RB5 Gearing and Maintenance Questions

[Kaipaki348]

Hi - great site!!

Just got an RB5, new to rc and want to know about the gearing and set-up. Am running a LRP Eraser 9.5 turn motor, 20t pinion with LRP Sphere Comp TC ESC. The spur is stock (78 I think). Battery is e-power 4500 NiMh run in forward position. I typically run on a loose 1/8th track and find the set-up sheets posted on this site very helpful.

Have a few questions (as am a novice) and would really appreciate any help:
- How do you work out the gear ratios, what do they mean?
- What is the best pinion/spur to run?
- What are the shock spring options (what are the different colours and what do they mean etc)?
- What maintenance do I need to do on the motor?
- How tight should I run the diff, and how noisy should it be?
- How tight should I run the slipper?

Thanks!

[caneye]

1. 20/78 is probably a starting point for your 9.5.
2. brushless is almost maintenance free. i think u can apply a drop of lubricant on the motor oil every few months. that's is all that's required.
3. setting clutch/gear - below tip is from Casper (kyosho usa team driver):

" Setting the slipper/ diff

With the gear cover off and the tires on the car, hold the right tire and the spur gear in your right hand. Then turn the left tire. Look at the slipper nut. If the left tire moves and the slipper nut doesn't your diff is set looser then your slipper. Back off the slipper and or tighten the diff. Repeat this process until the slipper nut turns. Especially with a brand new diff check the for the first couple runs. Once the slipper springs sets future rebuilds should hold a good setting from the get go.

Now that you have protected the diff with the slipper, you need to make sure the slipper is not too loose.

With a fresh battery in the car turn it on. Holding the back two wheels firmly to the table, punch full throttle on the radio. If the slipper is set right the front tires will just come off the table and come back down. Adjust the slipper until this happens. If you tighten the slipper make sure you check to make sure the slipper still give before the diff!!!!!!!

After all that you should be ready to rock and roll. As a starting point on the slipper I run the slipper nut about flush with the end of the top shaft.

It sounds more complicated then it really is. If you always make sure your slipper gives before the diff slips the diff should last a good long time!
"

[Kaipaki348]

Excellent thanks. Any idea on the springs, e.g. what does the different colours and numbers relate to?

[RogerM]

Hi mate ......

I set the diff and slipper in the following way (assumes freshly built diff)

Lock slipper up solid .... usually I use a bit of tube in place of the spring but if you are careful not to damage anything tightening the nut till the spring just goes coil bound will work ok.

I start with the diff loose so that I know I've never over tightened it.

Place the car on the edge of a table so that one wheel hangs over the edge, press the car down, hold the spur with one hand and use your forearm to press the wheel on the table down.

I then tighten the diff up a little at a time till a sharp turn on the free wheel only just makes the diff chirp. At this point, no further, you should find the diff as free as you'd ever want and that it takes a very deffinate effort to make it slip when holding the spur.
If possible drive the car on the street like this for a pack or so and re-check the diff setting as things will have settled.

The next thing I do is replace the spring on the slipper shaft, using a new nut (should have said use an old nut to set the diff as you'll upset the nylock part setting the diff) wind the nut onto the shaft so that it just begins to the thread the nylock section.
I then tighten the nut slightly and recheck the slipper till I get to the point that it takes some effort to set push the spur round with both wheels held ... but not so tight as it feels locked.
From there tune on the track .... usually set the slipper so that it slips just enough not to unload the front wheels on accel from a standing start on the most grippy part of the track.


Gearing questions are really hard to judge without seeing the track and equipment.

I often run a speed passion 9.5T (sintered) on small indoor high grip tracks (liek carpet) geared on 24/76.
My LRP 6.5 (bonded) stays on 20/78 everywhere.
I have just got a Novak 6.5L which I am running on 22/78

When ever I see gearing quoted from the US drivers it always seems several teeth under geared to me. I assume it is something to do with the style of tracks they are running on, my recomendations above are for UK style open, grippy, tracks.

As far as overall ratios are concerned you work them out as follows

Internal ratio of gearbox (2.6:1 on RB5) * (spur / pinion)

so for example, using the Novak 6.5L as a guide

2.6 * (78 / 22) = 2.6 * 3.545 = 9.22:1


With brushless it is advisable to keep an eye on the motor and speedo temp. If the gearing is wildly wrong then they will get too hot. So long as the electronics stay cool and the car still accelerates cleanly "gear 'tup" as Glyn Ward would tell me!!


As far as the springs are concerned I need to finish my spring chart ..... will do very soon.

From softest to hardest .....

rears

#60 Dark Yellow
#65 Yellow
#68 Blue
#70 Silver
#72 Cobalt Blue
#75 Light Green
#80 Dark Green

fronts

#55 Orange / Red
#60 Dark Yellow
#65 Yellow
#70 Silver
#75 Light Green

If you start with Casper's or Ronnie Gardener's set-ups you won't go far wrong on US style tracks. My set-up seems to work on most astroturf / grass tracks I've tried it on so far ...... just move the lower shock mountigns out for carpet and leave the rest alone!

Hope that helps

[Kaipaki348]

Cheers RogerM, that is really helpful. Will be very interested in seeing your spring chart if you are willing to share. Finding out info like that here in New Zealand is a little difficult.