8110 - Unimog - MODs and Improvements

[jabo]

@kevman,

i think i have almost what you are searching for. I have modified the unimog with RC-control, two gear automatic, steering, while keeping all other functions. Also the design is preserved as much as possible. There are though many modifications.

- Steering is done by an M-motor located at the front axle with a gear 1:9 and a friction clutch. This location is better for a low balance point and there is no problem with the loose force transmission when the motor is placed in the driving cab.

- Two gear automatic drive. The fast gear is driven by an M-motor. If the rotation speed gets too low, an XL-motor takes over the driving with low transmission ratio. A freewheeling mechanism decouples the XL-motor in case of fast velocity. It can climb up to 100% slope. It is necessary a hand made part. Cut a half long bush in two parts and polish them with sand paper down to 1.2mm thickness (see photo). It makes a well defined friction at the freewheeling unit.

- Lockable middle differential gear. The cross-country mobility is much better if the middle differential gear is blocked. Alasdair Ryan suggested that solution at page 36. Unfortunately the unit with lock is one stud too long. so it need a bigger modification in the center box of the unimog. I also reinforced the differential with a fourth gear wheel. Then it stands more than twice the force.

- The left back wheel suspension is half a stud higher than the right one to balance out the weight of the battery box.

- LED lights front and rear

http://www.brickshel...mog/Unimog2.mpd

Hi Markus,

I am really intrigued by your freewheeling mechanism!

Could you possibly supply some better photos and description please?

I am having trouble getting my head around your design........probably would help if I could see the mechanism clearly.

Many thanks!!

Edited January 6, 2014 by Blakbird
: Removed quoted images.

[legotechnicblue]

I put an L motor from 9398 to Unimog (under the bed) just a couple of days ago and it works quite well. Did you remember gear down the portal axles (3:1)? With that it's still quite fast (certainly not a crawler) and cannot climb much. I'm planning to put 25:9 gearing to the rear (will leave room in front for the servo, and I'm also avoiding putting too much torque to the universal joints there). The central diff should take care of speed / torque distribution, right? Of course XL would have more power (and maybe no need for gearing it further down?).

No I didn't gear it down. I just had an L motor sitting around and I thought why not put it in and see how much power it had. I just don't have enough of the correct gears to gear it down

While we're on the topic, would it be possible to use an L motor for the steering? Just curious

Edited January 6, 2014 by legotechnicblue

[afol1969]

Hi Markus,

I am really intrigued by your freewheeling mechanism!

Could you possibly supply some better photos and description please?

I am having trouble getting my head around your design........probably would help if I could see the mechanism clearly.

Hi Jabo,

Same here, I don't understand the freewheeling system clearly, and it doesn't work correctly in my Unimog. I'm reviewing and reorganize the steps for making instructions in a PDF file. Maybe I've made an error. But for control, I have to dismantle the Unimog again and rebuild it. I would send a message to Markus, but he hasn't the 10 posts that his message box does work.

Greetings

Alex

[kevman]

anyone make a front end bucket loader attachment ? would love to see some pics

[Pat-Ard]

Hi kevman,

yes, there are some... Look in this thread. Or take a look here: http://www.eurobricks.com/forum/index.php?showtopic=73376&hl=8110&st=0

Pat

[jabo]

Hi Jabo,

Same here, I don't understand the freewheeling system clearly, and it doesn't work correctly in my Unimog. I'm reviewing and reorganize the steps for making instructions in a PDF file. Maybe I've made an error. But for control, I have to dismantle the Unimog again and rebuild it. I would send a message to Markus, but he hasn't the 10 posts that his message box does work.

Greetings

Alex

Yes Alex, there is defiantly a piece of the puzzle missing. There must be a break somewhere on the Center axle but I can not figure out where. Additionally, if the mechanism works on friction, would some serious heat not be generated over time? Would this heat not be able to melt/warp plastic parts overtime.

Curious.

[legotechnicblue]

Yes Alex, there is defiantly a piece of the puzzle missing. There must be a break somewhere on the Center axle but I can not figure out where. Additionally, if the mechanism works on friction, would some serious heat not be generated over time? Would this heat not be able to melt/warp plastic parts overtime.

Curious.

Yes I am too curious because where there is friction, there is heat

[jabo]

Hi Jabo,

Same here, I don't understand the freewheeling system clearly, and it doesn't work correctly in my Unimog. I'm reviewing and reorganize the steps for making instructions in a PDF file. Maybe I've made an error. But for control, I have to dismantle the Unimog again and rebuild it. I would send a message to Markus, but he hasn't the 10 posts that his message box does work.

Greetings

Alex

Alex,

Were you able to open Marcus' mpd file? It leads me to a "file not found" error.

[afol1969]

Alex,

Were you able to open Marcus' mpd file? It leads me to a "file not found" error.

Yes, I've opened it, and built his model. But now I must overview the construction again. The portal axles work well with the M-Motors, so with these motors alone there is no problem. But I don't know at which moment the XL-Motor does work, if I turn it on, it directly interlocks with the 20-tooth gear driven by the differential. I think, both motors cannot work with different speed, that will damage the gears or the motor. Because the differential is driven by the M-motor two.

Maybe the transmission ring must be placed in an exact position for well-working function.

In next days I rebuild the model, and I hope I 'll find the issue.

Greetings

Alex

Edit: Here ist the gear driving system that I've taken out of the MPD file:

Edited January 7, 2014 by afol1969

[jabo]

Thanks Alex,

Any chance you could PM me and send me the file? I'd love to have a peek.

[legotechnicblue]

Yes, I've opened it, and built his model. But now I must overview the construction again. The portal axles work well with the M-Motors, so with these motors alone there is no problem. But I don't know at which moment the XL-Motor does work, if I turn it on, it directly interlocks with the 20-tooth gear driven by the differential. I think, both motors cannot work with different speed, that will damage the gears or the motor. Because the differential is driven by the M-motor two.

Maybe the transmission ring must be placed in an exact position for well-working function.

In next days I rebuild the model, and I hope I 'll find the issue.

Greetings

Alex

Edit: Here ist the gear driving system that I've taken out of the MPD file:

Now that I look at it, I don't see much of a problem. It makes sense. Correct me if I'm wrong but the M motor works for driving when the center diff is unlocked. When you lock the diff, you have to turn off the M motor and turn on the XL motor. It is kind of like shifting a two speed transmission. Although, if your model is RC, you would need some sort of motor locking and unlocking the diff.

Well that's what I think anyway, I'm not an expert so correct me if I'm wrong but it looks like it would work

[afol1969]

Here the Link for the complete original file:

http://www.brickshelf.com/gallery/markus434/Unimog/unimog2.mpd

I've made some corrections and I've uploaded a new picture. The universal joiner have to be replaced by 3L joiners, and there was an 4L axle too much.

I think too, that the speed change is made by lock/unlock the differential. Thats I've found out, and if so, functions are correct. But then it needs a catch to change the transmission ring, so some modification must be done.

[markus53]

Hi Alex,

It seems to me, that the XL-motor and the M-motor are working against each other. You must turn the polarity of one motor. Then it will work maybe. The lock at the middle differential is a real block of the differential function.

Markus

[afol1969]

Hi Markus,

Your construction is very interesting, that's why I want to build your modification. But I haven't thought about the polarity of the motor. I'll try it again, now I've dismanteled the Unimog und start up again, while controlling each step with LPUB, later I'll make instructions of it. There are also some minor issues in your mpd-file, which I can correct.

Can you send me a PM? Then we can discuss about further details.

Greetings

Alex

[markus53]

Hi Alex,

i hope you can finish it. Ours (actually that of my son) works pretty well. And of course there are many minor bugs in the mpd-file i m sure. And i noticed that i can send you PMs only when...

i have posted minimum...

...10 posts.

if the 20 teeth wheel runs counterclockwise faster than the 8 teeth one then it free wheels because the left 8t wheel is only pressed down with slight force and lifted up by the 20t wheel. If it is slower or even clockwise then it is driven by the 8 teeth wheel from the XL-motor.

Markus

Edited January 8, 2014 by markus53

[JGW3000]

Not worth a new topic

Unimog 8110 - RIP, had a great 3 year run! (although TRU still has plenty in stock)

posted on the US Lego S@H site

8110 Mercedes-Benz Unimog U 400

• Price $199.99
  

• Sold Out
  

Edited January 8, 2014 by JGW3000

[jabo]

Hi Alex,

i hope you can finish it. Ours (actually that of my son) works pretty well. And of course there are many minor bugs in the mpd-file i m sure. And i noticed that i can send you PMs only when...

i have posted minimum...

...10 posts.

if the 20 teeth wheel runs counterclockwise faster than the 8 teeth one then it free wheels because the left 8t wheel is only pressed down with slight force and lifted up by the 20t wheel. If it is slower or even clockwise then it is driven by the 8 teeth wheel from the XL-motor.

Markus

Oohhhhhhhhhhhhhh......

[Canmorite]

Not worth a new topic

Unimog 8110 - RIP, had a great 3 year run! (although TRU still has plenty in stock)

posted on the US Lego S@H site

8110 Mercedes-Benz Unimog U 400

• Price $199.99
  

• Sold Out
  

Glad I picked mine up! Handy of Lego Canada to have that "Retiring Soon" button!

[legotechnicblue]

Not worth a new topic

Unimog 8110 - RIP, had a great 3 year run! (although TRU still has plenty in stock)

posted on the US Lego S@H site

8110 Mercedes-Benz Unimog U 400

• Price $199.99
  

• Sold Out
  

Has it really been 3 years? Wow time just flies by

[Rishab N]

Has it really been 3 years? Wow time just flies by

It feels like i just got the set yesterday

[afol1969]

Hi Alex,

i hope you can finish it. Ours (actually that of my son) works pretty well. And of course there are many minor bugs in the mpd-file i m sure.

Hi Markus,

I'm working on it. But it needs time, the Unimog is a very complex construction, like the Excavator 8043.

As I have only one polarity switch, I must find another idea to switch between the functions. Maybe a 2nd BB, or better, a RC with changeover catch system.

Greetings

Alex

[KHthe8th]

Hello everyone, I received a Unimog for Christmas this year and it has succeeded in bringing back my inner child (I'm 23). I finished building it around New Years and then found this thread and found bricklink and started to buy all sorts of things to copy you guys XD

About half the parts have arrived so far and my current plans are to add an XL motor for driving, servo for steering, second gray pump for more air, an airtank, a digger bucket in the front, and a side tilting truck bed. So far I have already been able to mount and test the XL motor and servo motor and they are working great!

The main thing that bothered my girlfriend when I showed her the completed Mog is that the doors dont open. Does anyone here have a design that allows you to open and close the cab doors?

Cheers,

KH

Edited January 10, 2014 by KHthe8th

[JunkstyleGio]

http://www.flickr.com/photos/50191917@N06/sets/72157633139955433/ Edited January 10, 2014 by JunkstyleGio

[jabo]

After a few tantrums I have successfully install Marcus53's two motor/gear system with the freewheeling connection. I had to modify the design a tad but am now very happy with the result.

I could not make the M motor on the rear diff skip proof, so I put an L motor in the cab using the sprocket and shaft from the steering assembly and hitched that to the Center diff.

A servo motor on the front assembly replaces all factory steering.

I used slightly different gear ratios to get better speed, I found Marcus' painfully slow.

A great result that I'm happy with at the end of the day.

Marcus, your a genius! Cheers!

Pics to come.

[Dion]

I have designed a snowchain for it. Read this for more information. http://mocpages.com/moc.php/360192