[MAF]

OK here's one for the tuners out there, I've got my Jaguar MKVII up and running (pictures to follow) and runs quite nicely on scratchbuilt styrene chassis. It's using a Ninco sprung guide which is fully engaged to its full depth in the slot on my SCX compact test track. I'm running at 12V and have only a standard micro scalextric motor in it. Its not fast and I'm not looking for increased speed but the handling seems to be off. It's fine mid corner and corner exit where I can get a nice tail slide on it but on entry to the corners it will just roll over at relatively slow speed compared to the speed I can go through the corner. Any tips for improving which is a rather annoying trait on an otherwise pleasant car to drive?

PS. I'm running no mag, other than those in the motor.

 

[Lloyd.L]

Hi Marlon, your Jag has a light chassis, is relatively narrow and has a high C of G. I get a lot of the same problems on the grippy sections of my track so, to try and make the transition smoother, I round the edges of the rear tyres.

Have you loosened the body screws?

You may also need to add a lttle weight using trial and error, but I usually find that my cars work best without extra weight.

Regards, Lloyd

 

[Lloyd.L]

And I almost forgot. For my own use I always try to cast the upper sections of the resin body thinner tthan the lower parts to try to lower the C of G.

Regards, Lloyd

 

[Julian_Boolean]

Front tyres with LESS grip might help, sounds like a front tyre is gripping and causing the car to tip.

 

[MAF]

Thanks guys, I'll coat the front tyres with nail polish and round off the rears and see if that helps before adding an weight.

 

[356speedster]

How does it behave without the guide spring? A Too strong guide spring could lift the car as it tries to lean over into the front tires at entry.

Narrow cars often need the front wheels as "outriggers" to avoid tipping over at entry, so try to eliminate vertical slop in the front axle and keep the front tires barely touching the track by adjusting the guide height/load with shims or different guide spring strengths.

Weight down low will help, but try to make it run as good as possible before adding any, as it will only mask the real problem.

 

[MAF]

Here's the car in question...

I think I've got it quite nice and low, here's the plasticard chassis...

the front wheels are independent and run in 1/8" brass tubes. I've swapped out the spring in the guide for one that keeps the guide down better, the Ninco one was a bit weak, the new spring doesn't effect the guide ability to swivel, its still nice and free...

the front wheels turn freely and don't snag or rub on the bushings or bodywork.

I thought it would handle better than it does so a bit disappointed with it. I'll check all the points mentioned above and let you know how I get on.

Thanks,

 

[356speedster]

Very long and narrow, but should be great for long power slides once sorted

Looking at the guide, it seems very close to the front panel, have you checked that it turns freely when the spring is fully compressed?

I would also try to replace the spring with a styrene tube to seat the guide and transfer more weight onto the guide, the spring often leaves too much weight on the front tires and if they grip the track at entry it will flip over since it's so narrow.

I think this car wold run better if most of the front-end weight is on the guide (tripod setup), but with coated front tires that barely touch the track to support the car through the turns.

Tore

BTW: it looks great!

 

[MAF]

Perhaps I'm asking too much with the proportions of this car

Guide turns freely but will remove the spring and replace with tube to see if that helps. Tyres barely touch the track with the spring fully extended but perhaps it compresses in the turns and like you say the fronts grab.

 

[Lloyd.L]

That car certainly looks the part Marlon, it's gorgeous! Love the lights, whar lenses are they?

I am sure that you will get the car sorted a bit at a time. Is the body free to move a little in relation to the chassis?

Regards, Lloyd

 

[MAF]

Hi Lloyd, lights are 2mm 'lighthouse' LED's, they have a nice 2mm long nose to them so could stick them right through the bodywork at the rear. The lenses covering the fronts are all from the original diecast. The body screws are a little loose to allow a bit of body movement. I hope I get it sorted, spent far too much time on this one already

 

[Lloyd.L]

Any time spent sorting this one will make all the other ones you have lined up that much easier to do.

Regards, Lloyd

 

[Cjent1]

Beautiful car! Best of luck with tuning. I have nothing to add, these guys are the experts.

 

[pfuetze]

great looking car, Marlon!
coat the front tires, be sure the guide can turn free with the spring compressed (i don´t run springs on my guides, the guide wires add enough force for my feelings).
if the car still loves to barrel roll, you can add little weight under the chassis, in front of the motor or, better on the sides near the motor.
nice and clean chassis work!
what wheels are you using?
did you true the front tires?

 

[MAF]

Hi Peter, I didn't true the fronts

. I coated them last night and loosened off the body screws a touch. It was an improvement but still a bit roll happy so I added some weight, and bit by the guide and two bits on the bracket right under both rear axles. It's much better now and will slide out to its maximum guide rotation before coming off so have the time to adjust speed and stay on. Much more pleasant to drive.

Wheels and tyres are Penelope Pitlane type 'CB' with resin inserts I made from the wheels off the die cast.

 

[SlotSquatch]

Ill handling or not...amazing work on that Jag! Really enjoyed seeing it!

 

[jhrico]

beautiful car!
about the handling, is the guide to thick for the scx compact track? or maybe too long? it sounds like it is finding resistance at the very entrance of the curve. maybe wedging the tip to make it thinner will help? if the guide is too long it may be finding too much resistance on the sides given the radius of the curve. have you tried with an scx compact guide?
cheers

 

[MAF]

Thanks for the kind words guys

jhrico, that's a good point and one I haven't considered I'll have to watch out for that when I build my track as some of the turns will be tighter than the scx track.

 

[Datto]

Lovely car, Marlon! Sounds like you're getting it sorted bit by bit. Pfeutze has been using HO slide guides for many of his 1/43 cars I believe. They'd be small enough to handle the tightest curves I imagine. Instead of braid, they use trimmed motor lead wire as pickups, and don't try to lift the front end as much. Something to consider for future chassis.