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-   -   Tamiya mini cooper (https://www.rctech.net/forum/electric-road/20068-tamiya-mini-cooper.html)

M05 newbie 07-12-2015 06:49 PM


Originally Posted by Granpa (Post 14091985)
Actually the guy who could answer that the best is Howard Cano. He's an old time oval racer and those guys really knew batteries.

There doesn't seem to be an industry standard on the C rating, so at times can be misleading when comparing different makers.

And if you're planning on a 5700kv motor, buy parts. Lots of extra parts.

Hey Granpa how fast do u think a 5700kv and a 3700kv will get this going lol. Or should I just get the 20t brushed motor sitting in the guys tool box beside me lol

M05 newbie 07-12-2015 06:54 PM


Originally Posted by monkeyracing (Post 14091800)
Begin with the long steering connector rod removed

Make sure your servo is centered, using your radio settings. No trim or sub trim.

Place the servo saver on so it is as close to 90* perpendicular to the servo body as possible, pointed off to the right side of the car.

Set the steering rack so the main cross piece is as centered as possible.

With the servo powered up, so it doesn't move, test fit the connector rod. Did the center rack piece have to move left or right to accommodate it?

If yes, adjust the length of the rod. Re-test

If no, be happy and be sure you're outer steering linkages are equal.

K monkey... I centered the steering servo....adjusted the rack to center. The rod was off about 4 turns...so I squared her up. I was checking the steering play by turning the servo and the main arm that connects from the rod to the rack that pivots on the body with a metal bearing in it....I see a lot of flex and play in that peice. Now I've seen the tamiya arms at 45 bucks....and the 3 racing are at about half that. Is the 3 racing good enough. Regardless for a parking lot car that's all by its lonesome...it's an upgrade. Is there a real quality difference between the 2?

Granpa 07-12-2015 08:09 PM


Originally Posted by M05 newbie (Post 14092050)
Hey Granpa how fast do u think a 5700kv and a 3700kv will get this going lol. Or should I just get the 20t brushed motor sitting in the guys tool box beside me lol

Very. No.

M05 newbie 07-12-2015 08:44 PM


Originally Posted by Granpa (Post 14092195)
Very. No.

Straight to the point lol. Gotcha Granpa. So stick with the plan to save for a brushless w esc and diff. Now I have another goal, this is good. First I have to fix these arms and steering link. Cant have power without control, hurts the wallet pretty bad.

monkeyracing 07-12-2015 09:43 PM

I've been corrected. The connecting rod should be at a right angle to the servo saver. So line up rack, with the rod attached and the servo saver on the other end. Adjust until the rod is at 90* to the servo saver when it is dropped onto the servo.

M05 newbie 07-13-2015 03:51 AM


Originally Posted by monkeyracing (Post 14092309)
I've been corrected. The connecting rod should be at a right angle to the servo saver. So line up rack, with the rod attached and the servo saver on the other end. Adjust until the rod is at 90* to the servo saver when it is dropped onto the servo.

Can u post a pic of that. Because it seems to be perfect now the way you told me. Lol. I didn't drive it yet tho....lunch at work hopefully lol

filippimini 07-13-2015 04:00 AM


Originally Posted by monkeyracing (Post 14092309)
I've been corrected. The connecting rod should be at a right angle to the servo saver. So line up rack, with the rod attached and the servo saver on the other end. Adjust until the rod is at 90* to the servo saver when it is dropped onto the servo.

The reason for this is to do with the arc the servo horn/saver travels through. The arc needs to be the same for both left and right and the only way to achieve this is by having the long steering link at right angles with the servo horn/saver. If the horn/saver is not at right angles there will be a variation in the throw from left to right.

howardcano 07-13-2015 04:13 AM


Originally Posted by monkeyracing (Post 14092004)
A general rule of thumb is lower turns equal faster top end, but with lower torque.

A slight correction: fewer turns = higher RPM AND higher torque. To a first approximation, speed and torque are inversely proportional to the number of turns in the stator (or armature, if the motor is brushed).

filippimini 07-13-2015 04:14 AM

You can further adjust this using the endpoint settings on your transmitter. However, I think it's better to get the mechanical side setup as accurately as possible first.

The amount of throw/steering you have in either direction can be best measured by using a setup station. You could do a simple road test by driving in small circles at slow speed both left and right checking that each direction has the same turning circle, however this method can have other variables impacting the results, such as the diff providing different power to each wheel, different toe settings from left to right or bent components from left to right and front to rear. So really the best method is to use a setup station.

filippimini 07-13-2015 04:17 AM

I should also add that all steering setups should be done with the steering trim, endpoints and dual rates at a neutral setting on the transmitter.

Some more information on setting up steering on your transmitter can be found here. Not all entry lever transmitters have these settings but the principals are good to know and understand.

http://www.rccaraction.com/blog/2013...teering-setup/

filippimini 07-13-2015 04:28 AM

http://www.rccaraction.com/blog/2013...teering-setup/

sakadachi 07-13-2015 04:50 AM

I can almost never get the servo horn to mount perfectly perpendicular due to the splines by design. I need to use subtrim. Luckily most setups require to dial down EPA so no need to lengthen horn to compensate throw on one side.

My M05 also tends to turn more to the right due to unbalance while driving..

filippimini 07-13-2015 05:00 AM


Originally Posted by sakadachi (Post 14092548)
I can almost never get the servo horn to mount perfectly perpendicular due to the splines by design. I need to use subtrim. Luckily most setups require to dial down EPA so no need to lengthen horn to compensate throw on one side.

My M05 also tends to turn more to the right due to unbalance while driving..

You're right. I have also never been able to get it perfect. However if you set the subtrim before you change any other settings it shouldn't effect your throw to either side.

sakadachi 07-13-2015 05:29 AM


Originally Posted by filippimini (Post 14092561)
You're right. I have also never been able to get it perfect. However if you set the subtrim before you change any other settings it shouldn't effect your throw to either side.

Yeah, after placing horn onto the servo I subtrim to perpendicular, then attach the steering linkage too. :)

Tim K 07-13-2015 05:49 AM


Originally Posted by M05 newbie (Post 14092050)
Hey Granpa how fast do u think a 5700kv and a 3700kv will get this going lol. Or should I just get the 20t brushed motor sitting in the guys tool box beside me lol

To give you some idea, the Hobbywing sensorless 13T putting out 3200kv passes the radar at around 40kmh. Perfect for normal r/c track use.
The Hobbywing sensorless 5.5T putting out 6000kv passes the radar at 70kmh.
This is fine if you have a big oval or straight line track, but if you jam the brakes on you will crunch the gears.


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