Larger Revolver
06-28-2014, 03:56 PM
#7526
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Question on fuel barbs on gas tank tubing. Are they needed on the outside as well as the inside? I always have, but am just assembling another tank and am wondering if they're needed on the outside. Thanks.
06-28-2014, 05:51 PM
#7527
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The last couple I've done, I have not. I've been cutting 3/8" of fuel line tubing and stretching it with a pair of needle nose pliers (working in reverse), then sliding the end of the fuel line into that. End result is double thickness fuel line at all the fittings. Makes them very snug. Seems to be working well, so far so good, anyway. Some installs are over a year old... Still, your mileage may vary.
06-28-2014, 06:00 PM
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I use them in all gas fuel lines. They are so easy to install, why not? I'd rather not have fuel dumping anywhere on, or in my plane. I also put a small zip tie on the inside section on the fuel line to give it even less of a chance of coming off of the barb. I used to use wire, but the zip ties are wider so they have more surface area which requires less "squeeze" than wire. Plus they are easier to use...
06-29-2014, 01:07 AM
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Microdon, I'm surprised you'd ask this question. You've been flying gas for a while haven't you? I just saw you asked in the DLE20 thread too. What have you been doing in the past? Seems like most have replied that they do use barbs. Just solder those suckers on and live worry free!
06-29-2014, 04:46 AM
#7533
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I also use the chain saw type filters in my fuel tanks! They have a weighted clunk built right in them. Rotory makes them I think. We supply them at my cousins mower shop. I use two in my tank! One on carb pick up. One on the fuel and drain side! I don't have much trouble with dirt. Give it a try.
06-29-2014, 05:44 PM
#7534
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Funny thing at the field today. A buddy of mine has a 60-70 sized Corsair running a DLE20, and this thing is screaming fast. We were talking that just looking at the Revolver how sleek it is it should be even faster (and i have the 20RA). I am running a Zinger 16x8 while he is using a Xoar 16x6 (WWII) prop. I always thought that while the Revolver was fast, it wasn't as fast as it should or could be. So for the fun we swapped props and put the Xoar 16x6 on my plane. While i can't remember the exact number, i know it was not anywhere close to the 9300 max RPM that i got with the 16x6. And the proof is in the flying! We got 168Kmh or just a shade over 100mph out of the Revolver today. And tomorrow i am off to the LHS to buy new props!!!
06-29-2014, 08:47 PM
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Zinger props are only good for mixing paint. If you really want it to scream, throw a 15x8 Xoar on that puppy, get her tuned for top notch performance and you'll see fast! You'll be blowing the wings off that shoebox Corsair...
This dude is flying a 15x8
http://www.youtube.com/watch?v=BllA1VnwsSg
This dude is flying a 15x8
http://www.youtube.com/watch?v=BllA1VnwsSg
Last edited by mach2; 06-29-2014 at 09:07 PM.
06-30-2014, 04:32 AM
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Teckbot - a couple of things:
1. The details are important when reporting speed. Are you talking straight and level, maintained speed, or max speed coming out of a dive? Is that a radar gun, or an on-board pitot tube, or an on board gps, or a phone app (doppler). If you are using ground-based technology (radar, doppler), then you have to run exactly upwind and exactly downwind runs, both straight and level, and average the two. Best to do several replicates. The same idea is true with on-board gps, which references to ground (obviously). The only real airspeed device is an on-board pitot tube, and that has to be calibrated.
With a 6-pitch prop (assuming 10,000 rpm), your theoretical speed is just under 60 mph, so unless you were in a dive, or moving downwind in a stiff breeze, it is hard to see how you got her to 100 mph relative to ground, or airspeed.
I have set my R70 up for speed. For my bird, best prop is an APC 14x12, and can turn about 9800 rpm in the air (measured by Eagle Tree on board instruments). My top airspeed is 118 mph, averaging true upwind and downwind runs, straight and level. With that setup, my theoretical prop speed is 111mph, so it is in the same ballpark.
For me, the performance of the R70 is best with a quicker (9 or 10 pitch) prop. YMMV.
2. A 16x6 xoar is a great prop, but may not be quite enough load for the DLE20. Jody Haack (used to be at valley view) ran and posted rpm / thrust numbers with the DLE20 on a number of props, and thought that the loading of the xoar 17x6 was about ideal. From there, adjust diameter and pitch to get the speed you want.
A fast R70 is a fun flying airframe. Roll rate 600-700 */sec on low rates!
Bill
1. The details are important when reporting speed. Are you talking straight and level, maintained speed, or max speed coming out of a dive? Is that a radar gun, or an on-board pitot tube, or an on board gps, or a phone app (doppler). If you are using ground-based technology (radar, doppler), then you have to run exactly upwind and exactly downwind runs, both straight and level, and average the two. Best to do several replicates. The same idea is true with on-board gps, which references to ground (obviously). The only real airspeed device is an on-board pitot tube, and that has to be calibrated.
With a 6-pitch prop (assuming 10,000 rpm), your theoretical speed is just under 60 mph, so unless you were in a dive, or moving downwind in a stiff breeze, it is hard to see how you got her to 100 mph relative to ground, or airspeed.
I have set my R70 up for speed. For my bird, best prop is an APC 14x12, and can turn about 9800 rpm in the air (measured by Eagle Tree on board instruments). My top airspeed is 118 mph, averaging true upwind and downwind runs, straight and level. With that setup, my theoretical prop speed is 111mph, so it is in the same ballpark.
For me, the performance of the R70 is best with a quicker (9 or 10 pitch) prop. YMMV.
2. A 16x6 xoar is a great prop, but may not be quite enough load for the DLE20. Jody Haack (used to be at valley view) ran and posted rpm / thrust numbers with the DLE20 on a number of props, and thought that the loading of the xoar 17x6 was about ideal. From there, adjust diameter and pitch to get the speed you want.
A fast R70 is a fun flying airframe. Roll rate 600-700 */sec on low rates!
Bill
06-30-2014, 06:31 AM
#7542
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Bill has posted regarding his adventures in getting the R70 up well into the triple digits a few times. Guessing he knows what he's talking about!
I'm an APC fan, and prefer 2 props. 17x6 for vertical performance and low speed control (messing with 3D), and 16x8 for speed and vertical performance, maybe best all around if you are quick on the sticks (I'm not!).
I'm an APC fan, and prefer 2 props. 17x6 for vertical performance and low speed control (messing with 3D), and 16x8 for speed and vertical performance, maybe best all around if you are quick on the sticks (I'm not!).
06-30-2014, 06:33 PM
#7543
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Teckbot - a couple of things:
1. The details are important when reporting speed. Are you talking straight and level, maintained speed, or max speed coming out of a dive? Is that a radar gun, or an on-board pitot tube, or an on board gps, or a phone app (doppler). If you are using ground-based technology (radar, doppler), then you have to run exactly upwind and exactly downwind runs, both straight and level, and average the two. Best to do several replicates. The same idea is true with on-board gps, which references to ground (obviously). The only real airspeed device is an on-board pitot tube, and that has to be calibrated.
With a 6-pitch prop (assuming 10,000 rpm), your theoretical speed is just under 60 mph, so unless you were in a dive, or moving downwind in a stiff breeze, it is hard to see how you got her to 100 mph relative to ground, or airspeed.
I have set my R70 up for speed. For my bird, best prop is an APC 14x12, and can turn about 9800 rpm in the air (measured by Eagle Tree on board instruments). My top airspeed is 118 mph, averaging true upwind and downwind runs, straight and level. With that setup, my theoretical prop speed is 111mph, so it is in the same ballpark.
For me, the performance of the R70 is best with a quicker (9 or 10 pitch) prop. YMMV.
2. A 16x6 xoar is a great prop, but may not be quite enough load for the DLE20. Jody Haack (used to be at valley view) ran and posted rpm / thrust numbers with the DLE20 on a number of props, and thought that the loading of the xoar 17x6 was about ideal. From there, adjust diameter and pitch to get the speed you want.
A fast R70 is a fun flying airframe. Roll rate 600-700 */sec on low rates!
Bill
1. The details are important when reporting speed. Are you talking straight and level, maintained speed, or max speed coming out of a dive? Is that a radar gun, or an on-board pitot tube, or an on board gps, or a phone app (doppler). If you are using ground-based technology (radar, doppler), then you have to run exactly upwind and exactly downwind runs, both straight and level, and average the two. Best to do several replicates. The same idea is true with on-board gps, which references to ground (obviously). The only real airspeed device is an on-board pitot tube, and that has to be calibrated.
With a 6-pitch prop (assuming 10,000 rpm), your theoretical speed is just under 60 mph, so unless you were in a dive, or moving downwind in a stiff breeze, it is hard to see how you got her to 100 mph relative to ground, or airspeed.
I have set my R70 up for speed. For my bird, best prop is an APC 14x12, and can turn about 9800 rpm in the air (measured by Eagle Tree on board instruments). My top airspeed is 118 mph, averaging true upwind and downwind runs, straight and level. With that setup, my theoretical prop speed is 111mph, so it is in the same ballpark.
For me, the performance of the R70 is best with a quicker (9 or 10 pitch) prop. YMMV.
2. A 16x6 xoar is a great prop, but may not be quite enough load for the DLE20. Jody Haack (used to be at valley view) ran and posted rpm / thrust numbers with the DLE20 on a number of props, and thought that the loading of the xoar 17x6 was about ideal. From there, adjust diameter and pitch to get the speed you want.
A fast R70 is a fun flying airframe. Roll rate 600-700 */sec on low rates!
Bill
Bill, is there somewhere to find a formula (or better yet, an online calculator) to find theoretical speeds? You mentioned the theoretical speed for running a 6 pitch prop at 10k rpm is under 60mph. I can see that the maximum speed being found as if there were nothing being dragged behind the prop, but the coefficient of each airframe varies greatly and has a huge impact of how fast a plane with be.
Just a note, I've only flown the Rev with Xoar 16x6 and 17x6 props. I personally preferred the 17x6. It doesn't make her a total rocket, but the vertical climb is really nice.
Jeremy
06-30-2014, 06:41 PM
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Here is the one clocked with radar at 106mph . No dive, plus a headwind. He posted in the comments that he was using a APC 15x8. The radar gun may be off slightly, but I think its safe to say it was doing at least 100mph.
The actual pass is at the end of the video
http://www.youtube.com/watch?v=iu8HY2FaxuU
The actual pass is at the end of the video
http://www.youtube.com/watch?v=iu8HY2FaxuU
07-01-2014, 06:18 AM
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Hi Jeremy
I don't know of an online calculator.
RPM x pitch (in inches) / 12 (inches/ft) = feet per minute.
Divide that number by 5280 for miles per minute; multiply that result by 60 for miles per hour.
9000 rpm x 6 / 12 = 4500 feet/min
4500 / 5280 = 0.852 miles / min
0.852 x 60 = 51.1 mph
NOW, there are many uncertainties, only some of which i will mention.
1. drag from the airframe: a bipe or big round cowl will not approach theoretical max as well as a slippery extra or revolver might, which is the factor you mentioned
2. nominal pitch of the prop may be off, perhaps as much as 10-20%. A nominal 10 pitch prop may really be about 12. I have no experimental data to back that up, but knowledgeable experts say that is true.
3. the engine may unload to higher rpm that we see on the ground. The only way to get that number is to have onboard monitor for rpm. Unloading might be as much as 10-15%
4. it is said that "a prop is an airfoil and generates lift even at an angle of attack of 0* ". Of course, at max theoretical speed, the prop AOA is zero degrees. I don't know if that is true; by analogy with a wing, one needs at least SOME AOA.
5. Finally, and perhaps most convincingly, full scale pilots affirm that their planes routinely exceed theoretical prop speed in cruise.
Perhaps someone with aeronautical engineering background can explain how a plane can fly faster than its max theoretical prop speed, but 1-5 are the answers i have received.
Bill
I don't know of an online calculator.
RPM x pitch (in inches) / 12 (inches/ft) = feet per minute.
Divide that number by 5280 for miles per minute; multiply that result by 60 for miles per hour.
9000 rpm x 6 / 12 = 4500 feet/min
4500 / 5280 = 0.852 miles / min
0.852 x 60 = 51.1 mph
NOW, there are many uncertainties, only some of which i will mention.
1. drag from the airframe: a bipe or big round cowl will not approach theoretical max as well as a slippery extra or revolver might, which is the factor you mentioned
2. nominal pitch of the prop may be off, perhaps as much as 10-20%. A nominal 10 pitch prop may really be about 12. I have no experimental data to back that up, but knowledgeable experts say that is true.
3. the engine may unload to higher rpm that we see on the ground. The only way to get that number is to have onboard monitor for rpm. Unloading might be as much as 10-15%
4. it is said that "a prop is an airfoil and generates lift even at an angle of attack of 0* ". Of course, at max theoretical speed, the prop AOA is zero degrees. I don't know if that is true; by analogy with a wing, one needs at least SOME AOA.
5. Finally, and perhaps most convincingly, full scale pilots affirm that their planes routinely exceed theoretical prop speed in cruise.
Perhaps someone with aeronautical engineering background can explain how a plane can fly faster than its max theoretical prop speed, but 1-5 are the answers i have received.
Bill
07-01-2014, 09:41 AM
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07-01-2014, 12:53 PM
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With most anything, theoretical is achieved because of outside factors (resistance from friction, drag etc.). Anyway, exceeding theoretical prop speed seems like an impossibility. To even meet theoretical prop speed would mean that there is absolutely no drag and the prop has 100% efficiency. So, the only answer is that the pitch of the prop has a more aggressive angle of attack than what is advertised.
Either way, 118mph Revolver is fast...
Either way, 118mph Revolver is fast...
07-01-2014, 01:15 PM
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I have the DLE 20 RA flying with the APC 15x8 and can confirm that this combo is over 100mph. I have not done formal testing but using 2 marker posts at our field I have a pretty good idea comparing to planes that I have tested. It seems to be about 110 level turning out of a shallow dive. I know that public always find the speed awesome. However it is taching about 9300 -9500 on the ground and will clearly be unloading to well into the 10's -- too much for the DLE. I have just landed a Xoar 17x6 and will be interested to compare. Another factor is that with no wind, it is very difficult to get her down with the 15x8 when doing a standard landing pattern. However even a 1-2mph breeze helps a great deal. Still my favourite plane.
07-01-2014, 01:17 PM
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The covering had more wrinkles than I had thought. Fuse wasn't too bad, but the front of the canopy had a lot of wrinkles. The right wing looked like a pro had covered it, but the left looked like someone of my skill level had done it. No worries though, I spent about an hour and got it all pretty.
The Revolver is such a sleek and pretty plane, wrinkles just won't do. Even though it may not be as light, the sheeted foam core wings have a super clean look, like a full scale plane.
Last edited by mach2; 07-01-2014 at 01:23 PM.