2991Likes1/12 forum
05-29-2008 | 03:25 PM
Tech Master
Joined: Dec 2005
Posts: 1,259
From: Tewkesbury, UK via Plymouth, UK.
I went to the England v USA game at Wembley Stadium last night when I should have been installing the electrics in my new car!
I'm gonna get in all sorted tomorrow and then run it for the first time at the Plymouth club.
I'll let you all know how it goes! Cheers, Chris.
(Oh, and England won 2-0, just to let you know (!))
I'm gonna get in all sorted tomorrow and then run it for the first time at the Plymouth club.
I'll let you all know how it goes! Cheers, Chris.
(Oh, and England won 2-0, just to let you know (!))
05-29-2008 | 03:55 PM
Tech Adept
Joined: Sep 2006
Posts: 236
From: England
Depends on the dampers. The side shocks i've used most have been off an AE 1/18th scale buggy as I've found the damping too heavy on the VCS shocks - too much friction in the seals. Tried the VCS shocks again at my local club the other night and the car was awful. Just finished refitting the Associated ones.
For the side springs I've settled on the AE silver. Ran AE green on the first prototype but there was less leverage with that set up as the shocks were mounted higher. I'd tested the shock set up on a modified L4 (no tweak screws) for 4 months before building the first prototype and tranferred that geometry across. I then lowered everything for the car in the pictures.
Damping wise I switch between 30wt and 40wt oil in the AE shocks. The 40wt still gives lighter damping than the VCS shocks fitted with 20wt oil!
We did some tyre testing a few months back and discovered the car likes a harder rear tyre. Been running Jaco Prisms and it cooks the yellow tyres within 4 minutes and the grip goes off. I just drove round the problem but I'd given the car to Andrew Smith to try and that's when we discovered what was going on. Now run Magentas when the grip is low and switch to Double Pinks as the grip goes up. Always run Double Pinks on the front.
For the side springs I've settled on the AE silver. Ran AE green on the first prototype but there was less leverage with that set up as the shocks were mounted higher. I'd tested the shock set up on a modified L4 (no tweak screws) for 4 months before building the first prototype and tranferred that geometry across. I then lowered everything for the car in the pictures.
Damping wise I switch between 30wt and 40wt oil in the AE shocks. The 40wt still gives lighter damping than the VCS shocks fitted with 20wt oil!
We did some tyre testing a few months back and discovered the car likes a harder rear tyre. Been running Jaco Prisms and it cooks the yellow tyres within 4 minutes and the grip goes off. I just drove round the problem but I'd given the car to Andrew Smith to try and that's when we discovered what was going on. Now run Magentas when the grip is low and switch to Double Pinks as the grip goes up. Always run Double Pinks on the front.
i was going to run the VCS shocks on friday night to give it a go but now i've rmoved then and put the tube dampers back on until i get a chance to get some AE 1/18th shocks.
steve
05-29-2008 | 04:14 PM
Tech Champion
Joined: Nov 2001
Posts: 7,191
From: Hawaii, USA
It works pretty well too with 2nd place overall in the National Championships Sportsman Class (nothing faster than a 12x1) last season. First year back racing after a 15 year break too.
I started on the design back in the early 90's but never progressed with it due to giving up racing and the materials not being available. Carbon fibre was a lot more flexible then. It also looked clumsy with 6-cells in it. I did build a prototype back then but never drove it. Got some pictures somewhere.
Despite it looking like a lot of car it still only weighs in at 830 grams with a PT fitted. If anyone's after a compact pivot ball design I can recommend the centre pivot off the BMI. Couldn't have built the car without them!
I started on the design back in the early 90's but never progressed with it due to giving up racing and the materials not being available. Carbon fibre was a lot more flexible then. It also looked clumsy with 6-cells in it. I did build a prototype back then but never drove it. Got some pictures somewhere.
Despite it looking like a lot of car it still only weighs in at 830 grams with a PT fitted. If anyone's after a compact pivot ball design I can recommend the centre pivot off the BMI. Couldn't have built the car without them!
05-29-2008 | 04:53 PM
Tech Apprentice
Joined: May 2008
Posts: 51
From: Buxton UK
Steve
If you're gonna use the AE 1/18th shocks you'll find this link helpful. The mod takes about 10 minutes a shock.
http://www.rc-oval.com/?p=48
InspGadgt
Funny you should mention 1/10th cars as i first came across this rear suspension on a TRC LynxII Pro10 car. I then built my own (back in the days when i had access to free carbon fibre) and ran it a few times on an empty track before starting on the 1/12th car and giving up racing.
I've managed to build my current car using as many off the shelf parts as possible apart from the carbon fibre. I drew this in Autocad and emailed it to Fibrelyte here in the UK who had the bits done within a few days. My mate turned all the aluminium spacers. The rest is standard. Carpet Ripper pod side plates, Gen-X front (albeit 2mm narrower) AE and Hot Bodies shocks, BMI pivot balls. I've tried to share it around a bit!
Chris
Good luck with the testing.
If you're gonna use the AE 1/18th shocks you'll find this link helpful. The mod takes about 10 minutes a shock.
http://www.rc-oval.com/?p=48
InspGadgt
Funny you should mention 1/10th cars as i first came across this rear suspension on a TRC LynxII Pro10 car. I then built my own (back in the days when i had access to free carbon fibre) and ran it a few times on an empty track before starting on the 1/12th car and giving up racing.
I've managed to build my current car using as many off the shelf parts as possible apart from the carbon fibre. I drew this in Autocad and emailed it to Fibrelyte here in the UK who had the bits done within a few days. My mate turned all the aluminium spacers. The rest is standard. Carpet Ripper pod side plates, Gen-X front (albeit 2mm narrower) AE and Hot Bodies shocks, BMI pivot balls. I've tried to share it around a bit!
Chris
Good luck with the testing.
Last edited by Paul Lomas; 05-29-2008 at 07:04 PM. Reason: Forgot to insert link
05-29-2008 | 04:54 PM
05-29-2008 | 05:27 PM
Tech Champion
Joined: Nov 2001
Posts: 7,191
From: Hawaii, USA
The benefit of the floating rear suspension is in that it generates a lot of rear traction in general.
Paul,
I remember the Lynx...had friends running it. That was a very interesting design but was unfortunately very heavy. I found the PB Sizzler a much cleaner design but it was a pain in the butt to keep all 5 of the links in proper adjustment.
I guess I gotta get my ol Solid Works goin again and start working on mine now with all these new scratch builds inspiring me
Paul,
I remember the Lynx...had friends running it. That was a very interesting design but was unfortunately very heavy. I found the PB Sizzler a much cleaner design but it was a pain in the butt to keep all 5 of the links in proper adjustment.
I guess I gotta get my ol Solid Works goin again and start working on mine now with all these new scratch builds inspiring me
05-29-2008 | 07:02 PM
Tech Apprentice
Joined: May 2008
Posts: 51
From: Buxton UK
I switched it to the Gen-X front after that, which was a lot smoother, and also changed the rear links to angle upwards. This has the rear axle steering into the corner and stabilising the car.
Overall the car turns in much like my L4 did running side shocks. The difference is on exiting the corner as it holds a much tighter line, which is most likely down to the inline cell configuration. Where the L4 would kiss (or sometimes headbutt!) the barriers exiting a corner, this car can run in the middle of the track. It also has great traction which can usually gain me at least one place on the starting grid. Shame I tend to lose it all from being rear ended in the first corner!
05-29-2008 | 07:46 PM
I thought that only happened to me. Thanks for the insight on your car's handeling. I too am running the gen-X on my DB12R and like it very much, it does seem to me that frontend is a bit smoother than the AE.Chris
05-30-2008 | 03:42 AM
if you have never run 1/12 17.5 I'd recommend building up your 76t to 82t spurvand 47t to 53t pinion collection. I have different irs axles for each spur to continue to match rollout with tire wear.
05-30-2008 | 08:05 AM
Pardon me for being dumb about this but I dont exactly understand the "roll out" terms. I know its a combination of Tire diameter, spur, and pinion calculations.
Can it be simplified to just get a gear ratio?
I'm new to 1/12 and will be running the 17.5. My spur is 100, and I think the only pinion that I have at the moment is a 34. We run on asphault and run the tires un cut for wear longevity. I'm not running the pro cut wheels yet. So I have alot of foam out of the box which is a larger tire diameter.
I think my gear only drive is around 2.94. How critical are the "roll out" numbers?
Can it be simplified to just get a gear ratio?
I'm new to 1/12 and will be running the 17.5. My spur is 100, and I think the only pinion that I have at the moment is a 34. We run on asphault and run the tires un cut for wear longevity. I'm not running the pro cut wheels yet. So I have alot of foam out of the box which is a larger tire diameter.
I think my gear only drive is around 2.94. How critical are the "roll out" numbers?