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Old 01-10-2007, 10:42 PM   #826
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Thanks for the posts and the interest guys.

SpeedXl-We did discuss the DNA suspension which some of the Velodrome guys use. We could not use a low GTP or LMP body with it as it is quite tall. That's why Marty and I are working up a low front suspension. His might be ready for testing in a couple of weeks.

What I think we are doing with this thread is continuing the development of the pan car. Long electric mains are certainly possible. On an untreated track I think I could run 15 minutes with only one LiPo. With two LiPo's I can run 20 minutes on a treated track and go really fast and only weigh a few ounces over the class minimum.

Christian-good to hear from you. You could even drive the beast. It handles pretty good these days.

If you have a link to a picture of the HPI front suspension, I'll take a look at it. Or maybe Mathijs already showed it to us. Is it a strut front suspension. No thanks.

Marty includes adaptors for rubber tires with some of his kits. With the new 3-link suspension I don't see a need. I got pretty good traction through the dust today. I am pretty happy with the foams, I run purple front pink rears. I don't need to have any other flavors in the bag for different temperatures or track conditions. That sure simplifies things.

John
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Old 01-10-2007, 11:09 PM   #827
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It's an independant front suspension with upper and lower arms. It runs a spring on a kingpin about midway up the lower arm so it uses a conventional type pan car front spring. They used it on the HPI Roadstar and the HPI 10GW and a modified, though less successfull, version on the HPI F1 car. Unfortunately the plastic they used combined with the very long arms of an F1 car made it not work as well as the Tamiya front ends. I'll see if I can find you some pics.
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Old 01-10-2007, 11:14 PM   #828
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Haven't found pics yet but did find the instructions. As you can see it bolts up to the standard AE mounting holes and uses a similar caster adjustment. But both upper and lower arms move. On the F1 version some people modified it to use a pushrod suspension which is a bit more to my liking to keep the body low and it negates a lot of the arm flex due to a softer plastic.

http://www.hpiracing.com/graphics/instr/sm/sm-003.jpg
http://www.hpiracing.com/graphics/instr/sm/sm-004.jpg

*edit*
Found one pic but it's not real good...but with that and the instructions you can get a good idea how it worked.

http://www.hpiracing.com/kits/heritage/rs10gwm.htm

Last edited by InspGadgt; 01-10-2007 at 11:27 PM.
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Old 01-11-2007, 12:43 AM   #829
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Quote:
Originally Posted by John Stranahan
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.
Right! I see it now, on this pic:
http://www.rctech.net/forum/attachme...hmentid=191484

Cool, you can alter anti-squat by altering the angle of the top link! Should be more convenient than having to fiddle with the bottom links.
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Old 01-11-2007, 04:40 AM   #830
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He Speaks the Truth !!!!!!!!!!!!!!!!



Quote:
Originally Posted by speedxl
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.
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Old 01-11-2007, 08:08 AM   #831
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Elvo- the front of the bottom link is very easy to get to as well. Yesterday I added two washers under the rear of the top link to compensate for the new chassis and pod plates.

InspGadgt-I like that HPI suspension. Just needs a shock. I like the fact that the lower arm is longer and goes a bit behind the mounting screws. I intended to do that with mine. Combined with the short upper arm you get a good camber curve. All that is missing is that shock. My front using the stock associated parts does not have enought length difference top to bottom to get much negative camber gain. It has just a very little.

Thanks a lot for those links.

John

Last edited by John Stranahan; 01-16-2007 at 11:30 AM.
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Old 01-11-2007, 09:13 AM   #832
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John, couldn't something like this work?
(See below sketch)

Single suspension arm (carbon plate) with two pivot balls to actuate it.
You could mount a small shock on it. Let it pass through and mount the bottom of the shock on the bottom of the suspension arm. You could mount the upper part of the shock on a simple shock tower.
Put the shock on an angle to keep room for the body.
Use a stack of shimms on the kingpin to adjust ride height.
I think that with today's 1:18th scale offroad front shock this just might work!
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-front-end-sketch.jpg  
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Old 01-11-2007, 10:17 AM   #833
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Mathijs-With the prototype that I have now, the shock reaches full compression when the chassis bottoms. It has a full 6 mm or so of shock travel with bump. That's double or tripple what I currently have. Both of these are good features. You would need a shorter shock than I have available to mount it like your sketch. There would be an improvement by mounting the shock's lower end farther outboard. You could actually have a low shock tower just like the 1/8 scale guys. Without a shock tower, you would have some suspension block flex which I think is beneficial on asphalt. It acts like a flexure. My car with lightened aluminum narrow to wide adaptors (more flex) has just a little more turn in than the powel chassis. Try removing the brace for more turn in.
Your sketch shows a good place for the shock. I assumed you want an upper arm as well. I would, however, much prefer pivot pins over pivot balls. The center pivot ball is what causes me grief with the standard side link suspension. It groans, moans, creaks, wears, and is full of stiction after only a week or two of use. My original Aluminum pivot ball quickly wore .030 inch off the diameter of the ball. I use steel ones now.
I think the 1/8 scale guys have the same problem of suitable shock length and need for good shock travel. You get more travel and can use a longer shock if you mount it in front of the arms like they do. With an inline axle steering block you would also get good steering travel before the wheel rubs the shock. I plan to order a few parts and complete that prototype. I may have to machine an Aluminum Upright to get the steering link to pass through the upper and lower arms properly. I will note that the lower A-arm needs to be solid like your sketch in order to support the shock properly. The end cannot turn like the associated part I am using. I can glue it up solid.

I would actually prefer short pins on the outboard end of my A-arms as well. This is harder for me to prototype quickly.

Last edited by John Stranahan; 01-11-2007 at 10:35 AM.
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Old 01-11-2007, 11:57 AM   #834
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Prototype front suspension.
Here is a second take on the front suspension. I have moved parts a little. The lower arm now pivots behind the suspension block. The shock has great travel. I will have enough steering travel when I get in some inline axles. I have a small pass through for the steering link. I can tinker with roll center a little by shimming the outer ends to different heights on the kingpin. I can adjust camber without affecting roll center unlike our current cars. I can adjust caster in our normal manner. I may have some bump toe out, but a new part will cure that by leaving me more plastic to tunnel through. The lower arm is redrilled and tapped for an Aluminum 8x 32 stud with two locknuts. That's how I extended it the additional 1/2 inch. I can use a longer than Murdoch kingpin now to add more camber control (rigidity) to the wheel and allow more adjustability. I am a little wider than stock. This might be a great way to make a narrow car wide. If I was starting from scratch this could be corrected.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-prototype-front-suspension-ii-resized.jpg   Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-prototype-front-suspension-iib-resized.jpg  

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Old 01-11-2007, 12:47 PM   #835
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I was thinking of a single suspension arm.
here are some examples.
http://international.corally.com/cars/12x.htm
and see below picture

both feature a basic version of damping by using damper fluid on the spring posts.
I think it would be simnple to adept such a design to use a small shock for better adjustability and consistency.
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-matts-yrx2000-001-large.jpg  
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Old 01-11-2007, 12:57 PM   #836
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I think I would still like a freely moving upper A-arm attached to the wheel to better control camber. I see what you are talking about. I see that you could mount a shock to it. I would make it a coil over shock and get rid of the second pin and spring. This is basically a swing axle suspension.

It would be easy to change that suspension to a Flexure front suspension as well.

I added another view of my front suspension just above.
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Old 01-11-2007, 01:02 PM   #837
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John, good work on the prototype front end.
However you know how I like simplicity on these cars LOL.
The sketch I drew up was intended to make use of a 1/18th scale shock absorber. I think it could work.

I'll see if I can get my hands on some of those shocks and see if I can whip up something over the coming months.
You use associated RC18B front shocks right?
What partnumber are those?
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Old 01-11-2007, 01:10 PM   #838
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I edited my previos post a couple of times.

ASC21184 RC18T plastic front shocks. very light indeed.

ASC212116 Blue Aluminum front Shocks RC18 a little more durable with threaded spring seat.

Good luck! I like simplicity as well. I like good performace better. There is nothing complicated about a twin A- arm front suspension. Seems like the type to have on your full size car as well.

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Old 01-11-2007, 01:33 PM   #839
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I haven't read all of this thread, but has anyone tried to run these cars with stock motors? With the blow over issue and traction, shouldn't you have a power system that does not over power the car? If you tried a slower motor even a 12T mod would it make the handling better? These cars are already light, but would it make more sense to not make the car go into warp speed but to make it driveable? I remember the hay day of 1/10 pan and stock class was always fast very fast. Could anyone drive one of these cars with this type of power and really injoy it without all of the modifications being made? Don't get me wrong, what you guys are doing is awsome, and I hope you get others to gain more intrest in this class of racing, I would like to know how one of these cars handles with a stock motor and 4 cell pack.

Thank you
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Old 01-11-2007, 04:10 PM   #840
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They handle great with a stock motor and 4 cells. Little modifications would need to be done. This would suit most touring car tracks very well. On my 1/8 scale track the speed down the straight is a little lazy unless you run a 10 turn in a touring car. There is something quite satisfying about going 60 mph on each lap on the straight in the pan car compared to 45 mph in the touring car. I am not talking about having an overdeveloped suspension full of trickery just a plain old suspension that works just like we drive around with every day. I had upper front A-arms on my 1968 car. I had a four link rear axle on my 1985 car. I am not talking about anything super modern. What is so foreign about having a shock on each wheel.
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