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Post by volsfan on Feb 19, 2007 20:40:36 GMT -6
I have read conflicting ideas about angling the axles so the wheels ride away from the car body, some say this makes the car ride straighter and reduces wheel wobble and friction others say it greatly increases the friction against the axles head.
Please help I am very confused now, and my son's district race is this weekend. Thanks for any help.
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maxx
Addicted to Speed
Posts: 83
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Post by maxx on Feb 20, 2007 10:37:40 GMT -6
Hello Volsfan,
This is a hotly debated topic at numerous forums,I have read that at some events all the fast cars are running canted axles.
I think what you have to consider is that without substantial time and a track to do some testing on the results of canting axles it would be considered very risky.
If your sons car was say a 3rd place car in his rank and on to districts to compete against the same 2 cars you know he can't beat and you are willing to take the risk of maybe placing even further behind these cars than maybe it might be a consideration.
if on the other hand your sons car was fastest in his rank and maybe even the pack champ you may want to consider just leaving well enough alone.May be more important to work on a fresh lube and tweak the alignment a little.
I personally would explain the risks to my sons and then let them choose.As long as they believe they are trying to do their best, win or loose it is all good ;D.
I hope some of this helps.
Maxx
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Post by backcreekpinecars on Feb 20, 2007 15:37:31 GMT -6
looked at this when i got started and like you I considered it primarily due to decreased friction.
However, when building I found it very difficult to get each axle canted similarly and build a car that would track straight, run consistent, and provide any overall alignment "tricks".
Similarly, the extra friction on the axle heads I suspect is likely greater than that or rolling resistance against the track on the best alignment job you can do.
I ended up choosing rail riding as I was able to reproduce consistent cars and can now work on gaining speed as we continue to build cars.
There are many that can explain this better, this is just my .02 worth based on my limited experience.
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Post by Lucky 13 on Feb 20, 2007 16:07:16 GMT -6
Check the thread titled "axel squared vs angled"
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maxx
Addicted to Speed
Posts: 83
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Post by maxx on Feb 20, 2007 17:19:49 GMT -6
Check the thread titled "axel squared vs angled" I agree with Lucky,but in this instance with less than a week unless Volsfan has his son home and the week off of work to accomplish this it might be more trouble than it is worth. Backcreekpinecars I believe one of the reasons to do this is to guarantee that the wheel only rubs at the axle head and not at the car body.I think this is the main advantage to canting the axles.if you cant them to much you will end up with the wheel bores not riding flat on the bottom of the axle and this would be worse than hitting the car body.I think it is a technique worthy of ones time with "time"being the key factor.Just my .02 . Maxx
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Post by backcreekpinecars on Feb 20, 2007 17:49:50 GMT -6
Maxx - your point is exactly what I was trying to do - i guess my question would be replicating the effort. Consistency not just amongst cars but within the same car seemed to be my struggle. Let it be known, however, that patience is not my strongsuit - looks like a learning opportunity for me in this one
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Da Pine Racing
Head in the Pine
kamaniwannaracedakinepinekah
Posts: 172
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Post by Da Pine Racing on Feb 20, 2007 19:50:09 GMT -6
I totally agree with your suggestion due to limits of time maxx. But that less track contact thing that lucky13 mentioned is very intriguing being how I never experimented with canted axles on purpose (it just kinda happens sometimes). If running a 3 wheeler, I would think one would only cant the rear axles. Wouldn't the single canted axle in front want to turn the car? That probably could be compensated with alignment tweeking, but like backcreek said, I think it would be a bear. I would definitely do some testing Volsfan before taking a car to district with something new if you already have a good car in hand.
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Post by wheeler on Feb 20, 2007 21:13:17 GMT -6
Volsfan, camber will definetly improve performance, but does complicate alignment, both have to be correct to gain full benefit. Typically you should see .020 to .030 improvement. Recomend 3 to 5 degrees.
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Post by volsfan on Feb 20, 2007 22:14:35 GMT -6
Thanks for all the help guys!! especially the angled vs. square head string. We had tested against last year's car, which was 1st in pack (out of 10) and fourth in district (out of 80) on one of the BSA test tracks, which aren't very straight at all by the way. We repeatedly beat it by 1/4 to 1/2 car length. There were two differences though from last year, we cambered the wheels 5 degrees , and lifted one front wheel. He got a very controversial second on an extremely rough 2 lane track made from 1"x8" boards so no curve at all just 3 incline changes with about a 1/2" gap up and down between the sections. several cars flew off the track completely! My son's front end lifted alot due to rear weight, I noticed the one who beat him was evenly weighted keeping the front end on the track on the "speed bumps" I noticed every time he would be leading until the second "speed bump" So I wasn't sure what to do with these mixed results of beating our car from last year, but getting second on a crappy track. Also I didn't know if it was just due to the lifted front wheel. My son's (7 yr. old) comment comment was "I think we'll beat him on the faster district track Daddy!", which is a 6 lane track about 60 ft.
Thanks All!
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Da Pine Racing
Head in the Pine
kamaniwannaracedakinepinekah
Posts: 172
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Post by Da Pine Racing on Feb 20, 2007 22:49:31 GMT -6
Hi Volsfan, Yes, on that bumpy track a little more weight in the front is better. A wheel that leaves the track of & on definitely scrubs off speed. I don't believe that lifting one wheel in front was the problem at all. Your son is correct with everything else equal, his rear weighted car will do better than the other on a good track.
Best of luck & fun at the district race.
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hotrod
Head in the Pine
Posts: 136
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Post by hotrod on Feb 21, 2007 19:18:08 GMT -6
Hey Fred, just wondering....how are you measuring the 3-5 degrees for camber? BTW, congrats on your success this past weekend ;D ;D You definitely are flying with those cars!! Ed Half Moon Racing
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Post by wheeler on Feb 21, 2007 21:43:03 GMT -6
Ed, rule of thumb is .017 per degree per inch, this gets you pretty close. Thanks Ed, track is excellent and I can fine tune without having to run extra steer, that helps a lot.
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Post by Ricerocket on Feb 21, 2007 22:47:25 GMT -6
Hey Fred, just wondering....how are you measuring the 3-5 degrees for camber? BTW, congrats on your success this past weekend ;D ;D You definitely are flying with those cars!! Ed Half Moon Racing This should work: www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKHC3&P=CCamber gauge made for R/C cars. A bit big for pinewood, but should work nonetheless.
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Post by Magic Man on Feb 21, 2007 23:33:29 GMT -6
Ed, rule of thumb is .017 per degree per inch, this gets you pretty close. Thanks Ed, track is excellent and I can fine tune without having to run extra steer, that helps a lot. Wheeler, Would you be able to explain this further? (.017 per degree per inch) I am not following you, can you give me detail descriptoin on how to do this? What degree and what inch? Thank You, Magic Man
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maxx
Addicted to Speed
Posts: 83
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Post by maxx on Feb 21, 2007 23:49:42 GMT -6
Magic Man I believe what Fred is saying is that you would need to pivot from one end .017" per " to get 1 degree.
Since a BSA axle is about an inch long you would need to pivot the axle from parallel with the bottom of the car .017" for each degree of cant you wanted to put into the axle,obviously you would be pivoting the axle up.So if you wanted 3 degrees you would measure .051" for the location of the nail head.A better question might be how are you setting up the drill press to accomplish this action?
Maxx
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Post by Magic Man on Feb 21, 2007 23:59:09 GMT -6
Thanks, Maxx. I understand now.
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Post by wheeler on Feb 22, 2007 10:56:21 GMT -6
There are a number of ways to set camber. The method I recommend is to bend axle for desired amount of camber. I designed a tool to do this, which doesn't mark journal and makes precise bend just inboard of journal area. Procedure is as follows. Step 1- using edge of triangular file, file a mark on head of axle from center to edge. Step 2- prep and polish journal area. Step 3- install axle in tool with mark pointing up. Step 4- set tool for amount of bend you want. Step 5- move lever on tool to stop. Step 6- install axles on car with mark straight up (12 oclock ). Step 7- test roll car and adjust alignment for each wheel by rotating axle slightly clock wise or counter clock wise for adjustment. Referance these positions on paper for future use.
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Post by RacerX on Feb 22, 2007 11:34:44 GMT -6
It makes for a straight, fast, easy to align car especially with-out a test track.
Drill the body with a Pro Body Tool, straighten your axles with a Pro axle press and polish then. Mark the axle @ .350" from the head and put a dot at 12:00 on head with a sharpie. Instal the axle into the Pro Axle Press at the .350" mark with the dot on the head down and slightly bend the axle with a light hammer tap. I use a digital caliper to measure from the head of the axle to the work bench to verify my bend. On the rears .015" and .010" on the front. Install the rears with the dot up at 12:00 as well as the front (dominant wheel).
The car should roll forward and backwards with the wheels staying on the axle heads. If not. rotate slightly fore and aft untill both are perfect and do not migrate. Use slight rotation of the front axle to steer. There are several good table top formulas on here (someone chime in) but 1" drift towards the dominant front wheel over 6' test roll will get you going well.
Good Luck
Racer X
The trade off is positive vs. axle head to hub face friction.
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Post by Magic Man on Feb 22, 2007 12:04:57 GMT -6
Would you also be able to place a feeler gauge on your drill press table to the desired height or angle you want, then place the pine block on top of this. Top edge of car on gauge, then drill your holes in side of car. I have not tried this I was wondering if there would be a problem in doing this ?
Magic Man
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maxx
Addicted to Speed
Posts: 83
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Post by maxx on Feb 22, 2007 14:41:24 GMT -6
That would be an excellent way to drill the holes magic man.A fellow denmates father did exactly that but with the pro body tool.it worked out quite well.
Maxx
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