Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


hair-pin needle-clip-DIY Babe_b10
Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» 2019 CEF Run What Ya Brung Unlimited Speed Contest Build Log
by Ken Cook Yesterday at 8:44 pm

» How many engines?
by Davenz13 Yesterday at 8:28 pm

» Flying a pattern at the Triple Tree contest.
by Cribbs74 Yesterday at 7:10 pm

» How's the weather?
by getback Yesterday at 1:24 pm

» Some of my Cox engines
by Mike1484 Yesterday at 11:50 am

» 2019 World-Widw Ringmaster Fly-a-Thon---October 5th & 6th !!
by Kim Yesterday at 8:41 am

» Roll Call! Cars Are The Stars
by Kim Yesterday at 6:57 am

» LWS 3 with a Pee Wee
by dirk gently Yesterday at 3:38 am

» JEROBEE electric to TeeDee conversion
by OVERLORD Yesterday at 2:00 am

» Rubber tires for Shrike
by David S Sat May 18, 2019 11:57 pm

Cox Engine of The Month
May-2019
Tee Bee's

"This RR1 was restored for all the right reasons"


PAST WINNERS
Speed Contest 2019
CEF Traveling Engine

Win This Engine!
The Traveling Prop
Gallery


hair-pin needle-clip-DIY Empty
World of Aviation

hair-pin needle-clip-DIY

Go down

hair-pin needle-clip-DIY Empty hair-pin needle-clip-DIY

Post  roddie on Sun Jun 04, 2017 9:00 pm

Here's an idea that I thought-up in the last few days. It uses a common hair-pin (Bobby-pin) to make a clip for a needle-valve stem/shaft. It's applicable in this particular example to Cox 1/2A reed-valve engines. Its main purpose is to hold the needle-setting from drifting. Sleeves of silicone fuel-line are used for retainers. The loop on the hair-pin serves as the mount.

This is all it is... I'll show a mount example below.

hair-pin needle-clip-DIY Bobby-11

There are two types of "Bobby-Pins".. We'll call this type the "open-type". The "closed-type" were what I originally perceived for this.. but the clip-arms are too-close together.

A "Closed-type" example..

hair-pin needle-clip-DIY Bobby-12

The above "closed-type" didn't work-out. The hair-pin must be cut shorter if running the cylinder-orientation in the same plane as the needle. I used "vise-grip" locking-pliers having a wire-cutter to shorten my example.

hair-pin needle-clip-DIY Bobby-13

Note the gallon-size freezer-bag. It's plenty-big for inserting cutting-pliers.. and containing small fragments/parts that might otherwise catapult into oblivion when sheared. It's also a second-safety to protect your eyes.

Once shortened.. here's what it looks like on a Cox .049 product-engine with horseshoe-backplate.

hair-pin needle-clip-DIY Bobby-14

Here's the hair-pin mounted to an engine-stand with that same engine.

hair-pin needle-clip-DIY Bobby-15

That could just as well be the nose of a model-airplane. The hair-pin only needs a single anchor-point at its' loop. I used a small screw/washer on my bench-mount.. but the loop affords itself to other methods of attachment. A blob of epoxy.. Laughing a small capped dowel-pin... or on new-construction; a point/location that will suit the engine-installation.

I've had issues with needle-float.. running both; stock and modified needle-springs on horseshoe back-plates. Coiled compression-springs can recoil "radially".. and augment a needle-setting.. especially if the spring "grabs" on something.. It's then "pre-loaded" to recoil radially. Engine-vibration would no-doubt hasten that

Friction-collars for needles are nothing new.. so why not try to adapt them to any engine?



roddie
roddie
Top Poster
Top Poster

Posts : 6425
Join date : 2013-07-17
Age : 59
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  NEW222 on Sun Jun 04, 2017 9:13 pm

Great idea, but is it just me, or does anyone else have any trouble with seeing pictures?
NEW222
NEW222
Diamond Member
Diamond Member

Posts : 2147
Join date : 2011-08-13
Age : 40
Location : oakbank, mb

View user profile

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  roddie on Sun Jun 04, 2017 9:31 pm

NEW222 wrote:Great idea, but is it just me, or does anyone else have any trouble with seeing pictures?

I've seen images rotated the wrong way................... hurts my brain. I pray for the "mods" to fix them!
roddie
roddie
Top Poster
Top Poster

Posts : 6425
Join date : 2013-07-17
Age : 59
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  NEW222 on Sun Jun 04, 2017 10:49 pm

Its late here now, but I now see the pictures and it looks good. With the better half a hairdresser I may have to try this . Thanks for the great idea.
NEW222
NEW222
Diamond Member
Diamond Member

Posts : 2147
Join date : 2011-08-13
Age : 40
Location : oakbank, mb

View user profile

Back to top Go down

hair-pin needle-clip-DIY Empty update on clip application.

Post  roddie on Mon Jun 05, 2017 2:30 pm

NEW222 wrote:Its late here now, but I now see the pictures and it looks good. With the better half a hairdresser I may have to try this . Thanks for the great idea.

Thanks Chancey! I made some discovery that's worth mentioning. The previous open-style clip-example fits the product-engine's needle shaft well because the shaft is 3.18mm diameter. The gap between the clip-arms is approximately 4mm. The silicone tube-sleeves pinch the arms together with good clamping force.

I had abandoned the closed-style clip application.. but now find it works very well to clamp the smaller shaft-diameter of a Cox tanked-engine's needle. See below.. a Cox Babe Bee .049.

hair-pin needle-clip-DIY Closed10

There's already sufficient clamping-force without putting a sleeve on the open-end. There's also about 1/4"/7mm more distance between the needle and the engine-cylinder than the product engines' horseshoe back-plate. This distance obviously becomes a non-issue if orienting the cylinder in a different position (IE; 90/180 degrees) from the needle.

Another interesting feature between the closed and open-style bobby/hair-pins, is that the closed-style has 4 detents.. and they're only on one arm of the pin. The other arm is straight. The open-style only has 2 detents.. but has them on both arms.. equidistant.

hair-pin needle-clip-DIY Closed11
hair-pin needle-clip-DIY Open-s10

I figured that this was worth mentioning. If you search Google-images for "hairpins"... you'll see a myriad of shapes/styles.. but these two referenced in this thread, are generally the more common types. I was lucky.. in that my stepdaughter had some of both types.

The closed-type "will work" on smaller-diameter needle-shafts.. and would likely work well on a Cox Pee Wee .020 engine. It takes a good amount of force to spread the arms apart on the closed-style hair-pin. I used a small flat-blade screwdriver to spread the arms.. while installing the "clip" on the .049 tanked-engine's needle.

Take into account.. the hair-pins are spring-steel. Use caution when cutting/shortening them. As I mentioned.. I sheared them with the cutters in the jaws of my Vise-grip locking pliers while inserted into a plastic bag. A better way would be to clamp the hair-pin in a bench-vise.. and cut them abrasively with a dremel/cut-off wheel while wearing safety-glasses.

There is a coating on these hair-pins. It's some type of plastic or resin. This doesn't seem to interfere with the function for these applications.. but if able to be removed.. the hair-pins should accept solder. This would only be required on the loop-end.. where a bracket might be soldered. This could be valuable for fashioning a custom clip stand-off for other engines. Something of an L-bracket with hole to mount under a screw-head on a Cox Medallion, Tee Dee.. or any other beam-mount/front-rotary engine that could use some needle-stabilization.


Last edited by roddie on Mon Jun 05, 2017 3:48 pm; edited 3 times in total (Reason for editing : application)
roddie
roddie
Top Poster
Top Poster

Posts : 6425
Join date : 2013-07-17
Age : 59
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  getback on Mon Jun 05, 2017 6:46 pm

Good info man , looks like it would work just fine if application needed did'nt know there were so many difft. kinds of Bobbys Shocked But you would sure bee careful cutting them !! Most the time the application of a new seal on horse shoe back plates work IF the threads are not worn too bad or the fuel line for a seal at the needle will keep the needle stable if applied right ..... This is good but if the needle is turning it is loose,,  the spring is sprung or the wrong one ?! On these springs they should NOT let the needle move the way they're made being rounded at both ends with the edges turned in .. hair-pin needle-clip-DIY Needle10
hair-pin needle-clip-DIY Cox_0410
Of course i looked through their inventory and some DO look like they would do some digging into the back plate and make a groove == You could file down the edge of the spring end so it would rotate if needed ?? Eyebrows Beer Cheers
getback
getback
Top Poster
Top Poster

Posts : 5775
Join date : 2013-01-18
Age : 61
Location : julian

View user profile

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  roddie on Tue Jun 06, 2017 9:29 pm

getback wrote:Good info man , looks like it would work just fine if application needed did'nt know there were so many difft. kinds of Bobbys Shocked But you would sure bee careful cutting them !! Most the time the application of a new seal on horse shoe back plates work IF the threads are not worn too bad or the fuel line for a seal at the needle will keep the needle stable if applied right ..... This is good but if the needle is turning it is loose,,  the spring is sprung or the wrong one ?! On these springs they should NOT let the needle move the way they're made being rounded at both ends with the edges turned in .. hair-pin needle-clip-DIY Needle10
hair-pin needle-clip-DIY Cox_0410
Of course i looked through their inventory and some DO look like they would do some digging into the back plate and make a groove == You could file down the edge of the spring end so it would rotate if needed ?? Eyebrows Beer Cheers

I'm glad you replied brother. Worn parts should be replaced if possible. This clip design can function as a secondary stabilization for the needle-setting.. worn or new. The weight of the components is negligible. You have to source a hair-pin though... Laughing

roddie
roddie
Top Poster
Top Poster

Posts : 6425
Join date : 2013-07-17
Age : 59
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  Ken Cook on Sun Jun 24, 2018 6:23 pm

I'm no stranger to strange harmonics. Today resulted in a problem which ended my flying for that plane for the day. I have a very very good running Sure Start engine, all stock but it stands alone from the several others I own. The main problem is with the engine running, the needle is all over the map due to vibration. I wrap a rubber band around it and then around the fuse of the plane. Today I was prepping for the rubber band wrap around and got everything set in place. The engine was giving me quite a fit and opening the needle wasn't doing anything. I figured I would backflush the system so I removed the needle valve. Well, the needle came out and there was no point on it. Well, that pretty much explains my problem. Vibrations caused the needle to snap off directly on the threads. This actually didn't take very long to do so. While this might not sound like a lot, I have about 30 flights on this plane with this engine. So , in that time this is what happened. Roddie's hair pin clip would remedy this from happening.
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 3478
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  roddie on Sun Jun 24, 2018 7:16 pm

I'm sure that you'll replace the NVA in short-order. It'll be time well-spent for an otherwise great-running engine. I actually don't use the long-style needles anymore, without some type of support/clip.
roddie
roddie
Top Poster
Top Poster

Posts : 6425
Join date : 2013-07-17
Age : 59
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  getback on Sun Jun 24, 2018 10:48 pm

I just looked and no stk. i thought i, well i did have several new one but must have sold them . Doh!
getback
getback
Top Poster
Top Poster

Posts : 5775
Join date : 2013-01-18
Age : 61
Location : julian

View user profile

Back to top Go down

hair-pin needle-clip-DIY Empty Re: hair-pin needle-clip-DIY

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum