TGIF! Morning coffee with the latest Policar 312 B2

[HomeRacingWorld]

This one seems to be put together a little bit better than the first version. Least the wing foils are not drooping near as bad.

Just did some stock testing, seems to track just fine, although there really isn't much float.









Thanks Slot Car Corner for the service.

Now time to play a little more

[Aptosc6]

I have the previous version and thought it a little jewel. Once you true tires they are fast and handle pretty good too, but, I don't think there is any room left for body float in this car.

[Dogsbody]

FWIW, I find that I don't need as much, if any, body float on wood. If you do need it on an F1 car, try sanding sides of the chassis a bit. Same goes for the pod.

[chrisguyw]

I posted this a while back, and it may help those looking for some tuning ideas........it was a build of the earlier 312B2, but, mechanically it is identical.

Cheers
Chris Walker

The following is my original post..................

I built this for someone whose club has fairly loose rules,..so,....they may or not be usable in your particular club, but, if you can use them, they do help the car considerably

Cheers

Chris Walker


The chassis was straightened, edges sanded for body clearance, silicone washers used between the pod mount/front chassis plate, weight added, rear wheels replaced with the Policar aluminum ones, new trued tyres, the transmission bushings aligned, with "thrust washers" installed, lead wires re routed, and front axle bushings installed to minimize fore aft movement of the axle etc. etc.


The completed chassis......................





The lead wires fouled on the front axle, causing excess front axle friction, and they affected the front axle vertical height..............so,.....a couple of small dia. pieces of styrene tubing were glued to the chassis plate just under the front axle, with the leads routed through.....both problems solved !!

I initially used a reduced dia. axle, and while this helped, it did not fully resolve the issue.......the styrene tubes eliminated the need for this axle,..but, I left in in.

You can see the styrene bits of tubing (white), under the front axle. I did use some lead wire with a thinner coating, as they are more flexible , but, the stock ones work just fine.

You can also see the silicone washers between the pod lug and the front chassis plate....these quiet things down , but, offer a more controlled and progressive torsional flex.






While vertical travel of the front axle is easily and effectively controlled via the top/bottom grub screws......on mine, there was a fair amount of for/aft movement of the axle which create a bit of "steering" at the front end. This oscillation or "steering" of the front axle is not great on the straights....as it cause some wandering which results in excess friction on the sides of the slot, and in corners, it leads to erratic handling.

A few of the commercial track car manufacturers produce some very thin wall axle bushings (3/32 id.) and when I tried them they fit the openings of the front axle uprights on the Ferrari.

The particular bushings I used are from MRSlotcar, but, a few different manufacturers produce them.

A couple of quick strokes with a round file, and the bushing slipped right in......just loose enough to move vertically, to allow for front end axle vertical adjustments for different track, but snug enough to mostly eliminate for /aft axle movement.

Here is the stock front upright...lots of room for axle movement.





The reduced diameter axle bushings on the left.......typical 3/16 x 3/32 oilites on the right.





And popped into the front uprights.....not glued !!






While the gearbox/transmission is a delight, it can be improved, particularly with some thin (.005 thou) washers between any fixed and rotating surface...if two washers are used they will slip against each other instead of the rotating surface grinding against the fixed (stationary one),.....this reduces friction, improves precision, and greatly reduces wear.

Not the easiest to see, but, I have used 2 thin washers between all fixed/rotating surfaces.....you can just make the out between the"stopper" and the axle bushing, and between the final drive spur and the bushing.





While not performance related , I did do some cosmetic stuff........I could not stand looking at Jacky's eyeballs, so I put some clear smoke paint on his visor, took apart the exhausts, and re glued/painted them, a bit of flat/matt varnish on Jacky's suit, a bit of molotow chrome on the susp. bits, and as there were some little holes already in the valve covers, spark plug leads were added.

The wheels were fully painted gold...(they did not have chrome edges) , and front tyres from the Slot-it Alfa T33 were glued/trued/profiled.....these just look a tad more realistic to me.




Plug leads........and a bit semi gloss on the valve covers

I am a bit annoyed at the factory bleed through the roundels, but it is a minor complaint........and really a bonus not to see Jacky's goofy eyeballs anymore.



And a bit of paint on the engine..........

[HomeRacingWorld]

Very good article.

Except...I don't see any vertical movement allowed up front. The brake detail inside the wheel stops any of that. The set screw areas provided are basically useless.



In some cases the inside of the wheeI is rubbing on this detail. I took a file and sanded the assembly so it clears the wheel to make sure it does not make contact.

[chrisguyw]

Hello Harry, a couple of points on your front end comments/concerns

1/ When the front tires are trued (and therefore reduced a tad in diameter) the front axle will run somewhere in the middle of the "oval" holes in the front uprights.

2/ The spacer flange on the spacers I have used provides a slight standoff between the inside of the wheel hub and the outside of the upright, reducing friction/improving precision. (I have done a few without the bushings, but, have used some thin (5 to 10 thou.) spacers to achieve the same result.

3/ If you look at my pic. of the front end with the bushing installed, you will see that the upright has been filed/sanded to improve the allowable vertical axle movement.

4/ The bushing used, have a reduced od. bore, and are small enough to allow them to slide vertically in the front axle "oval" holes, while offering reduced fore/aft movement of the axle.....(these bushings are not glued in).

5/ With these changes, I had no issues in using the grub screws on the front axle to set the front ride height.

I have done several Policar Ferraris for club members/customers with no issues.

Cheers
Chris Walker

[HomeRacingWorld]

I do see the photo. Which is what I was referring to. Unless you sand/file that area of the upright detail, nothing else matters. It will not move.

[Lotus25]

Where did you find the reduced diameter axle bushings? I can't find them anywhere? Thanks.

Tom

[chrisguyw]

Where did you find the reduced diameter axle bushings? I can't find them anywhere? Thanks.

Tom

Hi Tom, Both JK and MRSlotcar offer reduced dia. axle bushings...............I used the MRSlotcar "MR1060" bushings on this and many builds. They are available at many "commercial" tracks/shops.......PCH parts has them in stock.

If you have trouble finding them , let me know, and I will send you some. They are also very good for replacing the "spherical" bushings on Slot-it, Scaleauto etc. motor pods.

Cheers
Chris Walker

[Lotus25]

Hi Tom, Both JK and MRSlotcar offer reduced dia. axle bushings...............I used the MRSlotcar "MR1060" bushings on this and many builds. They are available at many "commercial" tracks/shops.......PCH parts has them in stock.

If you have trouble finding them , let me know, and I will send you some. They are also very good for replacing the "spherical" bushings on Slot-it, Scaleauto etc. motor pods.

Cheers
Chris Walker

Thanks Chris.

Tom