E-pilot's Bump! - Page 15 - RC Groups
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Jan 22, 2007, 03:32 PM
Only nerd in the village

Bump in Korea

Here is a video of a a Bump built from a kit. Builder is Yukio Takahashi from Korea:

Bump Maiden Flight (2 min 20 sec)

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Jan 22, 2007, 08:29 PM
Registered User
Dear Michael
Thank you for sharing the BUMP kit. She flew very well at the maiden flight. Also, thank you for putting the link to my maiden flight video. I like the BUMP so much. Despite it was my first micro size craft ,the kit was so easy to assemble due to its sharp cuttings. As you reccomended on the instructions, the matching with the Minor Receiver, 7mm Didel Motor and 50mAh Lipo looks like a good choice. The maiden flight made me so happy and so amazed. How controllable and stable she was! I even did a loop! Believe your BUMP kit is one of the best choices for someone like me just stepping into the world of micro size airplanes, on the other hand, sad to know the sales didn't go well and no longer you are selling the kit.
Again, thank you so much for sharing the kit and your knowledges.

Last edited by Gopeewee; Jan 22, 2007 at 09:03 PM.
Jan 23, 2007, 08:30 PM
Registered User
Kelley's Avatar
Does anyone have a BUMP kit they are willing to part with or are there plans available? I should have bumps quicker and got one while they were still around. I just got all the electronics together :-(
Jan 23, 2007, 11:33 PM
Registered User
I want one too dag-gon-it.....I just got into this indoor stuff, and am really hooked.....
Jan 25, 2007, 08:41 AM
Registered User

BUMP goes brushless

My first BUMP as described in post no.178 is a winner and has meanwhile gathered much airtime. Therefore i decided to use the trusty BUMP-design as a carrier for my homebuilt brushless micro-outrunners. Currently i finished a tiny 3,6 gramm outrunner with only three teeth and four poles, which i made from the stator of a small brushed motor. This machine has not the highest efficiency, but the output is more than enough for a little Bump. My friend StephanB sent me a few weeks ago a parts-set cut from 1mm foam called styrodur. I added a Falcon Breezeblock, a single lipo 145 mA, an YGE4BL brushless controller and my new motor. Total flying weight with a STO 2,7 x 2,6 prop is 23 gramms. I could not wait till next indoor-session and maidened it outside, although the weather was really cold and a breeze has sprung up. It went straight away with just a little bit of throttle used. The wing from the 1mm styrodur turned out to be too fragile to withstand the gusts and bent a little under the loads, so i have changed meanwhile to a wing from 2,5mm depron. I'am really happy with my new brushless BUMP, very good flight-performance. Once again a success with a BUMP!. Have fun with the pictures :-).
Jan 25, 2007, 10:22 AM
Restricted User
StephanB's Avatar
Hi Dieter,
again, a nice one. I'am happy, that the parts-set worked. I wasn't sure, whether the material is strong enough. Good to know, that you could replace the wing with something stiffer before damaging this jewel of a motor.

Question: The propmount is integral part of the bell? That prop seems to have a huge bore.

Jan 25, 2007, 10:55 AM
Registered User


Yes, the propmount is integrated.
That was necessary, because the outside diameter of the ball bearings amounts to 4mm. The original drilling of the prop is 4mm. I have it drilled out on 4,5mm.
That was for me the simplest solution.
Jan 28, 2007, 12:52 PM
Registered User
MagnusEl's Avatar


No problem to fly this little beauti, very responsive on the rudder, OK on elevator.
Tried a loop, but didn`t had the oomp. Almost made a roll, but it "cut out" by itself after half a turn. Maybe trying it outside some calm day...
Jan 28, 2007, 02:02 PM
Only nerd in the village
You might have the CofG too far forward and perhaps a stiff elevator hinge. Try to mass balance the elevator. My Bump loops easily.

Jan 28, 2007, 02:28 PM
Registered User
MagnusEl's Avatar
The elevator hinge is running very smoth now, after I expanded the holes where the cf rod runs throu. Mass balancing it is a very good ide, as I think you are right about the CoG, and since it only weight`s 9,02g.

And, off course you was right about the 3mm act, plenty off power for a 9 grams modell!!
Just had to get every hinge pin running smoooth....

Feb 03, 2007, 10:06 AM
Registered User
my bump came in at 18.9grms with a 50mh cell and 20.6 with a 130mh cell. I am using the micoinvent gear with the 0.7grm actuators but I soldered larger wires to the actuators and that makes them a gram each!

Does anyone think this is to heavy for the orange 7mm DD motor? It flew great earlier with the wattage microflyer gear and th 7mm motor but I didn't weigh it.

Also has anyone got any advice on the setup of the DD motor , I didn't put in any right thrust earlier and didn't notice any problems, how about downthrust?

Great model Michael, I spent most of the morning trying to get my micromoth to fly, your model only took me an hour from scratch and it flew great straight off.
Feb 04, 2007, 01:50 PM
Registered User
well it flew great at that weight but loops weren't possible. It had a tendency to porpoise a little but I didn't want to add any weight to the front so just flew it around as it was for half an hour.

Started to build a 10" version and then decided to build it into a stick fuesalage. It AUW is 13.6 grams, I think it could do with more control surface for the rudder but I will give it a go tomorrow.
Dec 10, 2012, 08:05 AM
Registered User
rogenstein1983's Avatar
Such a shame these kits arnt avalible any more, I would love to see one in 1/72 scale with a dt rx52 and Plantraco motor etc, please tell me 1/72 kits could on day be a reality there so many kits id love to build in that scale the bump being one of them
Dec 15, 2012, 12:55 AM
Registered User
my BUMP model with differential motor for turn left / right

note : minggu = sunday......., it's in indonesian bahasa (bahasa indonesia)

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