shows the simple case,

- just change from 20t to 12t

Max...

Edited September 23, 2015 by MaxSupercars

[aminnich]

ok, i think i understand. I will try this the next time i have a chance to work on my crane. But just to clarify, the 20 tooth bevel and 12 tooth bevel are changing the turning angle for the 2 leftmost axles shown in the picture. So if i would add the same 20/12 gear set up after those axles, it would change the turning angle again. So i could have 6 different turning angles, using 2 gear changes.

[MaxSupercars]

Yes... on one side you change the turning angle by every gear change on central axle + you can adjust the turning angle with your method with beams by wheels...

Why do you need to turn so many wheels to one same side? In my mobile crane I got 8 wheel axles, the first 3 turn to one side, then 2 are static and last 3 turn to opposite side so turning centre is between two middle wheels...

Max...

Edited September 23, 2015 by MaxSupercars

[aminnich]

This is a trailer crane, they all need to turn the same way for it to work properly.

And thanks for your help! Now I can do what I wanted to instead of having to change design ideas

EDIT: my only concern is the number of gears for the servo, but if it is too much I can add a another servo, no problem

Edited September 23, 2015 by aminnich

[MaxSupercars]

OK, hopefully I helped you... :)

Small hint... In vehicles of this size is often not a lot place for motors etc... On my picture by avoiding the central area with steering axle moved to the side has been created place where I put the servo... So servo was connected to the central axle, left from 20t gear... :)

Max...

[aminnich]

The way that I'm doing the new setup for the trailer I will have a bunch of room for another servo, plus a lot of other fun functions :)

[MaxSupercars]

OK, perfect... ;)

Looking forward for your progress... :)

Max...

[aminnich]

Another small update, i am going to try and post often and pictures of my progress each time.

This time it is a successful steering update. And a huge thanks to MaxSuperCars!!! So here it is, a 6 axle steering chassis..

EDIT: now im working on the outriggers, trying to make them a decent size for the crane size.

Edited September 23, 2015 by aminnich

[MaxSupercars]

Yesss... it looks very good and clean... I'm glad that I could help... You make me tasty to finish my 8 wheeled mobile crane... :D but no time now...

So I wish you a lot of Ideas in further building... ;)

BTW... which axles will be driven? You need to find place for differentials or?

Max...

Edited September 23, 2015 by MaxSupercars

[aminnich]

I changed my idea from the original post, it is still a trailer, but it wont be self driven. So the trailer will not have any driven axles

[MaxSupercars]

OK, then it will be easier a little bit...

Max...

[aminnich]

Another update:

Now that the steering to fixed thanks to MaxSuperCars, i started working on an outrigger system. I was having a lot of problems with making it fairly compact and still functional. I was making different prototypes but, nothing was really working, so i tried it in LDD and this is what i made. I hope the link works, it should just download so you can view it. If you dont have LDD and you want to see it, i can post screenshots if you'd like.

https://www.bricksafe.com/files/Aminnich/idea.lxf

[Milan]

Post a screen, please.

[aminnich]

I have the sections of the outriggers apart. The yellow goes in the blue, and the blue in the red. The yellow will be extended via string and the blue section has a gear rack on the bottom.

[MaxSupercars]

It looks to heavy and complicated with 3 sections for me... And heavy ends... Do you need really something like this? Make it with 2 sections and you spare a lot of problems...

Max...

[aminnich]

The red section is the main section, it will not extend. Only the blue and yellow sections will extend

[miguev]

I don't have experience with many-axles steering, but I can't help thinking your setup will make up for a larger turning radius than if you'd leave the 5th axle fixed and made the 6th axle steerin the same angle as the 4rd, but in the opposite direction. Wouldn't that give you a smaller turning radius for better maneuverability?

[Milan]

Miguev, you are right, it would give smaller turning radious, BUT, since this is a trailer, not a truck (or mobile crane), it has to be like this, as he does not want to have center of the rotation in the middle (or worse, at the back) of the trailer.