ph2t
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OK, I’ve started on the setup that will enable me to program the mamba-25 esc without haveing to remove it. Pretty much it involves a simple switch that is put in between the ESC and the RX. This way when I need to program the ESC I just switch it out of circuit and that will ensure the USB program inteface all works OK.
Here’s a simple diagram of what I’m talking about:
The challenge is finding a switch small enough. I decided to hack an 8 pin DIL switch by chopping off one of the 4 SPST switches and leaving it with 3. One switch for each wire (GND, V+ & Signal). I then soldered this onto a small 3 pin terminator strip that I had also cut down to size. The goal being to mount it up the front somewhere….. That bit is still being worked on….
More to come…..
OK. Finally got this new motor into the chassis. The motor has a lot of drag, I think it was originally intended for a small heli conversion, not sure exactly. Given the drag I needed to make sure that my TX was set to +1 for throttle when in the neutral position. I seem to of been lucky, at this setting it’s not enough to go forward constantly but enough to stop the drag from kicking in at 0 throttle.
Took it out for a spin on the concrete driveway and it works well. So happy to be back in a MM config again and with a motor now that ISN’T 6 times heavier than a stock 130, lol…. (see previous RM attempt).
The acceleration is quite strong, faster than my 36t pattern wound motor I’ve got from flash (best off the mark accel motor I have, and I’ve got lots!). This is to be expected though. The Razor 300 is meant to be a replacement for a Speed 300 sized motor so you can see that it has some balls.
I put on a 9t pinion and on 4 cells the speed is comparable to the PN saber. It’s just what I wanted. The high 4900Kv rating of this particular motor is a nice sweet spot (on 4 cells). As I mentioned very early on in this thread, the goal is to make a comparable racer based on brushless, not to make a crazy speed machine (did I just say that? lol…..).
Anyways, next step is to fine tune the setup. I need to get the oil damper back on, may change to a thinner CF h-plate, rebuild the front end (concrete dust is a @#$%^) and FINALLY get that lovely MM shell I’ve got for it (RIP audi DTM, lol….).
More to come!
ph2t.
OK, bit of an update now. Hopefully I will have this running within the next couple of days….
Mid-Mount brushless is on it’s way!!
The motor is an RZ-300 brushless motor by Razor Motors.
You can purchase it from here: http://www.neumotors.com/20061222/Razor%20Motors.htmlThe specs of the motor are as follows:
– 2mm shaft (yay!)
– 4900Kv Rating
– 27g weight
– 28mm long x 20mm dia.Here’s another picture showing the fitment in the PN Racing (low CG) MM mount.
It’s using an 8t pinion at the moment. I’ll see how it goes with this. May be a bit
slow on 4 cells but we’ll see. The Kv of this motor is higher than the first version so
that should help offset some of my speed concerns.I had to do a fair bit of filing on the alloy to get the bugger to fit.
I did manage to get both screw mount holes in this time so it’s nice and
stable (unlike the first RM version that only had the single screw mount!).I managed to keep all the alloy in one piece without breaking the structure in any
part. This was a risk associated with going down this path.I’m just happy I got the buger in. Next step is to wire it up to the chassis and
mount the rear assemble and test it out!My only concern is that this particular brushless motor has a fair bit of drag when
off. I will see if the mamba-25 esc can help me with this, or if it’s just a case setting
the throttle neutral point on my TX.More to come! With a new (poor poor) shell too!
ph2t.
yes, again from Cowboysir from GSR.
Quote:
aparently it all fits, you need to mod the shock mount though since the motor gets in the way.
the other benefit is that it’s lighter a well.
it’s the RZ MICRO model:
Quote:RZ-Micro Car
The RZ-Micro-Car is designed for micro RC cars like the HPI Micro RS4. the motor uses the big block mounting plate, with very minor modifications. You need to drill out the single hole to 5/32.Kv: 5650
Io: 0.70A
Rm: .075
Weight: 27g
Length:
(w/o shaft) 27.8mm
