For well over a year I’ve been fascinated with the sub-micro electric heli called the Bumble Bee from MIA Designs. A couple of months ago I finally decided to give it a shot. I contacted MIA Designs about availability and received an e-mail back saying it was in stock. I then wrote back to inquire about pricing and never received a reply. I should have figured, I went back and noticed his web site still talked about Christmas 2003.

HeliHobby had the kit in stock so it was ordered from them plus a couple of GWS Pico ball bearing servos to use with the kit. MIA reccomends HS-55's but I've had good luck with GWS servos in small aircraft and the mounting holes are the same.
A few days later the kit arrived, with the wrong servos. Efforts to get the servos replaced have been one way only, No reply of any sort from HeliHobby. Okay, no big deal, flying will go on, I thought.
All my wife could say was “That little box cost us $200.00?”
I pretended I didn’t hear her.

The next problem I noticed was the advertised rotor diameter of 13.8 inches, it wasn’t, it was 15. That was a bit upsetting, I’ve got a cut down 15 inch Piccolo so a Bumble Bee at 15 inches didn’t seem like a big jump in shrinky-dink technology.

The instructions for the Bumble Bee are easy to follow and straight forward. Frame parts are CNC cut carbon fiber and the head is molded plastic. Engineering over all was very good at first glance. Ball bearings are included for the main shaft and tail rotor.
Assembly went without a hitch until I went to test the tail motor’s rotation. I hooked it up to a Pixie 7 ESC and slowly started the motor turning, after a few seconds and at about ¼ speed the motor stopped. Fearing I had blown my ESC I went through everything carefully and finally discovered that if the motor was spun by finger power it would start running again but if stopped would not restart. I did also notice at this time the screws in the kit were too long for the tail motor, if tightened all the way they hit and moved a magnet inside the motor.

I immediately wrote to MIA Designs and HeliHobby. MIA basically replied sympathetically that it was too bad, no reply at all from HeliHobby. I wrote back to MIA and ordered a replacement motor and gave him a Mastercard number, after over 2 weeks from the date he said he shipped it 2 to 3 day Air Priority I still hadn’t seen anything. A week ago I was finally able to get an answer from MIA on the shipping. It was sent to the wrong address, another was going out right away Priority Mail plus a free extra tail rotor, I’d have it this Wednesday... it’s Thursday, I still haven’t seen anything. I live in a very unpopulated area and know the Postmaster well. If any package had gotten within 20 miles of here I would have received a phone call from the Post Office.
After three tries still no response at all from HeliHobby on a tail motor, nothing on getting the wrong servos. At least all these guys are consistent.

So anyhow, in a bind, I pulled the tail motor out of my Piccolo, switched the pinions, used shorter mounting screws than MIA supplied and got the stock Bumble Bee in the air. Problems cropped up immediately.

The ball links for the head supplied in the kit have very little engagement. If you loosen them per the instructions they fall apart in the air or on a rough landing, tighten them just a little and they’re too tight to fly, loosen them a tiny bit again and they fall off again. There’s just not enough plastic wrapping around the ball to hold on if it’s even the slightest bit free moving. My guess is that the undercuts in the molds for these parts wore out long ago.
The next problem was the tail boom clamping with a single screw, I added reinforcements to the side frame made from scrap carbon fiber sheet, there’s still not enough clamping going on to hold the tail boom from twisting in a hard landing. Glue it.

The gimble ring that holds the flybar on with ball links is too loose out of the box, the flybar flops around on the gimble ring. Trying to gently squeeze the links down with pliers didn’t help much.

Flying the model was a real adventure never knowing what the rotor head was going to do next. Hover for a few seconds, then off it would go in any direction, forget getting it back into a hover and return it, the best thing I found was to get it on the ground as soon as possible when it went out of control, there was no getting it back. Progressively adding weight to the fly bar just gave the little heli more bone-headed determination when it went off on its’ own.
After days of this nonsense I noticed more problems, the single screw that keyed the rotor hub to a slot in the side of the main shaft could no longer hold the hub in place, it was twisting on the shaft about 30 degrees, the plastic hub the screw went through was too soft and had allowed slop to build up.

Also, the main rotor drive gear was losing teeth, on second look no it wasn’t, they were there just smashed down kinda like Bart Simpson’s hair when he's wearing a suit. Again the plastic used is too soft for the job. Now before anyone suggests I didn’t have the gear backlash set properly let me add I’ve engineered and built gear trains professionally for over 25 years. I know a little about gears and Mabuchi type motors, these problems weren't my fault, I’ve made a ton of mistakes in my life but the tail motor and then blowing the main gear aren’t on that list. The gear had also broken in one of the center spokes where the molding process had left a bad knit line where the flowing plastic joined together.
This gear was shot, I’ll order new one, aw wait a minute, from who?
MIA, HeliHobby, Iraqi Insurgents?

I’ve got the cutters, I pulled out the dividing head and set up the mill, I cut a new gear from Molybdenum Disulfide filled 6/6 Nylon. It's hard, tough and self lubricating.
While the copter was apart I had decided to rebuild it so it could actually be controlled in flight. I used the head from my Piccolo and cut the main blades down to a 12 inch diameter the fly bar is cut to 7 5/8 inches. I switched the original Bumble Bee main shaft from stainless steel to 3mm carbon fiber and replaced the main bearing to match the new 3mm shaft. The tail boom and skids were cut down to look better. I added some weight to the Piccolo flybar for early flights, though it doesn’t seem necessary. All up weight is 5.2 ounces with a 340mA 11.1 Volt Li-Po battery and the flybar weights. The servos are now Blue Arrow 3.6 gram units.

My gosh this thing now flies -very- nicely, the little blades are spinning at 2100 rpm and it sounds like a circular saw when it gets close.
The Piccolo head is like a fine Swiss watch compared to the original MIA head and fly bar.

So here we are about 1 ½ months after purchasing my little dream copter, the Bumble Bee. Still no answers from HeliHobby, no parts from MIA. With just a couple of “minor” changes the heli (you can’t call it a Bumble Bee anymore) flies great.
Would I recommend the Bumble Bee, MIA Designs or HeliHobbly to ya’ll?
That ain’t gonna happen my friends. I won’t even list their web site URL’s here. Don't get me wrong I'm not angry nor am I being vindictive, I don't need the parts from MIA anymore and anything HeliHobby has to say or offer is pointless by now, I've actually had much more fun with the copter than if it had flown decently off the board.

If anyone has any questions I'd be happy to try and answer them.

The picture shows the reworked and now flyable Bumble Bee with a pair of 8" calipers and one of the 80 tooth, 64 diametral pitch, 20 degree gears that I cut from MDS Nylon.
Best to all,
Denny

milwiron

Don't get me going about HeliHobby. Nikki who goes by the RR name of FemaleFlier (or FemaleFlyer ... forget which) infrequents the forums here on RR. She has provided minimal help, but my squawking did at least get me a phone call and a RR response from them.

Nice job on the BB! Can you do one up for me?

<>< Jim

"My wife is definitely a saint"

Hi Jim,
Do another one? I can't get parts for this one.

Good example: The tail rotor blade is a friction fit on the shaft which is a nice idea in crashes but it also flies off in midflight. I almost lost it one night outside in the grass so now it's glued on.
I'll probably take some dimensions off the one I've got just in case I have to mold my own out of CF sometime soon.
Denny
PS.
I'm sure I'll be getting word from HeliHobby or MIA any day now..............

I delt with helihobby once and they sent the parts i ordered late(i payed for 2 day) was told np she said would be out/ 6 days later i got the parts when i callled to get refund for the 2 day she became cold and and said basically it wasnt her problem that i had to talk to the postoffice. well since i didnt pay them they cant pay me . helihobby sent the stuff late also so was duel fault but should have been on them.even if they were the only supplier of a part i needed i would sooner trash the bird and buy new then regive money to people that dont have responsabuility! my name frustrated came from 1st getting into helicopters and and mad bad choice on bird then bad choice on business to deal with. since then i have gone through many brands helicopters to find one i liked and i have and am enjoying helicopters alot alot alot. BTW cute little bird you make me want a little one for fun

Is the Micro Star LH35 a better buy?
http://wes-technik.de/English/helistar.htm

Certainly never heard much problems about this one, except that parts from the rotor tend to fly off :S

For the last 3-4 years, I've only heard bad thing about Mario's business.

Dave.

(PS, could I use normal servo's, esc's, rx'es in that Micro Star?)

RaveDave

FemaleFlier

Denny - Above is user name of Nikki here on RR. Why don't you send her a PM and also post to her here on General Discussion. You may get a response, and you may not. It was only after a lot of bashing on HeliHobby that I finally got some assistance. I just refuse to purchase from them anymore. Hope this helps. <>< Jim

"My wife is definitely a saint"

RaveDave, if you want a sub-micro look at the HeliPro or the RotoFly. The Helistar has a reputation of being a bit fragile.
The RotoFly especially seems like a very nicely made model.
The Helistar needs sub-micro components to keep the weight down, all the sub-micros do.

Jim, thanks, I'll see if I can stir her up.
Though like I said I'm not really angry, I refuse to blow out an artery over this stuff and I'll choose where I spend money much more wisely in the future.

Denny

Milwiron

Hey Milwiron,

I saw some servo's lately that just weigh 3.6 grammes (with normal casing etc.) and a receiver that weighed little over 3.5 to 4 grammes. That means that the total weight might just exceed for example 120 grammes instead of 110 grammes.
Where can I find the HeliPro and Rotofly? I don't hope they're like the Hirobo XRB, I don't want toys. Got enough experience flying helicopters.

RaveDave

Hey RaveDave,
I've seen the RotoFly at a number of online hobby shops and also had a chance to look at them in person in the St. Louis area at a shop called Schaeffer's.
The price varies greatly from shop to shop, Tower Hobbies lists it but also seems to be one of the the most expensive.
HeliPros are harder to find.

I'm using Blue Arrow servos at 3.6 grams each from Hobby Lobby, they're not exactly great pieces of engineering but they are light and fly my remnants of a Bumble Bee pretty well.
I may go to a slightly smaller battery pack to save some weight but honestly it flies nicley at 5.2 ounces or 148 grams.
Denny

Can't I ust buy the RotoFly separately?
I got everything I need myself... I was thinking about those blue arrows, a RX from the same manufacturer, a CSM micro piezo gyro and two separate ESC's...

Can't find the rotofly separately...

Thanks,

RaveDave

Postscript:
After going back and forth for a couple of days with Mario at MIA Designs he offered to inspect and if he agreed, replace the parts I felt were defective.
I did thank him but said I am not interested in returning this heli to its stock configuration.

I fly this cut down 12” Bumble Bee remnant in a 3 foot x 3 foot area next to my desk. I can never escape the turbulence of the rotor off the floor, walls or furniture. The bird is stable yet responsive. I’ve whacked it in to the paper tray of my laser printer and was able to recover flying before it hit the floor.
Outdoors I have to fly if off grass, we have 36 acres and not a speck of concrete or blacktop. I use a Tupperware container lid or a foot square piece of cardboard to take off from and land on to keep the tail from snagging grass blades. I get well over 10 minutes from a 340 mA. Li-po pack. The gear I cut from MDS filled nylon shows no wear.
Like I said, I’m happy with this configuration, it’ll never be stock again. Stock, I couldn’t hold it in a hover for 5 seconds before things started going wrong.

I have started experimenting with a cut down tail blade from a Piccolo replacing the formed CF tail blade from MIA. It appears the Piccolo blade is more responsive and less work for the tail motor.
To finish my experiments (fooling around), I need to turn a better mounting hub for the Piccolo tail blade but I suspect it will only improve the performance.
I’ll let ya’ll know.
Denny
PS.
RaveDave,
I've never seen just a RotoFly without a radio, that's a problem. Like you, I don't need another radio laying around.

RaveDave, I hate to even mention this but HeliHobby had a RotoFly in their garage sale area for 189 bucks. With the radio that's still cheaper than a Bumble Bee kit, HeliPro or HeliStar and from my experience I wouldn't call the stock Bumble Bee a flyable machine.
If it's still there, $189.00 is a pretty good price comparing it to similar submicro-heli's.
Denny

Thanks for your help!
Well, I hope mario will just give you the parts you are entitled to!
Also... I want to ask you for a video ^^ do you have/can you make one?
Still, IMO, you have done a great job holding your head up high and making this heli fly

RaveDave

Thanks RaveDave.
I'll try to get a short video shot and uploaded.

I wanted to mention that I've been using an MS Composit heading lock gyro. You can see it clearly in the picture. The case has been removed and wires removed or trimmed to save weight.
Since everything I'm using on this thing is dedicated to sub-micro playing around I'll probably remove the plastic housings from all the servo connectors and replace them with colored heat shrink to save a few more grams.
Denny

I have 2 Bumble Bees. One for parts and one i am trying to get flying for the last 3 days.

But first. I agree with the RotoFly being a nice little bird. And you can buy them like I did off ebay from newbies for about $125. The electrics are almost worth that. The newbies get frustrated with them and sell them. But they fly OK if you know how to fly a helli.

I have 2 rotoflys and they fly right out of the box. Just get it out of ground effect and you can controll it. A little triming and you are all set. I even did forward flight at the park and it was OK other than you can get disorigntated easily with them that small. They do not cavitate or have blade coning problems as much as the hummingbirds do. With the training gear they are quite stable in a hover. Without it they take a bit to tame them down.

The humming birds I have, seem to fly the best. They are most stable in a hover, I have 4 of those. And they are quite durable but so are the RotoFlys (except the rortflys rotor heads break easily).

I also have a Caliber M24 EP Kyosho. It hovers nice but dang it is nasty on landing it a tad hard, bent the metal tail boom, broke the canopy, striped the plastic motor drive gear (plastic dang), broke the main landing gear all from one landing. I have only landed it 3 times. I think I will leave it on the self for a while. Stay away from that one. It also does not take lipolys. Looks nice though. The plastic gears are different mesh then the hummingbirds and will not take a metal gear as a replacement. The teeth on the plastic are real fine and pointy, not rounded like normal. And will not mesh with the very large main gear. Much larger than a humming birds main gear.

So I have a little history with flying electrics.

Back to the bumblebee... Mario at MIA is a nice guy, very busy and can be slow to respond. But he is concerned. And he even called me a month ago and talked for about an hour to me about hellis and live in general. Heck of a nice guy. He has hired some help and hopefully that will help the sales and response to emails get better. He did som nice stuff for me to. So he is trying to help us.

But unfornately trying to get this Bumble Bee choper to fly has been harder than all the others I have had. But I have only tried it about 8 times so far maybe 15 minutes of flight time, all sliding on my deck and bouncing off the deck. Little 1 foot out of control hovers followed by a hard landing. Nothing major broken yet other than a main bearing. Not sure how that happened?

Seems like the rotor head is too tight as are the links between it and the swashplate. I already went through one swashplate bearing and two links. It seems to be reasonably crash resistant, like a rotofly or hummingbird. But with wood blades they start to get banged up in a hurry. I like the plastics on the hummingbird and Rotofly for durability. The rotofly blades would probably fit fine on the bumble bee. But I have not tried it yet. I am using a RotoFly canope on the bumblebee.

The current problem is that when I try to get in a hover it wants to go to the left and rotates slightly left too. Adding right cylic trim makes it want to cyclic forward. trying to correct it with normal inputs when it is in hover makes it less stable and still uncontrolable. It contines to the left even with max right cyclic. Almost like it is 90 degrees off. But the controlls are setup correct. I even tried switching the cyclics so it was 90 degrees off but that did not help. It was no less controlable though!

I have had problems like this with other helicopters in the past. Ususally it is from stuff being to tight. Not sure how to losen this one up.
I am going to try to get this going, maybe with Marios help? But I would like to use this in it's stock form if possible.

I am still working with it but right now my best flyiers are the Rotoflys and the hummingbirds. The Caliber is a money pit.

I have not given up yet on the Buble Bee.

-Stacey

Hi Stacey,
Following Mario's directions I split the ball links and spread them apart a tiny bit. At this point they were free moving like other heli's like to have but not at all sloppy. The problem was at this level of engagement they just fell apart in the air or while trying to land. There simply wasn't enough plastic to form an undercut to hold the ball in the link unless they were too tight. The gimble ring was also a bad fit allowing the flybar to flop around wherever it wanted to go. I think if Mario wants to keep selling these things he’s going to have to invest in fresh tooling. Molds don’t last forever.

I had a heck of a time getting the stock wood blades to track, it took two nights of “adjusting” to get them to track sort of evenly. I have a feeling they were cut from two different pieces of wood, even though they were balanced and rebalanced and rebalanced, at high speed one blade always lifted above the other, adjusting the pitch and weight of the bade only made marginal improvements. I suspect one blade was just stronger/stiffer wood than the other.

I agree Mario is a nice guy but when he says he's going to do something or has already done it I kinda expect it to happen. Twice he told me parts had been sent, twice he never bothered to send anything.
I'm waiting for a credit to be applied to the credit card I used, we'll see how long that takes. If it takes more than another week I'll let Mastercard handle it. Mario has been around since 1985 according to his history page, I can see why he never built up a fan base or following of loyal customers.

I've been flying RC heli's on and off for well over 25 years and I couldn't get my Bumble Bee to fly decently for sh#!. I'm not a great pilot but I can set up a bird to fly, not this one. It all boils down to bad quality control, a marginal design and even poorer customer service.

By contrast, the rebuild I did of the BB with Piccolo parts flies beautifully. Last night I was outside flying in 10 mph winds, it was squirrely but I could still get it go where I wanted. On one takeoff I lifted off a little too slow, I slid in to the grass from the wind, before I realized the tail motor was trying to run I burned it out. That was all my fault.

I’m glad to hear the HeliStar and RotoFly are decent machines. The more good machines there are to choose from the better it is for the hobby.
The stock Bumble Bee is a full time job, not a hobby.

I think my next step in sub-micro playing around will be to fabricate my own heli chassis out of CF sheet and tube and get rid of what’s left of the Bumble Bee. You’ll notice on your BB that the main motor isn’t held rigidly, that allows the gears to slip under load, I’d suggest taking some scrap CF sheet and reinforcing the area where the motor screws are. There’s also no decent place to stick the batteries and adjust the CG on the BB, that’s an easy fix with a new fuselage.
Happy flying,
Denny

Bumble bee

Denny,

The new ball links do not require splitting according to Mario. They do push on hard but they fit. That may be part of my "too stiff" problem. I do not follow the problem you had with the gimbal ring and flybar. They bolt together with 4 bolts, how does it flop around?

It does pop off the rotor head easily but you want that in a crash.

The wood blades tracked OK for me. Hmmm this sounds like I am Mario's salesperson. I am not. But I did not have that problem.

I do see what you mean about the motor mount. I was surprised that it was not 2 closed slots. They are open to the gear. Does not see like enough to bite onto. But it is holding so far.

The battery I just let rest on the platform and rubber banded it to the vertical support and below the platform. I am using a Rotofly canope which is wider and fits the battery sideways on the platform.

I am 50. Been doing RC flying on and off for 32 years. First helicopter was in 1981. I am still not very accomplished as a helli pilot but I can get them up and run them around a bit before they need reassembly! They are way harder than airplanes but are more of a chalenge. ;-)

The landing gear on the Bumble Bee is pretty strong (so far) it absorbs a hard landing nicely. I broke the landing gear on a RotoFly once. It is a bit brittle but is OK if you are gentle. I practice hovering and adjustments on my wood deck so landings are a bit harsh sometimes, especially when they wrap themsevles around a chair or the table. The Rotofly does well on grass fields. I dropped one from about 25 feet and it was fine other than the broken landing gear. Why did I drop it you ask? I got disoriegntated and just lost it and I chopped the throttle before it went full power into the grass.

I will see if I can get a chance to run another battery down on the Bumble Bee today. Maybe it will loosen up a bit.

-Stacey

It flys!! - Well, hovers anyway

An update...

I went back and re-read one of Mario's emails to me and I realized I mis-read part of it.

He said that the control rotor had been upgraded and there was a new flybar and rotor gimbal ring in the kits now. The gimbal ring fits nice and smooth on the see-saw ball pivots so there is no need to slit the rings that fit over the see-saw balls, except for the ones the 2 control links go on from the swashplate.

I missed that last part and had not slit the control links. I thought they had been changed as well.

So this time I put a little oil on the link connections and swashplate bearing and nylon ball socket as he said I could do and slit the control links that were not previously slit. Those two things, oil and slits, loosened things up quite a bit.

Now it hovers and is controlable!!! I did not get it quite trimmed out completely yet before the 340 MAH battery gave up. But it is looking way better. I can control it with input in a hover. Before it did what it wanted to.

So there is definately hope that this Bumble Bee will fly pretty much stock.

By the way I took a nasty crash into the lounge on the deck in the process of trimming and getting out of groud effect. The flybar popped off the rotor and off the control links as it is suppose to. It all popped back on with no damage and flew fine afterwards untill the battery quit.

It seems OK so far. It just needed loosening up.

-Stacey

Hiya Stacey,
The gimble ring snaps on to the See Saw with ball links, those ball links on mine were very sloppy allowing the flybar to flop around, much more than any heli I've ever flown before. Squeezing them down with needle nose pliers only worked for a few seconds in the air before they loosened up again.

I also found that one of the two flat head screws that hold the See Saw to the rotor hub kept coming unscrewed. It's a real pain in the butt to get at them without unsnapping everything. I finally replaced them with a pin. The pin was an easy fit in the hub and tight in the See Saw so it stayed in place but allowed the See Saw to move easily.
I'm 52 and have been flying RC since I was 14 or 15, my first radio was a used Controlaire 10 channel reed unit. I've been around a lot of ball links, none as bad as the ones in my MIA kit. Like you, I did try some light oil on the links.

I got very little satisfaction from Mario other than broken promises to ship, he explained he's very busy, yeah me too, that's why I moved on and made my Bumble Bee flyable in a couple of hours with parts on hand. I also figured if I kept it stock and broke something I couldn't count on him anyhow.
Like I mentioned he did offer to look at the parts and replace them if he felt obligated to. He would need a week to inspect them. His cost on these parts is probably 10 or 15 bucks max, he's wasted more of my time than that.
I know I may sound impatient but honestly I never pushed the guy for a date and he never did what he said he did.

I spent 10 times more time trying to get his parts to work than it took to rebuild it with Piccolo parts... and it's now much smaller and very controllable.
The bottom line is if I had waited for Mario to do what he said he had done, I'd still be waiting.

Anyhow, enough about the Bumble Bee on to smaller and better heli's:
I've got some CF stock on the way and a new fuselage designed for this heli. I'll let you know how it turns out.
Best of luck with your Bumble Bee.
Denny

Oops, I wanted to mention I haven't forgotten about uploading a video.
I'm waiting on a new tail motor (no not from MIA) to replace the one I fried the other night stalling it in the grass.
I'm tempted to try a GWS IPS motor or a brushless motor in the tail direct driving but either will add quite a bit of tail weight, which this thing doesn't need.
Denny