So now next weekend I'm gonna build myself an adjustable length nutty bar
I'll post the solution to this problem for others in case they get stuck, and for consideration as an additional feature... I think given the blind nature of affixing the nutty bar, ensuring the loosest most perfectly centered fit is key. Two ways to do that... extremely tight tolerances in manufacturing, or make it adjustable.
After a bit of thought and planning and the obligatory run to Home Depot (and then the run back to return the item that someone had opened and returned with only half the parts... of course)... I set to work cracking the nutty bar
The only materials I needed were about 8" of 3/16" by 3/4" metal stock (Home Depot labels it weld metal), and a single baggie of #10 machine screws and nuts (the kind with the conical head and slot for flat head screw driver that are meant to be countersunk and sit flush)
Basically I did the following
- Drill 2 holes in the metal stock, just large enough for the machine screws, as close together as possible
- Dremmel the metal between the holes until the machine screws slid back and forth in the resulting slot
- Repeat to make another slot 2 inches further into the metal stock
- Clamp the stock to the nutty bar with vice grips
- Drill 2 holes through the stock and nutty bar.
- Counter sink the hole on the downward face of the nutty bar
- Insert the machine screws and nut the metal stock to the nutty bar
- Drill a hole in the nutty bar at the middle of each slot
- Unbolt the stock and countersink those holes, also on the downward side of the nutty bar
- Make sure everything bolts together nicely
- Take all the bolts out, remove a 1/2 inch section of the nutty bar (with hack saw)
- Bolt the nutty bar back together, the slots loose, the solid holes tight
- Loosely bolt the nutty bar to the tow bar (not on the vehicle yet)
- Once I had a fit that allowed the M10 bolts to rattle slightly I tightened all machine screws good and tight
- Dremmel the ends of the machine screws off flush with the nuts
- Make a vertical cut partway into the nut and the machine screw to inhibit unscrewing and generally mess with the thread
- Resume the BOE installation instructions with the adjusted nutty bar!
Step 6 - This is important because you don't want the bolt heads holding the nutty bar up away from the inside of the crossbar. That would cause the bar to bend when you torqe it down, and probably interfere with installing the rivets that hold the nutty bar in place permanently.
Step 7 - Nut it together fairly tight, so that nothing moves and the holes bot line up in the slots when you are done with step 8
Step 9 - Important for same reason as Step 6
Step 11 - Half inch is plenty generous. No need to take more for sure, could get away with less, exact amount removed is not critical.
Step 13 - This is the whole point of this process. Here is where we take a nutty bar that was tight fitting and make it loose fitting by allowing the machine screws to slide freely in the slots we drilled.
Step 14 - Once we have a fit we don't want to loose it, crank em down (but don't break em!)
Step 15. This is important! I used 5/8" long machine screws and without this the nutty bar wouldn't make it past the A-arm mount! 1/2" screws might make it, but I know that cutting them off does work
Step 16 - Lotuses create a lot of vibration. I didn't want the nuts to work loose and have nuts, and the metal stock bouncing around in there. Not 100% sure what I did was fool proof, but something should be done to prevent the nuts coming off. If I still had my welder, a tiny quick zap would have been ideal.
Here are the pics:
And here's the best one of all... once the nutty bar was adjusted, I got the bolts threaded in less than 2 min
As a side note, I was not suprised to discover that the tow bar is incompatble with the rear tow loop from Sector 111... Note how the hole for mounting the tow bar is covered, so these two items have to be swapped at the track if you want to use both.