wanting to do something different
09-03-2013, 02:29 PM
#27
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Would like to pictures of this or video sounds very interesting good luck and hey everyone can say your crazy but if you built your own helie and it worked let's here what they say than lol
09-04-2013, 03:55 AM
#28
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That K&B is an old school plane engine. I wore one out on my trainer planes 30 years ago!
it will not work in any application where there isn't plenty of cooling air flowing over the head, as it doesn't have the large fins like a standard car engines does. no one makes a replacement cylinder for water cooling for it. Also nitro $20 and up a gallon so it will be on the expensive side to run. it also prefers caster oil vs all synthetic oil in the fuel. 10% nitro is all the engine needs, 15% max.
In order to build a heli you would have to come up with some sort of gearbox that not only drives the main rotor but the tail rotor as well from the same engine. Not as simple as it sounds which is why nitro helis aren't cheap.
Building an air boat would be a fun and not that complicated a project. Dumas makes one in the correct size if you want to look for a kit. Google air boats and you can probably find plans online.
K&B sold out a long time ago and are now owned by MECOA (http://www.mecoa.com/) and are still produced in the USA, not sure about that model though.
Might be better to sell it in the right forums or the big auction site and put the $$ into something you can use.
Bill S.
it will not work in any application where there isn't plenty of cooling air flowing over the head, as it doesn't have the large fins like a standard car engines does. no one makes a replacement cylinder for water cooling for it. Also nitro $20 and up a gallon so it will be on the expensive side to run. it also prefers caster oil vs all synthetic oil in the fuel. 10% nitro is all the engine needs, 15% max.
In order to build a heli you would have to come up with some sort of gearbox that not only drives the main rotor but the tail rotor as well from the same engine. Not as simple as it sounds which is why nitro helis aren't cheap.
Building an air boat would be a fun and not that complicated a project. Dumas makes one in the correct size if you want to look for a kit. Google air boats and you can probably find plans online.
K&B sold out a long time ago and are now owned by MECOA (http://www.mecoa.com/) and are still produced in the USA, not sure about that model though.
Might be better to sell it in the right forums or the big auction site and put the $$ into something you can use.
Bill S.
09-04-2013, 10:48 AM
#29
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As far as cooling goes, could I put a small 2inch fan on it and duct the air past the cilinder and head?! That way I won't use a bunch of the power on a huge prop when all I need it for is to cool it down.. also, gearing stuff is easy, producing the exact needed ratio is what is hard. As for a gear box, I think I have some old drills and a one of those angle gringers, the kind with a ring and pinion gear set laying around. What do you want pics of exactly?
09-04-2013, 04:34 PM
#30
Wow, I didn't mean to offend anyone, I've only made gocarts, minibikes, and things.. In response to the 5000/1, (26" x π ) /12= feet per rotation(6.83),rpm for 1mph(7.33). Give the ability to pettle take off and the top rpm of 13000 of the .40( I'm not going to account for drag or friction but they are often under 20% at slower speeds) so you have to get 50 rpm at the wheel to be going 1 MPH. And one HP= 33000lb-ft /min. So let's say 33000/50(feet in a min to =1 MPH)=660lbs is the force at witch would be "applied" if mass and drag equal 660lbs, one MPH would be all you'd ever see with 1hp because you'd need the b&k40 to be raped out to make 1hp. In case you wanted to do some math on your own force in lb x distance in feet / all over time in min x 33000 lbft
No harm at all no one is offended at all,
what are u trying to show me? Are u trying to tell me with 5000:1 gearbox it will move 6.83 foot per rotation of the motor Because that's not right at all... And are u telling me that 50rpm at the bike wheel would be 1mph???
my advice, re check ur maths... It doesn't make sence or add up.
Forget using a gearbox, that will never work, the weight from something that can handle the required rpm and torque would be to heavy to see any real increase of torque.
the idea of fitting a nitro engine with a prop to a bike is a epic fail, it sounds ridiculously dangerous. We don't want to see u hurt
09-05-2013, 04:38 AM
#33
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6.83 is feet per rotation of the wheel. I don't remember what 50 was but its not rpm. 12.88 rpm at the wheel is 1mph.. I've reset my calculater already so I can pull this stuff up and look. I'm going to see what I can do and post pics and maybe a video much later on. Thanks for reminding me how dangerous a blade is.
09-06-2013, 09:37 PM
#35
6.83 is feet per rotation of the wheel. I don't remember what 50 was but its not rpm. 12.88 rpm at the wheel is 1mph.. I've reset my calculater already so I can pull this stuff up and look. I'm going to see what I can do and post pics and maybe a video much later on. Thanks for reminding me how dangerous a blade is.
just be carefull, no BS, when I was 8 one of my family friends dad lost a good 20mm from a finger using a windup starter on a air boat. Some how it back flipped and chopped it clean off. And myself on the same air boat.... I wound the starter spring to much and the hook came of the prop and went straight through my finger like a piercing.....then I had the fun part of trying to hold the spring in my finger so it wouldn't rip a chunk of skin and flesh off because the spring was still coiled up. It's pretty awkward trying to unwinding the spring where the only way u can is by turning the whole boat around ur forearm.... Oh yeah and back then my blood clotting time was 11min so it made a bit of a mess
Lets just say I didn't get to show the boat for show and tell and the teacher wasn't impressed
09-07-2013, 08:44 AM
#36
Do it, I love seeing scratch built stuff, it really brings a new dimension to RC.
just be carefull, no BS, when I was 8 one of my family friends dad lost a good 20mm from a finger using a windup starter on a air boat. Some how it back flipped and chopped it clean off. And myself on the same air boat.... I wound the starter spring to much and the hook came of the prop and went straight through my finger like a piercing.....then I had the fun part of trying to hold the spring in my finger so it wouldn't rip a chunk of skin and flesh off because the spring was still coiled up. It's pretty awkward trying to unwinding the spring where the only way u can is by turning the whole boat around ur forearm.... Oh yeah and back then my blood clotting time was 11min so it made a bit of a mess
Lets just say I didn't get to show the boat for show and tell and the teacher wasn't impressed
just be carefull, no BS, when I was 8 one of my family friends dad lost a good 20mm from a finger using a windup starter on a air boat. Some how it back flipped and chopped it clean off. And myself on the same air boat.... I wound the starter spring to much and the hook came of the prop and went straight through my finger like a piercing.....then I had the fun part of trying to hold the spring in my finger so it wouldn't rip a chunk of skin and flesh off because the spring was still coiled up. It's pretty awkward trying to unwinding the spring where the only way u can is by turning the whole boat around ur forearm.... Oh yeah and back then my blood clotting time was 11min so it made a bit of a mess
Lets just say I didn't get to show the boat for show and tell and the teacher wasn't impressed
Heard about that last night.
