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Old 08-15-2007, 05:13 AM
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Default speed control with reverse recommendation

Im trying to find a really good speed control for my rc10. I saw a novak rooster for $40 used. Is this a good speed control for the price or are there better ones? Im trying not to go too expensive. Definetly under $100. It must have reverse and at least a 13 turn limit.
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Old 08-15-2007, 06:00 AM
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Originally Posted by berlincam86
Im trying to find a really good speed control for my rc10. I saw a novak rooster for $40 used. Is this a good speed control for the price or are there better ones? Im trying not to go too expensive. Definetly under $100. It must have reverse and at least a 13 turn limit.
I use the Futaba MC330CR .It has reverse and reverse lockout and rated to 13 turns. Its 64.99 from Tower. Its decent and cheap. I havent had any problems with it so far.

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Old 08-15-2007, 06:37 AM
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Thank you anymore recommendations?
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Old 08-15-2007, 06:38 AM
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I've got a number of MC330CR speed controls and they work fine, but do not believe the 13T rating unless you are driving very casually. They overheat and shutdown on when used with 15T motors in a 1/10th off-road buggy.
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Old 08-15-2007, 06:49 AM
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Follow-on regarding reversible speed controls:

I also am looking for a good one and haven't found a good, small one yet. I have a Quantum Pro Reverse that is supposed to be rated down to a 7 turn motor and 120 amps and I ran it this last weekend in a BK2 buggy with a 15 single motor. It shutdown once in each 5 minute heat in spite of having a heatsink on the ESC and a fan blowing on the heatsink. I have a number of Tekin Titans that work great and don't overheat but they are HUGE by today's standards and are no longer made. There is no way that will fit in the BK2 unless I mount it in the center on top of the battery strap.

I might be worth trying the new Novak Rooster 12T with a fan on the heatsink. I just haven't got to that yet.

If you want it for an old RC10, you might have room for the Tekin Titan. You can find them on eBay every now and then for $60 to $80.
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Old 08-15-2007, 07:37 AM
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yes it is a old original rc10. I will look into it but that novak rooster i was talking about is the older version and i was wondering if its any good.
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Old 08-15-2007, 07:59 AM
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look for a Novak Super Rooster (the old one) on ebay, they are indestructible.
http://cgi.ebay.com/Novak-Super-Roos...QQcmdZViewItem
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Old 08-15-2007, 08:04 AM
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The super rooster does look better. I will try to get one. Thanks.
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Old 08-15-2007, 08:43 AM
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I would recommend Novak ESC's. Maybe the rooster or GT7 or even the GTX are very good ESC.
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Old 08-15-2007, 08:54 AM
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Originally Posted by ta_man
Follow-on regarding reversible speed controls:

I also am looking for a good one and haven't found a good, small one yet. I have a Quantum Pro Reverse that is supposed to be rated down to a 7 turn motor and 120 amps and I ran it this last weekend in a BK2 buggy with a 15 single motor. It shutdown once in each 5 minute heat in spite of having a heatsink on the ESC and a fan blowing on the heatsink. I have a number of Tekin Titans that work great and don't overheat but they are HUGE by today's standards and are no longer made. There is no way that will fit in the BK2 unless I mount it in the center on top of the battery strap.

I might be worth trying the new Novak Rooster 12T with a fan on the heatsink. I just haven't got to that yet.

If you want it for an old RC10, you might have room for the Tekin Titan. You can find them on eBay every now and then for $60 to $80.
TA,

How are your soldering skills? De-soldering skills?

I too had the same trouble when I went to the higher discharge rates, low turns, and hot days of massive bashing. My solution was to purchase a couple of the Dynamite Tazer's and modify them. They were the 15 turn models and they too worked lower then rated but would overheat. Great little ESC's for 30 bucks a pop and they included every toy I needed. So I cobbled together some upgrades from Mouser electronics (www.mouser.com) and tossed them in.

Now on one vehicle I run an orion 3200 carbon through a 13x2 and I'm killing the motors before the ESC even breaks a sweat! Of course now I need an endbell fan kit to tolerate my massive abuse The part number you would serach mouser for is 511-STP100NF04 which is a to-220 case style 120 amp MOSFET and 6 of them would be replacing the 6 60 amp MOSFET's that come stock. Note that this definately voids your warranty but I've have zero issues with mine. There are some surface mount goods in the direct vicinity of the work area so you would have to be VERY confident of your skills to make the mods. Just direct swap the MOSFET's in/out with no other changes.

the upgrade mosfets were only $2.37 ea. So for a total of 43 bucks each and a little time, I got a couple killer ESC's for brushed motors. Mod at your own risk.

- Matt
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Old 08-15-2007, 03:14 PM
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Originally Posted by TechWun
TA,

How are your soldering skills? De-soldering skills?

I too had the same trouble when I went to the higher discharge rates, low turns, and hot days of massive bashing. My solution was to purchase a couple of the Dynamite Tazer's and modify them. They were the 15 turn models and they too worked lower then rated but would overheat. Great little ESC's for 30 bucks a pop and they included every toy I needed. So I cobbled together some upgrades from Mouser electronics (www.mouser.com) and tossed them in.

Now on one vehicle I run an orion 3200 carbon through a 13x2 and I'm killing the motors before the ESC even breaks a sweat! Of course now I need an endbell fan kit to tolerate my massive abuse The part number you would serach mouser for is 511-STP100NF04 which is a to-220 case style 120 amp MOSFET and 6 of them would be replacing the 6 60 amp MOSFET's that come stock. Note that this definately voids your warranty but I've have zero issues with mine. There are some surface mount goods in the direct vicinity of the work area so you would have to be VERY confident of your skills to make the mods. Just direct swap the MOSFET's in/out with no other changes.

the upgrade mosfets were only $2.37 ea. So for a total of 43 bucks each and a little time, I got a couple killer ESC's for brushed motors. Mod at your own risk.

- Matt
I am an excellent solderer and have a fine point screw in tip for one of my Weller heaters that I have used on more than one occasion when replacing signal & switch wires on ESCs.

This is an awesome suggestion. My only question now is: how can I find out if the same upgrade is possible on one of my many MC330CRs?

I haven't checked yet, but if there is a part number or the like on the MC330CR mosfets (looks like the same TO-220 package) is it just a matter of seeing if the signal usage on the three terminals is the same? Or what else do I need to know? I would like to try it one one of those. I even have one of the taiwan (or chinese) clones that is dead that I could practice on.

One thing annoying about the MC330CRs is that one of the FETs always seems to installed at a slight cant to the others making it difficult to get a heatsink on them. I could fix that if I was replacing the FETs (I guess even if not) and have a much better ESC.
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Old 08-15-2007, 07:56 PM
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Originally Posted by ta_man
I am an excellent solderer and have a fine point screw in tip for one of my Weller heaters that I have used on more than one occasion when replacing signal & switch wires on ESCs.

This is an awesome suggestion. My only question now is: how can I find out if the same upgrade is possible on one of my many MC330CRs?

I haven't checked yet, but if there is a part number or the like on the MC330CR mosfets (looks like the same TO-220 package) is it just a matter of seeing if the signal usage on the three terminals is the same? Or what else do I need to know? I would like to try it one one of those. I even have one of the taiwan (or chinese) clones that is dead that I could practice on.

One thing annoying about the MC330CRs is that one of the FETs always seems to installed at a slight cant to the others making it difficult to get a heatsink on them. I could fix that if I was replacing the FETs (I guess even if not) and have a much better ESC.
TA,

Try and get me a number off the FET's in that ESC and I will tell you a little bit about them and what you can replace them with.

- Matt
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Old 08-15-2007, 08:36 PM
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it costs a little more but you can get the mamba max without a motor and run any brushed motor you like. later if you deceide to you can go brushless.

http://www2.towerhobbies.com/cgi-bin...&I=LXNKT9&P=ML

whatch for coupons also
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Old 08-16-2007, 07:38 AM
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Originally Posted by TechWun
TA,

Try and get me a number off the FET's in that ESC and I will tell you a little bit about them and what you can replace them with.

- Matt
Matt, I did that.

The first line had a 3 pointed graphic that remined me of the Mitsubishi logo. The 3 lines were:

[logo] B
FS100UMJ
03 1701

So figuring that if you could look it up, maybe I could look it up too, I googled FS100UMJ and found a link to a datasheet. Sure enough, one of the manufacturers of this part is Mistubishi, so I was correct about the logo.

Now the disappointment. According to the datasheet I found here:

http://www.ortodoxism.ro/datasheets/...S100UMJ-03.pdf

these parts are already rated at 100A. The ones you had used for your Dynamite Tazer are rated at 120A. So will there really be much to be gained by replacing them? Are there higher rated FETs available in TO-220 cases?

One thing I found interesting was that the power dissipation on the FS100UMJ was listed at 125W, whereas the STP100NF04 is rated at 300W. The resistance didn't seem to be any different but the FS100UMJ is rated at 30V and the STP100NF04 is rated at 40V. Comparing losses at max current and max voltage for both, the ratio gets me 266W for the STP100NF04. So maybe that is close.

Do you think replacing the FETs on the MC330CR will make enough of a difference to be worthwhile? There are only 6 FETs total on the MC330CR. Looking at the bottom of the circuit board it seems like either:

a) 3 are used for forward and two for reverse, or
b) 2 are used for forward and one for reverse

If it was case (b), I would wonder what the other three are used for, but looking at the specs for the MC330CR they say 200A rated forward current and 100A rated reverse. So that sort of matches with case (b).

It is kind of facinating how much one can figure out with a small pointer in the right direction! Now if I only knew how to specify search parameters for these items, I would look for myself to see if there are any higher rated ones.

Also: I looked at the specs on the Dynamite Tazer 15T. It said 1.57" by 1.57" by 1.06, so it might fit in the BK2. Can you tell me if that height is with or without the heatsink? Do you run the heatsink on your modified Tazers?

cmain: Thanks for the hint about the Mamba Max. But it is a little to big to fit where I want it.

Thanks, Mark
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Old 08-16-2007, 10:51 PM
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Hi TA, it's late so forgive me if any of this isn't right.

Originally Posted by ta_man
Matt, I did that.

The first line had a 3 pointed graphic that remined me of the Mitsubishi logo. The 3 lines were:

[logo] B
FS100UMJ
03 1701

So figuring that if you could look it up, maybe I could look it up too, I googled FS100UMJ and found a link to a datasheet. Sure enough, one of the manufacturers of this part is Mistubishi, so I was correct about the logo.

Now the disappointment. According to the datasheet I found here:

http://www.ortodoxism.ro/datasheets/...S100UMJ-03.pdf

these parts are already rated at 100A. The ones you had used for your Dynamite Tazer are rated at 120A. So will there really be much to be gained by replacing them? Are there higher rated FETs available in TO-220 cases?

One thing I found interesting was that the power dissipation on the FS100UMJ was listed at 125W, whereas the STP100NF04 is rated at 300W. The resistance didn't seem to be any different but the FS100UMJ is rated at 30V and the STP100NF04 is rated at 40V. Comparing losses at max current and max voltage for both, the ratio gets me 266W for the STP100NF04. So maybe that is close.
You do nice research! Your just not in the right areas for what your looking for. You are battleing a thermal issue. In reality ALL ESC's are overengineered. If for example purposes ONLY we assume hooking a battery directly to a motor. Let's assume the motor is a load of .5 ohm and the battery voltage is 7.2 volts. Ohms law tells us 14.4 amps of current flow or 103.68 watts of power. So why in gods name wouldn't your 6 100 amp mosfets in bridge mode do the trick with pleasure?

Simple really.. wattage is power, and power is not only electrical. There is a thermal wattage byproduct for your parts. Each of those parts commands a recomended heatsink area Vs. power dissapation. So what is a guy to do if he is engineering a device with space constraints? He adds 6 horses to a wagon that only needs 3 - so to speak

In implimenting grossly overrated parts, they run at a fraction of duty and require very small amounts of sink area. It doesn't help matters that they usually ignore the entire case of the part and only sink the top tab!! DOH!!

Originally Posted by ta_man
Do you think replacing the FETs on the MC330CR will make enough of a difference to be worthwhile? There are only 6 FETs total on the MC330CR.
Absolutely. Not only is the wattage difference an improvement, but look at the thermal junction to case rateings for both parts. The upgrade boasts twice the dissapation and thus the part gets the heat off the die and to the case quicker. The heat sink may heat up about the same in the end but the die of the part remains cooler which is the important part.

The other thing to look at is the stock part has a 4 volt gate as opposed to the upgrade with a 10 volt gate. The upgrade part will be running half duty to begin with in your ESC and will still yield the power demanded by your load (motor). Remember the load was never an issue to begin with, we just need to consider cheating the wattage lost in heat!

The upper limit of the operating temp is 25c higher as well. If you compare the internal diagrams of the part you'll notice something else too Besides all this you will be the envy of all your friends. You will also gain knowledge and open yourself up to a whole other rewarding aspect of your hobby for under 20 bucks..

Whats to decide?

Originally Posted by ta_man
Looking at the bottom of the circuit board it seems like either:

a) 3 are used for forward and two for reverse, or
b) 2 are used for forward and one for reverse

If it was case (b), I would wonder what the other three are used for, but looking at the specs for the MC330CR they say 200A rated forward current and 100A rated reverse. So that sort of matches with case (b).
None of those cases make any sense as none of them add up. Case A includes 5 MOSFETS and case B yields 3 Check the TOP and the bottom of the PCB traces. You'll come up with a different scheme.

Originally Posted by ta_man
It is kind of facinating how much one can figure out with a small pointer in the right direction! Now if I only knew how to specify search parameters for these items, I would look for myself to see if there are any higher rated ones.
Most manufacturers have parametric searches on they're sites. I never looked into anything higher then the 120's in my ESC. Like I said I bash HARD on a 3200 lipo and a 13x2. Stock the ESC would thermal 3 - 4 times before the pack was toast. Now it doesn't thermal at all. I am pleased to the point of populating all of my vehicles with this feature packed and inexpensive ( I like that part ) ESC and just moddin them.

Touch programming, forward, reverse, delay brake to reverse, thermal prot, and cool blue heat sinks! I mean c'mon now! it's a CHICK MAGNET!!


Originally Posted by ta_man
Also: I looked at the specs on the Dynamite Tazer 15T. It said 1.57" by 1.57" by 1.06, so it might fit in the BK2. Can you tell me if that height is with or without the heatsink? Do you run the heatsink on your modified Tazers?

cmain: Thanks for the hint about the Mamba Max. But it is a little to big to fit where I want it.

Thanks, Mark
I do run the heat sinks. I play hard with low turn motors. I like to do donuts on pavement, slam reverse, slam forward and do wheelies, and on 90 degree days I bash even harder. The mosfets are just not big enough to do all that and dissipate the wasted wattage through the mere part tab's. Not to mention there are a few other factors about inductive loads to consider that will generate additional heat to the parts.

I hope some of that helps and doesn't confuse. It is late, and I'm usually in my own world of understanding with these things and can't always express my thoughts well to others. Hopefully you managed to get the jist of it all.

It's a lot to take in in one shot, but I wanted to get the point across of the relationship between wattage/heat/parts because this is a thermal dissipation issue. The parts themselves are quite happy with the loads, they just can't get rid of the heat with those tiny sinks! The ESC engineer had a limited amount of sink area to work with. That plays a big part in dictating the parts he chose. So paying close attention to thermal ratings they try and come up with a part that will like the amount of sink area and the load together. Not as easy as it sounds though and how you effect the load (how you drive, runtime, etc) will also affect the heat generated by the part. Had they used more sink area the temp coefficient would not be an issue, but from the moment you short change the sink area, your facing certain thermal runaway. To the average layman this means things get hot and continue to get hotter This is why a lot of people can't understand why they use the ESC according to specs and it still thermals. When in doubt, get a bigger horse.. or three

My ESC's measure exactly 1" top of the sinks to the bottom of the case.

Do let me know how this turns out for you. Good luck!

- Matt

Last edited by TechWun; 08-16-2007 at 11:02 PM.
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