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View Full Version : ABC CRP problem: Turn left when accelerate


ikinari
11-05-2003, 10:19 AM
I have two sets of ABC Crp unit, one on the dtm-x4, one on the mini-z, and I found this prob. on the both two.
That's happens when the run time is ending or when I use some high performance motor, so I guess the diminution of Amp or Volt causes it.
When using a tuned motor, it's serious. With full-charged battery, the car won't go straight as long as you throttle on. The car turns left. It's definitly a crp problem, not the matter of car setting or tyres. You just pick up the car, and throttle on in the air, the car steers left. Too bad, isn't it?
Anyone has the same problem?

fastboy
11-05-2003, 11:58 AM
i would definately say its the voltage thats dropping too low under acceleration,are you using 6 cells or 4?
i assume the miniz is 4 cells,but you should be on 6 cells in the dtm.

you could pop a volt meter across the cells and see what the voltage is like under load when it makes the wheels turn left,the problem is with small cells,they struggle to deliver the amperage a quick motor needs and this may well be the weak link.

you could try hooking the car upto an external pack of larger mah and see if the car does the same,this way you will know its not the cells

good luck
dave

ikinari
11-05-2003, 07:46 PM
Thank you very much, fastboy.
I'll try it later.
Now I use on DTM:
300mAh x 6cells
http://www1.bbiq.jp/ikinari/smallrc/pict/Image2441.jpg
http://www1.bbiq.jp/ikinari/smallrc/dtm_x4.html
and on MINI-Z(not kyosyo, but Auldey):
2100mAh(AA) x 4 cells.
http://www1.bbiq.jp/ikinari/smallrc/pict/Auldey%20mini-z/DSCN2050.jpg
http://www1.bbiq.jp/ikinari/smallrc/auldey_miniz_escmod.html#abccrp

One is 6 cell but small Amperage, the other is large, but only 4 cells. So I'll try 2100mAh x 6 external supply for testing the CRP...:rolleyes:

fastboy
11-06-2003, 04:32 AM
i have a dtm-x4 myself but i use mini-x electronics in it with a 7.4v 880mah li-poly and 180 motor and everything works great,hop e you get yours sorted ok.

dave

ikinari
11-07-2003, 03:47 AM
fastboy, thanks for encouraging words!

I tried 6 cells of 2100mAh AAA on the ABC crp.
The test is just to throttle-on in the air.
The result varied for motors.

Result:
Plasma Dash : the same problem(steers left) appeared.
PN Racing S-03 motor: less appeared.
Core midified motor: hardly appeared.
Stock 130 motor: no problem.

So it seems to be a problem of the current draw.
The large curernt causes the servo trouble.
fastboy, I assume you use the "stock" 180 motor, right?
And that's why you dont face the problem, I guess.

But, I still wonder:
According to the specification note, the ABC crp should be able to take 60A continuous, 240A in peak.
But the Plasma Dash requires just 4.1A even ON LOAD. It's relatively small enough for the crp, isn't it? Why such a problem occurs?
In addition, the test above is done without any load. When the car runs on the ground, the current draw will be more, so the problem will appear more clearly...:mad:

fastboy
11-07-2003, 05:02 AM
ok,have you tried a volt meter on the cells while accelerating?
you could also try a volt meter across the servo(red and black lead,be careffull not to short anything tho!! ) to see if the servo is getting the correct voltage under load.

it seems either way there not alot you can do about it,maybe stick some other electrics in it, as i say the mini x stuff works great for me and yes its a stock 180(hpi) and way too fast for a small indoors room,i use it a small playground and its so fast.

good luck
dave

Cian
11-07-2003, 05:50 AM
Third post form the top , as you thought Ikinari , it is a CRP problem...

http://tinyrc.com/forums/showthread.php?s=&threadid=1307

ikinari
11-07-2003, 06:17 AM
Cian, thanks for the info.
I think it's the same problem that gertman faced... I'll return the crp to the ABC.:(

kylelucas
04-12-2004, 10:07 PM
ikinari -

Hello again.

I was wondering if you ever learned more about the ABC CRP problem from ABC directly, and what they might have said?

I have just built my first X4 and installed a 27Mhz ABC CRP with a stock 180, and found the same TURN LEFT issue.

I am just starting to search for solutions online, and believe this might be the only discussion about this problem (even though it's few months old now).

Did you ever discover a fix? Did ABC have any advice for solving this issue?

What motor do you use with the best results in your X4?

Any guidance would be appreciated.

I hope all is well.

Kindest Regards,
Kyle Lucas
kydawg1@yahoo.com

ikinari
04-13-2004, 08:58 PM
Hi Kyle,
unfortunately, nothing updated on my side. I've not even return it to the ABC Hobby.

But I'll try Lithium Polymar soon. If the problem was caused by current draw, the batteries which can discharge more amperage may solve the problem.

potentiality
04-14-2004, 05:44 AM
This may sound funny, but do those higher amp motors have the correct number of capicitors on them? 3 normally.

kylelucas
04-14-2004, 12:05 PM
Ikinari-

I have some of my cars Li Ion powered and I did a quick test and found that the CRP has no issues at all under Li Ion Power. The steering servo has no actuation during acceleration / throttle ON.

I have not ran it on the floor yet (which will draw more current due to motor load), but the bench tests look very promising.

The current packs are too large for a maiden voyage, but I will try to get my hands on some AA sized Li Ion cells and make a pack to fit the X4. I will give another update then.

Best Regards,
Kyle

potentiality
04-22-2004, 08:14 AM
Kyle, something that might help with the lower amp battery packs is a power capacitor. It gives the amperagea little bit of boost under hard throttle..

http://www.rczone.net/modules.php?name=News&file=article&sid=373

kylelucas
04-23-2004, 12:58 AM
potentiality-

Thanks for the info. I will check it out.

The combo of Capacitors and Li Ion or Poly batteries should solve the problem.

It would be shame if these did not, since these cars and CRP units are so nice ..... and quite costly. The small design of this CRP is so perfect for the X4, it would be shame to have to scrap it and have to track down alternatives (ie:Spy, XXL or ES-01).

My best to all.

MicroRCEngineering
05-02-2004, 11:18 PM
Why not just use 1/10th scale electronics, Kyle? I'll post a picture of my DTM SP this week and hopefully, it would be helpful.

kylelucas
05-02-2004, 11:40 PM
There is no room. My SP has twice the room for electronics than my X4 does. Have you seen the real estate available on the DTM-X4? The is no second level and the lower chassis is split with motor and drive shaft.

If you come up with a way, please let me know. Everyone will be interested in knowing.

Best Regards.

MicroRCEngineering
05-02-2004, 11:47 PM
Of course I do. I will post pictures of it this week. This set-up allows me to use the following:

GTP Bodies, All of ABC bodies, for RX-7 with little change in set-up.

As for the DTM X4, I even have 8 cells in that sucker.

This is probably the main reason why ABC DTM cars did not pick up to well in the US. It's too bad, because ABC DTM's and even the Rocket Racers will put any 1/18th scale cars in their place anytime, once it is set-up correctly.

kylelucas
05-03-2004, 12:11 AM
Thanks Micro-

I look forward to learning. An alternative assembly will be very welcome.

ikinari
05-03-2004, 10:55 AM
Hello everyone, I've bought KOKAM Li-Po 7.4v 720mah and installed on my x4. The result on load was good.

The withdrawal capacity of this batt. is 8C. Big discharge seems to have eliminated the problem of ABC Crp.

And the size is perfect, light weight, with no crp problem. So this is what I've long wanted.:D Thank you for everyone, and especially Kyle, you've helped me very much.
http://www1.bbiq.jp/ikinari/smallrc/pict/dtm_x4/DSCN0063.jpg

And I reported it on my website.
http://www1.bbiq.jp/ikinari/smallrc/

MicroRCEngineering
05-03-2004, 08:36 PM
Ikinari,

How does the S03 work with the X4? I would think that the motor will be struggling, since the DTM X4 has a 4wd.

TJFBryant
05-07-2004, 04:51 PM
I know your talking about the space for the DTM X4, but what about the DTM SP?
Can you fit regular 1/10 scale electronics on that Chassis? I have a Futaba RX and Servo that came with my Futaba 2pl. Will these work.

I apologize for the newbie-ish question, The DTM SP I recently purchased is quite a new monster I purchased (I am used to Mini Z's. )
What non expensive but Best Performance electronic setup do you all recommend.
Thanks

TJFBryant
05-07-2004, 05:00 PM
I know your talking about the space for the DTM X4, but what about the DTM SP?
Can you fit regular 1/10 scale electronics on that Chassis? I have a Futaba RX and Servo that came with my Futaba 2pl. Will these work.

I apologize for the newbie-ish question, The DTM SP I recently purchased is quite a new monster I purchased (I am used to Mini Z's. )
What non expensive but Best Performance electronic setup do you all recommend.
Thanks

cdog4w
05-07-2004, 06:05 PM
Funny, I picked up the 2PL too :P Rx is a bit big but will certainly fit. Servo is just too big and a waste of space. Pick up a cheap servo elsewhere, you can probably manage this for <$20 if you look (while same can't be said for the Rx). I picked up an XXL to replace the Rx on my mini-x (glitching at the track I just started going to) but I think I'm going to use that on my SP now. I'll post pics with the new electronics layout when I finish.

As for electronics, most people seem to recommend the spy for ESC, tho I keep hearing really good things about the IPD R18 if you can do without reverse (smaller too). XXL or an old hitec shredder seems to be Rx of choice. Like I said, the Rx that came with the 2PL will work fine. I'm going to try shrinkwrapping mine to see if I can save any space too.

Oh, first thing you should buy is a 180 or larger motor. The 130 that comes with it is crap. I've got a stock HPI 180 in and like it, but I've also got a used Team Orion Core mod motor that I'm eager to try out (after some dremeling to make space). Also heard good things about the GPM modifieds (though tough to find, do a search for them here and theres a link or 2).

TJFBryant
05-07-2004, 06:45 PM
Thanks alot for the reply, its a bog help.
Do you know if you need to Fet the PCB's. AS you know, the Mini-Z Must be Fetted if you want to put a high RPM Mod engine in it.

I ll try my futaba RX for now, with a Novak ESC, and maybe a hitec 55 servo? I dunno. The good part about a car like this is you have a choice.
What battery pack do you use??
THanks alot.

cdog4w
05-07-2004, 08:17 PM
I think the spy is rated up to a 280 sized motor? Check teamnovak.com for specs. R-18 goes a bit higher, check ipdracing.com. Pretty much any aftermarket ESC will easily handle a 180 (tho I hear the ES-01 maybe not).

Hitec 55 should work fine. Most people seem to put the HS-81 or HS-81MG on theirs. I've got a DRR servo on mine.

For batteries I'm using a 6 cell 1/3AA saddle pack that I made. Bought raw cells off batteryspace.com. I'm reconsidering battery choice, but it will also depend on layout and I'm not ready to put any more money down yet.

cdog4w
05-10-2004, 02:04 AM
pics of my electronics layout if you're interested Bryant:

http://tinyrc.com/forums/showthread.php?s=&threadid=19250