Home Made Cox Tee Dee .051 Carb. Fuel Nipple

sosam117 Thu Mar 04, 2021 10:39 am

Well, while trying to hook up my Cox Custom Tee Dee .051 engine, my Carb. fuel nipple broke.
I went on line to see if Cox International had one (Nope). Well let's try EX Model Engines (out of stock).
Dam. DAMMIT!

Well, let's see "IF" I can make my own?
I had some metric (6mm) brass bar stock and it was close to the same diameter as the original part.
Measured the I.D. diameter and it was close to 4.7mm (about 3/16").
Measured the O.D. of the mating part ( with my micrometer) and it was close to 4.7mm ( less than 3/16").

So, I chucked up the small piece of 6mm brass bar stock into my lathe to drill a hole with a #13 numbered drill.
After drilling a hole 1/2" deep in the bar stock, I checked to see the id. size ( it was undersized -- the way I wanted).
Using a slightly undersized 3/16 reamer (well worn), I cleaned up the drilled hole.
The wall thickness of my part was a little less than 1mm (little over 1/32") thick.
I took the bar stock out of the lathe and took ot over to my mini mill and drilled an angle hole for the fuel line tubing.
I used 3/32" O.D. tubing and carefully drilled he angle hole in my bar stock.
After that I reinserted the bar stock back into the lathe and cut off the "tubing" to 1/4" length.

Next was to silver solder the 3/32" tubing to my 6mm dia. tubing I made from my lathe.
After the 3/32" tubing was soldered to the 6mm tubing, I cut the 3/32" tubing to 5/16" length to accept the fuel line.
I cleaned up the solder off the part and buffed it up to give it a good shine and installed it on the mating part on the carb.
It was a good tight fit over the mating part (don't want any air leaks) and probably better than the plastic OEM nipple?

I may make a few more to have as backup for the other OEM nipples on my other engines.

Home Made Cox Tee Dee .051 Carb. Fuel Nipple Broken11

Home Made Cox Tee Dee .051 Carb. Fuel Nipple 001_ni10

Home Made Cox Tee Dee .051 Carb. Fuel Nipple 002_ni10

davidll1984 Thu Mar 04, 2021 11:10 am

It hapen To me tink y wil try build one look Good and solid Good trick Thumbs Up

sosam117 Thu Mar 04, 2021 12:24 pm

davidll1984 wrote:It hapen To me tink y wil try build one look Good and solid Good trick

If you can find some thick walled 3/16" I.D. tubing, it may make the job easier for the main body.
Standard K&S tubing was used for the fuel line connection.
Drill the fuel line hole just a little smaller on the main body tubing and file the hole to accept the fuel tubing at an angle.
Remember to angle the end of the fuel line tubing before soldering it to the main body tubing. To clear the mating part on the carb.

balogh Thu Mar 04, 2021 1:02 pm

This is great, sosam117, I wish I had the tooling and manual skills to produce a nipple like that. This is certainly a weak point of the stock TD050 R/C carb, I had also broken a bunch of them before I shifted to Tarno carbs with brass nipples.

It is to be noted that the 050 and 09 TD R/C carbs have the same size of nipple, so this one would work on a TD09 too.

Bernie and Matt might probably do some turnover from such brass aftermarket nipples, should someone of your skill start producing a few tens, maybe hundreds of them...(the TD050 was the 2nd rarest serial production COX engine with only maybe 2 times 2000 ever produced, and perhaps only a few tens, or at best, hundreds of them have remained in active use by today..myself being one of the users.)

EXModelEngines Thu Mar 04, 2021 3:26 pm

balogh wrote:This is great, sosam117, I wish I had the tooling and manual skills to produce a nipple like that. This is certainly a weak point of the stock TD050 R/C carb, I had also broken a bunch of them before I shifted to Tarno carbs with brass nipples.

It is to be noted that the 050 and 09 TD R/C carbs have the same size of nipple, so this one would work on a TD09 too.

Bernie and Matt might probably do some turnover from such brass aftermarket nipples, should someone of your skill start producing a few tens, maybe hundreds of them...(the TD050 was the 2nd rarest serial production COX engine with only maybe 2 times 2000 ever produced, and perhaps only a few tens, or at best, hundreds of them have remained in active use by today..myself being one of the users.)

There are plans for an aluminum version, perhaps a two piece design with a thicker tube that has an offset machined to accept a threaded nipple/barb. I ran some from a 3D printed setup but obviously metal is more durable than plastic.

Matt