Bill Hall
08-27-2007, 03:50 AM
And thanks to the Gang for piling on. Looks like a great start. Lets make this forum a going concern! C'mon you wiley veterans! Post up and spill your guts.
For new tuners, IMHO, there are three magic words.
"Concentric". Is it round? Does it run true? Be it an Arm, a gear/shaft, an axle, or a wheel/tire. Swamper pointed out some time ago that a cockeyed pancake armature pinion can transfer it's wobble/bind down the gear train thereby affecting multiple components. Just as a whacked axle makes wheels and tires run kerflunky. The nugget there is to pay attention to how a component relates to the rest of the components. It's imperative that you proceed systematically rather than throwing a bag of new parts at something and not solving the problem or worse yet...LOL...Fixing a problem and never knowing how the heck ya got there. D'Oh!
Any one or a combination of wobbles WILL hurt you bad whether the symptom is gear binding or chassis hopping.
"Friction". It's a YES or NO question! Really a simple matter to isolate but care should be taken to not over relieve or excessively clearance friction points. Always take little bites! Then retest. Keep in mind that over relieving a bound friction point can create an un-concentric conditon if not approached with care. Excessive friction kills cars. No exceptions!
"Ballance". Can apply in several different areas. Armature(both electrical and mechanical), magnet strength and comm spring pressure. Bigger magnets and gunning the comm down do not always make a better running car. Ballancing pick up shoe profile and spring pressure is paramount to good handling and proper current transfer. Then of course chassis ballance...if it's a three wheeler its always gonna have a quirk or two no matter how much fiddlin' you do.
So by the numbers.
1. clean the factory grease out and re-service the oiling points.
2. roll the drive wheels on your fingers to check for binding and figure out/fix any weirdness.
3. If you got it clean and loose then a gentle break in is in order. This is the time to watch for wobbling, out of round wheels and gears. The wobbles are a LOT easier to spot at low speed. I like to check just off the throttle stop myself. Stop and fix it! Also stay attentive for, any rapid heat build up. Again stop and figure it out, then fix it!
4. Drop the rear tires on some 180/220 paper and feel for any bounce or vibration. Some times a 'lil scuff is all you need. Be careful! Dont cook your motor by leaning on a tire that will never true up. Most times it's an irregular wheel that mishapes the tire as it tries to conform. Toss it and replace it! then try again. The idea is to knock the nibs off the tire and flatten the contact patch to its optimum footprint.
5. Raise the back wheels and slide the front end along the slot carefully feeling for binding, high spots and wobbles in the front wheels and tires. I true my fronts on a slave chassis.
6. Clean the pickup shoe contact patch and run a few laps. Recheck the the rub pattern and adjust it so that it's centralized in the contact patch.
FUNDAMENTALS!!! It may be mediocre on power or speed but it's gotta be smooth and stay in the slot before ya go all crazy on speed parts and tweaks! If you cant lap a stock car consistently no amount of gearlapping, arm ballancing, or hotrod parts will keep you out of the ditch. Tuning is not something one can learn overnight. With practice/repitition combined with careful observation the "feel" will come in time.
Perhaps this post was a skoshe redundant, and sorry to the veterans that can do this deaf, blind, and dumb; but it seemed important to start at the beginning for any newcomers. I've purposefully omitted many points as tuning each make of chassis would fill several volumes. I'm counting on the gang to fill in the blanks and keep this thread growing like a noxious weed.
For new tuners, IMHO, there are three magic words.
"Concentric". Is it round? Does it run true? Be it an Arm, a gear/shaft, an axle, or a wheel/tire. Swamper pointed out some time ago that a cockeyed pancake armature pinion can transfer it's wobble/bind down the gear train thereby affecting multiple components. Just as a whacked axle makes wheels and tires run kerflunky. The nugget there is to pay attention to how a component relates to the rest of the components. It's imperative that you proceed systematically rather than throwing a bag of new parts at something and not solving the problem or worse yet...LOL...Fixing a problem and never knowing how the heck ya got there. D'Oh!
Any one or a combination of wobbles WILL hurt you bad whether the symptom is gear binding or chassis hopping.
"Friction". It's a YES or NO question! Really a simple matter to isolate but care should be taken to not over relieve or excessively clearance friction points. Always take little bites! Then retest. Keep in mind that over relieving a bound friction point can create an un-concentric conditon if not approached with care. Excessive friction kills cars. No exceptions!
"Ballance". Can apply in several different areas. Armature(both electrical and mechanical), magnet strength and comm spring pressure. Bigger magnets and gunning the comm down do not always make a better running car. Ballancing pick up shoe profile and spring pressure is paramount to good handling and proper current transfer. Then of course chassis ballance...if it's a three wheeler its always gonna have a quirk or two no matter how much fiddlin' you do.
So by the numbers.
1. clean the factory grease out and re-service the oiling points.
2. roll the drive wheels on your fingers to check for binding and figure out/fix any weirdness.
3. If you got it clean and loose then a gentle break in is in order. This is the time to watch for wobbling, out of round wheels and gears. The wobbles are a LOT easier to spot at low speed. I like to check just off the throttle stop myself. Stop and fix it! Also stay attentive for, any rapid heat build up. Again stop and figure it out, then fix it!
4. Drop the rear tires on some 180/220 paper and feel for any bounce or vibration. Some times a 'lil scuff is all you need. Be careful! Dont cook your motor by leaning on a tire that will never true up. Most times it's an irregular wheel that mishapes the tire as it tries to conform. Toss it and replace it! then try again. The idea is to knock the nibs off the tire and flatten the contact patch to its optimum footprint.
5. Raise the back wheels and slide the front end along the slot carefully feeling for binding, high spots and wobbles in the front wheels and tires. I true my fronts on a slave chassis.
6. Clean the pickup shoe contact patch and run a few laps. Recheck the the rub pattern and adjust it so that it's centralized in the contact patch.
FUNDAMENTALS!!! It may be mediocre on power or speed but it's gotta be smooth and stay in the slot before ya go all crazy on speed parts and tweaks! If you cant lap a stock car consistently no amount of gearlapping, arm ballancing, or hotrod parts will keep you out of the ditch. Tuning is not something one can learn overnight. With practice/repitition combined with careful observation the "feel" will come in time.
Perhaps this post was a skoshe redundant, and sorry to the veterans that can do this deaf, blind, and dumb; but it seemed important to start at the beginning for any newcomers. I've purposefully omitted many points as tuning each make of chassis would fill several volumes. I'm counting on the gang to fill in the blanks and keep this thread growing like a noxious weed.