Pee Wee Horseshoe back plate

Here are pics of the backplate on the engine. I polished the reed seal area with 400 grit. It seals nice and engine has a nice pop when turning over. So far no oil seepage from the backplate.

That looks really cool!

I can't wait for the test results

Good job Jason can always add two caskets to seal it up if push comes to shove.
The intake will need to be free of any possible ingestion of carbon scraps.
The stuff wears out applicator tips there is an alt. tip for this Carbon mix.
Hex head screws should do well to join the backplate to the crank case.
Post a running vid if you can.

That's Sweet !! I likeie the black to , Fingers crossed to hear some noise .

Very nice. I too like the black. Can't wait to see the test video or just hear of results.

Changed the intake area a bit. Got rid of that gear shape cutout and went with a funnel shaped inlet and another funnel shape where it necks down for the reed valve area. Hopefully the run tonight goes well and then I'll print this version to test.

Hopefully the mods you made to the original work out good. I definately like the look of it.

It ran until the nitro in the Cox super power fuel softened the ABS and the NVA was loose and the reed melted into the face of the reed seal area. So it shows promise just wrong material. I have carbon fiber nylon I can try. Also have POM or also called Acetal.

I only caught the last few seconds of the run but YouTube is being cranky. Here are pics of the meltage.

Oops. But on the bright side, it did show promise and run!

IT Ran !!! ++++ How was the short run ? Performance wise .

I don’t know. By the time I got the needle set it was starting to die. Slowly melting.

The CF ABS print above was 1.25 hours of print time and about $.30 of material. However it proved the concept worked so it wasn’t considered a failure. Just poor choice in material.

The CF nylon spool I have was a sample from a filament extruder that was free. PLA is about $.02 per gram. Standard DuPont Zytel is $.09 per gram.

Well done Jason! Excellent work.

I should really follow this forum more closely. I did some test mills on my hobby grade CNC machine last year with the same 020 backplate in mind. I was milling them out of a solid chunk of hdpe since that is what glow fuel bottles are made of. Unfortunately HDPE either melts or chips when being milled. Chips are what you want when milling HDPE but they lead to a lightly faceted texture all over the product which caused dimensional issues in the reed seat area. I also realised I hadn’t considered the heat from the running engine in my material choice.

What material are the .049 back plates made from ? Jason , these .020 horse shoe back plates are going to be the new hot thing in the Cox world . I would think nylon would work for these back plates .

Mike1484

You dah man, Jason!

I guess the plastic should be the same Cox used on their PT-22s and .020 helicopters.

ticomareado wrote:You dah man, Jason!

TRUTH !!!!
We may have to petition the Admin to create a C.E.F. Hall of Fame !!!!

Kim wrote:

ticomareado wrote:You dah man, Jason!

TRUTH !!!!
We may have to petition the Admin to create a C.E.F. Hall of Fame !!!!

I second the motion

Sometimes things go bad when changing nozzle sizes on the 3D printer. Almost new .4 mm plated copper nozzle twisted off in the heat block. It started to squeak when tightening it up. I stopped and tried to turn it out and this happened. Good thing I have spares on hand.

Been fighting nylon and the .25mm nozzle all day. Jamming up. I tried to slow down the print speed without luck. Back to .4mm nozzle and .2mm layer height for the backplate with nylon.

I seen that pic and thought man that back plate had a BAD melt down , well glad you had a back up , Hope you can get the nozzle size figured out for the right layering .

That picture Jason resembles some of the engines I have been working on lately.

Bob