3D printed beam mount .049 backplate

Hey congrats Jason yea did you notice how well it ran with that coarse
thread NV. I was quite impressed with the steady NV even in
richer mode. Was fun to put it on the edge of singing. Old school
CL for stunt flying nose up and off she goes level off and easy as
she goes. No issues yet but then I am doing pure function checks.
The 45 deg. angle looks good and delivers smooth flow the next
test vid will be looking for rpm backplate gain.

King Bee?
Killer Bee case, crank and piston 290 #1 thick walled cylinder SPI.
2 head shims to marinate the piston and cylinder together.
Vid on Sunday.

In the end this one will get a Kamtechnik turbo plug adapter and
OS Gold RP6 turbo plug after base line testing.





Valentine spinner
APC modified carbon drone prop 4.44 x 5

Loud open exhaust with SPI and bowl style plug creates more noise then
a turbo plug / trumpet adapter. Brief run up to see it works with 92 mph pitch speed this makes for a very fast RC reedie!



Quick idle check was down in the 5.6k range, again what a ear buster reedies are!

Quick test very loud top end and low end bit rich still.
Need to tinker with the throttle stop can fine tune with a servo.
Needs a manifold / header and pressure tap!

Cox King Bee RC!



 

Next up to bat, required a NV so put in a 128 TPI from a postage stamp
engine shown, the engine was featured in the first vid I posted on this thread.
Engine now has a modified Mecoa plug adapter, ground down to provide better
compression similar to a Cox high compression head.

Ready to test thanks to Jason providing yet another one of his latest creations!

1/2A Nut wrote:

If I still still smoked, I'd need one now.
Tanks Jason. namaste
Bob

Looking good.

I have 2 sets of beam mount backplates yet if anyone wants to experiment. Send me a PM.

Ran the vintage engine #2 cylinder / 1 bypass port
Mecoa plug adapter and glow plug / 6x3 prop.
Mount worked great used 3 screws to hold it down.
Had a broad range NV with the 128 TPI

Engine ran steady but no power house due
to cylinder type and plug.

Probably the plug adapter. Try with a standard 325 glow head. I bet performance improves.

The bore of the intake is .2”. Same size as a killer bee backplate. I could print one smaller like on product engine backplates for lower performance applications and it would probably have better fuel suction.

Actually fuel draw was great. Yes for sure the plug type
but then it is a single port cylinder don't expect a screamer.
The main thing is the engine ran steady with the backplate
configuration. I was not expecting anything stellar was fun
to see what it could do in this config.

Put the Cox plug on it and the old vintage #2 single port gave
it's best effort. Engine ran steady easy precise tuning with 128 TPI
I have plenty of performance cylinders was just fun to see what
the older thin walled could do.

APC 4.75 x 4 / .060 hp - 53w / 61 mph pitch speed

1/2A Nut wrote:Ran the vintage engine #1 cylinder / 1 bypass port

I believe a #1 cylinder is a two port.  The #2 is the single type.

Here is the run steady once the NV was set.
I would consider the backplates a success!
Ran with the original copper reed! Turbo plug
and mylar reed should boost it up 1.5k or more.

Hello, I am very impressed with this amazing 3D printers applications for our engines.

Congratulations Jason.

I made years ago complete engines non functional in PLA material in I-Prusa3 printer and don´t blieve tha PLA could resist high temperatures, now Ihave a very good 3D printer at work, Ultimaker S5 able to print ABS and high quality, in a few month we can print COX backplates to test.

I like to have stl archives to print or better original cad archives, I use solidwork program to design.

Warm regards
Jose

I still not have time to read complet post.

How about a 3-D printed entire crankcase with integral beam mounts a la Space Hopper, a crankshaft bushing insert and a threaded ring insert for the cylinder. Then a ground off the edges postage stamp or Sure Start back plate could be used. A good pace to start would be with an examination of a Testors plastic pipe bomb crankcase.

ticomareado wrote:How about a 3-D printed entire crankcase with integral beam mounts a la Space Hopper, a crankshaft bushing insert and a threaded ring insert for the cylinder. Then a ground off the edges postage stamp or Sure Start back plate could be used. A good pace to start would be with an examination of a Testors plastic pipe bomb crankcase.

I just stick with backplates for now. I’m sure it could be done though.

1/2A Nut wrote:Here is the run steady once the NV was set.
I would consider the backplates a success!
Ran with the original copper reed! Turbo plug
and mylar reed should boost it up 1.5k or more.

Thanks for taking the time to run these. I ran them but didn’t capture video.

Please suggest any improvements. I know moving the needle back a bit would help with the burnt fingers.

Most welcome Jason I was happy to help out and appreciated testing your designs.

Regarding burnt fingers, .2 movement will need to extend the venturi too.
I was lucky the exhaust ports are facing to the sides for both engines.
A manifold / header to redirect the heat and oil would solve it.

A 3D printed crank case with bearings would be interesting for the .020
I have three Olympics it is a nice touch / able to turn up big props without
wear on the crank case runs cooler perfect for speed props.  Small bearings
for the .020 will be reasonable in price the engine displacement should not
put too much stress on the case.  A screaming TD would be quite the treat.

Ode to the power of the 3D printer.





Perfect for profile RC stunt planes or throttled CL - For RC vertical NV and Cylinder is ideal.

Looking good. The car exhaust deflector will keep the slime off the plane.

Needs to be modified has a choke point at the start of the header robs 30% of the power.
Eye candy if left alone at best, choke point needs to be drilled out and flared at the cylinder.

The channel around the ring needs to be blocked out to turn the cylinder into a single exhaust port.

I have often thought of making a tight sleeve and relieving the back, drilling and tapping for a tube out the back. A bit hard to make the sleeve without a CNC, it may need to be offset or just fairly thick. It would block the one exhaust port on the front which could be machined to make a schnuerle port rear exhaust. Only problem is the existing exh. port is a bit high already and would need to be filled or the other exhaust port raised or??? It could use up some single bypass cylinders which are not good for much.

60 degree angle vs 45 degree. Added more material for support. Should shorten the overall length a small amount with a Tarno or TD RC05 carb attached.

I had selected the Cox carb based on weight, given the reed engine's potential power.
The TD can make more so save my Tarno carb's for that. I can see where you want to reduce
the footprint of the larger Tarno carb on the back end of the mount. At 60 deg. there is less
hanging mass / stress so a plus with a vibrating engine. Bit more beef on the beam is always
a plus over time will pay off.

That's going to make for a short mount up front or raised hard wood to clear the CC But does look good !!  

I bought a Cox RC carb from Fred to help out on his quest and mine.
Here it can be used with the straight flow backplate version.

Note the distance it takes up in comparison. The carb should be
rotated so the NV clears the profile fuselage / ease of adjusting.