WHEN: Most Friday evenings. TIME: 7:15pm.

05 June 2019

Ecurie Professor throttle controller quick and dirty guide

The excellent Professor controllers have been an Ecurie go to for some years and personal preference has swung to the dual transistor plus heatsink versions, now available from Raceworld in Cape town in fixed sensitivity and brake version:

This guide is for fitting the stage one to stage three adjustment controls - Professor does strongly recommend (no I don't know why not the earlier compact version) this 25 ohm sensitivity potentiometer for these controllers despite the fiddly fit requiring short wires, so I ordered accordingly:

Per Professor: "This pot is used ONLY on the newer version circuit boards that are fitted with or have the capability to have dual transistors installed - That includes controller model numbers PMTR2104, PMTR2106 and PMTR2130 AND may also be used at times in other models." 

This the Professor version brake potentiometer, although one can leave the wire bridge in and externalise with pretty much any after market 5 watt 25 ohm (ish) wirewound potentiometer as I have done on top of the three pin plug in pics below, simply splice in to the "red" brake lead (nicely marked by Raceworld) and leave the brake bridge intact:

Stage 1: Fine for clubbie magnet racing and 1/24 production, the bridges shown in the bottom pic, un-solder for which ever potentiometers you are fitting, that is all that is necessary for this level of racing:

The stage 2 fixed sensitivity average resistor of 8 ohms only needs to be switched for a 4 ohm (between 2 ohm and 5 ohms is fine) if you intend doing 1/32 plastic non magnet racing ala the South Africa series and require a softer bottom end sensitivity - very likely voids warranty.

The resistor cut is to splice in the stage 3 Cranmer Curve 50 ohm preset if you considering doing plastic non magnet racing only - very likely voids warranty.

The pic below illustrates the fiddly fit for the recommended Professor Sensitivity potentiometer - shorten the solder tabs right down and it will fit with a push and turn to locate as shown:

The stage 2 and stage 3 tweaks can be ignored for most clubbie magnet and 1/24 racing, the pics below show the location of the 50 ohm Cranmer Curve pot super glued in and accessible through the controller top. A quick test on the home brew tester and the controller working sweet:

This very crude (but surprisingly effective) Cranmer Curve preset emulates the variable resistance boards used in top end transistor controllers, by changing the final "step" in the resistor chain. Sir Lancelot himself indeed finding it useful in other classes as well.

There we go, a controller for all my racing needs from 1/32 plastic non magnet series right through magnet and on to Falcon and S16D type 1/24 metal racing, as we will encounter at Raceworld. 

21 April 2019

Plastic track rubber tyre pre-scrubber, a first?

The proven method of the tyre preparation for the South Africa non magnet racing series has been lots of plastic track time and benzine or lighter fluid tyre cleaning.

Took us wood track magnet racers quite a while to come to terms with that, compounded by not  having a coastal plastic track to achieve same....

Whilst looking at online tyre saucing machine (not applicable for this game) we challenged local Guru Lance Cranmer to come up with a gizmo that would achieve the same result as the scores of laps and copious tyre cleans a plastic track achieves. Ruaan of Modeltech had kick-started us on to track trued rubber tyres and he too was taken with the same idea.

Lance did just that.....

I collected my neat and solid 3D printed box with lathe trued and ball bearing scuff roller a week ago and was promptly waylaid by hospital visits before I could test drive for this report but am pleased to report that it is an extremely worthwhile nominal investment.

The neat 3D orange box with ball bear bearing scuff roller is mated up to a power source pretty much anywhere from 3.7 volts (single lipo battery) to about 6 volts - I used a RC charger in motor mode in my case, allowing me to experiment with different voltages at 4, 5 and 6 volts.
The unit is taylor made for the popular long Lola LMP Chassis (ignore redundant magnet from wood racing) but can also cater for anything smaller by simply turning in the large plastic bolt till the rear axle aligns over the centre of the scuff roller. Pretty much any pod will do but I was eventually pleased with the inline pod weighted down with the Boxer motor, proving to run cool even at 6 volts. 

A set of N22 (20mm) tyres was carefully fitted on to a 16.5 rim, along with a harder Sideways Prospeed (19mm) tyre on a rim. I had been pre-warned to seat the tyres carefully and that paid significant dividends as the combo ran smooth as a baby's bum from the get go, despite the back ground noise evident in the video. A short run at 5 volts to check for smoothness and then ten minutes at 4 volts with the N22 provided a smooth finish pretty much as promised. 

I then went a bit over the top in experimenting with benzine on a rag and different voltages - the benzine really not required to aid truing as there is zero track dirt to be removed ;-). The tougher soft prospeed proved a longer exercise and three sessions of twenty minutes got me to where I was after.

The part that tickled me most was how the unit auto aligned itself and ran true as a die!

The Prospeed eventual tyre finish immaculate, as can be seen from the pic. The N22 also buffed up glossy and shiny like the fancy tyre cleaners and were carefully put away for track use in due course.
This unit will save time for all racers, including those with tracks, in minimising much trackside tyre preparation :-)