3D printed beam mount .049 backplate

Welp the socket head bolts showed up so I can assemble the next version.
So much faster to install the screws compared to the flat heads making for
easy non slip removal / maintenance much quicker and it looks good.
With a handle type wrench it is easy to gauge the torque applied.





1996 Real Killer Bee .049 RC

Looks fantastic, Brad...I guess it may take an engine cowl with the carb fully embedded in the plane's nose behind the firewall, and only the NV sticking out , so that the CG should stay aft. I mean having the rear mounted carb completely exposed in front of the firewall would pull the CG too much to the front?

Thank you Andras  

The RX battery will be enough to correct the CG should you use a cowled engine.
The wonderful transition of it all is turning a reed engine into a RC engine.
Throttle rings is one way of course, this version allows a muffler or header etc.
If used with a profile plane the plane itself has it's incorporated beam mounts.
Could have a access hatch for a scale planes to set the NV / hide the engine.

I prefer to expose the engine for all for it's beauty a most unique Cox KB engine and assembly!
Ultimately for me the power plant is a big part of the hobby interest I want to see it running / pulling
the plane fast and slow passes.




A mere 67g as shown / major eye candy encourages me to use it in a project!
The 65 degree mount should allow the use of a typical engine mount I don't have one to check this.
Here shown would need to remove a bit of material for it to clear and set fully on the beams.


 

Update
Ran the engine see results APC 4.1x4.1E / 23,336 rpm.
The E prop unloaded well providing stellar static power.
This prop is better than the APC 4.2x4 due to the thinner
blades and weight. Idle was checked to 9.2k rpm then
pushed it too far and the engine stopped. Will take some
setup efforts to get if functioning down to 7k with small
speed props, with a larger 6x3 idle would be easy to obtain.

Great performance with that COX RC carb..I have never really been able to tame that carb to a really low idle. Maybe a hot turbo plug will help keep the flame even at lower idle in your Killa Bee?

Yes true a turbo plug #3 would provide the best possible idle.
Really for what I do anything under 10k is enough to have it slow
enough for landing then kill the engine when it is close to the ground.
The carb is nice for safety if the radio starts acting up. The SPI
engine in conjunction with a reed induction valve makes it snap
and bark as the fuel and air gets choked down. My Nano X
low idle purrs on a #6 and the Tarno Carb without a pressure tap.

Finally got around to print the 60 degree angle venturi version and the extended needle version to prevent burnt fingers. I need to run these yet and capture some video. I printed them in natural zytel.

Printed 4 of each type and it took 26 hours at .1mm layer height.

Jason,

Do you plan to make these in black, and release some to Bernie and Matt for resale?

Would be nice to have one in .049 size, to match the .020 size I have yet to run.

Bill

I might but the carbon fiber Zytel is hard on the $30 hardened printer nozzles and the extruder drive hobs.

I’ve been printing a batch of .020 horseshoe backplates in natural zytel for testing. Better surface finish and easier cleanup.

Beefed up the mounting holes and cut out a notch in the back as a stress reliever for 3D printing. With zytel the solid long block tends to warp. Hopefully with the notch there it will prevent that when printing.

Jason_WI wrote:I might but the carbon fiber Zytel is hard on the $30 hardened printer nozzles and the extruder drive hobs.

I’ve been printing a batch of .020 horseshoe backplates in natural zytel for testing. Better surface finish and easier cleanup.

Would a 25% or so glass filled nylon alleviate any strain on the nozzles?

I have a sample spool of GFR zytel. It has an even more porous finish than the carbon fiber zytel and it is just as abrasive.

I have had pretty good luck printing direct to glass using Dimafix. First layer height is critical. Once the bed cools down the parts pop easily off the glass.

https://www.matterhackers.com/store/l/dimafix-3d-printing-adhesive-pen/sk/MR0VKNJY?rcode=GAT9HR&rcode=PPCADS&gclid=Cj0KCQjw-Mr0BRDyARIsAKEFbediPPW3Se6WuugKvfPxfxpE7rRjVzGDpaFxaFf3hllpXKnaxCmyBIIaAqKKEALw_wcB

That's really cool Jason. Looks strong.

Printing one of the heavier design in CF Zytel. About an hour left.

Simply amazing Jason. I cannot believe at how smooth it looks. So you mention that there was about an hour left from where you posted the picture, how long does it take to print out a single part from start overall? Is the time also affected by what materials you choose to use?

Here it is complete. Now just need to run it.

Beautiful pieces, congratulations Jason.

60 degrees looks right does not waste space should do well on the bench with a venturi or rc carb.

Can't wait. You're not just helping the hobby survive, but advancing it.
Thanks Jason.
Bob

That looks great! Fantastic design. I hope it runs even better than it looks!

NEW222 wrote:Simply amazing Jason. I cannot believe at how smooth it looks. So you mention that there was about an hour left from where you posted the picture, how long does it take to print out a single part from start overall? Is the time also affected by what materials you choose to use?

It takes ~ 3 hours and 40 minutes to print one of them.

Material plays a factor in how fast you can print but the 100 micron layer height is the biggest factor. 10 layers per mm with a .25mm nozzle diameter.

Looks great Jason!

I'll be watching for the release and saving my coins.

Bill

Ok so I printed 6 of each and contacted 2 interested parties already. So there are 4 sets available for testing. I say testing as I want feedback to see how they perform. All I ask is you run them. Treat them like a rented mule. I wanna see where the faults are.

I will include gasket, reed, circlip, and screws for easy installation. You just need to add the front half of an engine of your choice and either a needle valve assembly or TD venturi/NVA, tarno carb, Cox RC05 carb, or carb of your choice that’s threader for 1/4-32.

Send me a PM if you’re interested.