SS Mini Update

BKH, I think you're right about the torque - I was just making guesses at peak line tension, which is not the same thing. 500 pounds of line tension (the force at the top of the pole) would result in 3500 ft-lbs of torque exerted at the bottom of the pole (in a cantilever situation). In straight towing (skier dragged behind the boat), the strap would bear most of this. In cutting, the lateral component of the force (the force to the side) would be 71% of the line tension at it worst (assuming that a skier's horizontal pull is maximized at 45 degrees - my experience is that you start pulling less once you get past 45 degrees), resulting in about 2500 foot lbs at the base in a lateral direction. This is really a worst case scenarion - since you pull the most the closer you are to the wake, the actual lateral torque is probably much less. The good news about the lateral torque is that the boat tilts to ease it. The bad news is that this is the force most likely to break your pylon, since the strap doesn't do squat for it.

So, I know 3500 foot lbs of torque sounds like a lot, and it is. Any pylon design would need to take this into account. A good way to test it would be to take a pylon, mount it sideways on a sturdy base, attach a tire on a rope to the free end and put a big fat guy like me on it and swing him around. If it holds up to the lard-butt dchris17 test, it should be sturdy enough for wakeboarding.

This is a fun discussion. It's brought back a lot of the old stuff I studied in school. Maybe I should have actually gotten a job in my degree...

One more thing. I bought a homemade tower on eBay for my last boat and bent it within two weeks. The reason? They had drilled holes in the vertical supports of the tower about a foot from the top on the stern side of the tower. These holes weakened the tube enough to cause it to bend. Later towers by the same guys have fixed this problem by welding back over the holes (they needed them for mounting stuff).

One final note: I'm less worried about the extended pylon buckling in my design than I am the regular pylon buckling with skiers. Tubes are pretty common with the extended pylons, but not at all for the regular height ones. That one makes me nervous, but I'm going to try it out.

    Dave, I find the wiring to be pretty neat and safe considering how the grounds are all "daisychained". I left mine alone as I didnt feel it was worth the effort and concentrate on more issues of proirity.
    My .02

                             Jeff...

It's not a very good picture, but here you can see the dash stripped down.


Thanks Jeff. My problem is the previous owner had apparently done some things with the wiring. Some of the gauges had 5+ grounds coming out of them. It was a total mess. Has anyone ever used a connector at the dash side of the wiring harness to make it easier to remove the dash? I'd like to be able to remove the dash without unwiring all my gauges.

My new wiring harness will arrive this week too. My little brother manages a production line that makes wiring harnesses for military aircraft and he has printed the wires for me.

I hope I'll have better pictures to post soon.

I'll post some photos of the wires when they get here. My brothers also sending the wrap/etc to keep the wires together - all military aircraft grade stuff.

    Nice harness, even a heatshrink end. Are the wires the cloth woven type with a plastic coating??
                                  Jeff..

Jeff: There are two layers of insulation, one cloth and one plastic.

John: These wires would have cost $400-500 if I'd had to pay for them, but fortunately my bro was able to use "scraps".

One of the reasons these are so expensive is because of the fact that they are for military aircraft and the quality control procedures are so rigorous. To tell you the truth, it's probably not going to make my boat run any better to have such a fancy harness in it, but darned if it doesn't make my boat that much cooler!

Got the wire harness built today. It took about an hour for me to get the wires pulled through the abrasion protection and shrink-wrapped. The hardest part (if there was one) was just getting all eight wires bundled together properly to pull through.

Any suggestions about mounting this in the bilge? I've noticed on both boats I've had that the pull-ties get brittle and break off over time. I was thinking of using 3/4" PVC pipe, screwed into a stringer to put the wires through. Overkill?

Sadly, my brother's company doesn't make those. I'm on my own!

Here's a picture of the dash wiring. I've only done the gauges - I'll do the switches next. Turned out a lot cleaner than the original setup.

    Dave, I am totally amazed on the progress!!! Nice, clean and better than original. I recall and laugh at a post you made asking for a kick in the butt or something like that.
    Great JOB as always!!

                                  Jeff....

     Sorry Dave but the 74 is still buried in the back of the shop. I have managed to get the 76 on its feet, but its still at NECC checking on why the new engine hesitates. I am way behind schedule this year. I sure would like to see your 74 in person someday. Not many of that model year around.


                                    Jeff...

Again, GREAT PROGRESS!!!!

I'm about five minutes shy of having finished the whole wiring job, plus some clean up. I used heat shrink connectors everywhere - I think it's a quality job.

I think next winter I'll build a wiring harness board for the 302 and build a quality engine harness. The wiring harness I build only runs from the dash to the engine connector. My brother and I are going to research a better connector than the 8 wire bullet type used for towing.

I hooked the steering back up, so the dash is looking almost normal. The hour-meter is broken, so I'm going to put a depth sounder there once I've got some extra cash. I'll live with the hole for now.

So, now all I have left is replacing the fuel hose (rotten), the bilge pump hose (too short), arranging some sort of pylon (might end up being a piece of iron pipe until I get my custom one finished), installing the horn, and cleaning up the whole big mess.

Oh yeah, I have to figure out why the motor doesn't turn off when I turn off the key. That's wierding me out a little bit. It's a new ignition switch, but maybe it's gone bad already.

Jeff, and anybody else, for that matter, who has contributed to this project of mine by giving me advice and/or encouragement, you're always welcome for a ride on the SS Mini. I hope to be able to bring her out to a reunion next summer.

Incidentally, my wife has gone crazy. Next winter when I replace the floor, upholstery, and fix the gel coat, she says I should paint the thing red and airbrush in some flames. Another retro-rod boat.

I can't make the schedule work this year for the reunion. My wife had a surgery recently that used up a lot of my time off.

Jeff, I think I have got the ignition and the output mixed up. I'll look at that tonight.

I'm going wakeboarding on Friday. This will be the first skiing trip of the SS Mini. I'll take some pics and post them. Unfortunately, it's going to be with a bubble-gum-and-scotch-tape pylon because I don't have a good pylon yet.

Thanks Joe. Will do.

see this, it should clear everthing up

http://www.skiboathelp.com/tech/colorcode.html

     Dave, a quick thought....are you still using the ammeter, or are you using a new voltmeter?? If using an ammeter, make sure NO wires connect to the ign switch. If a voltmeter, that doesnt apply.

                                  Jeff..