Hey guys, newbie here!

As per my introduction, I've come back to Lego after at least 10 years.

I picked up the 9398 as a spontaneous purchase for my greedy self the other day *yay*

It was a very fun build, took just over a day, as I work and stuff.

So far I have played with a few gear ratios and have settled with the drive ratio of 8/24, for torque. However I'm currently having trouble with the rims slipping on the tyres when put under force, like a step or a large incline.

Does anyone have a fix for this?

On a side note, how do the XL motors work on the 9398, with the ratio 8/24? I purchased loads of motors for the 42006, and will have some spare, as I over-ordered. :)

I'm looking at a few other mods for the 9398, but I will be doing one at a time.

-Steve

Welcome to Eurobricks! If you go to your local Hobby Shop, you should be able to get RC-type tire glue. All you need is a small dab of it to secure the tire onto the wheel.

The Power Functions XL motors have more torque than the L-motors that came with your 9398, but you lose ~1/2 of your rotation speed.

You can fill the tire with 7 much smaller tires or put elastic bands around the edge of the rim where the tire sits or... I came up with making a cut out on a 50p sponge from asda and basically filling the tire with it, I used 2 sponges though.

Welcome to Eurobricks! If you go to your local Hobby Shop, you should be able to get RC-type tire glue. All you need is a small dab of it to secure the tire onto the wheel.

The Power Functions XL motors have more torque than the L-motors that came with your 9398, but you lose ~1/2 of your rotation speed.

Thanks for that reply. I don't have a 'local' hobby store, but there is always Ebay. I have 'air-fix' glue (plastic) if that would do the same job?

Onto the ratio then... using 8/24 with XL motors would make it hideously slow....

Would stock be better or even 16/16? I've seen video's but not many using XL motors, they all seem quite sketchy about applying them to the model.

I may have to experiement once I have the parts.

You can fill the tire with 7 much smaller tires or put elastic bands around the edge of the rim where the tire sits or... I came up with making a cut out on a 50p sponge from asda and basically filling the tire with it, I used 2 sponges though.

This seems like a reasonable option to try before glue, as I'd rather not risk damaging or even heavily marking the plastics. 50p is nothing compaired to what I have spent on Technic in the last week. :)

Thanks for that reply. I don't have a 'local' hobby store, but there is always Ebay. I have 'air-fix' glue (plastic) if that would do the same job?

Tire glue is just CA (cyano-acrylate), otherwise known as superglue. You can get it anywhere.

Thanks for that Blakbird, good to know. The new motors arrived for the 4x4, though currently struggling for pieces for the adjustment :(. will see how I get on lol.

Hey Steve. There's an interesting thread on using RC tires with lego rims including those on 9398 here: http://www.eurobricks.com/forum/index.php?showtopic=70865&st=0

If you haven't waded through it yet, the original 9398 thread also has a lot of information regarding mods to this set: http://www.eurobricks.com/forum/index.php?showtopic=65692&st=0

Welcome! I hope you enjoy your time here. Your tires should fit snuggly enough so that they don't slip, so maybe your tires have a design flaw. If that is the case then I would suggest writing or calling LEGO and telling them, they should send you some new ones ASAP.

Hope that helped!

Hey Steve. There's an interesting thread on using RC tires with lego rims including those on 9398 here: http://www.eurobrick...opic=70865&st=0

If you haven't waded through it yet, the original 9398 thread also has a lot of information regarding mods to this set: http://www.eurobrick...opic=65692&st=0

I have had a look through those threads, I was going to buy a set of new tyres, but they are far more pricey over here in the UK. I had a good glance through the 9398 thread, however I could do with a refresher, thanks. :)

Welcome! I hope you enjoy your time here. Your tires should fit snuggly enough so that they don't slip, so maybe your tires have a design flaw. If that is the case then I would suggest writing or calling LEGO and telling them, they should send you some new ones ASAP.

Hope that helped!

Thanks for that, I have a video uploading to YouTube at the moment. My internet connection is hideous, so it will be a long wait, but that will be put on here shortly, with my attempt at the XL motors.

-Steve

[EDIT]

Closer look at my XL MOD, though this will be changed shortly as the suspension isn't very well connected.

http://youtu.be/OzZefYcfWTk

Tyre slip

http://youtu.be/ZM2KSHd9goU

Hopefully these videos work :)

Edited April 29, 201311 yr by Vr5fx

Take the differentails out and put there knob wheels.

Honestly, the differentials kinda make it slightly more challenging. I have been thinking about changing them, though I wasn't sure what with. I will try it out and see how it goes when the new parts arrive. :)

I played around with mine a bit, in the end I pulled it down for parts to do some MOCíng. What I would love to see is a automatic gear box which changes gears as you drive for speed or climbing ability.

I played around with mine a bit, in the end I pulled it down for parts to do some MOCíng. What I would love to see is a automatic gear box which changes gears as you drive for speed or climbing ability.

Is that possible? I haven't even made a simple gear box, as I wouldn't know where to start, but making one that would shift for more torque when needed? I don't think there would be enough room in the chassis for it... It would have to be a new build from scratch, right?

Is that possible? I haven't even made a simple gear box, as I wouldn't know where to start, but making one that would shift for more torque when needed? I don't think there would be enough room in the chassis for it... It would have to be a new build from scratch, right?

m

aybe, I am not experienced enough to know if it is possible.