9
Sep

Building an MG-TC pedal car: Part 2

   Posted by: Mark   in Pedal car

In Part 1, I showed pictures of the basic frame of the car, as well as the mounting of the rear wheels. In Part 2, I will explain and show the mounting of the front wheels.

I should start off by saying that this is not a go-cart, is not meant for high speed or heavy drivers, and is supposed to be basic enough to not require welding. And I’m learning enough with this go-around that I would likely not do a lot of this the same way a second time.

That said, the front wheel mounting mechanism outlined in the plans is really pretty neat and creative. A kingpin assembly is built up from a galvanized pipe T, with male reducers fitting into each end of the “top” of the T, and a three-inch length of pipe screwed into the “vertical” part of the T to allow for the tie-rod. The wheels are mounted by drilling through the T pieces perpendicular to the three-inch tie-rod post (study the pictures and it should make sense):

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The T’s are then mounted “sideways,” with the reducers attached through the two 3/4″ thick wood cross-members to galvanized pipe caps. The wheels spin freely on their axles using the stock bearings (and the stock axles, which happened to be just long enough), and rotate left and right on the reducer threads for a very simple but effective steering mount.

I mentioned previously that some of the supplies available today in the big-box hardware stores are not of the same quality as the supplies available 20+ years ago when these plans were written. One example of this is the tie-rod that is supposed to be used to connect the two front wheels together (not shown in any pictures yet). The plans call for a threaded rod that mounts a steering rod receiver and is bent on both ends to fit into the steering arms on the kingpins. Unfortunately threaded rods today are incredibly cheap metal, and will invariably break when bent. But in the end I discovered that this is a very limited tie-rod design anyway, and allows for absolutely no adjustments after mounting. I surely don’t expect to be able to fully align the front wheels, but there is an advantage to being able to at least rough-tune the alignment.

After stopping at Coventry Cycle Works in Portland last weekend, I came away with some really great ideas for a steering mechanism (I was thoroughly impressed with this place, and am grateful for the assistance they provided!). I learned about a connection called a heim joint that is essentially a ball-and-socket assembly that allows more freedom of motion than a straight bolt and tie-rod might. If I build another of these cars, one of the changes will be in the steering assembly, and I would really like to mount the wheels differently and make use of a pair of heim joints. This would likely coincide with a much lighter kingpin assembly, too, since the galvanized pipe, although creative and cheap, is bulky, heavy, and a “brute force” solution instead of a “finesse” solution.

The cross members are spaced to allow them to slide over the front of the frame, and the top cross member is screwed to the frame sides. The notches in the frame just in front of the front wheel assembly are for the tie-rod, and will be covered with a strip of aluminum to provide a more finished look in the completed vehicle.

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At this point, the frame is complete, the rear free-wheel is mounted, the drive axle is bent and mounted, and the front wheels are mounted. I still need to finish the mounting of the rear drive wheel, but will wait to address that in Part 4 since I’m not really sure how to do it yet.

The next post, Part 3, will cover the rough building of the fenders and body, and will get the series of posts caught up to where I actually am right now with the project.

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This entry was posted on Tuesday, September 9th, 2008 at 10:06 pm and is filed under Pedal car. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

4 comments so far

Jason Fabbri
 1 

Question, did you have to extend that axles in the wheels to fit through the kingpin? You noted that they were just long enough, but where the bolt (that would typically mount in a bicycle fork) goes through the kingpin it looks really long so I was curious if you extended is somehow.

April 18th, 2009 at 6:10 pm
Jim
 2 

Wow, this looks great. My sons and I have been looking for a pedal car kit or plans.

How did you get the drive axle bent to the right shape? Did you buy it that way, or were you able to bend it in a vice accurately enough?

Great job! We watched the videos of the car driving, and now my boys can’t wait to order the plans.

Any advice would be GREATLY appreciated!

Thanks,

– Jim

November 21st, 2009 at 9:58 am
 3 

Jim, I’ve been so remiss in checking my site. If you like to build, a pedal car is sure a fun project to work on with a couple of boys!

Yes, I was able to bend the axle in a bench vice. The plans I have suggested using a pipe for leverage, and that worked quite well.

I just mentioned this on another post comment, but be sure to check out Jason Fabbri’s site, as he has some great info and pics as well: http://thegokart.wordpress.com/

Advice? Finish it! :-) Seriously though, enjoy doing it. Expect that you’ll probably have to re-work some pieces; don’t worry about it and keep moving.

December 11th, 2009 at 3:48 pm
 4 

I couldn’t agree more with Mark’s last comment. Getting there is half the fun don’t forget it! I would also agree that you should be prepared to make progress only to go back and slightly rework it. I’ve found myself doing a number of things a couple of times to get it “just right”. One more bit of advice… take pictures and share the results. It’s always fun to see how others solve problems along the way.

December 17th, 2009 at 3:28 pm

One Trackback/Ping

  1. TheNorwoodHome » Blog Archive » Building an MG-TC pedal car: Introduction    Sep 15 2008 / 11am:

    […] Part 2: Front wheel mounting […]

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