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View Full Version : Eight tips to improve your AM Frequency Mini-z


eztuner12
2009.05.12, 05:52 PM
Hello.

I will like to share with ya all the improvements I have carry out on my AM frequency PCB, in order to improve its performance, thru absolutely removing any steering glittching or any other rare behavior, as well as improving the motor response & power conductivity.

Here is a list of the changes that will have to be executed, in line to accomplish and excellent AM frequency PCB performance;

1. Swap the following wires with PN Racing Mini-Z Motor Wire i-Mac (part # 700207) --Wires that provides the batteries power to the e-board.
-Wires that provides power to the e-board system which are attached to the
wires that provide the batteries power to the e-board thru a couple of screws.
-Swap the servo pot & motor wires with standard hobby servo wires, those that
come in three colors, red, black & white and attached as on cable.

2. Solder a PN Racing High Feq 104 Cap (part # 100501) to the servo motor on the - & + motor poles.

3. Remove the OM small antenna and add a standard R/C antenna wire and calibrate the new antenna by running the car and observing if it has any glitching or interferences. You can cut the antenna wire centimeter by centimeter, until no rare behavior is felt. If you cut too much and some rare behavior appears again take another antenna and cut it to the length the first one was, before it started to behave strange. Use a regular hobby antenna tube with an ATM antenna stand (part # Y-001.
Make a new hole on top of the e-board cover directly above where the new antenna wire was soldered on the board, pass the antenna wire through it and thru the frequency lay down crystal adapter (ATM part#AWD175 or PN Racing part #MA0114) directly to the left side of the ATM antenna stand and make a new hole in the antenna stand left side to pass the antenna wire to the antenna tube. If you can cover the portion of the antenna wire that goes from the board to the antenna stand with a silicone wire cover from another thicker wire, much better yet. The idea is to avoid that the antenna wire goes near any other wires of the car including motor wires & PCB.

4. Disassemble you steering servo and grab the servo Porientimeter, remove the clear plastic cover and spread some electricity conductive grease, I use graphite grease, throughout the area were the Pot wiper runs inside the black Pot case, as well as on the back of the Pot chase where there is a center pin or wiper shaft. Dot limit the amount of conducive grease, but don’t exaggerate too. Place back the Pot clear plastic cover, but make sure this cover rotate free around the front wiper are that goes inserted to the directional servo gear, if need it, enlarge the cover center hole until a free movement is achieved.

5. Place a piece of antistatic paper between the motor, servo are were the power supply wires are attached & the e-board bottom. Also on the top area of the electronic board covering, the big black square resistor near the motor FETs.

6. Soldering a connector to the motor pods on the e-board will provide excellent conductivity, many like to solder the motor wires directly to the pods.

7. A power Capacitor with 5v or 5.5v is recommended in line to maintain an constant stable power voltage to the e. board. I am actually using PM Racing 5.5V 0.22F Power Capacitor (part # 500604) with superb results.

8. If can afford a better Transmitte,r I would certainly recommend you do get one. With a better Tx as Ko propo brand, you will take good advantages of the setting options this one provides and your AM frequency mini-z would definitely perform much better all @.

Well this should be all. I really hope you accomplish the superb performance I have achieved from my AM Frequency MA-010AWD car through the application of this suggested improvements, so that you can enjoy to the max your AM Mini-z.

Thank you for your time.:)

Cheers;)

Felix2010
2009.05.17, 08:40 AM
Eztuner,

Thank you for the write-up. I've used your tips on my MA010's and they do help. I remember reading the thread on here where Tjay was having a hard time getting his MA010 to track straight. You recommended soldering a 104 cap onto the servo motor, and this was the key to solving Tjay's dilemma:)

About the antenna replacement, how long of an antenna do you start with? Right now I have tried both a hobby-grade antenna for one car, and on the other a piece of solid CAT-5 wire soldered directly to the PCB. This did help boost reception power. But I just guessed at what length to use.
Each time I left the antenna pretty-long; Up to 20"+. Then I eventually trimmed the CAT-5 wire down to 27.5cm (Around 10.75 inches). I didn't use any method deciding on the starting length or the final adjusted trimmed-length.

Your help on what length to start with and what length the final trimmed-length (Around-about, on average) should be would be much appreciated! I have an AM- MA010, and also an AD-Band(FM) MA010 : I don't know if there is a difference for the proper antenna lengths for AM and FM bands. For reference the Mini-Z AD-Band frequencies used usually run between around high-24.xxx FM into the 25.xxx for channels. You are familiar I'm sure with the AM-band Mini-Z frequencies.:) In case this info makes a difference also.

Thank you in advance for your help, and also for the info you have already posted.:D

arch2b
2009.05.17, 09:40 AM
there is a very good thread on antennas HERE (http://mini-zracer.com/forums/showthread.php?t=21910&highlight=frequency+antenna+length&page=3).

eztuner12
2009.05.17, 03:38 PM
Hi Felix
I actually cut the OM antenna wire to about 450mm and started from there & ended with 310mm my actual antenna l length
It is "very important" to maintain the Pot clean, as well as, the servo motor too:).

Felix the “xxx” stands for?

Thanks arch2b for the extra input provided.

Thx...
Cheers

PridgeoK
2009.05.26, 12:43 AM
Richard - awesome post! I'm definitely adding these to my notebook. :cool:

A few quick questions:

#4 - Any chance you can post a picture of the POT before/after the mod?

#5 - I'm finding it difficult to tell exactly where you place the antistatic sheets. Is the idea to separate the servo motor and any static it might have built up away from the mini-z PCB above it?

#6 - What kind of connector do you mean on this step? Something like a mini deans plug? If you have a picture of what you do here, that would make it a little clearer. I don't think I'd like to solder the motor wires on since I end up swapping the motor every now & then.

#7 - where would you put the in-line capacitor? Is this to regulate power between the batteries to the board? Is this something that can only be done on the AWD, or can it also be done on the MR-02, do you think?

Thanks a bunch for writing this out, Richard. Definitely appreciated.

Kevin.

eztuner12
2009.05.26, 02:13 AM
Richard - awesome post! I'm definitely adding these to my notebook. :cool:

A few quick questions:

#4 - Any chance you can post a picture of the POT before/after the mod?

#5 - I'm finding it difficult to tell exactly where you place the antistatic sheets. Is the idea to separate the servo motor and any static it might have built up away from the mini-z PCB above it?

#6 - What kind of connector do you mean on this step? Something like a mini deans plug? If you have a picture of what you do here, that would make it a little clearer. I don't think I'd like to solder the motor wires on since I end up swapping the motor every now & then.

#7 - where would you put the in-line capacitor? Is this to regulate power between the batteries to the board? Is this something that can only be done on the AWD, or can it also be done on the MR-02, do you think?

Thanks a bunch for writing this out, Richard. Definitely appreciated.

Kevin.

Hi Kevin
I am actually in Pittsburgh and didn’t bring my mini-z with me so pots of the pot will not be possible. Any ways the mods on the Pot are very simple; only change the original manufacturer wires for the ones that come on the regular hobby servos. Those that come attached as one and colored on red, white & black; if your Pot is a three wires Pot (2 side signal wires and one center power wire) you can use the three regular hobby servo wires as well. If your Pot only has two wires, (one side signal and one center power combined with the other signal) just use two of the three reg-hobby servo wires.

A bout spreading the electric conductive grease just spread it inside the Pot all @ on the back area, move the Pot wiper left to right a few times spread more grease and that’s it. Put some grease to the back side of the Pot too, were you can see a center shaft attach to the center power pin (that comes from the center Pot wire is soldered)

About the clear Pot cover, just make sure it moves free when installed on the pot.

About the antistatic paper. First, you have to assemble the servo guts, place the servo cover and screw-in that one screw on top of the ON/OFF switch. Screw-in the two screws that provide power to the PCB, certainly with the four wires tips in place. Then comes the antistatic paper, which you have to cut about the same size of the PCB and make a cut from one side to the center so that the servo wires can go thru when you slide the paper in from the left side of the PCB and in between the servo cover/motor and the PCB bottom. This paper should cover the servo area and the car motor as well and separate these areas from the PCB bottom.

Yep, mini deans plug it is, see this link http://mini-zracer.com/forums/showthread.php?t=31599

The power Capacitor goes soldered to the positive & negative metal plates where the wires that provide power from the batteries to the PCB are soldered.
See on the top link the Cap placed in front of the frequency crystal and you can see the negative metal plate between the Cap and the PCB cover.
Yes, this PN Racing 5.5V 0.22F Power Capacitor (part # 500604) will indeed provide a constant 5.5v from the batteries to the PCB, so you will accomplish a lineal electrical power thru your receiver. And yes, they work too on the MR-02 cars.

Hope this clear up better your uncertainties,
You are very welcome any time.

BTW maintain your Pot & servo motor clean. As soon you feel your steering is starting to shake. A good key to know your Pot & servo motor is about to need clean-up is when your car won’t go straight on reverse, with frot wheels are centered.

To reduce these two parts from getting dirt, I place some type on the bottom of the chassis over a slot you will see at the center/front near the servo area. It is a small slot.

Again, welcome any time;) & thxxx... for your comments:)
Cheers

ianc
2009.05.26, 02:18 PM
Hi Richard,

Great post!

You forgot step #9 however, so here it is:

9) Remove AM board from car and throw in trash, or sell it to someone who still wants it. Install new 2.4 GHz board.

That's it!

Just kidding of course, but I guarantee this one step will be more effective than all the others... ;)

ianc

Tjay
2009.05.26, 02:25 PM
Almost 95% of my drivers are already converted to ASF. I'm sure there's still folks out there that runs AM band. Thank you Richard for sharing. I'll forward this to those who needs them.

eztuner12
2009.05.26, 03:12 PM
Hi Richard,

Great post!

You forgot step #9 however, so here it is:

9) Remove AM board from car and throw in trash, or sell it to someone who still wants it. Install new 2.4 GHz board.

That's it!

Just kidding of course, but I guarantee this one step will be more effective than all the others... ;)



Hi ianc
Certainly step #9 would be the next, that is, if you still encounter issues with the AM frequency and you have the extra $ to buy a 2.4g. Perhaps buying another AM will be the solution too.
I personally have the $ but still run an AM and still see no need to go into 2.4gs.
In occasion, I have thought to get a 2.4g board and module. But any time I go thru the ASF thread just find myself asking, if I need to go into so much issues in place of having fun and If I have to pay Kyosho so much $ for a cheap tech as the 2.4g? In which sooner than later I will have to buy a new better Tx & 2.4G module. My opinion, too much $ for this little "toy".
With that $ I can buy a new 2,4g helicopter RTF or a "real" R/C racecar.
Just a joke, hehehehehe:):):D. hope you have the good humor as I always do have.

Yep TJ, this in line to help those that are having some kind of issues with the AM If any, complying with the most important part of any forum, shareing and helping:). The servo pointers will help on 2.4G as well;).

Thxxx...;)
Cheers

bermbuster
2009.05.26, 10:24 PM
I just noticed this thread and you have excellent steps. I still many am cars collecting dust and now Im going to do some mods....
With so many running asf now running am will be easier....not too many crystal swaps etc....

eztuner12
2009.05.26, 10:51 PM
I just noticed this thread and you have excellent steps. I still many am cars collecting dust and now Im going to do some mods....
With so many running asf now running am will be easier....not too many crystal swaps etc....

Hi bermbuster.
Yep, good point there, no need to be changing frequency crystals that much.
Thxxx… 4 Ur comment:)
Cheers

bookmarkmaster
2009.09.05, 01:07 AM
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Keywords: High-throughput; NMR; Probe design; Multiple coils; Parallel data acquisition

eztuner12
2009.09.07, 08:55 AM
Can you please be little more clear to those of us we are not very knolage with electronic lenguage???:confused::confused:
Thxxxx

syafiq
2010.07.12, 09:36 AM
Hello.


4. Disassemble you steering servo and grab the servo Porientimeter, remove the clear plastic cover and spread some electricity conductive grease, I use graphite grease, throughout the area were the Pot wiper runs inside the black Pot case, as well as on the back of the Pot chase where there is a center pin or wiper shaft. Dot limit the amount of conducive grease, but don’t exaggerate too. Place back the Pot clear plastic cover, but make sure this cover rotate free around the front wiper are that goes inserted to the directional servo gear, if need it, enlarge the cover center hole until a free movement is achieved.


Cheers;)

can you show how to remove clear plastic cover for the servo Porientimeter. i like a picture of it if possible.

eztuner12
2010.07.12, 03:13 PM
can you show how to remove clear plastic cover for the servo Porientimeter. i like a picture of it if possible.

No pics, sorry.:o
I use an Exacto blade tip, try to introduce the Exacto tip between the POT black case and the clear plastic cover and pop it out.
Hope this helps.
Cheers

syafiq
2010.07.13, 03:12 AM
No pics, sorry.:o
I use an Exacto blade tip, try to introduce the Exacto tip between the POT black case and the clear plastic cover and pop it out.
Hope this helps.
Cheers

then how did you put it back?

eztuner12
2010.07.13, 03:53 AM
then how did you put it back?

Just press the clear cover back into place.

Be sure the POT is centered & aligned with the steering gears as with the steering system, at the time you place the POT back into its place in the chassis area.

Cheers;)

syafiq
2010.07.13, 05:20 AM
Just press the clear cover back into place.

Be sure the POT is centered & aligned with the steering gears as with the steering system, at the time you place the POT back into its place in the chassis area.

Cheers;)

do i need to glue the clear cover?

herman
2010.07.13, 06:48 AM
do i need to glue the clear cover?
no need to glue it... just press it back into place as eztuner mentioned...

eztuner12
2010.07.13, 12:51 PM
no need to glue it... just press it back into place as eztuner mentioned...

“NO” Don’t glue it, as herman said!!!!:eek:
In fact I enlarged de center hole of the clear plastic cover just a bit in line to avoid any binding between the plastic cover and the center pin of the Pot, which I noticed makes some resistant due to some binding between the clear plastic cover and the steering gears case were the pot is placed.
Cheers

syafiq
2010.07.14, 09:20 AM
“NO” Don’t glue it, as herman said!!!!:eek:
In fact I enlarged de center hole of the clear plastic cover just a bit in line to avoid any binding between the plastic cover and the center pin of the Pot, which I noticed makes some resistant due to some binding between the clear plastic cover and the steering gears case were the pot is placed.
Cheers

do you have any tip to make sure i dont crack the plastic cover. because it seem that the potentiometer was never meant to be open.

cowboysir
2010.07.14, 10:22 AM
its a somewhat flexible plastic and the pot is originally assembled so the cover could come off...its a procedure thats done for other scales of servos as well so just be careful yet desicive in using the hobby knife to pry open the pot cover.

The best description i can give you (without pictures of course)is:

1. Hold pot in fingertips of left hand
2. hobby knife in other hand
3. slide blade carefully under cover on one side and pry a bit
4. Work blade around to other side while slowly prying with the knife all the while.
5. This method should slide the pot coer up the pot shaft.
6. Remove and perform maintenance.

eztuner12
2010.07.14, 12:13 PM
do you have any tip to make sure i dont crack the plastic cover. because it seem that the potentiometer was never meant to be open.

If we are talking about a Kyosho Mini-z MA-010 the clear POT cover won’t crack. Just pull open with the tip of a Exacto blade one side, then go to the opposite side and pull too, repeat until you get it completely out. With a 800 or thinner water sand paper you can enlarge the clear plastic cover center hole, by rolling the sand paper to a size it would fit into the cover centre hole, file even just a bit so that the plastic cover fit into the POT center pin and still can be rotate smoothly when you place it back on the POT. Thru enlarging “just a bit” the plastic cover center hole it makes it easier to remove the cover next time you have to clean the pot, plus it will eliminate any bindings when the pot is in action (moving left to right) in its place against the steering gears case.
Hope this helps:)
Cheers

eztuner12
2010.07.14, 12:17 PM
its a somewhat flexible plastic and the pot is originally assembled so the cover could come off...its a procedure thats done for other scales of servos as well so just be careful yet desicive in using the hobby knife to pry open the pot cover.

The best description i can give you (without pictures of course)is:

1. Hold pot in fingertips of left hand
2. hobby knife in other hand
3. slide blade carefully under cover on one side and pry a bit
4. Work blade around to other side while slowly prying with the knife all the while.
5. This method should slide the pot coer up the pot shaft.
6. Remove and perform maintenance.

Great instructions to follow...
Note: When I refer to the POT pin, I am talking about the POT center shaft.