BobbyMcGee

Youhave got to be kidding me, right? I didn't know anyonestill reads that magazine anymore!
I got tired of seeing the same articles re-hashed every 18 months.

countilaw

I've been in the hobby for about 44 years. I've seen alot, learned alot, and still learning. I learn something new every time a read an issue of MA. And anybody that says that they don't learn anything from it is either a world class genius, or has not the ability to learn anything.

Live Wire

65 yr's and +1

Hobbsy

My Feedback: (102)

http://www.microfasteners.com/catalo...cts/TNMTAP.cfm

They are readily available here. It looks like they no longer carry the die. I have lots of their stuff.

earlwb

I like to peruse MA magazine. I have no problem with it. Granted I might not read it so much, but from time to time something catches my eye and I read it more closely. It makes for good reading material in the bathroom when you are using the throne.

Hobbsy

My Feedback: (102)

It has little to distract you from the real job[8D]

crash1ace

Wow, cant believe some people. To have such a dislike for the magazine. I find the articles both entertaining and helpful, and do like to keep up up current events. To say that one uses the mag
as a "cutting board" seems a lil bit much to me. Did someone have a bad experience with the magazine or something? I'm very glad to get it monthly and will continue to do so and support it 100%.

Charlie P.

GITS oil/grease fittings (not to be confused with 1/4-28 Zirk fittings), glow plugs and flintlock vent liners. About the only things that use 1/4-32 threads.

Which brings us to . . .

http://www.trackofthewolf.com/Catego...1/TAP-1-4-32-P

A $13.99 tap from a muzzleloading gunsmith supplier. Though if you'vetorn out the threads I'd recomemnd a Helicoil replacement.

Sport_Pilot

Must be the same salesman that told me Metric would never last. Also one never heard of numbered drill sizes. Lots of stuff not found in Home Depot.

blw

My Feedback: (3)

I knew a guy who used MA magazines for mixing epoxy. He just tore off the pages when done.

aspeed

Don't forget the Tee Dee .049 carb is 1/4" 32 UNEF (unified national Extra fine I think). I am making all of my heads with the Turbo plugs now. 8mm x .75 .May as well get an extra 1000 rpm if you are going to the trouble of making a head. The Nelson plugs are harder to find the tap and are a bigger diameter for the smaller motors. And to get off the topic, I wouldn't mind reading a MA mag again for a change. I thought they were fairly good for the few I read.. They only print what is handed to them in most cases likely. If no one contributes then they get kind of dry. (zone meetings and rule changes) I read MA Canada and it is kind of similar. We can contribute articles if we want, and they might get printed depending on things.

1QwkSport2.5r

I have a Higley 1/4-32 tap but no die. The tap cost me $7. I haven't had any problems stripping threads with my McCoy plugs. Though your comment does inspire me to get a 1/4-32 die just to have one. My hobby shop has a Higley die for $14

earlwb

That isn't a bad idea using turbo plugs. The small 1/2a engines are quite sensitive to the slight compression loss from just the threads on a glow plug. So using a turbo plug that seals at the bottom does correct for that issue.

Ernie Misner

>>> Though your comment does inspire me to get a 1/4-32 die just to have one. My hobby shop has a Higley die for $14 >>>

Here's a little more poop then on why threads strip out of the head often. What happens is sometimes when we unscrew the plug, it has become welded to the aluminum in the head so the aluminum comes out with it. That happens because of poor fitting glow plug threads that cause little tight fitting spots. Then with a hot or lean run those tight spots become even tighter causing the bonding or welding of the plug and head together. Simply running new plugs into the die eliminites this from happening.

The local screw products store ordered my die for $9.00.

Ernie Misner

qazimoto

My Feedback: (1)

Actually the shavings coming off the plugs are most likely making them fit much worse in the head.

The worst case scenario is that after chasing them the plugs now seal at the copper washer under their head rather than at the first thread.

Not a good idea at all, and really the reason that bottom sealing plugs like the Turbo and the Nelson give about a 1000 rpm advantage over the stock standard threaded ones.

Yours will be much worse!.

Hobbsy

My Feedback: (102)

I hava 1/4x32 die and tried it on a couple of plugs with cut threads, after running them in and out of the die they fit pretty loose, that made me nervous. Fox plugs have rolled threads and the first thrad is tapered, the die doesn't do much to a Fox plug.

dirtybird

My Feedback: (5)

I like to keep MA beside my bed. When I wake up at night and can't go back to sleep I read it. It puts me to sleep.

aspeed

I have noticed that the threads on one brand are sandblasted which made for a not so good seal. I had to tighten one to more than I was comfortable with to get a seal.  It would abrade away at the softer alum. threads after a while. Maybe some scotchbright carefully twisted on the threads might help polish the threads if you are careful to not touch the element. I use antiseize grease on the plug threads, or castor oil.  I also use the castor on the head gasket if I remember. I have never stripped one yet in 40 years.(yikes I'm old, I started as a little kid though) I wouldn't run a die on  the plug unless it doesn't want to go in.  The factories likely have cut the thread to the right tolerance.  You could check the size to the spec. with a proper size wire (best wire size  BWS) and figure the measurement over the wires(MOW), but I am sure they are likely good.  They should definately not be too loose because the rpm's will suffer. There are special micrometers made for checking the tread pitch dia. as well.

Ernie Misner

My earlier post (below) was quoted pretty much word for word from Clarance Lee. His advise is usually right on. It was in an article about how to avoid stripping glow plug threads if you like to keep your engines around a long time.

Thanks, Ernie




ORIGINAL: Ernie Misner

Best thing I ever did was get a 1/4x32 die for cleaning up new plugs before installing. Apparently the plug's threads are just rolled and not precision cut from the factory. You would be amazed at all the shaving that come off of new plugs to make them right.

Ernie Misner


Actually the shavings coming off the plugs are most likely making them fit much worse in the head.

The worst case scenario is that after chasing them the plugs now seal at the copper washer under their head rather than at the first thread.

Not a good idea at all, and really the reason that bottom sealing plugs like the Turbo and the Nelson give about a 1000 rpm advantage over the stock standard threaded ones.

Yours will be much worse!.

qazimoto

My Feedback: (1)

Clarance who?

BarracudaHockey

My Feedback: (11)

THE RC engine guru north of the equator. Kind of like your Brian Winch

qazimoto

My Feedback: (1)

C. Lee can't be that bad!

My point was that "cleaning up" the threads on a conventional glowplug is going to lose rpm This is an accepted fact amongst those who treasure
every extra rev of the prop.

If your aim is to preserve the threads in you g;ow engine head then that is a different story.

This may have been important in an era before CNC manufacturing. These days both plug and head are made to exacting tolerances.

I just don't think it's important anymore.

Four Stroker

1) You guys that drop a 1000 rpm by cleaning up the threads should try using the copper washer that comes with the plug to seal it.
2) I just cleaned up 10 new "CNC" plugs because I broke a chip off of the last head thread.
3) C. Lee's advice is just as valid today.

Sport_Pilot

The advantage of Nelson plugs has to do with detonation and pre ignition at high nitro precentages, because of the smoother surface and transition.  There will be little to no advantage on lower nitro engines, and no advantage due to fuel and air between the threads.  The copper washer is there for a reason.

Also the rolled threads are very precise and more desireable.  If your die is cutting substantial metal off it is because you tend to push the die into the thread.

fizzwater2

My Feedback: (61)

back when I dabbled a little (played at..) Formula 1 racing, we cleaned up the threads on the 1/4-32 glow plugs before we used them. Changing a plug every flight, the heads would wear out prematurely if you didn't.

I had an adjustable die that you could open or close slightly with a screw - it was set to just barely clean up the threads a little to reduce wear on the head.