Slot machine ad­dic­tion

Australian Muscle Car - - Resurrected -

Ire­mem­ber the first time I heard about run­ningin elec­tric mo­tors by fully im­mers­ing them in wa­ter. It took me straight back to the time I’d de­cided to try to stream­line my morn­ing rit­ual by mak­ing toast while show­er­ing. In­stead, I pre­fer to drop elec­tric mo­tors into a jar of kerosene.It sounds crazy, I know, but run­ning-in slot car mo­tors un­der­wa­ter is a real thing. It works a charm, too, typ­i­cally bring­ing up to a 10 per cent gain in mo­tor rpm – and con­se­quently, in your car’s top speed.

The prin­ci­ple is that run­ning the mo­tor for about one minute in fluid, at very low volt­age (typ­i­cally 3-5V), beds in the spring-loaded brushes against the com­mu­ta­tor – very much like bed­ding-in a set of drum-brake shoes. The liq­uid both pro­vides load on the mo­tor and car­ries away the tiny swarf.

I pre­fer kerosene be­cause it’s eas­ier to clean up af­ter­wards, in terms of avoid­ing cor­ro­sion. The clean-up part – and other tricks – will re­quire that the mo­tor be pulled apart.

If you’re not that com­mit­ted, plenty of gains can still be had with a dry run-in, ei­ther in or out of the car. It’s im­por­tant to do this straight out of the box: once you’ve run the mo­tor at full speed, any man­u­fac­tur­ing im­per­fec­tions will be etched there for eter­nity.

If you’ve got a vari­able-volt­age power sup­ply, you can sim­ply turn the car up­side-down and run it at 3V for about 30 min­utes. Al­ter­na­tively, put the car on your track, el­e­vate the rear tyres, and sticky-tape your hand-con­troller onto a light throt­tle set­ting.

The next level of com­mit­ment is a dry run-in with a proper in­ter­nal clean-up af­ter­wards. Mark the mo­tor’s di­rec­tion of ro­ta­tion first.

Re­move the mo­tor and tape it to some­thing. To cre­ate a load, I pinch a square of mask­ing tape to cre­ate an air-pad­dle. Run the mo­tor at 3V; I’ll run that puppy for half an hour or more.

At this point, it’s the same process for a wet run-in, al­beit mi­nus the pad­dle. In fact, you’ll need to re­move the pin­ion gear, best ac­com­plished with a pin­ion-puller tool (in var­i­ous lev­els of trick­ness, from $10 to $70).

For a wet run-in, place the mo­tor in a small jar and pour in enough wa­ter or kerosene to com­pletely cover it.

Tape the wires to the out­side of the jar, at­tach the al­li­ga­tor clips and run it for five min­utes.

Now the tricky part. Wrap the mo­tor in a towel and shake to help it dry. Bend out the small tab on each side of the mo­tor hous­ing and care­fully slide out the whole giz­zards. You’ll feel a bit like James Bond dis­arm­ing a nu­clear weapon.

SCX-type mo­tors have their brick-shaped brushes held into the plas­tic hous­ing by tiny hair­pin springs, eas­ily dis­en­gaged. When slid­ing the brushes from their tubes, re­mem­ber that you’ll want to put them back in ex­actly as they came out.

The more com­mon Mabuchi-style mo­tors, as used by Scalex­tric, have their brushes at­tached to fine, rocker-type arms. Reach inside the plas­tic hous­ing with a tooth­pick and lift them slightly, to clear a flange at the end of the com­mu­ta­tor. Now slide out the giz­zards.

Wipe down ev­ery­thing with cot­ton-tips and iso­propyl al­co­hol, in­clud­ing the mag­nets inside the can. See the three splits, each at 120 de­grees on the com­mu­ta­tor? Re­mem­ber­ing the di­rec­tion of ro­ta­tion, I run the back of a scalpel care­fully along each lead­ing edge, cre­at­ing a tiny cham­fer. Run a tooth­pick along each chan­nel to clean it out.

After re­assem­bly, I like to leave the mo­tor for another day or two be­fore run­ning it. And it never ceases to amaze me that not only does this work re­ally well, but that it works at all. There

are few mus­cle cars as cel­e­brated as the XB Fal­con hard­top Mad Max In­ter­cep­tor, which will very soon fi­nally reached hobby scale thanks to Scalex­tric (cat­a­logue C3697). Scalex­tric is the only man­u­fac­turer pro­duc­ing the big Ford ‘tu­dors’, in­clud­ing another new ver­sion in Al­lan Mof­fat’s 1978 Bathurst XC (C3741).

Both are avail­able to pre-or­der now. On the other side of the fence, Chevro­let’s 1970 Ca­maro gets another out­ing in the Brut 33 liv­ery (C3612) in which Stu­art Gra­ham won eight rounds of the 1975 Bri­tish Tour­ing Car Cham­pi­onship.

Mean­while, Span­ish out­fit Slot Rac­ing Com­pany will soon rein­tro­duce its Ford Capri 2600, in both bul­ge­guarded RS and blis­ter-guarded LV ver­sions. Per­haps the best known of the liv­er­ies first time around in 2013 were the 1972 Paul Ri­card 6-Hour car of Jackie Ste­wart/Fran­cois Cev­ert (SRC-301) and the 1973 Le Mans mount of John Fitz­patrick/ Hans Heyer (SRC-401).

Those keen to get be­yond the reg­u­lar RTR (ready-to-run) se­lec­tion should take a look at the ex­pand­ing cat­a­logue of Aus­tralian kit mod­els from Ade­laide spe­cial­ist MJK En­gi­neer­ing. To go with their im­pres­sive stain­less-steel chas­sis, wheels, gears and ure­thane tyres, there’s now a range of plas­tic bod­ies in­clud­ing VH Valiant Charger and XW-XY Fal­con GT. Older tin-top fans might pre­fer MJK’s Holden EH and FJ, the Jag Mk2 or Valiant S-Type. Left, top: Trick Slot-it “Boxer” type mo­tor on left (note 24,000rpm at 12V, ver­sus SCX RX-81 16,400rpm Left, below: Reg­u­lar Mabuchi 18,000rpm in front, Scalex­tric Sport ‘FF’ mo­tor (nar­row, long can, for F1 cars and other com­pact fit­ments). FF is avail­able in var­i­ous rpm ver­sions, this green one 25,000rpm. Left in­set: Mabuchi-type Pro-Slot mo­tor 26,000rpm! 1. Mo­tor im­mersed in kerosene in glass jar, wires taped to top so they don’t fall in! 2. When it comes to pin­ion puller tools, var­i­ous types avail­able. The writer has three of them. To re-in­stall pin­ion gear, one also needs a pin­ion press or tools that do both jobs. 3. Mo­tor di­rec­tion is marked with a pen­cil. 4. Stan­dard SCX-type mo­tor, show­ing how the ends of its brushes are ex­posed, mak­ing them re­ally easy to re­move. The red ar­row points to the square end of the brush, which has a ver­ti­cal groove in it. In that sits the end of a spring, which you can see coiled around a post im­me­di­ately below the brush. To the left of the brush is the other end of the spring, held un­der a tab. All you need to do is push that out from un­der the tab, ro­tate it away from the mo­tor, so that the other end of the spring will re­lease the brush. 5. After bend­ing back tabs on side of mo­tor to open can, the gunk is cleaned out. 6. These are the brushes inside the Mabuchi’s end-bell. (Not bell-end). They’re ten­sioned by metal spring-arms that are moulded into the plas­tic. Here the brushes’ inside sur­faces are cleaned. 7. Cop­per-coloured part is the com­mu­ta­tor; the lit­tle black lines in it are from the sides of the brushes wear­ing in against it. 8. It’s im­por­tant to mois­turise. With the back of the scalpel blade, the lead­ing edge of one of the com­mu­ta­tor gaps is scraped. This helps the brushes to slide over it a bit faster. 9. Scrap­ing any gunk out of the com­mu­ta­tor gap with a tooth­pick. Could have found a sharper one. 10. The Mabuchi mo­tor’s brushes. 11. It’s im­por­tant to ma­noeu­vre the brushes out of the way when re­mov­ing the giz­zards and when re­in­stalling so the bear­ing and flange can clear them. 12. Note giz­zards only half-way into end-bell; brushes sit­ting on flange, next step they will seat against the com­mu­ta­tor. 13. Us­ing MB Slot press to re­in­stall the pin­ion gear. 14. A mini-dyno! At 12V, the run-in Mus­tang clocks 24km/h, ver­sus non run-in Ca­maro – iden­ti­cal mo­tor, gear­ing, tyres, etc – which ‘only’ does 22km/h.

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