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Old 01-10-2012, 06:54 PM   #16
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I have had a good look at this car whilst up at Ardent raceway, and it works really well. Hopefully Paul (the car designer) might pitch up on here and tell us how it works!

Cheers.
Paul Lomas by any chance?

He has been developing this since '07. The idea is to dig out an old concept from the Composite Craft Lynx II and PB Sizzler of having the rear pod move vertically rather than pivoting around the mounting point.

You can see in the underside shot that the back half of the chassis is separate, and it forms a large rear trailing arm that moves up and down pivoting around the aluminium hinge either side of the chassis and held up by the main shock. The upper links means as the lower trailing arm moves up and down the rear pod is kept level and doesn't twist backwards and forwards like a normal pod.

The single lower pivot ball pod fixing lets the pod rock freely from side to side and the side springs are mounted on the cross brace fixed to the pivoting back half of the chassis so they move with the rear pod and work just like a normal link chassis.

The principle is that it takes the motor torque twisting the rear pod out of the suspension action. With a normal chassis under acceleration the motor tries to lift the rear of the chassis as the motor twists the pod as it tries to climb up the spur gear. Conversely under braking the motor pushes down, trying to lift the rear tyres and pressing down on the rear of the chassis. By preventing the pod from twisting up and down the chassis should stay level and the handling more consistent under acceleration and braking. With the links no longer all in a straight line it also means you can tune in anti squat and even add a little bit of rear steering to make it turn in harder or make it more stable through corners.
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Old 01-10-2012, 08:57 PM   #17
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Paul Lomas by any chance?

He has been developing this since '07. The idea is to dig out an old concept from the Composite Craft Lynx II and PB Sizzler of having the rear pod move vertically rather than pivoting around the mounting point.

You can see in the underside shot that the back half of the chassis is separate, and it forms a large rear trailing arm that moves up and down pivoting around the aluminium hinge either side of the chassis and held up by the main shock. The upper links means as the lower trailing arm moves up and down the rear pod is kept level and doesn't twist backwards and forwards like a normal pod.

The single lower pivot ball pod fixing lets the pod rock freely from side to side and the side springs are mounted on the cross brace fixed to the pivoting back half of the chassis so they move with the rear pod and work just like a normal link chassis.

The principle is that it takes the motor torque twisting the rear pod out of the suspension action. With a normal chassis under acceleration the motor tries to lift the rear of the chassis as the motor twists the pod as it tries to climb up the spur gear. Conversely under braking the motor pushes down, trying to lift the rear tyres and pressing down on the rear of the chassis. By preventing the pod from twisting up and down the chassis should stay level and the handling more consistent under acceleration and braking. With the links no longer all in a straight line it also means you can tune in anti squat and even add a little bit of rear steering to make it turn in harder or make it more stable through corners.
The Mugen K2-X(Spirit) is like this also.Its very strange to feel the movement of the rear pod goes up and down but does not twist.
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Old 01-11-2012, 12:44 AM   #18
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Paul Lomas by any chance?

He has been developing this since '07. The idea is to dig out an old concept from the Composite Craft Lynx II and PB Sizzler of having the rear pod move vertically rather than pivoting around the mounting point.

You can see in the underside shot that the back half of the chassis is separate, and it forms a large rear trailing arm that moves up and down pivoting around the aluminium hinge either side of the chassis and held up by the main shock. The upper links means as the lower trailing arm moves up and down the rear pod is kept level and doesn't twist backwards and forwards like a normal pod.

The single lower pivot ball pod fixing lets the pod rock freely from side to side and the side springs are mounted on the cross brace fixed to the pivoting back half of the chassis so they move with the rear pod and work just like a normal link chassis.

The principle is that it takes the motor torque twisting the rear pod out of the suspension action. With a normal chassis under acceleration the motor tries to lift the rear of the chassis as the motor twists the pod as it tries to climb up the spur gear. Conversely under braking the motor pushes down, trying to lift the rear tyres and pressing down on the rear of the chassis. By preventing the pod from twisting up and down the chassis should stay level and the handling more consistent under acceleration and braking. With the links no longer all in a straight line it also means you can tune in anti squat and even add a little bit of rear steering to make it turn in harder or make it more stable through corners.
That's Paul's car alright!

It ended up in two pieces after racing at the club last weekend so he might be busy putting it back together!

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Old 01-26-2012, 04:43 PM   #19
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Yep. Collecting 30 feet of track marker with your back wheel at full chat does tend to pull a car apart! Broke the centre pivot and the winglet where the left link connects to the pod. But I've taken the opportunity to rebuild it with slightly improved geometry and damper tubes instead of the AE shock. The back end is a lot smoother now.

As for weight, its a whole 10 grams over the weight limit. The alloy hinge is overengineered as its only a prototype, and it has 4 front axle bearings in there. I've now realised it will work just as well with 2 if I alter the layout slightly. The top deck can also be slimmed down. The locating points for the top links can eventually be incorporated into the top deck/pod top when I've finalised the geometry. So it will eventually need ballast.


Terry is correct in his explanation. I ran a Lynx II rear end on an Associated Pro10 car years ago, and started planning how to fit it into a 1/12th car 15 years ago! The problem I currently have is that its producing too much rear end grip!


I ran it at Plymouth National last weekend, but had a troublesome time. I lost Saturday after someone drove straight through the car when I was on the startline for round 1 and spent all day sorting out a massive tweak. Then I had to pull out of the event on Sunday due to a numb hand (keyhole surgery in 2 weeks!). I did discover though that by running the links flat, instead of angled down to the front (which gave passive rear steering into a corner) I get even more traction, and even with Magentas all round and full front additive, the front just scrubs wide under power! I reckon it'd be great on asphalt though.


I'll be testing it again at the local(ish) club this weekend, so I'm hoping to get some trouble free running in.
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Old 01-29-2012, 03:50 PM   #20
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Imagine trying to race with the batteries we were using back then. Try running an 8 minute race with only 1400mah batteries, then you need every last ounce of power and motor choice, gear ratio and driving style were all based on reaching the end before dumping, even to the extent of having your car placed on the starting grid in finals so you never had to touch the throttle until the race started.
TRUE. Or to set trim on the car, by hand you gave it a good push down the straightaway, never touching the throttle. Couldn't waste a second. Or when you saw some dude KILLING IT early on, you couldn't wait to see his car stalled on the track at the 6 minute mark.

But the joy of watching a well managed race back in the day. Everybody skillfully using just enough of the trigger, and the cars all slowing down 1-2 seconds a lap toward the end, and finishing perfectly with less than 5 seconds left in the pack. Not even enough juice for one extra lap. PERFECT, and a thing of beauty to watch. You could hear the dump happening, motors changing pitch and noise. It was a thing of beauty. not like the "grip it and rip it" racing we have today with 3-4 minutes of what seems like "Open practice" before a heat starts. Although I must confess to enjoying that.

Do I miss the limping in at the end of a run? Probably not. But I do miss the skill and planning that was inolved. And knowing how and when an opponent was overgeared, and when it was okay to let somebody pass in a main, because you'd see them dead on the track at 7:45. Lot more tactical back then. Much more interesting.

Oh, the irony. Now, motors are so efficient very seldom do I use more than 2000mah out of a 6500mah pack. We should be racing for 20 minutes. (different debate, best left for a thread of it's own.)
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Old 01-29-2012, 07:04 PM   #21
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But the joy of watching a well managed race back in the day. Everybody skillfully using just enough of the trigger, and the cars all slowing down 1-2 seconds a lap toward the end, and finishing perfectly with less than 5 seconds left in the pack. Not even enough juice for one extra lap. PERFECT, and a thing of beauty to watch. You could hear the dump happening, motors changing pitch and noise. It was a thing of beauty. not like the "grip it and rip it" racing we have today with 3-4 minutes of what seems like "Open practice" before a heat starts. Although I must confess to enjoying that.
That was always the fun part of racing--letting the fast guys battle it out and pass them at the end when you have power left because you did not waste it. The fast car did not always have to win nor did the guy who had spent the most money. Plus you did not have to run each lap like you were qualifying. It was all driver and race management/strategy.

We've been running 21.5 1cell 1/12 blinky to try and build the class back up (it was Bob Stormer's idea to do it that way--thanks Bob!). We are all within .2 sec. of each other and the racing is close and fun (4 cars within 3 sec. of each other at the end of the race or even closer). The cars, batteries and motors are all different makes and the only thing that matters is driving. It is very close to the way it used to be.

The fast guys complain that it is too slow. But the racing is close and guys are having fun. That is what it used to be about--fun.

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Old 01-29-2012, 07:16 PM   #22
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We've been running 21.5 1cell 1/12 blinky to try and build the class back up (it was Bob Stormer's idea to do it that way--thanks Bob!). We are all within .2 sec. of each other and the racing is close and fun (4 cars within 3 sec. of each other at the end of the race or even closer). The cars, batteries and motors are all different makes and the only thing that matters is driving. It is very close to the way it used to be.

The fast guys complain that it is too slow. But the racing is close and guys are having fun. That is what it used to be about--fun.

John Kissel
Sweet. I'd say if the fast club guys are complaining it's to slow, it's about right. It's a different mind set. It's not how fast you go, but how you go fast And it's not about low lap times but a better quality of racing.

I don't want to win by 12 laps, I want to win by the skin on my teeth, and have some other car following me within inches and NOT taking me out, or vice versa. Or maybe I lose by a car length, having gained maybe only 12 feet over the course of 8 minutes, but it was just enough and the racing tight and it looked good on the track. Where you lose, because you didn't drive as well as the other guy, not because you missed the speedo setup and went 4 laps down.

We have guys around here that complain about this oval class I wrote the rules for. Well, only one guy complains. But he practices a lot by himself, and in that situation, the car can seem slow. But when you get it on the track with 9 others... NOW it's a race. It's hard to explain. But you can then drive in traffic, not mow them down. And you can run for longer. that's all any of us want too. More track time. I measured it out, a 5500mah pack on our oval dumps in about 5 actual miles of real driving ( or about 19 laps = an actual mile). Kind of fun at the end of a long night, car is shot, full of mud and dirt and you put maybe 40-50 miles on it. ...lol...

By the way, the guy that complains, I always offer to buy him out to keep the peace so he can quit. He hasn't sold out yet. Nor, has he won...(Car is to slow, sure it is).

What kind of run time is your group seeing with the 21.5 blinky stuff?
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Old 01-29-2012, 08:24 PM   #23
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We could easily run 20 minutes plus. There is basically no tire wear and no broken parts or bodies. The rollout window is fairly large too (3.5 in. to 4.0 in.) with a choice of being faster on the straight or in the infield with the same overall lap times. Right now we are sticking with 8 min. races. 8 min. is a long time for the new guys running 1/12. We have 50 to 60 entries on a Friday night (vta, slash, short course open, traxxas rally, 17.5 tc rubber tire and 1/12) and get done late even with keeping things running. We'd love to run longer with 1/12, but with that many entries there is no way right now.

We've had a nice group of guys graduate from the slashes and short course trucks and move on to vta, rally or 1/12 this year. This is the first year we have had growth in the "real" onroad classes.
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Old 01-29-2012, 08:56 PM   #24
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Nice. people know where the fun is. The trick is toss out the crabby people and the people that think it's slow. get 'em outta there.

Last time we actually raced a long run time format is starting to be back there a ways. We ran 34 turn mod motors I had wound (we still stock them, I call them "Dad" motors. Makes dad's life easier when he puts them in a youngsters car) with I think 5 degrees of timing. on 4200 round cells we ran 15 minute qualifiers and 20 minute mains. lap times "just" short, of what the 27 turn dudes did for 8. was fun to see numbers in qualifying like 115 laps compared to 40 or so.

Why we don't just do it, is beyond me. In a club scenario the longest part of the day is ALWAYS waiting for people to get on the stand. It's not the actual track time.
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Old 01-29-2012, 09:24 PM   #25
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Nice. people know where the fun is. The trick is toss out the crabby people and the people that think it's slow. get 'em outta there.

Last time we actually raced a long run time format is starting to be back there a ways. We ran 34 turn mod motors I had wound (we still stock them, I call them "Dad" motors. Makes dad's life easier when he puts them in a youngsters car) with I think 5 degrees of timing. on 4200 round cells we ran 15 minute qualifiers and 20 minute mains. lap times "just" short, of what the 27 turn dudes did for 8. was fun to see numbers in qualifying like 115 laps compared to 40 or so.

Why we don't just do it, is beyond me. In a club scenario the longest part of the day is ALWAYS waiting for people to get on the stand. It's not the actual track time.
I hear you. I have been pushing for longer heats and mains since I started racing 2 years ago. People always complain when we can't fit 3 and a main in every day. We could get alot more racing time in if we just ran longer races and had less down time waiting for the last couple guys to mosey on down to the driver's stand. Even when when it isn't someone being lazy or unprepared holding things up there's always something happening to throw a wrench in getting the race started.
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Old 01-29-2012, 10:53 PM   #26
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I hear you. I have been pushing for longer heats and mains since I started racing 2 years ago. People always complain when we can't fit 3 and a main in every day. We could get alot more racing time in if we just ran longer races and had less down time waiting for the last couple guys to mosey on down to the driver's stand. Even when when it isn't someone being lazy or unprepared holding things up there's always something happening to throw a wrench in getting the race started.
You have to start leaving guys and starting races without them. Even if it's you or I. Makes no difference. People see guys getting left, they're on time the VERY NEXT TIME. every time. One guy misses one heat or 45 guys get twice the track time. It's a no brainer.

When you bring it up as "it's unfair to everybody else" you can kinda guilt them into it a bit.
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Old 01-30-2012, 11:08 AM   #27
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Since our local club went to 10.5 blinky, it is so close it is unreal! 3 out of 4 racers in one heat had exactly the same fastest lap time and there was less than 2 seconds between the top 3 at the end of the 8 minute heat! That was with 3 differant chassis's, 3 differant speedo's and 3 differant makes of motor! It is all about the driving and one mistake costs you a lap!!!
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Old 01-30-2012, 11:37 AM   #28
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Nice. people know where the fun is. The trick is toss out the crabby people and the people that think it's slow. get 'em outta there.
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Old 01-30-2012, 12:51 PM   #29
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We could get alot more racing time in if we just ran longer races and had less down time waiting for the last couple guys to mosey on down to the driver's stand. Even when it isn't someone being lazy or unprepared holding things up there's always something happening to throw a wrench in getting the race started.
I'm with Bob, run the race timing on automatic and only pause it for exceptional circumstances such as track repair. If they knew they had to be ready to go then amazingly they usually manage to be ready.

For our evening racing we have very limited time to get all the racing in, so we actually run with only one minute between race end and the next race start. It might surprise you, but almost all drivers manage to get out in time for every round, all it takes is a bit of forward planning to make sure your car is ready to go at the end of the previous race.

It's a bit selfish of the drivers to expect everyone else to wait until they are ready.
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Old 02-01-2012, 08:18 PM   #30
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Yep. Collecting 30 feet of track marker with your back wheel at full chat does tend to pull a car apart! Broke the centre pivot and the winglet where the left link connects to the pod. But I've taken the opportunity to rebuild it with slightly improved geometry and damper tubes instead of the AE shock. The back end is a lot smoother now.

As for weight, its a whole 10 grams over the weight limit. The alloy hinge is overengineered as its only a prototype, and it has 4 front axle bearings in there. I've now realised it will work just as well with 2 if I alter the layout slightly. The top deck can also be slimmed down. The locating points for the top links can eventually be incorporated into the top deck/pod top when I've finalised the geometry. So it will eventually need ballast.


Terry is correct in his explanation. I ran a Lynx II rear end on an Associated Pro10 car years ago, and started planning how to fit it into a 1/12th car 15 years ago! The problem I currently have is that its producing too much rear end grip!


I ran it at Plymouth National last weekend, but had a troublesome time. I lost Saturday after someone drove straight through the car when I was on the startline for round 1 and spent all day sorting out a massive tweak. Then I had to pull out of the event on Sunday due to a numb hand (keyhole surgery in 2 weeks!). I did discover though that by running the links flat, instead of angled down to the front (which gave passive rear steering into a corner) I get even more traction, and even with Magentas all round and full front additive, the front just scrubs wide under power! I reckon it'd be great on asphalt though.


I'll be testing it again at the local(ish) club this weekend, so I'm hoping to get some trouble free running in.
Terry Rott was working on something similar way back. He used a piece of graphite channel for the chassis and mounted the links to the outside of the "tub". His had no center pivot, like the original Predator. He couldn't find links that didn't get sloppy too fast or broke too easily.
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