Bob, Thanks for your comment about the header and tunnel. Maybe I can get to that job this week end if time will allow. Oh and by the way to anyone who saw my earlier comment about the 27-1/2" pipe length, I was wrong about it being to the end of the pipe. It is to the baffle as I'm sure Bob & Matt know. Don't know why I thought it was to the end of the pipe. My bad.[sm=72_72.gif]

Matt, Yeah my bad ! Sorry for the wrong information. Don't know what I was thinking.

Hey gang, for any one that still builds their own wings, just found out that National Balsa carries 1/32" contest grade now. That's excellent

Finally found some Focus [link=http://www.carden-aircraft.com/wingbags/index-wingbags.htm]wing bags[/link]! And other Pattern wing bags, probably fit most other F3A wings as well.

Just scroll down. $85 shipped.

Started mulling over the nose ring design for the Focus.

It does not look feasible at all to make something that anchors to the firewall. As Matt suggested, some reinforcement of the cowl and then attaching the nose ring mounts to the inside of the cowl, and adding to (or beefing up) the cowl firewall attachment fastemers, is the logical way to proceed.

I understand that Syssa plans to make the nose rings, but since they aren't available yet I will make one from ply as I did with the nose ring for the YS110 in the Focus Sport. Circular hole with a cut-out for the Hall sensor... I know, make damn sure the nose ring doesn't contact the Hall sensor at any time.

Hopefully, the weight of whole modification won't exceed 2 oz.

Bob,

I like your thinking. Let me see if I can explain what Ed, Todd and me discussed and se if you can proceed down that path

The hall sensor does not have to be potted in the current housing. The actuall hall sensor is tiny so building a ring that surrounds the sensor and secures to the crankcase is the first step. This piece may be made in two pieces and the assembly can be secured onto the case. The outside OD can be polished and the nose ring can be slipped over this assembly. In other words, the first ring is a rather thin protector, a spacer if you will, of the hall sensor with an outsiide diameter that is intact to accept the nose ring

Nothing wrong with a plywood ring to house the current sensor pot. That's how I was going to make mine and may still do it if Todd's protector/spacer ring doesn't become available in time. The main difficulty is in machining the ply protector ring true and then adding a pair of bolts across the plane of the ring to secure it in place. I'm thinking 1/4" thick which will accept 4-40 bolts/blind nuts.

The actual nose ring would be made from rubber sheet. I have some nice 3/16" stock that has worked great in past projects.

The weight of the whole contraption should be less than 1 ounce

Matt

Matt, thanks for the additional ideas.

Seems this will work out okay because the SAP acutally has MUCH less vibration than the YS110.

I will start posting some progress photos when I fire up the Dremel.

Matt, I just re-read your description of the planned Syssa nose ring and now have a clearer picture. I'm sure Todd's will be functional and durable but it doesn't sound like something I'd try to replicate with my limited tools and metal fabrication knowledge, which is practically zero - as you know, I only recently found out what a Bernzomatic torch is!

With the ply nose ring, only a few degrees of the circle arc will have to be relieved for the sensor, which I don't think will compromise the ring's ability to do its job. I have some 1/32" maple ply and I plan to laminate 4 small sheets of it together to make a super-tough 1/8" 12-ply for the actual nose ring, and use some split smoke tube to line the inside of the ring.

Time to get to work on it. Well tomorrow anyway.

So from the center of the spark plug to the interior baffle of the ES pipe should be 27 1/2 inches, correct? A dimensioned picture would be great, or lay a tape measure next to it and take a picture, please! I just got mine, how are you all doing the rear support?

Hi Gary:

Yes, from plug to baffle, straight back. Also for the 30G pipe Matt measured it as 33-1/2 inches to the end of the pipe, if you don't want to stick a ruler into the pipe.

There was a fair amount of back-and-forth about anchoring the pipe back on page 12. Final analysis is the farther back the better. Engine vibration creates less flexing of the coupler the farther back the anchor is located.

For an idea of how a commercial mount looks, check out the Dave Brown Hush Mounts. Even the large one can't handle the circumference of the ES pipe, but it gives you some idea how they might be anchored.

All my experience thus far - on my first pipe - indicates that Ed Alt's use of the O-rings at the tail of the pipe, anchored on the sides of the pipe tunnel (also on page 12), is probably the best solution.

My Velcro strips are working well now, but it took some finagling with various insulators. Ended up using some of the Teflon-impregnated fiberglass tape with silicone adhesive, the same stuff Matt uses for his header/pipe coupler, which is McMaster-Carr catalog # 76495A56, wrapped around the pipe.

Hey Guys,
Got my motor and pipe! Dave Ruminski was helping me set things up on his test stand. Measuring things out to get the 27.5" from plug to the 1st baffle or 33.5 to the end of the pipe..... Right? So therefore it should be 6.0" from the 1st baffle to the end of the pipe...Right? That distance is 6.5 on my pipe....Also.. Should I have to add a 2.5" piece of pipe to an uncut header to achieve the 27.5 inches? Could I have recieved the wrong pipe?

Dimensons of the Pipe are 23" long (body not including stinger)
7/8" inlet
2" od
16.5" to the 1st baffle
Thanks for the help,
Rick

Rick,

The ES30G pipe is 23" long (X 2" OD ) from inlet to the back (no stinger included). First baffle is 17" from the inlet which definitely means 6" from baffle to end of pipe.

If you are measuring 16.5" I suggest that you email Ed Skorepa and ask him about it. If you need to add another half inch, some pipe tunnels may not accommodate it. I know mine would not. I am maxed out.

Adding 2 1/2" to the header also doesn't sound right. It shouldn't be more than 3/4". Please measure the length of the header from exhaust flange to the end. My header is one for the webra so I can't help but Bob and Ed both have the one intended for the OS so they could measure and report. It could be that the header you got from Tower may have been a modified return

Matt

I will check tomorrow to see what the coupler gap is. It is more than Matt's, but again it's a different header. Should be the same as Ed's, however, but I don't know if he has got his installed yet. I recall he is breaking in the engine on the Aquila with the stock Pitts muffler.

I measured as best I could and the gap between header and pipe on my set-up is approximately 1-3/8". Hard to get any more precise than about +/-1/16" because the coupler tape, of course, is covering the gap.

Header lengths will vary, so this number isn't going to be the same unless you're using the Macs header for the OS 1.40RX that is of the same vintage as mine.

Bottom line, do whatever it takes to end up with the 27-1/2" plug to baffle distance.

I have the ES30G pipe. When I measure from the front edge of the pipe to the baffle, I get 16-1/2" approx. OR 18". I found that if you use a piece of 1/4" square balsa to stick down the pipe it will go down farther and therefore the 18" dim. I first used a 3/8" square piece of balsa and came up with the 16-1/2 dim. So depending what dia. you stick down the pipe, willl get you an 1-1/2" different dimension. Seems to be two baffles in the pipe. Also my Macs OS 140 header is 7-15/16" from the flange face to the end of the header. Hope this helps Rick.

Guys,

Rick (RC11) communicated with Ed Skorepa. It turns out the 30G is different than mine in its baffle placement. Ed said to Rick that the 30G has the baffle installed 16.5" from the stem. I didn't know that since Ed stated to me that my version of the 40G pipe was being offered as the 30G. He never mentioned that he changed the location of the baffle on the 30G. The baffle in mine is located at 17" from the stem

Regardless, the measurements we have discussed, hold.

Dan, the first baffle is the right one. It's a disc actually with a large hole in the middle. The wave reflects off this disc to produce the super charging effect, on the pipe perimeter. The baffle behind this one also reflects but at lower frequency. They both establish resonance in the pipe starting at fairly low rpm and continue to resonate to high rpm. The second baffle is more complete block than the first...it has an exhaust hole off center, discharging into the aft section which really settles down the noise generated

Matt

Hey guys BTW, who was the guy who is planning an EF extra 300? Decided to buy one of these myself. I hope the weight comes in as advertised at 11.5 lbs. With a 1250 sq inch wing it should fly light. SAP up front of course

BTW, anyone interested in a NIB OS160 with a muffler?

Dan, if you shine a light in there, you can see the little gaps on the sides of the baffle that are part of the design. I would guess that the 18" measurement went past the baffle.

How is the hard mount coming along? Did you have an opportunity to start on the pipe tunnel? How is the overall quality and fit of your Focus? GOOD I hope!!

As I mentioned before, if it seems a bit of a struggle, keep the faith because in the end it is an excellent flyer. I have not yet flown a top-shelf pattern ship, but I have taken the sticks of some nice 35-40% aerobats (and my "dinky" 30% AW Yak) and this plane handles crosswinds and holds a line better than anything I have flown. I had heard this is true of good pattern ships, but to experience it first-hand is a real epiphany. My buddy Anthony R told me this evening at our club meeting that he thinks I am officially a pattern addict!

Bob,

I made a end grain balsa ply sandwich spacer 7/8" thick which the 3 stand-offs mount to. The spacer is epoxied to the firewall. My intent using this end grain balsa/ply sandwich is to help dampen engine vibration. We'll see how well it works. I started on the pipe tunnel, but have not yet glued in the 1/16" balsa as the replacement for the fiberglass tunnel as you did. I have to make it fit properly. The fit and finish of my airplane is average. Nothing to brag about. I'll keep you posted. Thanks for all your help.

That's the trick, and they make it difficult by having all the former shapes different. I Dremeled out the middle one to get a proper fit, then made a little template of it from some scrap ply and used the template to shape the other ones to match. The design doesn't make it easy!

The Extreme Flight Xtra 300 ARFie arrived today. SAP 180 on my soft mount and ES 40G pipe will make this one go

First glimpse in the kit reveals a thin, sizable wing. This means nimbleness in things like snaps/spins. Generous fuselage with simple snap on canopy. Cowl is vinyl ester glass which is ok but not my first choice. Ally landing gear, vinyl ester pants, and typical mounting hardware.... I will probably make a carbon copy, glass pants and my system for mounting the wheels which will save 6 ozs.

Covering job in UltraKote is good. Decent hardware package.

I will probably start a new thread to post build photos, weights etc.

Matt

Excellent! EF designs good stuff.

But you plan to finish the Aesthesis first, no?

BTW, got my nose ring finished, but I don't want to post too much on it yet.

Similar to my nose ring on the Focus sport, it adds 26.5 grams to the cowl weight.

Flying it today, so I will start to learn if it is going to work out.

[/quote]

Excellent! EF designs good stuff.

But you plan to finish the Aesthesis first, no?
[/quote]

I have quite a bit to do on Aesthesis yet. I sprayed the wing panels last week but the paint just didn't cover. I used KlassKote epoxy yellow which I just found out was the worst color for coverage they offer. It added about 50 grams per panel and it didn't cover. Very dissapointing.

That's one of the things that drove me to get the EF xtra, to take my mind off the plane. Anyway, I started over on the wings. I sanded the epoxy paint off and am in process of prep. Bunches more work that I planned. Hopefully it will be flying sometime this summer.

Matt

The total painted weight gain from prep to clear coats usually only is around 65-75 grams per panel so adding 50 grams just for base coat is more than 2x more than it should be. It aggravated me enough to take it all off and start over. I have run out of my favorite paint, OMNI, and haven't found a shop near me yet so that's why I tried KlassKote.

I use KlassKote clear for bedding the covering and primer too which is excellent, and so I decided to give colors a shot too. Turned out that yellow was a big mistake but who knew?

Matt

Some recent updates on the carb and coupler and header...

The static nipple on the carb plate - with the attached fuel tube run inside the fuse - totally elminated the engine sagging (nearly deadstick!) issues when doing outside maneuvers. No change in engine performance at all with the static line installed.

Re the coupler: My max rpm's went down steadily, to the point that the engine was only capable of making 6800 rpm with the 18x10PN. So yesterday I cut the coupler and found that the coupler tape under heat and pressure was somehow rumpling up and constricting the exhaust by about 40%. I didn't have a camera and forgot to keep a piece of it to photograph, but after changing to a piece of Teflon tube the rpm's went right back up. Unfortunately, the Teflon tube I used was not the correct variety and it burned out after a quarter tank of fuel, but at least I have identified the culprit. Unfortunately (further!) the piece of Teflon I have is 5 feet long, so I now have about 4' 8"that I will have to find other uses for. Probably OK for glow, so if anybody has a glow engine and needs some 7/8" ID Teflon, let me know and I'll send you some.

The tape is fine heat-wise, so my back-up plan is to use a piece of aluminum tube between the header and pipe and then wrap it with the tape. This will prevent any constriction of the tape and should solve the problem. I still have the 7/8" aluminum wing tube for the Focus, so I know what I'll be using for that job!

The header bolts are holding up absolutely perfectly with the method I used of drilling the bolt heads and making a big clip from 5/64" piano.