Some modification on YM34 Type Si

After another week of work, I could go to the RC track to enjoy a Sat afternoon, followed by a enjoyable "movie under stars" program. Weekend is always great.
There was new look on my YM34 Type Si over the past weekend. I made a few modification -
(1) changed to Checkpoint 6x1 motor comm instead of the team Br00d 6x1 comm which is under 7mm in diameter
(2) changed to 48pitch spur and pinion (22/86T)
(3) more importantly, make the upper camber link longer for both front end rear suspension
(4) insert 1mm shim in front and rear wheel hex to widen the track-width
(5) adjust the shims of the front steering arm to make 2mm shim above and 2mm shim below
Chassis is now more stable - a bit too stable and I will have to find more steering in its next track visit.
However, I decided to go for YM34 Type Si2 in my next visit and put my Type Si to rest for a while.
Here I would like to share some pics of my Type Si after the recent modification.

First trial - 6x1 motor on 5cell platform

After a few weeks of fun, my Checkpoint 8x2 comm was down to 7mm and it was time to say "goodbye". In average, I cut comm after ~5 packs of runs, and changed to new brushes after 25-30 packs. I ran the 8x2 comm for about 50-60 packs in the past couple of months.

I have an old Team Br00d 6x1 comm which is around 7.1mm in comm diameter. I replaced it into the 8x2 Checkpoint can, adjusted a bit on the timming to make it around 11amp @2v. Sounded good and powerful !

Changed the final gear ratio on YM34 Si to be around 1:9, tested for another 3 packs before the end of the day on Sat.

With the existing old IB4200 WC battery packs, 8x2 motor can last for about 6-6.5 mins in run time, the 6x1 motor can barely make 5mins !!

During the last pack, I made some mistake and one of the 5cell pack has dropped out from the chassis. Spent sometime on Sunday evening to shrink-wrap the individual cells and re-connect the whole battery pack.

Finally, the new brushes for new Yokomo end bell has arrived the local shop - got a few packs on hand in case I am going to run 6cell stock anytime soon ;)

Rebuilding the differential

After over 60 packs of batteries, it is time to rebuild the real ball differential for my YM34 Si.
The design of the differential is simple, but lack of the most useful D-ring. I used shoe-goo to glue the diffential ring to the hosting and waited for one day, and then applied instant glue to the contact surface again. Surface of the ring has been filed by sand paper.





After fixing the ring on the hosting, I applied Diff Lube from AE on the rings and black grase from AE on the thurst washer/balls.

Finally, stick the differential cover stickers for HPI Cyclone - they are the same size and installed the differential on the chassis again.

Back in home

Due to construction in kitchen, we have moved out from home and stayed in my friend's home in the past few days. Finally, the work is completed and we moved back to home this evening - together with my two bunnies - they were staying with a bunny's expert and separated from us during the construction period.

See - they are more relax now.

Practising at BK track in Singapore over the past weekend

Visited BK track on both Sat and Sun - it is not usual for me to have RC on both day during weekend. Weather was nice on both day, after rain, a bit cooler on the track surface which is great for both the driver and the electronics.

Was running a mid age car - YM34 Type Si, by Team Atlas. Already forget when this car being released, at least 4 years from now. Did not run it a lot in the past few years until I digged it out again and run 5cell mod lately.

The car is equipped with old but reliable ESC - LRP 7.1 ! Yes, the one with large footprint but proven to be a bull - can work with almost any low turn modified motor, take any abuse, under super hot weather ... and yet, still powerful. I used to run 6cell on this car with a Checkpoint 8x2 motor - but found it too fast for me to control, so I downgrade 1 cell to make its speed more acceptable and most importantly, make the chassis more balance and lighter overall.

The chassis weight around 1460g fully loaded, gear at 1:8.09. I managed to run 18 packs of battery over the weekend. I might try to run 1:7.85 next time.

See the little cooling fan I installed for the motor end bell ? It keeps the motor +/- terminals from overheating.