$229 Street Price
First off the question you are asking is "Why a 4.5R Brushless system on a Stampede?" The answer is because no one else
One of the big reasons I choose Novak for a brushless system was because of my previous experience with their products and not so great experiences with a couple other brands. My Novak Rooster still survives today after surviving jumps, over gearing, over peaked packs, not following manufacturers recommendations and warnings, and my general driving style which in short is just abusive. Support from Novak is also supposed to be some of the industry's best and when you are dropping some serious cash on electrics, you want to know it will work.
Sensored Brushless Systems
First off the Novak system is a sensored and brushless system, meaning Novak's design specifically eliminates cogging by using a sensored motor/controller system (indicated by an extra bundle of wires going from the motor to the controller). Sensored motors are able to be more precisely controlled in theory because the sensors can talk to the controller and tell it exactly what position the rotor is in at any moment. The theory being that a sensored system can provide much smoother exact control throughout the RPM range than a sensorless system's method of motor control through suggestion. Most brushless systems (sensorless or sensored) are highly efficient and can attain much higher RPM and torque than brushed motors.
By comparison, on a sensorless system such as a Castle Creations Mamba Max, the controller makes suggestions to the motor to move forward, stop, or backward and how fast to do each very similar to your old "brushed" stock system. The thing people have noticed on older systems as glitching and stuttering at very low speeds is called cogging and was pretty annoying on older sensorless systems simply because the intention of a brushless motor was to crank continuously at near max RPM for hours on end, not rev up and down the RPM range. New sensored systems and new sensorless controllers and higher quality motors such as the Mamba Max's almost completely eliminate cogging. My experience is that I can take the Novak GTB 4.5R equipped Ultra-Pede to a obnoxiously slow dog teasing crawl with no cogging whatsoever. Need more information on brushless systems see this article by yours truly.
About the GTB Controller
What is special about the new GTB controller from Novak is that it is super crazy small with a 1"
The GTB has four brushless modes/profiles that can be tweaked via a simple but not the easiest to use "blink and click" one button interface - you really need to be paying attention. The interface allows control of Minimum Brake, Drag Brake, Deadband, and Minimum Drive. The brushed mode is also fully programmable with all of the adjustments of the brushless
Sadly the GTB's cell count is from 4 to only 6 cells, and although this produces more speed and torque than should be legal for an RC, it is a design limitation of a sensored system. Sensored systems just don't have the voltage flexibility of the sensorless systems. There will be some speed freaks out there that want to turbo charge the setup with a few extra cells, and on the GTB that would not be advised.
The GTB has included a industry standard spec brushless fan to assure the controller is kept cool. An opportunity for me to run GTB for a while without the fan occurred when my fan suddenly stopped working and I waited patiently for my warranted replacement from Novak. The GTB didn't thermal once, however I can see that running 3 or more battery packs through it in a row would really heat things up and the fan would be required. The fan really does need a little protector or cage (which I later fabricated) as any little item will remove a fan blade.
About the Motor
Novak has been selling brushless motors for a while now. The SS series motors and equipped systems were extremely popular and the SS5800 equipped system still remains a top seller and smoking deal direct from Novak's refurbished equipment department. The new Velociti motor series with accompanying GTB controller, promises more power, higher RPMs,
The new motors delivers:
No Cogging--Thanks to constantly knowing the rotor position, drivers experience instantaneous throttle response & smooth transitions from neutral to drive. The rotor position knowledge is attained due to the ESC & motor being continuously synchronized via the motor harness.
Smooth & Controlled Low Speed Drivability--Always knowing the rotor angle is key to smooth acceleration without delivering abrupt and uncontrolled bursts of power (i.e. cogging).
Strong/Consistent Brakes & Starting Torque--Rotor position knowledge results in consistent starts & stops, without hesitation or inconsistent lag times before acceleration or braking--this translates to consistent lap times.
Thermal Protection--Position & temperature sensors inside motor provide unparalleled thermal protection, letting you to run pack after pack without worrying about overheating the motor, ESC, or magnets.
Cooler Operating Temps -- This new aluminum ribbed case is supposedly lighter and radiated heat better to keep the motors running cooler.
Complete Mounting Control-- This is via use of your choice of 6 motor mounting holes on the end bell, and new higher current solder tabs on the end bell which allow for a wider variety of soldering positions.
Novak 4.5R Specs:
Resistance 3.1 Mili-Ohms
Input Voltage 4-6 cells
Watts 415
KV (RPM/Volt) 9000
Some Considerations
A huge consideration is the quality, type, and capacity of the battery. Let's say you understand a garbage battery compared to something like a Trinity, GP, IB, or Sanyo and that you understand battery capacities 1500Mh, 3300Mh, 4400Mh and the like. You may also know that there is a difference between NiMH, NiCad, and the new high current LiPo (Lithium/Polymer) batteries. Before you even think the question - yes you will need the best batteries you can afford at the very least Radio Shack GP3300s.
What you probably don't know is that a good high quality battery such as a GP3300 fully charged in a Stampede running a 4.5R GTB wide open off road in the grass will last about 7-10 Minutes if you are lucky, with a IB4400 about 10-15 until full discharge. The motor is over stressing itself and is drawing tons of current in the process. The simply fact is the motor is attempting to hit supersonic speeds on speed limiting terrain with gearing that is already geared down to its limits at 12/87 on the Stampede. Those same batteries in the Stampede with a 7.5R GTB and you are looking at nearly double the run times and still about the same speeds off road. Again a 4.5R is way overboard
The 4.5R is like putting a Ferrari motor in a 4X4, it will work and be insanely fast, but it's going to work really hard in the process. You should also consider that although a 4.5R in your Stampede would be nice and will be very fast, it's not the best choice from a battery discharge perspective. You should consider a 7.5R or 6.5R for the Stampede and leave the 4.5R and new 3.5R for the touring cars or at least the high speed on road RC's or a road tuned Rustler. Honestly with pretty much any brushless systems the biggest problem will be keeping the tires from flying off the rims and having enough batteries to make it through an hour or so.
Like every other brushless system out there this system is a current hog, big time (read below), so you will need to buy a Novak 4700mFor 5700mF capacitor and wire it to the receiver as described below to eliminate almost certain glitching from receiver power brown outs. Second, you WILL need either very high quality battery packs, ones that have soldered connections between cells, or you will need to rebuild them (as described here) to provide the current this beast requires to run properly. I reformatted all my batteries both the cheap and expensive ones to side by side packs with Deans Power Pole battery bars. After the high current conversion all worked well (although the better batteries had noticeably more punch and/or runtime) with the 4.5R brushless system.
Packaging and Installation
Novak has beautiful packaging with a nice sturdy box, and full foam cutouts that securely hold the controller and motor in place. Included in the box is the system pre-wired, a user manual, programming manual, stickers, double sided adhesive gel tape, zip ties, and warranty card. The information on the manuals is first rate, error free, contains lots of clear diagrams, and easy and simple to follow.
The system comes fully pre-wired, all that needs to be done is install in the vehicle, connect battery, program, and go. Aside from the need for a capacitor on the receiver (see below the Old Capacitor Trick) installation was simple and easy.
I would also recommend applying tape over the un-used mounting holes on the motor to further limit dirt getting into the semi-sealed motor can, and be very careful with the fragile fan that comes with the system, mine was missing one blade by the second day.
What do I think of the GTB 4.5 System?
I was disappointed and very happy with the system at the same time. There are some things that will annoy me about it and others which I was ecstatically happy about.
+ Packaging is great as well as instructions. Novak is not some slacker manufacturer that just tosses stuff in a box and leaves you to figure things out. Complete instructions, warning sheets, configuration diagrams, and ESC setting guides are supplied with plenty of links to supplemental info on their website. The ESC and Motor is nicely nestled in formed foam in an easily open-able and reusable box.
+ Installation was straight forward however I would really like to see, Novak add paragraph or two about running power and signal wires separately along the chassis as I believe this reduces radio interference and is just good practice.
- The need for a capacitor on the receiver thing really ticked me off. Novak included everything except the kitchen sink with the GTB 4.5 kit, such as nice little wire ties, double sided gel adhesive tapes and other little niceties, which were great touches and I think for the price they are expected, but left out a part that seems to be a known issue. I feel at the very least, this potential issue should have at least been noted in the instructions or a supplemental card tossed in the box as a warning.
+ My initial assessment was correct, the 4.5 system is about twice the motor as my old reliable Titanite is from a torque perspective, speed there is no comparison, the 4.5R is really fast, stupid fast. From what everyone has been saying about the brushless systems I was expecting this just wacky uncontrollable amount of power like the Hacker in Swami’s videos which seems to spend more time on it's back or wheelie-ing than driving, with so much power it is hard to
+ Is it faster than just about anything you can put in a RC on 6-cells? With my limited experience and according to Novak, YES! It is nutty fast on the top end. Visually about as fast as my over gearing experiment so I am anxious to see what the speed looks like at 15/87, 17/87 and beyond and with peaked batteries. I can see where the mid forties are easy to hit with this unit for everyone. That said the new Mamba Max from Castle Creations is coming out, Novak now has a new 3.3.R motor coming, and Reedy has just introduced a brushless motor also. Hold on to you hats people the speed war has only begun.
+ & - Does it have the insane amount of wheelie popping torque which I was expecting? Yes but not like I expected. It has that power wheelie-ing flip on the lid power, but it does it in a more restrained way than I was expecting. I was expecting rolling 20+ MPH wheelies which it did not do – may be I haven’t peaked my packs yet before running or that I am a little over geared at 12/87, but unlikely.
+ To explain expectation further, let’s assume you have two cars racing, a vintage Mustang with a huge powerful motor (what I was expecting), then on the other side of the track you have a modern sports car like a Nissan 300ZX (the GTB 4.5R) which though the miracles of modern technology is just a quick. Although both will hit the finish line at the same time, the Mustang’s muscle-ly power is hard to control requires a wheelie bar and a good driver, the 300ZX with vehicle stability control, power management systems and the like is predictable enough your grandmother could drive competitively at the track. The GTB 4.5R system is like the 300ZX, you could drive is slow, you could drive is fast, it delivered a smooth power band from beginning to end. Turns out I really like the smooth output of the system.
+ Do you need a wheelie bar? Yes, buy a good one like Swami’s. You will wheelie a lot with a Stampede but not on the Rustler. The Rustler just jets off in a highly expedited manner.
+ Does the motor or ESC get hot? With my current 12/87 gearing and Moab tires, it was not even slightly warm after 3 battery packs. We will see hot it warms up at 15/87.
+ Another up is that I think my days of replacing motors which have been eaten by our wonderful gritty clay Nebraska soil are history, the motor is almost completed sealed. I did seal the other un-used mounting holes with simple electrical tape cover.
+ Cogging? – Didn’t notice any at all even a insanely slow tease the dog speeds. It's how I get my dog to chase my RC's - it's good exercise for him.
- This is a love hate thing with the fan. In my case - I hate it, I hate it, I hate it. This thing should have a thermal switch that kicks on when needed. I am sure it will be needed as gearing ratios are up’ed and the ESC heats, but it seemed kind of stupid to have it running all the time when un-needed and …I already broke a blade on the fan, isn’t heavy duty by any sense of the imagination. The fan did just stop working completely about a week in. I did notice that you DO need it after a few runs with 3 or more packs in a row. Novak did replace the fan with no questions asked.
+ Stellar post sale support - see above fan issue.
+ The GTB 4.5R is a current hog, no doubt about it. I can't give them a negative for this because every brushless system hogs current. Not a big issue but in light of the required capacitor for the receiver, I think it should be noted that a person really needs some decent long running batteries to take advantage of the system. My run times are a little shorter than with my old Rooster and Titanite and average about 7-10 minutes in grass and around 15 on hard packed and smoother surfaces.
+ Changing of profiles via the "blink and click" interface was a little tricky if you are a instruction manual skimmer vs. reader or not paying complete attention. You have to read the manual to make it work. Follow the directions and all works great. I like the profile 5 with 20% brake, reverse, and zero drag brake. The zero drag brake makes the car coast with zero braking effect from the motor and really seems to extend run times.
+ Long term testing and use has been great, I cannot think of a better setup for the Stampede. I am lying of course because the 7.5R or 6.5R would be a much better fit for a normal person but just not as much fun on smooth surfaces. I also love the look on people faces at the track when I warp by them with a Stampede. I would have however liked to see a broader cell input range so that I could drop 8-12 cells on the system. Still very impressed with the power of this system and really is un-needed for it's intended purpose - racing.
+ So far I think I would do it again - the Project Stampede Ultra-Pede Lives, It's ALIVE!!!!
- Installation Problems
So I slapped that puppy in there and glitching problems galore. Initially geared 13/87 - which from the online threads seems to be a little under geared. Da..da..da..da..daaaaaaaaaaaa.. Like it's attempting to send Morris code.
I get Zero glitching and almost non-existent cogging (as advertised) when running with the wheels off the ground, however the moment the Pede hit the ground I get Glitching when attempting a full throttle take off. If I do a slow start no glitching then I can punch it full throttle without glitching. I also get some glitching at extended 20+ foot ranges.
I also seem to only get a feel of the full power and speed when the wheels are off the ground otherwise when on ground it only seems to only have let's say about twice the power of the old Titanite.
Attempting to move the antenna around to see if it was a antenna/power wire related issue, but did nothing. Tranny is packed with plenty of Lithium Grease to minimize radio interference. Dropped a new battery in and thought for a second that cured the issue but started glitching just as before. The ESC was set at factory default, with the exception of running Drive Profile 2 (100% F/R mode). But have tired other profiles with the some glitching results. Drive frequency is fixed in brush-less mode.
The Install Resolutions from conversation with Novak
Talked with Novak tech support. Their recommendation was two fold.
A. Separate the power and signal wires, currently my are all zip tied together in a 1/2" bundle. That did nothing.
B. Purchase a 4700 or 5700Mf capacitor to plug into the battery pack slot on the receiver or use a battery pack. That should provide enough juice to the receiver to get through the power hit on the battery during hard acceleration.
What they say occasionally happens is that the is such a huge initial current draw that the receiver current drops low enough (a brown out of sorts) that you momentarily loose signal, then of course everything rebounds and the process starts over again and then the voltage pogos until you let off the trigger.
Novak was correct in diagnosing my issue. Moving the cable did nothing, although I left them separated as it seemed like a good idea.
I tucked the cap around the front of the receiver. The esc is mounted in standard placement with the power wire side of the ESC on the left (antenna side of the Pede) and the receiver and wire harness bundle is on the right. This points the blinky ESC lights forward and allows the two separate groups of wires to go around each side of the rear shock tower. I also twisted each group of wires to shorten them and hopefully cancel out any potential other interference problems. That process in itself did not relieve the major glitching issue but may reduce any other issue that may have occurred - i.e., still need a capacitor. Just covering all the bases in advance.
The receiver was in fact experiencing a "brown out" during full acceleration and with the addition of a Novak 5700Mf capacitor and the glitching issue was resolved completely.
The day after update and the snap judgment April 2006 and apparent need for better batteries.
Three things are needed to prevent glitching, an RC antenna of the correct length, very good or re-built batteries, and a receiver capacitor. Without all three glitching will continue.
Adding the cap worked. No glitching at all out to about 1/2 block then everything went nuts until I replaced my antenna wire with the correct length instead of "kind of the right length", and rebuilt the battery packs.
Once that was done:
A. All Problems were resolved. If you buy one you will need the following:
1. Novak 5700mF or 4700mF capacitor and do the below explained simply wiring and attachment to your receiver external battery slot. Last week I went to the Novak 5700mF from the humongous the cap I had previously due mounting issues of the cap. The Novak is small enough it can be easily mounted to the receiver on the right side and works just dandy.
2. You will need either good quality "soldered" stick or side-by-side- brick packs, a good pack like a Trinity, GP, IB or other pack, or rebuild you old packs to for high current use with battery bars such as Dean Probar 3. Converting all my old packs made an enormous difference and made that motor come alive and perform like it should. If you have some lower quality packs you will need to re-build them see this on rebuilding battery packs.
3. Your antenna at the exact correct length.
B. I really love this setup know, after getting over the cap and low output battery issues, this thing is a monster and would highly recommend this to anyone looking for some serious speed and power from their Stampede.
PS. I still hate the fan.
Conclusion
Novak is a great company and the support with the glitching and the fan replacement was first rate with no complaints.
The system is reliable, fast as anything I have driven, and makes the Ultra-Pede just a blast to drive. Love it.
Testing the GTB 4.5R in something Else?
Ultra-Rusty goes Brushless
So let's say you are not quite as insane as me and have something like a Rustler or Bandit that needs a little help in the propulsion department. I am here for you. I ended up hi-jacking the Novak GTB 4.5R Brushless setup from the Ultra-Pede temporarily. In my opinion this is about as good as it gets for a race legal brushless setup for the Rusty (although the rumor is that Novak will be releasing an even faster 3.5R soon, no word on whether it will be race legal). The thought was that I need to know whether it's going to do the job or not before slapping down more cash, so why not do a test drive. I kind of wanted to see how the Rustler would handle the power anyway.
Wonderfully by the way, but I am sensing that idler gear will need replacing quickly if I don't swap back to the 15T (the 4.5R later shredded the idler gear in less than 10 runs). Again I was really expecting some wheelies with the 4.5R locked into the Ultra-Rusty's motor
Overall I really liked the 4.5R system on the Rustler and is probably what I will go with when it comes to that point. Although I would also consider the Reedy system, the GTB 4.5R is just a really nice efficient system that just works without having to pile on a bunch of batteries to see power and speed. I am going to play around with gearing a bit and have a little fun then it will go back on the Ultra-Pede where it belongs.
Perhaps Novak will grant me a test 3.5R when they come out to test on the Ultra-Rusty.
The Old Capacitor Trick - and some background on why and when to use it.
The problem - Bought a GTB 4.5R - Had tons of Glitching
So I slapped that puppy in there yesterday and glitching problems galore. Geared 13/87 - which from the online threads seems to be a little under geared. Da..da..da..da..daaaaaaaaaaaa.. Like it's attempting to send Morris code.
I get Zero glitching and almost non-existent cogging (as advertised) when running with the wheels off the ground, however the moment the Pede hit the ground I get Glitching when attempting a full throttle take off. If I do a slow start no glitching then I can punch it full throttle without glitching. I also get some glitching at extended 20+ foot ranges. Any ideas?
I also seem to only get a feel of the full power and speed when the wheels are off the ground otherwise when on ground it only seems to only have let's say about twice the power of the old Titanite.
Attempting to move the antenna around to see if it was a antenna/power wire related issue, but did nothing. Tranny is packed with plenty of Lithium Grease to minimize radio interference. Dropped a new battery in and thought for a second that cured the issue but started glitching just as before. The ESC was set at factory default, with the exception of running Drive Profile 2 (100% F/R mode). But have tired other profiles with the some glitching results. Drive frequency is fixed in brush-less mode.
The Solution from conversation with Novak
Talked with Novak tech support. Their recommendation was two fold.
A. Separate the power and signal wires, currently my are all zip tied together in a 1/2" bundle. That did nothing.
B. Purchase a capacitor to plug into the battery pack slot on the receiver or use a battery pack. That should provide enough juice to the receiver to get through the power hit on the battery during hard acceleration.
What they say occasionally happens is that the is such a huge initial current draw that the receiver current drop low enough (a brown out of sorts) that you momentarily loose signal, then of course everything rebounds and the process starts over again and then the voltage pogos until you let off the trigger.
Novak was correct in diagnosing my issue. Moving the cable did nothing, although I left them separated as it seemed like a good idea.
The receiver was in fact experiencing a "brown out" during full acceleration and with the addition of a simple 1000uf (1000mf) 35V polarized capacitor from Radio Shack the glitching issue was resolved.
What I used was a 1000uf 35V Axial-Lead (polarized) Electrolytic Capacitor .
What Capacitors do for your RC car: Caps store energy, like a battery, so think of a capacitor as very short term battery backup for your receiver or ESC. They can be used on the ESC or the Receiver whichever needs it. I found one article which indicated that your should have a cap on both your ESC and receiver as a standard piece of equipment to prolong the life of each which is typically shortened from continuous voltage fluctuations. Think of it also as a power conditioner for your electronics.
How do I make one of these things: I thought a simple Google search would turn this up, but it took some digging. What I found was that sure the more expensive and preferred 4700mf caps available at Towerhobbies.com will work, but so will the $2 ones from radio shack. The key is that it needs to have arrows on the label of the cap (a polarized capacitor), be of decent quality, 10+ volts (35V is the norm) and be at least 1000uf (same as 1000mf). The bigger the number the more current it stores, but keep in mind there is a point where bigger is just bigger, on the big side the Novak caps at 4700uf (4700mf) and 5700uf are plenty huge.
The arrow on the cap. points in the direction of current flow (from + to -) so the tip of the arrow is - and
Scrounge a spare receiver jack and solder the red (+) lead to the + end of the capacitor. And the Black (-) lead to the - end of the capacitor. I also picked up the variety grab bag of Radio Shack shrink wraps and shrink wrapped everything up so no sparking could occur. I also put a nice big shrink wrap over the whole cap for protection - gee looks just like the Novak on the ESC. Then plug it into the spare battery slot on receiver, the same one you would use if you were using a battery pack on your receiver. That's it. The capacitor will charge from the power supplied from the ESC as needed and will discharge when current drops suddenly.
Crude picture but you get the idea of how to solder it together. Make sure you shrink wrap everything well. Capacitors can spark. Also note that Capacitors generally don't last forever, so if you get a year or two with heavy use you are doing great.
The glitching issue was history after this very minor upgrade.
I later gave in and picked up a Novak 5700mF cap, which I should have done in the first place it was only $5 from the hobby shop. The big difference is that although it is still 5700mF it is 10V versus 35V and is about half the size and is much easier to mount on the Stampede.
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