An M.G. Locost Build
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July 16, 2012
Putting on the Brakes

We ran out of welding wire. We were hoping this wouldn't happen, not because we couldn't get some more wire, but because of the weight. That's 11 lbs. of metal we've added to the Locost. We can take some solace in the fact that we ground a lot of it away, but still, if we'd built the whole car with a single spool of wire, we'd never have to know exactly how much we used. We could've guessed maybe 5 lbs. That would've been okay. Now we can't do that. Now we know. The good thing is, the new spool will go the distance, and we won't ever have to go through this again.

  One of these calipers has been cleaned
click to enlarge

We haven't quite started on the rear axle yet, but we did practice cleaning it up by wire-brushing the front brake calipers, which were nearly as cruddy as the rear axle. We originally thought we'd paint the calipers, and we might yet, but they looked so nice and shiny after cleaning that we went ahead and mounted them on the hubs. Unfortunately the calipers aren't marked right and left, or even top and bottom, so it took a little research to figure out how to attach them, but we finally did get them in place and we think they're right.

Caliper possibly installed right side up  
click to enlarge

Once the calipers were installed we decided to try to see if we could route the brake lines. This has long been an intimidating task, partly because having the brakes work correctly is sort of important, and mostly because we'd never done it before. Ever. On any car. It didn't look all that difficult, but of course we've been fooled by that before, and not just a few times. But we went ahead anyway and cut and drilled a tab for the flex line junction, clamped it in place, and then dug out the old brake line from the donor to see if we could make it fit.

  Donor brake lines filling in for now
click to enlarge

Incredibly, we did. The brake line itself was easy enough to bend by hand, and I think if we'd started with new brake lines the end result would've looked almost professional. Of course without any pressure or even fluid in the lines we wouldn't guarantee right now that the brakes will work, but still, it's very encouraging. The Locost uses a total of eight brake lines, and none of them have to be bent very much. All we need to do now is figure out a way to clamp them to the frame. And the good news is, we're pretty sure the technology for this already exists.

While digging through scraps for the flex line tab, we came across a pristine sheet of 1/8" steel that we must have bought months ago and forgotten about. It was a 6" x 24" sheet, which we'd earlier worked out was just enough to build a single motor mount. Since we'd already built a motor mount out of cardboard, it seemed entirely plausible that we could make one out of metal. So we did, using our latest advanced motor mount design, which is slightly shorter and wider than our cardboard prototype, which means the new mount doesn't look as good, but might be a little more stable.

One of these engine mounts is metal  
click to enlarge

The cardboard mount was made at a time when we were still cutting sheet metal with a Dremel. So the idea of cutting six large pieces of 1/8" steel was a little foreboding. As it turned out, cutting six large pieces of 1/8" steel with an angle grinder wasn't exactly child's play, but it only took a couple of hours, and finishing the edges took only a few hours more. In the end we were able to clamp together a mount that looked a lot like the cardboard mount, with the added potential of being a lot stronger.

As you can imagine, we were sorely tempted to weld the thing together, or at least tack weld it. We held off on this for two reasons. The first of course is our reluctance to do anything that might result in ruining hours of hard work. The second reason, a.k.a. our official reason, is that we want both motor mounts to be exactly the same, and the best way to achieve this is to make sure all the pieces are the exact same size. It's easier to do this if all the pieces are flat and not welded to anything. So we ordered another piece of steel for the other mount, and we're anxiously awaiting its arrival. Okay, not so much.

  World's strongest pedal spring mounts
click to enlarge

While making tabs for the brake lines, we also made tabs for the pedal springs. These would've been easy to overlook, so that when we were getting the car ready for its first drive and realized we'd forgotten them, we would've had to jury-rig something that would've looked bad and failed after only a few miles. These tabs will never fail, being at least eight times as big and heavy as they need to be. Most people would've used thin sheet metal. Not us. We used the same 1/8" steel that went into our extra-sturdy motor mounts. Plus a few ounces of welding wire.

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Comments:  
posted April 27, 2017 at 21:15:19  
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posted September 20, 2017 at 11:15:35  
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posted November 8, 2017 at 11:57:20  
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