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Discussion Starter · #1 ·
I never get tired of building Ferrari 312 P coupes, this being my fifth. I like trying different motors and layout so this'll be an inline slimline motor for our club's Speedway 95' track with a 20 foot main straightaway and banked corner.

Starting off with my tried and true adjust-o-wheelbase inline motor chassis.

The usual components were gathered and include,

  • main rails and front axle tube support- 3/32" square brass tube
  • guide tongue - .062" x 3/4" brass strip
  • guide tube - 5/32" brass tube bored with 9/64" bit to accept Slot Plus Universal 7mm deep guide
  • guide tongue sliders - 1/16" piano wire
  • motor pod support cross members - .062" x 1/4" brass strip
  • front axle tube - 1/8" brass tube
  • side pans - .032" x 1/2" brass strip
  • side pan flex supports - .032" piano wire
  • motor pod - my own 3D printed slimline pod with Parma/Champion 3/32" x 3/16" axle oilites glued and epoxied in

Drive train includes,

  • Professor Motor PMTR 1532 slimline motor, FK050, 35K
  • Slot It 10t pinion and 28t crown gears
  • All Slot F1 rear rims with my own cast urethane tires
  • Slot It 15.8 x 8 plastic rims and urethane copies of the Scalextric Caterham front tires

Heard about the motor from chrisguyw and was curious that it has neo magnets with good braking characteristics.

H



Mounted the resin body, tri-post, my usual practice.



Got the body low.









Weighs in at 87 grams and after painting and installing the vac-formed windscreen and interior driver tray, it'll be over 90.

Hope it performs well on the club's Tanex speedway track.



Dan
 

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Lots to like about that....
Great guide lead dimensions.
maybe you could report on the motor performance once you have run it.
I thought you had it geared too tall.....but what do I know....maybe with those magnets it will have heaps of torque and great braking...???
 

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Discussion Starter · #5 ·
Yes, I'll be commenting on how the car performs. I'm a big fan of the FF050 slimline motor but most have little braking. This new offering from Professor Motor has more powerful neo magnets and by accounts, good braking.

I'm going to test as well, my own urethane shore 30 tires against the new Scale Auto rubber AS25's that some report to be a good alternative to NSR rubber for better performance on wood tracks.

I already know the Scale Auto rubbers out perform urethane as my Ferrari 612 Can Am improved from a fastest lap of 7.43 seconds to 7.27 on Tanex Speedway.



Dan
 

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Discussion Starter · #6 ·
Cosmetics done.

I'm liking Ferraris in yellow these days, so sprayed Tamiya TS-16 Yellow over Tamiya white primer followed by brush details in flat black, flat aluminum and gray and protected with semi-gloss clear. Wheel inserts contrast in Tamiya brush painted X-14 Sky Blue acrylic.















Glued in my so-so vac-formed windscreen that's good enough for me.

My driver figure's going to need trimming to clear the motor.

Fabricated exhaust pipes with 3/32" aluminum tubing, painted white, and conveniently joined to the 3/32" square brass chassis main rails with 1/16" piano wire.

Will test performance on the Tanex Speedway club track with urethane and rubber tires next week.

Dan
 

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Discussion Starter · #9 ·
Tested today on the club's Tanex Speedway today with power set at 10.3 volts. Ran the tighter and shorter inner lane and got a fastest lap of 7.328 seconds. Good results in comparison to my stock Thunder Slot (TS) Lola T70 spyder @ 7.645 seconds and recent scratch built chassis under a TS Lola T70 coupe body @ 7.628.

The taller gearing gave me plenty of speed at the end of the 18 foot straightaway entering the track's banked corner. As well, the motor braking was noticeably better than the coupe's Scalextric Sport 25K slim line motor.

Next test is introducing motor pod movement with the same rear shore 30 urethane tires.

Dan
 

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Discussion Starter · #10 ·
Did some incremental changes and glad to say that I got improvement in my fastest lap.



Incorporated adjustable motor pod movement with M2 nyloc nuts and bolts cushioned by urethane and metal spacers. Yielded a slight improvement from 7.328 to 7.283 seconds.

Then replaced the 28t Slot It crown gear with a 30t one for a 3:1 gear ratio and setting my Slot It controller for maximum braking. Got a real improvement of just over 2/10s with a 7.075 fastest lap.

Pretty pleased with the results.

Next up will be changing to treated rubber tires, either NSR or Scale Auto.

Dan
 

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ParrotGod
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Wow! that is a lot of improvement. I would have thought that increasing the gear ratio would have required to dial down the brakes.
The urethane spacer are between the pod and the chassis?
 

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Discussion Starter · #13 ·
My understanding is that a higher numerical ratio increases acceleration and braking. The latter seemed to be key to the improvement. I could now go further into some corners and then accelerate out.

A future change to a lower tooth pinion from 10t, say to 9t, is an option. Chrisguyw has advised that I can go even lower with the MRSLOTCAR 6t - 8t ones.

Yes, there's a cushioning urethane spacer between the chassis and motor pod. Would have placed one between the motor pod and securing nyloc nut instead of a metal washer but ran out of urethanes. Another feature learned from Chris.



The packing tape across the motor below helps dampen movement too as many have done.

Dan
 

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Thanks. With the urethane shims between the chassis and pod then the COG of the car is even lower, which might have contributed to the improved performance.
 

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Where can I get some urethane spacers? I only use the Slot it, Nsr spacers and 3dp (this last would be of any use?)

Cheers
 

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Discussion Starter · #20 ·
I like how thin the Dart Hobbies one's are. Couldn't really say the benefits (shock absorption, rebound) of different material composition.

As for testing, I've lost access to Tanex Speedway till the fall, but I still wanted to see if there was difference using treated and trued Scale Auto AS25 rubber tires.

The new test track's my own in-progress Land & Sea themed layout. It's quite different from Tanex being tight and twisty with hillclimb-like elevation changes.



With urethanes, I got a fastest lap of 5.65 seconds. The rubbers yielded a slight improvement to 5.60. Not really that much but I think the improvement on the bigger Tanex would have been more significant.

Dan
 
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