HK600GT Gasser Conversion

So I picked up an HK600GT helicopter kit and decided to convert it to a gasser (A spark plug engine powered heli). I am doing a series of videos of the build and will post them here as I progress. Quick specs:

HK600GT
600mm CF Main Blades
25cc Sears Craftsman string trimmer engine
All custom work
Will be used for FPV

Video link:
http://youtu.be/mZH-pV6SR44

Pelagic,

Oh... That was just awesome.  Loved the video!  Even got a glimpse of your CNC.  Was surprised to see you using flood coolant.  Not many guys doing that on open machines, but it's so important.  Hope you keep the camera rolling as the project progresses.

...Tiger

Thanks guys, I tried dry cutting at first, then with a mister nozzle and realized in about 10 minutes that both methods suck, once it starting flooding around here I never looked back  8) it is the only way to go. I have a shower curtain that goes around the spindle area when I really need to turn up the rain. A 1/2" EM at 4500 RPM with throw coolant 15 feet away.

GC, this is just a prototype and not even the helicopter that I wanted to build. I wanted to buy a cheap .90 size kit like a JS models and install a Honda GX35 4 stroke engine inside and run 800-810mm main blades and if things worked out then sell them. But all of the low to mid end .90 kits are sold out and even some being discontinued. So I decided since the HK600 is available in the USA, and parts from the T-Rex line can be used, to just build a smaller (and even cheaper) helo and see how well it does. I don't have any idea what the performance will even be. I know it will fly, but I doubt you can get this thing upside down for very long if at all.

So to answer your question when I do finish parts anymore I either shoot for a nice machined surface finish and leave it natural, or if I have enough parts I get them annodized at metal finishers here in town, they do really good work, and engraving shows up very nice in an annodized finish. I do get things powder coated on occasion, but usually only larger steel fabrications at this point.

As I am sure Tiger noticed in the video, the part that was to be kept (engine bracket), was falling out un-clamped from the part that you throw away (which was clamped). This was backwards and not the right way to do things, but it was fast and easy to obtain a test part to see if it would even work at all. If I made more that needed to be really nice then I would make a sub plate to bolt the stock to and hold the part rigid all the way until finished. The difference being about 4 more hours of setup and planning for a part that simply looks better to the human eye, but functions exactly the same (the human eye so dang picky about things all the time).

PP - I had not heard of Metal Finishers.  I just looked them up on Google.  What is their minimum?  I'd sure like to find someone local that wasn't super expensive for hobby quantities.  I've used a place in Medford, but they are expensive, inconvenient, and the work is ho-hum.

Also, you were reading my mind about the fixturing. 

...Tiger

P.S.  If anyone needs powder coating, Ferguson Fabrication (now in Merlin) is really nice to work with.

Metal Finishers does top shelf work, they are part of Siskiyou Corp and do high end medical research componants. So there is still some cost there, but quality is high and they are very easy to work with and helped me out a lot when I got started. The minimum is/was $60.00 per batch. But we could all bring everything in and combine it with no problem, and the minimum will do a lot of surface area.

http://www.metalfinishersinc.com/MetalFinishersInc.shtml

Bill Ferguson is the only guy I go to for powder coating, he is very good at everything he does and very easy to work with. If he sees a problem with your design and how the coating with affect it he will let you know.

Don't believe I almost missed this thread ...
 
Wish I had the cash to drop on such gorgeous machinery like teh CNC luv I'm seeing here
{LMAO} Last time I worked w/ milling machines the concept of CNC wasn't even a thought    8)  ;D

Yes I too ... will intently be following this thread

One question though, why the Weed-Eater engine 
I would have thought you would have gone with an engine specifically tweaked and/or ported
for Rc-GASSERS these days ...

PP - The $60 isn't bad at all.  And I agree that if we put the word out, any number of other guys might have something to throw on the pile.  Their site seemed to indicate they only did clear and black.  Is that the case?  Wouldn't want those colors on anything that flys.

Looked at your other videos.  I thought your brass "turning" video was clever with the "gang" tooling.  Think I'd still rather use the lathe, but that was pretty neat.

...Tiger

Your dating yourself a bit there Wood! John T Parsons invented CNC in the late 40's - early 50's! Ha, J/K, I know, shops didn't really see these until the 80's and then 90's for smaller companies. But it should be interesting to note that CNC was invented specificly for the purpose of making helicopter main rotor blades!

http://en.wikipedia.org/wiki/John_T._Parsons

As far as the engine choice, I went this route for a number of reasons. I like a challenge and since the world has already established that you can go down to the store and pick up a nice T-rex 700N for $3K and go flying with a very nice helicopter, I wanted to see what could be done using ordinary items usually found laying around the house with very little investment. My hope is to be flying for less money than what a 450 electric costs. So far I am on track for completion at under $400.00 which does not include the FPV stuff, but a flying helo. And as I said earlier for this project I have zero interest in 3D, I even like the idea of it being under powered, it would be very cool if it was a little bit susceptible to Vortex Ring State (not too much) and require you to be concious of maintaining ETL when flying like a real one.

Tiger, they only do Black that I know of, so for bright colors we would probably need to look at powder coating. I don't know what that stuff is that Bergen RC machines his frame rails out of, but it is very bright and used a lot in helicopters. The brass turning like that is because for the product I manufacture I need two parts turned, the brass battery knob and a plastic insulator. To save me the $10,000 from buying a lathe I spent 6 weeks figuring out how to do that. It was the first G Code I ever dealt with, all hand written in Notepad, all mapped out to the tool holder I made for the operation, I don't think I have it in me to ever do that again anymore........ But I paid for my mill off that product......

Your dating yourself a bit there Wood! John T Parsons invented CNC in the late 40's - early 50's! Ha, J/K, I know, shops didn't really see these until the 80's and then 90's for smaller companies. But it should be interesting to note that CNC was invented specificly for the purpose of making helicopter main rotor blades![/quote]

Yeah I was thinking the early 70's which was my first year of high-school when I played with the schools milling machines

Re GASSERS: Fair enough, racing GASSERS are pretty expensive, well the ones that have been really worked over are. Where as the humble weed-eater is relatively cheap and especially when one has one in the garage doing next to nothing. Of course if we "ported" your weed-eater you'd get some extra go for next to nothing

Dang, where do all you CNC guys keep coming out of the wood work from? I never heard of any place in Merlin that does any of the stuff that you do? Yeah, we ALL need to talk sometime! I am finishing another video installment to upload later tonight. Gotta go eat something first.

BTW it looks like Bergen RC uses G10 (Now known as FR-4) for his frames, it is basically like carbon fibre and comes in colors like bright orange.

http://en.wikipedia.org/wiki/FR-4

Got some work done this weekend, uploaded videos #2 and #3 tonight, things are going very well and much easier than I thought they would (I never built helicopters before, ok actually I never even saw an RC helicopter before August of this year). I have the top half mounted to the bottom half and need to work on the drive train now, but there is only 3 more parts I need to design and make for that.

Video #2:
http://youtu.be/Di3P0uDjERM

Video #3
http://youtu.be/Og6raayo6Mk

The next videos will probably just show the progress, I think everyone gets the point on how things are made now.

Oh... That was great (again)!  Thanks for the update PP.

...Tiger

A couple of photos with the hood on:

Image #2:
http://www.bluefincnc.com/pics/HK600_2.JPG

Image #3:
http://www.bluefincnc.com/pics/HK600_3.JPG

Image #4 (My favorite):
http://www.bluefincnc.com/pics/HK600_4.JPG

The hood makes it actually look like something  8)

PP - STOP what your building and go over to Chief in Merlin and get one of these.  This will solve all your problems and make you the most popular guy at the field.

http://www.chiefaircraft.com/radio-control/engines-turbines/jetcat-turbines/jc-hp5.html

You're only going to be able to fly at Redwood once so wait for me to get there!

...Tiger

I was kinda optimistic in thinking that you might have a 5 axis laying around in your shop and had plans for building a turbine that I could swap out when I was ready for the power upgrade? no?

Actually I was wondering if we could somehow make this thing into an RC of some sort?

http://youtu.be/BZoymnZRBVc

Don't pay any attention to the big puddle of fuel slopping out underneath it, he is obviously a scale modeler and going after that authentic SR-71 Blackbird look.

Too late to turn that into R/C anything.  I heard the place blew up right after the video ended.

...Tiger

Got a little bit of work done, here is another video update:

http://youtu.be/hLtCv1l2aWw

Pelagic,