R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 01-09-2008, 10:55 PM   #1
Tech Elite
 
Bob-Stormer's Avatar
 
Join Date: Dec 2001
Location: Glasgow, Montana USA
Posts: 3,518
Trader Rating: 8 (100%+)
Default enough chit chat. compared, Mabuchi, 21.5, 19turn and 8.5

There's a few threads floating around with people talking maybe this is good, perhaps this works, but a lot of them haven't tried the crazy stuff, or the facility to do it accurately.

I'd like to see a serious wheel like Cyrul, Toso, Blackstock, or Rott, do the same testing. everybody has an ability level, and when you cross it, the laps could likely be better. But as long as you're turning faster laps with little or no error every time you step up the motor, you're getting good results.

The other real problem is those guys really need to work on race setups, they have responsibilities to sponsors. I don't. If I want to spend all weekend rolling out a mabuchi motor, I do it. I suppose it's my idea of hitting a high score on a video game.

Here is what was tested.
Mabuchi stock motor
Novak 21.5
Money 19turn
Novak 8.5

This was 1/12th scale 4 cell on our test track. Track is small, 24x48 crc carpet.

I don't claim to be a major wheel, but I'm no slouch. But here's what qualifies this as reasonably useful information. We change the track for fun, but when we test, it's always the same track, and we convert it back. This is no joke. I have (and you can track it in RC scoring pro) just short of 30,000 test laps on this track. That's about 400 packs on the same exact track layout under the same circumstances. Giving me a fairly decent gauge of performance. These are all done solo. I won't test with another car on the track. That doesn't even include cars we just mess around with on the same layout. I want the best result to shine through. Anybody that follows my ideas on (error factor), knows these are INSANE correction numbers. Don't take that to mean that I'm a racing guru. What that means is that I have absolutely mastered our test track. This was no weekend of mastery. It's about 12 months worth of only driving this exact layout. over and over and OVER. To the point where I can see and test very small things and get a good result from lap times, and consistency.

Without over explaining this, here is what I found on our track. I have very consistent packs to test with. and this assumes I've got the car as good as it can be, given each situation.

Run time: For fun, when I'm testing stuff, I listen for the fastest lap, and wait until the car is doing about 1 second slower than that, and that's when I stop driving the car, and it's usually the end of the pack anyway, maybe a smidge past. So as an example a car that maxes at 7.2 seconds, I stop running laps at 8.2 seconds. But experience has shown, it's a very good spot to stop for testing.

Error is the difference between the best lap the package will do, and the average top 20 laps done with the car on that pack. If the package is good for a 7.2 and the average top 20 is 7.65, the "error" is (.465) and this can be used to gauge driver error, and accuracy of the test.

Here is a thread on (error factor) that I started, to further explain it.
http://www.rctech.net/forum/showthread.php?t=199909

Silver can Mabuchi, This was done last year on 3300's to test endurance racing. I'm going to run this again on 4200's, I suspect there will be some improvement from voltage but typically a mabuchi is like a 35 watt motor and really can't put out much over say 15 amps. Likely will get hotter faster with maybe a 1/10th or two for speed increase... maybe.
RO 49.3, fastest 7.845, (error .078) runtime 17 minutes. temp 115 degrees.
RO 54.4, fastest 7.341, (error .148) runtime 16 minutes. temp 127 degrees.
RO 58.9, fastest 7.219, (error .115) runtime 15 minutes. temp 140 degrees.
RO 60.4, fastest 7.151, (error .078) runtime 15 minutes. temp 154 degrees.

First passes on 21.5 Brushless This was done Yesterday. 450 second 4200mAh practice packs, super fresh match. Firstly, I ran out of gear. to run this motor you need something smaller than a 88 spur and that's with a full size tire (I felt like a noob with it on there)! and, that's on a smaller track. I'm curious where this ends up. but here are the first 3 runs. and I had trouble getting enough drag brake to put the car where I wanted it to go.

run 1) RO 58.5, fastest 6.960, (error .139) run time 23 minutes
run 2) RO 66.8, fastest 6.762, (error .201) run time 19 minutes
run 3) RO 66.8, fastest 6.806, (error .084) run time 20 minutes

Here's some qualifiers for the numbers on the 21.5 runs. First run was an all out guess on rollout, but I got close, based on mabuchi and high wind endurance motor testing I've done in the past.

run 1) Seemed good, but could be faster, 42mm tire. The car is only good for 127 teeth in mesh (that's spur and pinion added to each other). And I didn't have anything smaller than an 88... so am temporarily stuck at a 39/88 and using tire diameters to change roll out. Right now, with these 3 runs, I'm done testing until the smaller spurs get here. VERY uncommon to need spurs under 88.

run 2) Put on a full size yellow rear (48mm) trying to free up the car it worked for about 6 minutes and got me a good maximum potential number/fast lap. and then it got loose (wrong tire for the track). Hence the .201 error. also, pushy entering needs more drag brake.

run 3) back to magenta rears, car was excellent. Added max drag brake, and it helped, but not enough. The car just rolls and rolls. Front left tire was down to the plastic (thought I had enough left for the run). Car started pushing at about 15 minutes which is why it ran for about a minute longer, less amp draw. Had the front tires held up. I'm guessing it would have shaved the runtime about 2 minutes, down to 18 minutes. Car actually felt very raceworthy. You had to have your head in the game. I was a bit surprised.

run 4) I can't wait to get the RO up around 70-80mm and see where this leads. Car set up will be important these motors want to roll.

19turn Money
after some tuning, fell here:
run 1) RO 34.3, fastest 6.495, (error .107) runtime 11:30
run 2) RO 34.3, fastest 6.483, (error .127) runtime 11:30

Trying to knock down a single fast lap hurt the consistency of the second run.

8.5 brushless testing.
Sphere 80500 set up, 2-3-2-2
after some tuning (4 or 5 test Roll out packs) here is where it ended up.
run 1) RO 38.5, fastest 6.225, (error .068) run time 13 minutes
run 2) RO 38.5, fastest 6.110, (error .111) run time 11 minutes

Run 1) was good, but the car felt "bound" worked the diff over for run 2, cleaned the king pins, car was a bit more aggressive.

I want to do the mabuchi testing again though.

But fun information. I don't know about offroad, but 21.5 is a legitimate /12th motor. I'd race the class. The racing would be excellent. I still like the silver can for the noobs, based on pricepoint.

More to come. Doesn't mean this is the gospel either. What it means is here is some stuff to look at, rather than, "I think" or "it should". Your results will very.
__________________
www.stormerhobbies.com "Where the world shops for radio control."™
www.facebook.com/stormerhobbies
www.twitter.com/stormerhobbies

looking for....vintage 1/10-1/12 pan, need Schumacher 1/12th cars and parts.

Last edited by Bob-Stormer; 01-09-2008 at 11:21 PM.
Bob-Stormer is offline   Reply With Quote
Old 01-09-2008, 11:28 PM   #2
Tech Elite
 
Bob-Stormer's Avatar
 
Join Date: Dec 2001
Location: Glasgow, Montana USA
Posts: 3,518
Trader Rating: 8 (100%+)
Default In a nutshell.

My testing, so far, in a nutshell.

66/8:04, 7.151 fast lap (error .078), Silver can Mabuchi,
69/8:02, 6.806 fast lap (error .084), 21.5 Brushless,
72/8:02, 6.483 fast lap (error .127), 19 turn Money
77/8:05, 6.110 fast lap (error .111), 8.5 brushless
__________________
www.stormerhobbies.com "Where the world shops for radio control."™
www.facebook.com/stormerhobbies
www.twitter.com/stormerhobbies

looking for....vintage 1/10-1/12 pan, need Schumacher 1/12th cars and parts.

Last edited by Bob-Stormer; 01-10-2008 at 12:40 AM.
Bob-Stormer is offline   Reply With Quote
Old 01-09-2008, 11:29 PM   #3
Tech Addict
 
gubbs3's Avatar
 
Join Date: Aug 2006
Location: MN
Posts: 619
Trader Rating: 7 (100%+)
Default

Bob, I just have to say that is some great testing you have going on there.

One thing that has me thinking, and without a specific tutorial of your purpose, I can only assume this testing is done primarily to compare motors? All else being equal the motor was the primary variable that was changed.

So that brings up the question: So are you going to test a 27 turn brushed motor, and a 13.5/17.5? With the consistency of your test this would be a perfect opportunity to run a comparison.

Lastly, if done as motor comparisons, I would like to see the test done under a race format. Knowing the difference in race times between motors would be very interesting. Something such as if you ran the Mabuchi 67laps in 8:03 and the 19turn 79 in 8:01 and for both of them to have the same consistency value would be pretty cool.
gubbs3 is offline   Reply With Quote
Old 01-09-2008, 11:44 PM   #4
Tech Elite
 
Bob-Stormer's Avatar
 
Join Date: Dec 2001
Location: Glasgow, Montana USA
Posts: 3,518
Trader Rating: 8 (100%+)
Default

Quote:
Originally Posted by gubbs3 View Post
Bob, I just have to say that is some great testing you have going on there.

One thing that has me thinking, and without a specific tutorial of your purpose, I can only assume this testing is done primarily to compare motors? All else being equal the motor was the primary variable that was changed.

So that brings up the question: So are you going to test a 27 turn brushed motor, and a 13.5/17.5? With the consistency of your test this would be a perfect opportunity to run a comparison.

Lastly, if done as motor comparisons, I would like to see the test done under a race format. Knowing the difference in race times between motors would be very interesting. Something such as if you ran the Mabuchi 67laps in 8:03 and the 19turn 79 in 8:01 and for both of them to have the same consistency value would be pretty cool.
Got the race times for you.

You are correct. I'm just testing motors for the sake of it, really. I kind of enjoy it. When people say, this motor is crap or that motor can't possibly be raced, I'm thinking "really?..why don't we find out!". As it relates to carpet, you can race about anything. I'm all about endurance testing too. I think we are ready to start knocking down the 15 min qualifiers and 20 minute mains. I want some track time for my racing dollar. And I'm ready to prove it with numbers, not speculation to anybody that's interested, help their club and keep people on the track!

I could do a 27turn brushed stock. But which one? X, MH, CO, all have their quirks. Last time I raced 27t a month ago I chose an X. time before, C0, time before that was the handouts in Cleveland.

To get an honest result would be a LOT of work. The reason I ran the money, and it's not exactly known as the killers of the 19 turn motors, is because it is known to be a good motor for "just leaving it in the car" if you feel like it. But I treated it like the others. Left it in, ran it.
__________________
www.stormerhobbies.com "Where the world shops for radio control."™
www.facebook.com/stormerhobbies
www.twitter.com/stormerhobbies

looking for....vintage 1/10-1/12 pan, need Schumacher 1/12th cars and parts.
Bob-Stormer is offline   Reply With Quote
Old 01-10-2008, 12:15 AM   #5
Tech Elite
 
SWTour's Avatar
 
Join Date: Sep 2003
Location: Central Coast...CALIF.
Posts: 2,873
Trader Rating: 9 (100%+)
Default

Quote:
I'm just testing motors for the sake of it, really. I kind of enjoy it. When people say, this motor is crap or that motor can't possibly be raced, I'm thinking "really?..why don't we find out!".
Bob,

Glad to see you doing this testing...

I was involved in testing the 17.5, 21.5 and 25.5 motors most of last season...and we had a multitude of very good drivers do the driving. (For Oval)

Not only that, but we put these motors in race winning cars, and mixed them into classes to see how the actually reacted under RACE CONDITIONS on a track prepped and race ready.

When we found most of the data we were looking for - well, we tested in some areas we weren't looking for too, just to have that data as well.

YOU THINK 21.5 was hard to find a roll out for - try a 25.5 YIKES

We are running a 76 spur on the 21.5's with LIPO batteries on the BIG track - I think (if I remember w/o notes in front of me) that we ran either a 88 or 96 on the short tracks. (With pinions in excess of 50)

Personally, being involved in testing almost ALL year last year...I'm really looking forward to the actual RACING of these classes in '08.
__________________
Joe Myers
R/C Racing since 1985 ~ Santa Maria, CA (Central Coast)
2001-2012 - South-West Tour R/C Oval Series...will the SWT be revived?
Things are headed towards a return of the SWT Series, but for
2017 the focus will be on the Encino Velodrome (and dirt oval racing)
SWTour is offline   Reply With Quote
Old 01-10-2008, 12:27 AM   #6
Tech Elite
 
Bob-Stormer's Avatar
 
Join Date: Dec 2001
Location: Glasgow, Montana USA
Posts: 3,518
Trader Rating: 8 (100%+)
Default

Quote:
Originally Posted by SWTour View Post
Personally, being involved in testing almost ALL year last year...I'm really looking forward to the actual RACING of these classes in '08.
I think I've read some of your posts. You seem to have some excellent information as well. I enjoy oval, but we don't get to do it as often. So I'm curious where that all works out too.

As Dawn mentioned in the ROAR brushless thread, they're really trying to iron out classes for the big events, and encourage clubs to do what does the best for them.

All any of us have is our experiences and thoughts. And it's hard not to pick your favorite motor and wave it's flag as THE ONE.

Time will tell on that one. But I can tell you, I like this little 21.5, so I'm guessing I'll also be happy with the 17.5
__________________
www.stormerhobbies.com "Where the world shops for radio control."™
www.facebook.com/stormerhobbies
www.twitter.com/stormerhobbies

looking for....vintage 1/10-1/12 pan, need Schumacher 1/12th cars and parts.
Bob-Stormer is offline   Reply With Quote
Old 01-10-2008, 03:05 AM   #7
Tech Champion
 
Join Date: Nov 2001
Location: Hawaii, USA
Posts: 7,185
Default

We've done some very limited testing with 17.5 vs Sport Tuned Mabuchi on our 60' by 60' track and found the times very close so long as we limited the gear ratio on the BL system. I've been wanting to try 18.5 and 21.5 but none of the guys seem to have them to test with...maybe in the near future. For now the motors are approved for testing only in my race and do not score points in the series.

With the price of brushed ESCs coming down so low now that Tamiya is including them in their M03 kits and BL being approved in some of the TCS classes I don't think it is going to be much longer before we see Tamiya coming out with a Mabuchi BL equivalent and including it with their kits. When this happens this will be a major change in the industry.
InspGadgt is offline   Reply With Quote
Old 01-10-2008, 11:34 AM   #8
Tech Regular
 
JevUK's Avatar
 
Join Date: May 2005
Location: Dover, UK
Posts: 310
Default

Quote:
Originally Posted by InspGadgt View Post
With the price of brushed ESCs coming down so low now that Tamiya is including them in their M03 kits and BL being approved in some of the TCS classes I don't think it is going to be much longer before we see Tamiya coming out with a Mabuchi BL equivalent and including it with their kits. When this happens this will be a major change in the industry.
The only way I can see Tamiya include brushless tech with kits is if a company mass produces an entry level combo by the millions. One obvious solution whould be to have the esc inside the motor.
JevUK is offline   Reply With Quote
Old 01-10-2008, 03:30 PM   #9
Tech Champion
 
Join Date: Nov 2001
Location: Hawaii, USA
Posts: 7,185
Default

Quote:
Originally Posted by JevUK View Post
The only way I can see Tamiya include brushless tech with kits is if a company mass produces an entry level combo by the millions. One obvious solution whould be to have the esc inside the motor.
I never thought I would see Tamiya package a brushed ESC with their kits let alone in kits under $150...but it has happened. All it will take is time for BL to be more mainstream and the cost of the technology to come down.
InspGadgt is offline   Reply With Quote
Old 01-10-2008, 08:16 PM   #10
Tech Champion
 
skypilot's Avatar
 
Join Date: Mar 2007
Posts: 9,524
Trader Rating: 14 (100%+)
Default

good info there sir, a while back, when we used to have a very competitive silver can class at SIR and a very nice flowing layout, (indoor pavement) my fastest and almost perfect run with a silver can, was like 5 seconds slower then my "stock" motor run, both runs were track record runs.

but those days are over, i'm not that good anymore and would have to re-learn to drive like that. (smooth and flowing)
skypilot is offline   Reply With Quote
Old 01-10-2008, 11:31 PM   #11
Tech Fanatic
 
trailranger's Avatar
 
Join Date: Feb 2007
Location: Springfield, MO
Posts: 946
Default

Thanks BOB for all the testing.

Yes the push to slow down cars with higher winding motors leaves little room for gearing.

In 1:12 gearing would be very important. Thank god I have the old "small" D-ring diffs and axles in my parts box. I could run spurs down into the 60's when they start making them for the 99.5T uber slow motors.

21.5, 23.5, 25.5 may be fine for oval racing, but really lets keep the motors turning a little faster and make the 17.5 the lowest. The racers that start off in the really slow classes will outgrow those slow motors so fast that they will need a faster motor by the 3rd heat.

Since we are all stuck on 540 motor size, we have to live with the windings offered to get the power output lower. What if we switched to a smaller motor for classes like the 1:12s. If 1:12's went to lithium they would require even higher windings to keep the speeds down for new racers. Why not in the conversion to lithium start over with a new motor size like the 380's. The cars will require a new chassis design, why not include a new motor pod.
trailranger is offline   Reply With Quote
Old 01-11-2008, 02:53 AM   #12
Tech Elite
 
Bob-Stormer's Avatar
 
Join Date: Dec 2001
Location: Glasgow, Montana USA
Posts: 3,518
Trader Rating: 8 (100%+)
Default

Quote:
Originally Posted by trailranger View Post
21.5, 23.5, 25.5 may be fine for oval racing, but really lets keep the motors turning a little faster and make the 17.5 the lowest. The racers that start off in the really slow classes will outgrow those slow motors so fast that they will need a faster motor by the 3rd heat.
I still haven't gotten enough gear to accurately test the 21.5 against a silver and then a 27t Brushed.

But on just 3 packs, before I ran out of gear, it was already substantially faster than a silver. I'm gonna wager that it ends up just at the level of a 27t brushed motor of CURRENT power. So we really won't have done ourselves any favors... still to fast.

I ran 7 more packs in silver can Mabuchi tonight. for our track, I've hit the wall, we're done, it can't go any further, I have reached the limits of the motor/battery/chassis package. Until I find something on the chassis or tires to make it rotate even harder (it's on the edge of loose now), diff is perfect.

I can't get it any hotter than right at 167-170 degrees, I can't dump it, I can't roll it out any harder than right at 62mm (for our track). And I can't drive it any more accurately. I even tried heating the packs a bit more, say to 140 degrees during peaking, after a run, they still come back, at around 90 degrees. So the cells are capable of massive power and their not being worked. I think when I mentioned the max the motor will do under load is about 15 amps. I think that's accurate. The wall for 4-cell is about 165 degrees for rollout. Roll it out by temperature.

4200, 4600, good pack, practice pack, made little or no difference. And I think the extra 7 grams of weight on the 4600 might have slowed it down just a smidge. Extra weight to haul around and change directions with, and with a motor that's limited to 15 amps, it's of little advantage, except it ran about 150 laps instead of 125 on 42's.
__________________
www.stormerhobbies.com "Where the world shops for radio control."™
www.facebook.com/stormerhobbies
www.twitter.com/stormerhobbies

looking for....vintage 1/10-1/12 pan, need Schumacher 1/12th cars and parts.
Bob-Stormer is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Chit Chat with Brahma Racing BillyCaldwell Electric On-Road 76 08-11-2005 03:24 PM
Xxx-s Slow Compared To Tc3 losi211 Rookie Zone 20 03-11-2005 06:41 PM
Generic Chit Chat with WeelNut Coxy Australian Racing 632 06-23-2004 06:33 AM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:20 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net