8428 Update

[chorlton]

Hi. I've been a member on Eurobricks for a while now, making the odd post, but it's taken me this long to create my first MOC.

I picked up set 8428 on eBay recently and was very impressed with the style - midway between studded and studless. I hoped that I could start with something easy as a first MOC and just add a couple of PF motors to it as my first attempt at straying from the boxed instructions.

This didn't work as the torque from even an M-motor could rip out axle mount points held on using studded construction. I therefore chose to try and recreate the set using modern, studless construction techniques.

So here it is.

• Length is 33 holes + flex-hoses at front and rear. This is the same number of holes as the original but results in one stud length less.
  
• Width is 15 studs + flex-hoses and wheels. This is one stud wider than the orginal and a result of the original being an even-number width. A 5-wide XL motor will throw that off.
  
• Weight is 825g.
  
• Return-to-centre steering is based on Sheepo's Return to centre type 1 design.
  
• Drive power is from 1 XL-Motor geared up through 24:8 * 20:12 * 20:28 = 9600:2688 ~ 3.5:1. I should try again to replace the 20:12 gearing with another 24:8 but had a lot of clicking and slipping during the build when I tried this. It might be held together a bit better now but it's a pain to get into the gearing now.
  
• The original 8428 came with adjustable suspension, moving from an off-road buggy configuration to a "sleek street-roadster". This is now also motorised and uses a small LA.
  

Steering

I mounted the gears "upside down" so that they hang underneath the chassis. At the time I thought I needed the space immediate above the motor but it turns out I could turn this assembly round and raise the gear wheels. Something to do when/if I try to increase the gearing up.

Link to my brickshelf folder is here: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=504696

You'll also find a work-in-progress folder with some earlier versions showing how much I changed as I went. The build process was very much a case of having something working early on, but then pulling out the steering to make the assembly half a stud shorter; moving the XL-Motor from the rear-wheel section to the main body and using a uv-joint. (I broke a couple until I geared it up); mounting the battery box on the rear before I decided to implement the adjustable suspension.

Edited June 4, 2012 by chorlton

[DLuders]

@ chorlton: What a great adaptation of the 8428 set! I own that set, and always wondered whether it could be "motorized" with modern Power Functions components. Those wheels really make it look sharp! Nice job!

[timslegos]

Nice pf features. I like the lowering and raising rear axle. I should start building more smaller MOC's...

tim

[DLuders]

Here's a side-by-side comparison of the original 8428/8432 Turbo Command/Concept Car set and chorlton's "updated 8428":

Edited June 5, 2012 by DLuders

[chorlton]

Here's a side-by-side comparison of the original 8428/8432 Turbo Command/Concept Car set and chorlton's "updated 8428":

Thank DLuders. I fully acknowledge it doesn't have the 'grace' of the original, there's a lot of bulk in the middle that I'd like to have avoided. But I'm fairly happy with it as a first public model.