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Old 06-24-2007, 08:30 AM   #1501
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pro ten, you mentioned that your new chassis could be "extra" wide.. how wide would that make the front end? 235mm f and 235mm r?
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Old 06-24-2007, 08:52 AM   #1502
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Quote:
Originally Posted by Pro ten Holland View Post
With my motor centered in the rear pod I can now use short-shaft pinions.
This should preserve the motor bearing longer.
Does this mean the motorplate sits a little more to the right and the rear pod maybe is a little wider overall?
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Old 06-24-2007, 10:09 AM   #1503
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The front is 229mm wide, the rear 235mm. Wheelbase is 255mm.
I placed the motor approx 12mm to the right to balance the rear pod and shorten the distance between the motor and the spur.
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Old 06-24-2007, 10:23 AM   #1504
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wow, that is a good bit wider. youcan probably run nitor 235 bodies at that width.. infact, you may have to..
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Old 06-24-2007, 10:45 AM   #1505
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I think you canīt use the narrower bodies like Protoform Nissan or Associated nissan with the wide frontaxle. This means Serpent 962, HB Nissan or Andys Nissan only.
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Old 06-24-2007, 10:49 AM   #1506
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That was the idea.
I have the normal front axle position built in as an option if that proves to handle better.
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Old 06-24-2007, 11:05 AM   #1507
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How much is the difference between wide and narrow front axle?

Iīm not sure how this front brace works. Is this really a dampener?

Overall the car looks very good, especially with that silver carbon.
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Old 06-24-2007, 03:22 PM   #1508
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Mathijs-Be sure and give us a detailed report on the wide front end with wide body. I would like to see if this matches my recent experience with the Parma Lola T530.

Wye vs Delta Wind

Here is a quote from a brushless motor building tutorial. They are buiding AC synchronous motors but the terminology is probably the same. Thank you Don and V12 for pointing this out.

"Wye (AKA star) connection. You take either the beginning 3 ends or ending three ends, twist them
together and solder them. The other three connect to your ESC."

The Novak Motors are wound like this.

As for the other termination,
"Delta is only slightly more complicated. You need to connect the
6 wires thusly: End of phase 3 to start of phase 1, end of phase 1
to start of phase 2, end of phase 2 to start of phase 3."

Note that the Trinity and Mamba motors are wound like this this.

"Ok, if you insist here is the quick and dirty on Delta versus Wye.
Wye uses fewer amps, gives more torque, and uses 1.7 times less
number of turns versus a similar Delta wound motor."

John

Last edited by John Stranahan; 06-25-2007 at 01:35 AM. Reason: Novak motors are Wye wind
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Old 06-24-2007, 03:42 PM   #1509
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Star/Wye vs Delta Wind
If you compare, Delta wind is very similar to what we use in brushed motors. The commutator is just replaced with the electronic switching in the ESC.
From what I know the more advanced boat and airplane BL motors usually are delta wound.
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Old 06-24-2007, 06:39 PM   #1510
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Thunder Power 3800 2s1p cell
Thuderpower Extreme Series
This cell went through my big crash. It seems to be OK after quarantine for 1 day. I put new shrink on it and tidied up the ends. This shrank its long dimension to only 134 mm which is the same as the 4000 Max Amps pack on the bottom. It will now fit a wider range of RC cars.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-thunder-power-cell-after-reshrink-resized.jpg  

Last edited by John Stranahan; 06-25-2007 at 01:43 AM.
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Old 06-24-2007, 07:24 PM   #1511
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Quote:
Originally Posted by adamge View Post
John, I should announce that I also discovered my first while-running stutter with the Mamba Max brushless system in my TC. This was after 8 months of not seeing one. The big change is that I just started running asphalt-rubber, whereas the 8 months were on carpet-foam. The stutter occurred at the end of the straight, when I would give a pulse of brake to slow down for the sweeper, then almost immediately apply a little gas to get back to even weight distribution for the sweeper. It did this repeatedly when I used this driving technique. I wonder if this is the same braking issue you are observing.
After speaking with Castle techs about this, they told me and posted that the MAmba MAx ESC will work flawlessly only if you are using high quality LIPO or sub-c cells, due to the amp draw process of the MM. If its a cheap or weak pack it will stutter at times, cogg, etc. I had this issue the first fwe times with the MM, and was running Thunderpower cells, and Maxamps cells..and it'll stutter on ocasion. So I switched to the Orion Lipo cells, and its been stutter free for over 6 months now...Orion 4800 Platinum cells are of the highest quality and the MM seems to agree...

Also, the Novak GTB, since its not LIPO ready, will have the same issues when using Maxamps cells. This was also posted, and again, the Orion Platinum or Peak Racing 4800mah lipos are the ones that work best w/ the GTB so there is no stuttering, coggings, etc...However, the new GTB Spektrum solves these issues, and it can work well with maxamps and thunderpower type packs...
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Old 06-24-2007, 09:28 PM   #1512
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YYhayim-Thanks for the report on what they say. I'll have to disagree a little. Firstly there is nothing special about the Orion pack except that it has more capacity, if you have the 4800 mA-h. It does have a hard case. The Orion voltage (KOKAM, the safer variety) is lower than all the other cells that I have tested. In fact the average voltage after 50 cycles of use on a normal LiPo equals that of the new Orion pack. At this voltage I quit running the cell.

I have run 2 packs in parallel (8000 mA-h) with the Mamba Max. That is more capacity than the Orion. It solved no drivability issues. I find it hard to believe that a stutter that occurs just after light braking on initial throttle application, or a stutter at light part throttle on a delicate corner could be explained by the lack of amperage available at the battery. These are low drain situations.

My current GTB is LiPo ready and has a low voltage LiPo cuttoff. Drivability is indistinguishable from the earlier GTB's. I have also tested the earlier GTB's with 4200 NiMH in the touring car. There were no drivability issues. Only Thermalling issues.

I do agree if you run mod that LIPO is the way to go. Even when ballasted to the same weight as 4200 NiMH, they are faster in the car for the whole run.

I would also say that I have run high quality single LiPo's with the Mamba and it had drivability problems. I would not go off buying new batts to solve this problem. You pretty much will just get used to the little problems and live with them just fine, unless you use brakes. Now azmio uses some brakes with his Mamba but they are turned down pretty far so they would be useless for me.

John

Last edited by John Stranahan; 06-25-2007 at 01:45 AM.
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Old 06-24-2007, 09:40 PM   #1513
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from my experience, the lack of sensor for sensorless brushless system affects mostly during start up from standing still. I am yet to identify any hesitation or drivability problem when the car is moving.

So far, I could not feel any difference between sensor and sensorless once the car is on the move. It's almost the same and almost as smooth as one and another.

With regard to the stuttering when braking. I had that too, but this is a common problem with direct drive pan car or F1. After I finetuned the differential, there was no more funny sound. So, it's not BL system related problem.
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Old 06-24-2007, 09:50 PM   #1514
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azmio-I agree that on some tracks with some drivers the Mamba seems to work well. It favors tracks with high traction, moderate to high throttle. It does not like low traction, neutral to low throttle. It hates tapping the boards and will sit there for an eternity, if you race it, thinking about what to do next. It starts poorly from a stop.

When I drive a Mamba and a GTB back to back in the pan car on my track the difference is more apparent. GTB 70% brakes are usable because they are smooth. This is in the same pan car. Mamba 40% brakes are almost usable. This is only slightly above a normal drag brake setting. There is a spinout every 4 or 5 laps. The driver really does not suck that much at this point. No diff or gear problems.


I was told the Mamba was more heat resistant. I found this to be true.

I was told the Mamaba would run flawlessly, if I changed to the Mamba Motor. I found this to be not true. It runs the Novak Motors exactly the same as the Mamba motors on my track in a pan car.

I was told Mamba motor temperatures were low and lap times were as good or better. I found these not to be true. The Mamba Motor ran 20 degrees hotter. The batteries were overheated insanely with a 3.5R. My lap times are poor because I cannot run 17 clean laps with the Mamba on my track. Stutters generally cause a spin in a pan car, if you are at the limit of traction. I can run this many laps clean with the GTB.

Now I am told that the Mamba will behave if I buy an Orion battery. I don't believe it.

If you have no problems with the Mamba then you have good conditions for it. I do not.
John

Last edited by John Stranahan; 06-24-2007 at 10:10 PM.
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Old 06-24-2007, 09:52 PM   #1515
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John,

For some reason, most of the rc car tracks in the capital of Malaysia have a hairpin right after a long straight. TC cars with spool or differential, brake really well and entered the hairpin smoothly.

I have tried that with 2WD 1/10 and 1/12 pan cars, both have difficulties in reducing speed without losing the rear end. The problem is even worse with sintered rotor.

In this situation, Mamba max programmability really shines as I can put any number that I want for the brake and I can even program the brake curve. Viva castle creations!

Any tips on how you tackle the rear end problem during braking?
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