I think the drawing is either an Aztec design or a map of Hampton Court Palace Maze or am I missing something....
You might be on to something there...
Actually, the light bulb went on, and I did a sketch of Peter's diagram. However, I have no software to convert my sketch to a picture file. I saved the sketch as a PDF and attached it, but it failed to open. Perhaps that's just as well, since my skills in this area seem to have regressed over the years. But I'm feeling pretty good that I finally figured out at a schematic drawing.. not my strong suit.
Last Edit: Aug 3, 2012 12:12:46 GMT -5 by Mark Huber
Of course Peter, so stupid of me with the gear ratio, now I'm angry at my self . At least David we know that it also not a Aztec design ;D
But serious now, with all these gears won't you lose to much power with all that friction? Don't you loose speeds on the straits, that you gain in the curves I think you'll gain benefit out the system on a race circuit with lots of curves, but on a circuit with long straits it's in your disadvantage.
You should definitely follow your therapy Andi, and we hope you'll find your sanity back keep us posted.
Post by Peter Seager-Thomas on Aug 3, 2012 14:50:59 GMT -5
Danny, with friction between two sets of gears rather than the normal one, I'd guess it would be slower all over the circuit, whilst there would be the added problem of reduced tyre contact with resultant wheelspin!
This little project is for fun, and judging by the results so far, it is already working...
okay, I understand the diagram although it took me a few minutes. Very interesting approach. I wouldn't worry too much about the losses due to the extra gearing. I built up a P99 a few years back that was a bit of a clockmaker's nightmare at the rear end.
There were two points to all the flying teeth – the main one was to move the driveshaft to the left-hand side of the cockpit à la the prototype to permit a full driver figure. The other of course was simply to see if I could do it. As I recall from the results on the course, the car suffered from a number of ills but seem to have comparable straight-line speed.
Getting back to the swing axle idea, this approach would allow for a sprung rear end but I'm not certain, at the end of the day, whether there is any performance benefit to be gained. On the other hand, it would also allow a fixed rear end with some degree of negative camber. This was of course, an idea tried in the one-to-one world sometime back. I wonder if there is anything to be gained in our miniature world?
I remember building a ball diff for a 1/32 scale car back in the early 1980s, just when the first 1/12 scale RC car ball diffs came out.
The problem with mine was that I could not find hardened washers small enough, and the pressure that was needed between the washers and balls to actually drive the car forward resulted in a groove being worn in the washers after about 3 laps, with consequent loss of drive.
But for those 3 laps at a time, the car was as good as anything else I had, and much better in the twisty sections of our track where there were quick left-right-left changes. There was a lot less tail slide.
It might be worth trying again, now that better components are available.
Post by maxrossmassler on Nov 23, 2012 12:20:05 GMT -5
I am liking that P99 in the biggest possible way!!!
Great thread. Andi - that photo of the swing axle rig at the beginning of this thread -- what is it? Is it 1/32?
I have been mulling over suspensions and steering for some years now, built a couple (see my 1962 BRM in builds thread) - several issues arose in my first test car (imagine that)...
1) pivoting the guide on the front axle center line made for awful squirrelyness, so I added a secondary pivot plate with a spring-return- that way the guide itself doesn't actuate the wheel movement. This helped a lot, I haven't had any "crossed-up" problems at all.
2) damping is an issue! Once you have springing, you have to damp it so the car doesn't just bounce up and down and (of course) right out of the slot.
The simplest solution is to make the springs inactive by adjusting their length - its also possible that an extremely weak spring would be OK - haven't tried that yet. I also need to try various grades of oil along the shock absorber travel - or (now i'm getting truly crazy) a closed-end damper with some oil inside(not sealed tho, I think -some things really are too small!!) Anyway the idea would be to "thicken" the sliding motion of the damper, hoping that surface tension would keep the lubricant on the moving parts and not oiling the track instead. That might work to slow the return of the mechanism.
3) rear axles & U-points - I have also been banging my head against the idea of a 4-joint rear axle. I have several ideas but have not been able to actually make any due to insufficient time/machining skills & equipment, etc..... I will upload some images next post, I have to create them from the CAD program, need to use my work computer..!!
I am very grateful to have discovered this thread!