Project: brushless motor for Blade CP Pro

[zen]

I am installing the Park 370 brushless motor that Eflite sells for the Blade CP and CP Pro:

- the aluminum adapter plate that screws onto the pinion end of the motor is a good fit with the helicopter's frame.

- my Microheli main gear and shaft adds a small wrinkle: the big gear is incrementally larger in diameter than the stock main gear, and meshes with the new pinion with a slightly granular feel, unless I make it quite loose.

- a fine, white residue on the frame where the gear teeth mesh shows that the stock brass pinion was abrading the white plastic Microheli gear. Whether it was 'wearing in' or 'wearing out' remains to be seen....

My Blade uses stock landing gear. After I get the motor installed and adjusted, the next step will be to add an extra battery tray to the horizontal carbon fiber rods to hold the ESC, since I don't want to put it on top of the receiver and 3-in-1. If I can't get the CG right, I may resort to the more forward position, but underneath it has less chance of causing glitches.

The ESC and extra wiring (two 'Y' connectors!) will require more take-apart to change landing gear struts. I am thinking about piano wire struts of the same length and diameter as the CF, with stronger home-made skids, to reduce landing gear breaking without adding (much) weight.

More later as this conversion progresses.

[ranger306ci]

Zen,
I would think twice about stronger landing gear, because they are strong enough to absorb a good amount of abuse. If you make them stronger, I guarantee the part you will break next are the little frame tabs that the landing gear bolts to. If those break, you have to resort to longer screws to hold the landing gear on, and that puts stress on the frame in an area that was not designed for it. Ask me how I know!
I treat the skids as a "fuse" They are wonderful for absorbing crach force.
Anyhoo, what kv is that park motor, and what size pinion are you using?
What esc, and how are you plugging it into the 3 in one?
Nosy people want to know!
Ken

[zen]

Hi Ken-- the Park 370 is rated as 4200kv, not that I know exactly what that means! I am using a 30 amp ESC that came with my Walkera #60, but the motor only demands 20 amps to operate. Two connections with the 3-in-one are needed: power and signal from the Rx. Maybe I will create a wiring diagram (conspicuously absent from Eflite's Blade manual) and post it here.

I get your point about LG. You probably know that the struts do not bolt to the Blade CP and Pro, but slide into bosses where they are held by geometry and sections of silicon tubing. The struts seem more fragile than necessary. I think a crash that would break the frame bosses would mess up the head, 'cause the frame is pretty strong. I have been having a conversation with another R/C'er about developing LG with a shock-absorbing capability. Maybe we'll come up with something.

[zen]

First flight after the installation: everything is hooked up. Way more wires than this heli usually has. The ESC works, motor spins—really, really fast—heli takes off ... pinion spins off of the main shaft and the heli comes to earth piroetting because the tail rotor is turning.

Next: order another/the right pinion from the LHS.

Temptation: press the existing pinion back on, heat the main shaft and sweat solder the brass pinion to the shaft. Otherwise it's no flying until next Wednesday!

Opinions?

[G-MRM]

Maybe worth a try but don't get the motor shaft too hot. With a drill, by hand make a shallow dip in the top of the brass pinion to help solder collect and make a stronger bond. You will need a good flux, I find the one you use for house hold copper pipe work good if you scratch up the steel first, brass is no problem. try it and keep the heli low when testing.

If it still is a good fit, loc-tite ?? (the green one) !!

[estarter]

zen

Where 're you fly in Berkeley? I usually fly in Marina every Tuesday afternoon, there's a large group of people flying slope and gliders by the dog run area. Some flyers also fly helicopters, they fly Trexs.

Back to your BL, for your Park 370, 4200kv use 8T pinion and you'll have insane power and may need to use DD or dual tail motor setup to catch up with the rotor speed.

[swatson144]

I always use green loctite on pressed on pinions. While preesiing them on it acts as a lube and dries without air to keep them in place.

Steve

[zen]

I fly the Blade at Willard Park, morning or evening, depending on wind and my schedule. I've thought about the Marina, but my impression is that it is quite windy. At my skill level the Blade likes little or no wind.

Green locktite might be a thought. Does it really keep the gear from turning on the shaft?

Also, is the 10-tooth gear I have too fast? I can wait ('til next Wednesday!) to get an 8 or 9, #%$!

Before the pinion departed the heli, head speed was awesome. Much more power than stock. The 30 amp ESC seemed to work okay. Wires all over the place. I can't wait to get it in the air.

[swatson144]

Zen to be honest I only have experience with the CP2 (esky) which IMO I think has enough common roots to speak to. I have found that spinning the head to as high a speed as you can without it sticking is as good as it gets. Excuse me, but Period the end. :oops:

I have a CP2 sitting on my monitor with a mamba 20mm 4200 10t and the last decent flight I got from it was w/ TC=75% So maybe a 8t would be better for efficiency. I can't seem to get the CP2 to fly well at less then 2400 rpm HS and I can't seem to get it up around 2600rpm without sticking.

I personally appreciate your efforts in this class heli and hope to learn from your experience. I find them (at least the CP2) confounding and aggravating. Having a 15yr old son I'm not in the market for aggrevation, nor being confounded. :D

Yes on the green loctite. It really is amazing stuff. Use it sparingly.

Steve

[zen]

Swatson— yes, efficiency needs to be optimized or the point of this conversion will be lost. I think I'll wait for the correct gear and see what I can do about mounting it firmly.

As far as the mini class is concerned, my first BCPP drove me right up and into the veritable wall. I judged it to be unflyable. However, persistence has demonstrated that the Blades, and presumably the HB's, actually fly pretty well and are a cheap ride with less attendant risk than Trex, Hirobo, etc.

At this early stage I am doing things with the Blade that I would not think of trying with the Trex, so I'm grateful to have the Blade.

BTW: where are you located? Ready availability of Eflite parts in the Bay Area frees one from having to order on line and waaaiiiit for parts.

[MAXXED]

zen,

I ran an eFlite 4100kv inrunner brushless with an 8 tooth pinion with the stock 4 in 1, and 3 cell li-pos, and it had lots of snap.
You may want to consider going to separates, as I discovered the 4 in 1 does not take well to anything above 10 volts.
My 4 in 1 acted like it was possessed with a fully charged 3 cell pack.
eddie was the one that led me to investigate this erratic behavior of the 4 in 1.
It would glitch like crazy, throw the proportional way off, and then settle down at 10 volts or less.

[swatson144]

I'm in virginia and can order parts from www.bphobbies.com and they arrive within a couple days, so it's not very bad.

I haven't been doing much with the CP2 as I have a few other projects in the works. It hovers easy but really is nasty in flight. A good crash with it is about as much as with the BP explorer (well really 1/2 but 20$ vs 40$ is so close and the BPE isn't nearly as likely to crash) so it's side lined for now. I don't know why I set another up I really didn't care much for the first one I had. It's all BL/separates and a bit portly so when I get back to it I'll try a set of Like 90 255mm blades on it.

Steve

[zen]

Maxxed— I am running separates. (FWIW: the CP Pro has a 3-in-one mixer.) I installed the 30 amp ESC I had laying around from a Walkera #60 and it worked okay during the test hover.

I will wait until I can get a 9-tooth pinion in hopes that flight time, power, and temperatures will be within acceptable limits.

Swatson— I am glad that parts are not a problem for you, but am curious about your characterization of the HB as crash prone. At first I thought the same about the BCPP; recent improvements in skill have me feeling that it flies pretty well. The brushless motor is smaller/lighter than stock, so the only added weight is the ESC (should have weighed it!) and wires. I guess my HH gyro and Microheli gear and shaft also add some weight.

[swatson144]

I base my opinion on crash prone on the tail. It's pretty lame and tends to blow out very easily leaving me trying to catch it's orientation. The other helis have no bad tail problems.

Whip it into a stall turn and get a puff of breeze and it never makes the transition to nose down. So there you are stalled tail down slamming collective on it with down elevator to get moving and playing recovery with it at the edge of the field. So far I haven't been able to make it behave with a MS-44 gyro or the very nice 2100T. I've run them stock with DD and with a 12mm BL motor on the tail.

I'm not knocking it but I was stating that I have a very hard time flying it well. Personally I crashed the CP2 more than any other heli I own because it'd let me down at the least oportune moments.

Steve

[estarter]

Zen,

The head speed may be too high when you use 10T with the 4200kv motor, 3S lipo pack. My BCP and BCPP are with stock motor only, and have enough power to loop and flip using 10C 3S 800mah lipo pack.

I use the Himax 4015-4100 (similar to the Eflite 370) on the gear driven 3Dpro with 8T pinion, very good power for aerobatic and the 3Dpro is about 4+ oz heavier than the BCP.

[zen]

Swatson— there have been a lot of threads on a lot of web sites about the Blades' tails. You are a hotter pilot than I am, so have encountered more of the heli's characteristics.

estarter— I just found a nine tooth pinion! That would also make the head speed to much, wouldn't it? Trying to restrain myself from installing it ... argh! Don't suppose you have an eight tooth on hand, do you? I could run by and pick it up, and would be at your mercy for price.... PM me if you have one, will you?

BTW: what time are you in the Marina on Tuesdays? I'd like to meet you there and see what everyone is up to.

Glen

[swatson144]

If the BCP is anything like the CP2 (and I assume they are as they share the same roots) when your HS starts getting high the head will start sticking even with all the mods. So I'd start slower and maybe try working up keeping an eye out for it starting to stick.

Steve

[estarter]

zen

You are flying with separates, which Tx are you using?

If you use the computer radio, you can program the Throttle curve to get the head speed you want.

The 8T pinion I have is in the 3Dpro.

Link for 0.5M pinion, please double check the motor shaft size before ordering, it is for reference only:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBGE4&P=7

[estarter]

Zen,

People usually show up around 4pm, I get there around 4:30pm. Believe or not, couple weeks ago, someone was maiden a flying Homer Simpson doll (dress up like a super hero).

[estarter]

Zen,

For the 8T pinion, have you try Boss Robot? He carrys many Blade parts.

[zen]

estarter— I have a Futaba 7CHP, so it is progammable. I have a feeling that the mechanical ratio between main and pinion governs how bogged down the motor gets at higher pitch; and flight duration. Still I may give it a shot. I can always take it off.

Johnny is out of small pinions. I bought the motor from him.

[swatson144]

Zen I think it'd be a good idea to give the 9T a try. The 8T would be better but it'll really make only a slight difference. As always check it after about 30secs and then after 1min etc to make sure the temps stay in control.

I'm having a hard time finding 8T 2mm .5mods also. So I was running a larger motor on 10T (from a H2 I sold) . I'd say on the 9t bring it up to 75% in normal before any pitch comes on and keep 75% across the upper 1/2 of the board to do the hover maiden. Then adjust it from there. You should see about 2100 if you tach the HS that should keep you below any problems from running too high a HS and you can always go up later(I'd start with stock blades). I hope I'm wrong and there is no sticking on your Blade head. I think the machine would be a lot sweater around 2500-2600 rpm, more responsive, and a lot less "wallowy".

I can't find my micro logger plots for mine :oops: so I guess I'll get it in the air again and get a good set from the main and tail while just putzing safely around.

You are correct about proper gearing but as long as you aproach it with caution "not so" gearing is still useable but not optimal. Have fun and enjoy. improve things later.

Steve

[zen]

I put on the 9-tooth pinion to see what would happen. What happens is this: I take off, seconds later the main motor shuts off. It lands, tail rotor still spinning. Naturally I put the stick all the way down when it touches. Then it will spin up again, take off, main motor shuts down. This has got to be the ESC, right?

[swatson144]

Sounds like LVC (low voltage cutoff) on the ESC. Full charge on the pack? Try another pack?


Steve

[estarter]

zen

More info of your setup like what you have in your separates like gyros, esc, lipo specs (C rating, size..) the AUW...

[estarter]

zen

Most BCP AUW around 300g (10.5oz).

My BL 22e is around 11oz, I use CC10 esc, Eflite 3in1, AR6100 rx, 3S 800mah lipo, the average amp draw is around 3.6A and can hover for 10 minutes.

[zen]

The battery was a freshly-charged 800mah Eflite 3s li-po. I'm not seeing a 'C' rating on it. Maybe it's getting tired. I'll try the other one, but would expect at least eight or ten minutes out of it.

The rest of the set-up is: Eflite 3-in-one and Rx, Hitec servos, Telebee dual-rate gyro. ESC came from a combo sold with a Walkera #60. It ran a 3200kv outrunner with a 1800mah 3s li-po. Weight without the canopy is 350 grams.

[estarter]

Do you use the stock brush tail motor? With the Eflite 3in1, how you hook up the gyro? Do you use a esc for the tail motor?

I can't see the tail from your pic, you definately needs the motor heat sink for the 370.

[zen]

I have a stock tail motor.

The rudder control from the 3-in-one plugs into the gyro. Then the gyro's leads connect to channels 4 (controller) and 5 (gain sensitivity, single wire) of the Rx.

I bought a heat sink; haven't installed it yet.

With both of my Eflite 800mah's I get less than a full minute of hover. I suspect this ESC is pulling too much current. Probably have to buy the Eflite one, although I had hoped to duck that expense by using the 30 amp.

[estarter]

Any reason to use a Telebee/Eflite style HH gyro on top of the Eflite 3in1? I used the Telebee HH gyro on my Trex before, I can't tell much difference between the HH/rate mode in the air, that was a while back I was just hovering.

Frankly, both the Eflite 4in1 and 3in1 work great in my BCPP and 22e, I don't even have to dial in any Rev Mixing or Rudder/throttle mixing. They do need some minor rudder trimming at the beginner and toward the end of the 10 min flight. The tail has very good authority when exit the stall turns.

[estarter]

zen

I'll bring the BCPP and 22e to the Marina around 4:15pm tomorrow, bring your helo to share, may be other helo guru can figure out the power issue.

[zen]

Cool! I'll be there with the Blade. Might even bring the Trex, in case the wind isn't too strong.

[estarter]

OK, I'll bring a tachometer to check the rotor head speed. I fly my 22e (same size of Blade CP) there with 12+ mph wind before. The slope flyers meet by the ridge close to the dog run area, look west toward the GG/Richmond bridge and follow the sailplance in the sky.

[MAXXED]

zen,

The eFlite 4100kv (didn't know they made a 4200kv inrunner) with an 8 tooth pinion gives me around 2000-2100 rpm.
With a 9 tooth pinion, you'll get closer to 2300 rpm.
The magic headspeed for the Blade seems to be around 2400-2500rpm.
The Blade head isn't as prone to the sticky collective issue as the CP2 head.
It's actually much more sloppy on the center hub slider, which is an advantage at higher head speeds.
I wouldn't try pushing more than 2500 rpm with a plastic head. Parts may start bending out of shape and launching like shrapnel.
The 3 in 1 is identical to the 4 in 1 except they separated the receiver from the gyro and ESC, and made the connections a little more user friendly.

[estarter]

zen,

It was nice meeting you this afternoon, too windy to fly on top of the ridge. The 10+ mph wind really bounce the 22e in the air, the parking log flying was good, but the air was kind of unsettle, the stock motor BCPP handle it OK.

[eddiemoth]

zen

I'll bring the BCPP and 22e to the Marina around 4:15pm tomorrow, bring your helo to share, may be other helo guru can figure out the power issue.

estarter, where is Marina? I am working tomorrow but in case I can make it, I'll join you guys there too.

[estarter]

I was still a bit puzzle about the set up in your BL BCPP, I never done the HH gyro connects thru the Eflite 4in1.

I have a spare 22e, Eflite 4in1 and a Telebee HH gyro and will duplicate your set up and see how it goes on mine.

[zen]

estarter— that was some bad-ass heli flying in the wind on top of the ridge overlooking the Bay!

For the rest of the readers, R/C glider guys get sustained flights from all the wind blows where we were. Estarter took off his Walkera and put it up rather high, surfing the breeze just like a glider, then brought it back and down for a perfect landing.

Then he flew circles in the parking lot, including some very casual, expert nose-in.

[estarter]

[quote="eddiemoth
estarter, where is Marina? I am working tomorrow but in case I can make it, I'll join you guys there too.[/quote]

Exit University on 880 and go west, make a right at the end of the flags, follow the road to the end, the ridge is about 200 yards to your right.

[estarter]

Eddie,

Please join us next Tuesday afternoon, bring something to fly and prepare for windy condition.

[estarter]

I have a stock tail motor.

The rudder control from the 3-in-one plugs into the gyro. Then the gyro's leads connect to channels 4 (controller) and 5 (gain sensitivity, single wire) of the Rx.



Could you elaborate how you hook up the gyro to the 4in1 and the tail motor, also the BL esc, I try to duplicate your setup but lost at the gyro part. A diagram would be very helpful.

[zen]

estarter— ironically, I have taken the brushelss motor, ESC, and Telebee gyro off of the BCPP and am flying it bone stock! Decided I've had enough wrenching for a while and want to concentrate on flying. BTW: had a good flight at the park this morning with the Trex, which is beginning to feel more familiar. By the time I had the Blade in the air, wind was up and I could only fly inside.

The Gyro goes as follows:

1. The rudder signal lead from the 3-in-one that would normally plug into the receiver plugs into the gyro. The lead from the gyro plugs into receiver channel #4. If the gyro has a gain wire, it goes in receiver channel #5. The proportional and gain pots on the 3-in-one get turned down all the way.

The brushless motor is as follows:

1. The throttle lead from the 3-in-one that plugs into receiver channel #3 goes into a 'Y' connector, which in turn goes into the receiver #3 and the ESC.

2. Power from the battery goes into a 'Y' connector, which distributes it to the ESC and the 3-in-one. Some soldering was necessary on my machine because I converted the batteries to JST from Dean's.

The 'Y' connectors are available pre-made from Eflite. Johnny has 'em. I have the Eflite manual if you want to look at it.

[estarter]

Zen,

I only have the Eflite 4in1, it does not have the wiring like the 3in1 to plug to the HH gyro, it may requires some hacking to the board.

[swatson144]

If you want to continue to use the gyro and tail ESC it's simple to cut the trace to the signal pin on the last row of pins (bat) and jumper the signal from chan 3 over to the signal pin on "Bat". That leaves the mixer getting throttle signal and working, and a place to plug in the BL ESC. It's easy to go back later if you want. Just reinstall the brushed motor and ignore the mod.

Steve

[estarter]

I have to cancel this project since I don't have the 3in1 and I already used the spare Telebee HH gyro in the HDX300. Also I don't want to hack into a perfectly working 4in1 as the BCPP is flying really good with it.

[zen]

Here we are some time later and I put the Park 370 back on the Blace CP Pro because the main motor quit and the LHS doesn't have another one.

This time I shortened every lead that is too long and put the ESC under the main gear. Oh yes, one other thing: in the meantime I more or less learned how to fly the Blade—a step I had omitted when I started this thread.

The 370 moves the Blade along much faster than the stock motor. It runs hot, and weighs more than a comparable outrunner would. Weight is about 1.5 oz. more and the CG is ahead of the main shaft. But the additional power and speed are noticeable.

[estarter]

Zen,

Your brushless BCPP has insane power, there's enough power to do wild 3D.

[zen]

estarter—

ah ... the heli is willing, but the pilot is weak!

[estarter]

We all started from the beggining at the novice level and will progress after crashes.

[estarter]

Hehehe, the more crashes you have, the better pilot you'll be ???

But I'm sure that a better repair tech you'll be.