Building a Javron Cub

[RaisedByWolves]

George needs to come back down and show us how to fly floats

[skywagon8a]

Bill, Your smile says it all!

I'm curious as to the noise level in flight. Since you have a full interior, did you install any sound proofing under the interior panels? If so, what is it? Have you noticed a different sound level between the front seat and the back seat? Recently I let Seaworthy fly my Cub with me sitting in the back seat for the first time. Mine has no interior at all and I noticed that the noise level in the back seat was not only loud but actually headache producing. When I used my $300 Bose noise suppression headset it was bearable. The front seat isn't nearly as bad though the headset is needed.

I suspect that my dual exhaust does contribute to the noise and that likely a single tailpipe would be quieter. I'm wondering if a "piccolo tube" tailpipe would help?

[Bill Rusk]

Tom - or maybe we can go up to him. That would be fun!!

Pete - I did not put in any sound proofing at all. Just the firewall blanket. My interior is 16th with a fabric glued on. No foam padding or insulation. I'm not really sure about the noise level. I use Lightspeed zulu headsets and feel quite comfortable, even listen to music when flying. The Sutton exhaust seems a little quieter than some other exhaust. My friend, Charlie, just dropped in for a visit today, he has the Atlee exhaust, and I noticed that it seemed much more "throaty" and louder than my Sutton.
I'm not sure if that is the difference between dual pipes, or what. I have read a number of blogs on the European piccolo pipes and they certainly reduce the noise. It would be interesting to run a few pull test to see if, and how much, the performance penalty was/is. Low noise is a good thing. Being a good neighbor on the lakes is important. Don't know if this helped much

Bill

[RaisedByWolves]

I didn't realize how loud the hot rod atlee exhaust was until i switched to the Sutton. Piper sprayed some kind of like undercoating on the inside of the metal panels I'm assuming to help keep it quiet.

I'd love to fly up bill. One of these days. Guess I better start saving.

[Eddie Foy]

Bill,

What is the material you used on the firewall.

I went thru the 8amp alt program , used them for 8 years finally enough !! B&C 20 amp on my plane since 2008 never a issue of any kind
I'll suffer the two lbs weight increase for reliability!! mikeo


Sent from my iPhone using Tapatalk

Tom - or maybe we can go up to him. That would be fun!!

Pete - I did not put in any sound proofing at all. Just the firewall blanket. My interior is 16th with a fabric glued on. No foam padding or insulation. I'm not really sure about the noise level. I use Lightspeed zulu headsets and feel quite comfortable, even listen to music when flying. The Sutton exhaust seems a little quieter than some other exhaust. My friend, Charlie, just dropped in for a visit today, he has the Atlee exhaust, and I noticed that it seemed much more "throaty" and louder than my Sutton.
I'm not sure if that is the difference between dual pipes, or what. I have read a number of blogs on the European piccolo pipes and they certainly reduce the noise. It would be interesting to run a few pull test to see if, and how much, the performance penalty was/is. Low noise is a good thing. Being a good neighbor on the lakes is important. Don't know if this helped much

Bill

[skywagon8a]

Thanks Bill, I've been told that the exterior noise level is reasonably quiet. More so than some of the other planes which fly around here. I'm thinking that the dual pipes sticking below and aft of the firewall may be causing the loud noise box effect in the aft cabin area. I found these Piccolo pipes at Wicks. The claim is a 3 db reduction. That doesn't mean much to me. They only come in 1-3/4" diameter. My pipes are 2". I'll have to get some stainless and try to make a set. The possible power loss could be measured just by noticing if there is an rpm change at take off power.

[Eddie Foy]

A 3DB reduction means the volume is halved. Huge.

[Bill Rusk]

Eddie

I'm using my cell phone so I don't know how to hot link stuff but the firewall blanket info is in the shopping list in post #1431. It has the Aircraft Spruce part number. It is called Thermo Guard Firewall Blanket.

Hope this helps

Bill

Pete - good point regarding static RPM.

[wireweinie]

Louis

I just went to the local Radio Shack. There are probably better out there and perhaps one of the electrical guru types like Fobjob, Wireweenie, etc will chime in and give us better info, but this has been working just fine for me so far. I used #276-1661
It is a four pack of 6 amp, 100V (the motor can only draw about 1.1 amps even when stalled out) diodes. You could also use 276-1114 a three pack of 2.5amp 100V

Hope this helps

Bill

Sorry for the slow response to this question . . .

I second Mike's opinion of Digi-key. Lots of electronic type stuff, from terminals to IC chips. Another good source is Mouser Electronics.

As for those particular diodes, I don't have an industry part number to give you any specs on, but they look like what are referred to as power or rectifier diodes. They should be plenty large enough to handle the load. If you need to size a diode for a particular circuit, first make sure that it is the right style. The diodes in Bill's pic have the wire leads that most are familiar with. But they can also be found with solder tabs for circuit boards, threaded for mounting with nuts/washers, and even with no leads at all for soldering to a frame (remember this one). As for ratings, bigger is better. For example, if a circuit is fused for five amps, don't use a five amp diode, unless the directions tell you. Try to find a diode with a current rating of 25% to 50% greater than the max current of the circuit. For the voltage rating, I always go with at least double the voltage of the circuit. You hear me preaching about voltage spikes in the electrical system. Well it's common for these spikes to be twice the system voltage or more. The good news is, even small signal diodes are commonly found with 40-60 volt ratings. The current rating is extremely important for normal operations. The voltage rating is not as important for normal ops as we are usually working with 12 volt or possibly 24 volt systems. But the voltage rating is very important in abnormal situations, such as those voltage spikes (which, by nature, are usually reverse polarity), when circuits are connected/disconnected while powered up, or when chargers and external power is used.

Remember me telling you about the diodes made to be soldered to a frame? I discovered these while working on cars. Some of the older Motorcraft alternators (and I'm sure others) soldered three diodes onto each of two frames, forming the rectifier for the output. If you are quick with the heat, you can unsolder them from the frame and solder leads on to each side of the diode. This will give you a diode that will handle thirty or more amps. These make great blocking diodes when wiring backup batteries or emergency power supplies for avionics or electronic ignitions. Your imagination is the limit.

Web

[Bill Rusk]

Thanks Web. Good info.

Bill

[wireweinie]

It's good timing. I'm going to be wiring an electric trim system, sometime in the next few weeks. Only difference is that I'll be using relays to perform the switch functions. I like this approach as it allows me to route very small wires to the stick.

Web

[OLDCROWE]

I had Steve insulate all the forward panels in 604 and all of the interior panels have fabric glued to them. I already had the Attlee hot rod exhaust and it is now significantly more quieter inside.

[Bill Rusk]

Folks

It is time to take the floats off and begin getting ready for next summer. There are a whole host of things I would like to do before next flying season to improve, tweak, adjust etc. So there will be more posts as I "improve" things.

First we will start with the fuel pod. I purchased a used Airglass LT32 Fuel Pod - link to Airglass website here.....

http://www.airglas.com/FixedWing/Products/tabid/1022/ctl/ProductDetails/mid/3050/ProductId/19/Default.aspx

Before taking the floats off I decided to do a check of the fuel pod mounting to see what problems I might have. Sure enough there are a couple.

1) Forward attach eyebolts are interfering with the pod
2) Water rudder retract cable hits the pod
3) Front of pod hits/interferes with the hydraulic lines where they penetrate the fuselage.



The rear brace wires go through specifically made holes in the pod. This sets the for/aft orientation of the pod. You can't just "adjust" it where ever you want.

As you may remember I welded in some saddles on the longerons so I could use eyebolts to hold the pod on, making install and removal, easier, quicker and cleaner. That worked well for the aft attach point but the front did not work out as well. The forward part of the pod is just about the same width as the fuselage so it does not fit between the eyebolts.


Here you can see it jammed up against the eyebolt and on the other side it is about a 1/4 inch too tight. It will be easy to make a little "L" shaped bracket and that will still be better than slitting the fabric but I wanted to point this out just in case someone else is thinking of doing the same thing. You could install the eyebolts at a slight angle, or weld a tab that hangs off the outside of the longeron like the step tab located right behind the right strut attach point. I will just make a small L shaped bracket.


This is the front of the pod under the fuselage. You can see the openings for the inspection covers. You can also see that the hyd line exit points need to go about as far forward as possible. This is hindered by the cross tube which you can see in the opening. It can be redone fairly easily by making new inspection covers and just running the lines right to the front of the opening. But obviously, had I known this, I would have done it right the first time. So, now you know.



This is the water rudder retract cable hitting the pod. That won't cut it, or maybe I should say it will cut it. It would cut right through the pod.



I know someone is going to say "just make a longer tube with a bend in it". Let me nip that in the bud. The tube would have to extend this far below the fuselage and that would not work. It would bend, bind, flex, and fail. So that is not a possible solution.




My solution will be to make a bracket that uses the existing bolts in the spreader bar to hold the pulley in this area. This changes the angle of the cable where it goes up to the front pulley and eliminates the pod interference issue. This way I am not welding on the spreader bar, drilling new holes, etc. Everything can be returned to factory specs easily and in a manner that leaves no sign of the previous "modification".



I will remove the pulley closest to the center of the picture (and put #10 screws in the holes to close them up) and effectively move the pulley to the top outside edge of the spreader bar. I think this will work and create a clean, sturdy, water rudder retract cable system.


More to follow as I do all this. Hope this helps

Bill

[cubdriver2]

Perpendicular idle pully on front right corner of pod ?

Glenn

[skywagon8a]

2) Water rudder retract cable hits the pod.


This is the water rudder retract cable hitting the pod. That won't cut it, or maybe I should say it will cut it. It would cut right through the pod.



My solution will be to make a bracket that uses the existing bolts in the spreader bar to hold the pulley in this area. This changes the angle of the cable where it goes up to the front pulley and eliminates the pod interference issue. This way I am not welding on the spreader bar, drilling new holes, etc. Everything can be returned to factory specs easily and in a manner that leaves no sign of the previous "modification".



I will remove the pulley closest to the center of the picture (and put #10 screws in the holes to close them up) and effectively move the pulley to the top outside edge of the spreader bar. I think this will work and create a clean, sturdy, water rudder retract cable system.

Bill, Just some random thoughts for your consideration.
1/ Get a piece of tough heavy duty plastic type of tubing. Glue a length of it to the tank and pass the water rudder cable through it. Use this as a chafe proof guide for the pull up cable and it is replaceable. No pulley relocation required. Also less weight.

2/ Pulley relocation. When you place those pulleys on the spreader with the float pulleys removed, will the cable have a straight run to the water rudders or will the cable move over to rub on something? If not, leave the pulleys on the floats.

3/ When you place those pulleys on the spreader, be sure to check the geometry of the new angles. Sometimes when changing the legs of the triangle formed from the swage where the cables are joined to the first set of pulleys, the travel at the water rudders is changed. You may need to pull the handle further or less. The rudders may not retract all the way or perhaps one will be lower than the other. This sometimes can cause an interference situation with something else.

4/ Make the attachments for the spreader pulleys flexible since the cable/pulley alignment will change during the retraction cycle due to the apex and two legs of the triangle changing dimension. The left leg will grow more than the right.

[OLDCROWE]

Perpendicular idle pully on front right corner of pod ?

Glenn

Good call, West Matine will have what you want and you should be able to surface mount it with ease.

[Bill Rusk]

Glenn, Kirby, - I considered adding something to the pod but rejected it for a couple of reasons. If just glued on I don't think it would hold. If I layered up a bunch of epoxy it would work but then I would have to repaint the entire pod, and if I ever tried to sell the pod it is entirely possible the potential buyer would not be impressed by all the extra added junk on the pod. By moving the pulleys, it keeps the permanent "mods" to a minimum, and everything can be returned to factory new (so to speak) if necessary.

Pete - excellent inputs. Thank you.


This is the little bracket I made out of stainless steel to fix the eyebolt issue on the front. I think it is going to work perfect.



Did not get much else done today. Feeling under the weather, and speaking of which, boy did we get some of that today. Too bad I don't have the skis on yet. We got close to 12 inches. But it is a heart attack snow. The heavy, wet kind, that makes you feel like you are going to have a heart attack when you are trying to plow and shovel it.

BIG SHOUT OUT

I just have to tell someone........Grant is awesome. I needed some stuff from Wipaire, and once again Grant took really good care of me. He is sharp, friendly, and takes good care of his customers. I can't tell you guys how nice it is to deal with Grant at Wip. It is just something that is so rare and so nice when it happens. Great guy. Here is his build thread.....http://www.supercub.org/forum/showth...Grant-s-J3C-85
Thank you Grant!!


Hope this helps

Bill

[skywagon8a]

This is the little bracket I made out of stainless steel to fix the eyebolt issue on the front. I think it is going to work perfect.

Bill, from here the bend on that tab looks to be of TOO small a radius for the applied loads. I would suggest making another with a greater radius and adding a special washer such as the "L" shaped ones on the tail wires. With the loads of the straps around the pod coupled with the normal vibrations of the plane your tab COULD crack and break either at the bolt hole or at the 90* bend. Also while stainless is good it is more susceptible to cracking than 4130. Thus more care in it's use is needed.

[Bill Rusk]

Pete -.... hmmmm.... you have a point. I used a piece of stainless "C" channel that was extra from an Atlee Dodge engine cowling channel. (the ones ((4 of them)) that go from the firewall to the nosebowl) that hold the cowling on. So I didn't make the bend, I just cut off one side of the "C" channel. I got busted. I'm pretty lazy and will make a part in the easiest manner I can dream up.
I'm guessing that Atlee does not bend them either, they probably come that way from the steel mill. You are right, it is a pretty sharp radius, interesting dilemma. It is also with the grain rather than against it. I will look into this. Thanks.
It would be pretty easy to make a radiused washer to go in there to support the bend.

Bill

[Jim A.]

Keep the white stuff there for a few more weeks. We're finally making some ice. A snow like that now will really screw it up. What a weird year!

[Bill Rusk]

Folks - as always I appreciate the inputs. We all learn from each other. Its a good thing. I have not done much, just sleeping and resting. I did get to the hangar for about an hour today.



This is the new routing for the water rudder retract cable. You can see the pulleys on the rear spreader bar. This changes the cable angle enough to clear the pod. It is nice to have a clean, cable free, path up to the rear spreader bar. It makes maint and cleaning a lot easier. I think I will retain this routing even without the pod. I just like it better.



The cable is about 1.5 inches above the float and completely clear of other cables, pulleys, etc., at all extremes of travel.



Pulley location. Again this uses existing bolts, it does not require welding, drilling new holes, or any other permanent change to the floats, or aircraft.



Pulley bracket. Made from .063 4130. I will clean it up, prime, and paint. I think this will work well.


Hope this helps

Bill

[SJ]

Bill,

Hope you are feeling better soon!

Thanks again for this amazing thread on your plane.

sj

[Jonnyo]

Who makes the lowered engine mount?

How much does it lower the engine?

Does it also change the incidence?

[Bill Rusk]

The engine mount is made by Javron, in Brainerd, Minnesota
http://javroninc.com/index.cfm/pageid/26

Jay builds them lowered 1" or 2"

He can build it with the thrustline mod included or factory standard incidence.

Hope this helps

Bill

[Bill Rusk]

Updated post # 265 and #268 to give info on the source, and part #'s, for the composite floor boards.

Hope this helps

Bill

[cubdriver2]

Sorry, thread drift.. Look here Bill

http://generalaviationnews.com/2015/...mate-man-cave/

Glenn

[Bill Rusk]

Ohhhhhh mannnn I miss that Hatz. It was an absolutely wonderful airplane. If I won the lottery I would buy it back or build one JUST like it. It was just so perfectly balanced on the controls. Pure magic. Thanks Glenn. I had not seen that article. I have spoken to Greg a couple of times when he had questions. I hope the weight of the starter did not mess it up. It looks great and it is nice to know it is well cared for. Thanks again.

Bill

PS Got the floats off the Cub and starting to work on the "do list". Hopefully I'll get in a little ski time this winter as well.

[Charlie Aileron]

I have know Gregg for many years. I am the one who restored his first J-3 and the Flitfire j3. His shop is amazing. It is so clean and organized. You could eat off the floor. I am amazed everytime I go down to his place.

[Bill Rusk]

Thanks to Grant, I spent the day yesterday with an "expert" float mechanic and learned a ton about how to maintain my floats. Although they are in excellent shape I am looking forward to doing a really thorough "annual" inspection on them in anticipation of next summer. With the holidays I have not had a lot of time to work on the plane. It will all get done......somehow.

I did order a new sleeping pad. My old Thermarest is about the only thing that somehow survived the mishap, and at about 10 years old, it has developed a slow leak so I wake up on the ground. MMR (Mark) did his usual awesome internet research and recommended the SynMat9 from this company.......http://www.exped.com/usa/en

Looking forward to seeing everyone at the Alaska Airmans Trade show in the spring. Already got reservations at the Courtyard Marriott.
http://www.marriott.com/hotels/trave...orage-airport/

Will post more as I get things going. I'm excited about 2016, its going to be great!! Happy New Year everyone.

Bill

[cubdriver2]

That sleep system looks great. Whats the cost?

Glenn

[Bill Rusk]

This is the message I got from Mark.........


Bill,
Here’s the link to the pad I bought.
Promo code is: save20 (20% off)
Over $50 free shipping
https://www.campmor.com/c/exped-synm...ping-pad-91306

Mark


This got it to 119.00 with no tax and free shipping. It is about 7 ounces lighter and packs about 1/2 the size of the Thermarest. If you are super worried about weight the SynMat7 is a little thinner and thus about 7 ounces lighter than the above mentioned SynMat9

Hope this helps

Bill

[fancypants]

I have the same pad and it has held up well over the past 4+ years of occasional use. I think you'll find it's more comfortable than the Thermarest, though a bit more work to inflate.

[RaisedByWolves]

Downfall is it takes kind of a lot to inflate. But it's super comfortable and doesn't leak down at all

[cubdriver2]

I have the same pad and it has held up well over the past 4+ years of occasional use. I think you'll find it's more comfortable than the Thermarest, though a bit more work to inflate.

My 6" thick Wally World mattress that cost $14 was working fine for over 6 years till some Yahoo's at LHV zip tied it and my tent to the side of a chain link fence one night.

Glenn

[fancypants]

With friends like those, you might need a German Shepherd to go along with your comfy new sleeping pad.

[brown bear]

". Ifound these Piccolo pipes at Wicks." .

Skywagon
I have ran a set of these for years on my 0320 , they work great and I have see no power loss,
Doug

[RaisedByWolves]

My 6" thick Wally World mattress that cost $14 was working fine for over 6 years till some Yahoo's at LHV zip tied it and my tent to the side of a chain link fence one night.

Glenn

Sounds like a real Dickhead move.

[cubdriver2]

Sounds like a real Dickhead move.

Yea, Amy told me she knows who it is

Glenn

[OLDCROWE]

Yea, Amy told me she knows who it is

Glenn

What and there were no pictures of this fine vertical sleeping event?

[cubdriver2]

What and there were no pictures of this fine vertical sleeping event?

No, they were too busy TPing my cub at the same time.

Glenn