Originally Posted by
Farmer_John
The internal ratio is 2.4. I suppose That's from the belt reduction. Lon and I are running 44t spurs, He's got a 21t pinion, I have a 20, but still have a 19t on it. Joe T. has a 47t spur, I don't know what he's got on it for pinion.
Not sure about the clutch. There appears to be something to adjust, but I haven't had to do anything to mine.
Phil, If I've understood your description of layout correctly, You're going to run essentially a half GT drive train? pinion to shaft mounted spur to half shaft, then rear dif?
Are you concerned with what that will do to the balance? Do you expect to have "the shaft effect" that you get with shaft driven 4x4s?
Exactly. And there should be no prob whatsoever with balance since nearly everything will be level, small o rings to take up slack in the ends, and of course the shafts will be balanced. It's gotten even easier on us in planning since we decided to go with the Edam front and rear hub assemblies, using the pillow balls to mount into aluminum bulkheads...so you get to keep all your adjustments, and even if you break a part, they're so cheap it doesn't matter. Not that I forsee much breakage since we're looking at piano wire rear bumper on the back, nerf style bars on the sides (not fixed, so they still allow chassis flex for traction) and slightly upswept front end and bumper backed by an aluminum front axle. The only issue we haven't quite mapped out yet is gear ratios, ensuring there is enough at take off and not winding completely out before the end of the backstraight, but it's not looking like a prob...I'm just doing the homework to make sure it's not going to be a prob. And with the adjustable rear end, we'll be able to run either new rears with low clearance, or after a simple adjustment, run 'em right down to the rims, literally. In the lower setting, the rear rims will be level with the pan, so some of you guys having to change tires during a main would no longer have to do that. The shafts, turnbuckles and steering links will be heavy duty stuff as well. I did a little computation today and parts wise, I'm looking at about 200 before tires, engine and radio gear. I'm sure that'll go up a little bit but the target for the prototype is less than 250 bucks material cost, we'll be fabricating the pan, bulkheads, nerfs, and servo tray.
If all this works and there is interest in it, we're trying to design it so simply that anyone with the desire to do so could just get the specs off us and build the thing themselves. Access to aluminum, drill, cut off wheel and taps would be a must. I'm really hoping for a low cost, durable as Delta car that is fast and competitive, but I think there's a few guys out there that would enjoy doing the whole thing from scratch like guys did in the beginning, and we're trying to stick with off the shelf parts for what we or others can't make and to save money. We'll probably begin in earnest at the end of the season and I'll post pics as we go so everyone can see what we're driving at.
Thanx for the numbers...now I get to do math....lol.