Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.
01-09-2007, 02:28 PM
#812
Tech Adept
Originally Posted by John Stranahan
So here is the thing. If the force line the red line in the figure is below the center of gravity or at the center of gravity you will get some chassis lift. The lower this red line is the more the force will just propel the car forward and not lift the chassis. So higher is more antisquat. At the center of gravity is 100%. The percentage is an arbitrary construction of one author Carol Smith in Tune to Win. We could talk about the angle of the red line as well, but it would not show the upper limit of usefulness to antisquat which would be at the center of gravity. If the red line goes below the ground we have prosquat.
In your case, the instant center is at infinity. (extend the line through the centers of the pivot balls of the 2 drag links, from the pics the drag links look to be parallel to the ground) So, at normal ride height, the anti-squat angle would be 0°... ... I think. It's kinda hard to tell from the pics.
For a CRC pivot-ball-style car like the Carpet Knife (haven't had a good look at the pantoura), the pivot ball would be both the rear roll center and the instant center for anti-squat.
I've been meaning to update the info about anti-squat on my site (http://users.pandora.be/elvo), but never got round to doing it. It's the exact same theory as roll center, just in a different plane.
P.S.: this thread rocks. That car rocks.
01-09-2007, 05:16 PM
#813
MarcosJ-Check back in a month. Work is possibly underway.
Elvo-I have to disagree here. My 3 link has the same angles and would be dealt with the same way a four link would. Yes that Caroll Smith Figure applies just like you say in your last sentence. The motion is the same as a four link with less binding on roll. The lower links are elevated at the front. The upper link is lower in the front. I made and posted a scale drawing of the links in a view from the side. The green lines represent the true angles of the links. Thanks for the interest. The suspension is quite a bit different than a pivot ball suspension. The roll center is at the center of the Panhard bar. The antisquat is substantial. The completely different and improved forward and cornering traction tells the true tale.
Motor Plate Wear
If you looked close you see that I replaced my motor plate with a blue one. The oval hole in the old plate had enlarged and had play on the plastic axle ride height inserts. This may have been the source of my 64 pitch noise on braking. I'll try them again one day. I never would have thought that that plastic insert would wear the aluminum like that, but you can see a silvery film of Aluminum on the plastic. This wear is probably greater due to the very small pinion I need to run with the 3.5R and its resulting vibration.
Note that you cannot run the Blue IRS motor plate with the Associated plastic left side pod plate. The IRS part is lowered, so the two are different heights at the axle.
There is a new picture of the 3-link car on the wide Powell chassis on the previous page.
John
Elvo-I have to disagree here. My 3 link has the same angles and would be dealt with the same way a four link would. Yes that Caroll Smith Figure applies just like you say in your last sentence. The motion is the same as a four link with less binding on roll. The lower links are elevated at the front. The upper link is lower in the front. I made and posted a scale drawing of the links in a view from the side. The green lines represent the true angles of the links. Thanks for the interest. The suspension is quite a bit different than a pivot ball suspension. The roll center is at the center of the Panhard bar. The antisquat is substantial. The completely different and improved forward and cornering traction tells the true tale.
Motor Plate Wear
If you looked close you see that I replaced my motor plate with a blue one. The oval hole in the old plate had enlarged and had play on the plastic axle ride height inserts. This may have been the source of my 64 pitch noise on braking. I'll try them again one day. I never would have thought that that plastic insert would wear the aluminum like that, but you can see a silvery film of Aluminum on the plastic. This wear is probably greater due to the very small pinion I need to run with the 3.5R and its resulting vibration.
Note that you cannot run the Blue IRS motor plate with the Associated plastic left side pod plate. The IRS part is lowered, so the two are different heights at the axle.
There is a new picture of the 3-link car on the wide Powell chassis on the previous page.
John
Last edited by John Stranahan; 02-13-2007 at 09:33 PM.
01-10-2007, 04:55 PM
#815
Prototype twin Active A-arm Front Suspension with Coil over Shock
Ok here is a prototype twin active A-arm suspension. Key design features are short upper arm long lower arm. Very direct shock action. Very smooth. Low stiction. Huge travel. Ride height adjustment at the kingpin or the attachment screws to the frame. Now this is not a completely working prototype yet, nor does it use the factory chassis mount holes, but I think you can see that it will fit 1/10 bodies fine. The body clip on the body post is the lowest point of the front of the body. I'll see if I can test it later on our straight. These are just slightly rearanged and trimmed pan car A-arms. I will need a pass through for the steering link. This is similar to the way 1/8 scale guys can get a low body on their road cars.
3-link continued
I got the Powell chassied 3-link car tuned up today. The track was a little dusty, but after four packs I had it up to race speed. I worked on the blowover problem and made improvements. The car is just faster than before and has more traction lifting the front up. I went back to putting on a soft dam, and I ease throttle on the worst bumps. I found a better line through the straight. Speed is very good but could be better if I were able to use full throttle the whole time. Yes it can pass Nitro cars at the end of the straight.
Ok here is a prototype twin active A-arm suspension. Key design features are short upper arm long lower arm. Very direct shock action. Very smooth. Low stiction. Huge travel. Ride height adjustment at the kingpin or the attachment screws to the frame. Now this is not a completely working prototype yet, nor does it use the factory chassis mount holes, but I think you can see that it will fit 1/10 bodies fine. The body clip on the body post is the lowest point of the front of the body. I'll see if I can test it later on our straight. These are just slightly rearanged and trimmed pan car A-arms. I will need a pass through for the steering link. This is similar to the way 1/8 scale guys can get a low body on their road cars.
3-link continued
I got the Powell chassied 3-link car tuned up today. The track was a little dusty, but after four packs I had it up to race speed. I worked on the blowover problem and made improvements. The car is just faster than before and has more traction lifting the front up. I went back to putting on a soft dam, and I ease throttle on the worst bumps. I found a better line through the straight. Speed is very good but could be better if I were able to use full throttle the whole time. Yes it can pass Nitro cars at the end of the straight.
Last edited by John Stranahan; 01-10-2007 at 05:07 PM.
01-10-2007, 05:10 PM
#817
Tech Apprentice
Im scared to say......but this car is slowly turning into a touring car 
LOL no even close 
01-10-2007, 06:42 PM
#820
i have held the car in my hand and it is nothing like a touring car it is one of a kind .and it is to dam fast for some of you you to understand it is like nothing else .
01-10-2007, 07:06 PM
#821
This car with four shocks is at 39 ounces. Touring cars are at 54 ounces (or 48 with one lipo). If you run the pair (a touring car and this pan car) on the same track with the same electrics, it is not even a contest, the pan car is so much faster, and then the touring car will thermal and not even finish the race with a brushless setup. The 3 link Pan car even worked well on a very green track today. Ever see a 3 link touring car. I know that some of you have this fond wish to keep pan cars unchaged, but if you do there are all these performance issues that are unsolvable. They are enumerated in the thread. The key to a pan cars speed efficiency and workability with brushless at the present time is the solid axle direct drive. I will keep this the same as well as the body. Everything else is up for grabs and it might be called a Sidewinder.
Lets see you fit this body on your Touring car.
John
Lets see you fit this body on your Touring car.
John
Last edited by John Stranahan; 01-11-2007 at 07:13 AM.
01-10-2007, 07:25 PM
#822
John I have followed your thread closely and I am really impressed by the development of the chassis. I'm gonna have to stop by the track to see it run one of these days. This could be the beginning of long electric car mains. Really promising. Might have to pick up one of those chassis once they become available.
01-10-2007, 08:05 PM
#823
John, I race for Doug Powell and I can say your doing a hell of a job with this car. I see the future of touring going this way.
Its like your taking the pancar in the direction it should have gone. This car is simple, light, and durable. I have been a supporter of bring back the pancar, even keeping track of the Japanese market where they run the direct drive touring cars.
Also There is a company out there that makes an independant front end to race on velodromes for pancars! Hope this helps with Ideas.
I would like to see manufactures follow this thread because I truley see this as the future of onroad.
John one more thing I like to see you try the car with touring car type rubber tire's. It may also give you better traction on the unpreped track you guys race on.
Here is a pic of the dna front end.
Its like your taking the pancar in the direction it should have gone. This car is simple, light, and durable. I have been a supporter of bring back the pancar, even keeping track of the Japanese market where they run the direct drive touring cars.
Also There is a company out there that makes an independant front end to race on velodromes for pancars! Hope this helps with Ideas.
I would like to see manufactures follow this thread because I truley see this as the future of onroad.
John one more thing I like to see you try the car with touring car type rubber tire's. It may also give you better traction on the unpreped track you guys race on.
Here is a pic of the dna front end.
01-10-2007, 09:09 PM
#824
Personally I'd like to see the old HPI independant front end come back with some modifications.