OS 33GT Gasoline Engine for Pattern
#401
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I've seen the 4 stroke ads but have not seen one run yet. I would bet it works pretty well. The couple sport fliers that have it seem to report mostly good experiences. One guy had lots of pain early on but eventually he figured out how to tune it right and now seems happy with it.
For me tho, it doesn't appear from what the sport guys report, that it has the power of the 2 stroke 33.
Bottom line, I think the sound would be terrific but lack of power and heavy weight are handicaps for pattern
For me tho, it doesn't appear from what the sport guys report, that it has the power of the 2 stroke 33.
Bottom line, I think the sound would be terrific but lack of power and heavy weight are handicaps for pattern
#403
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Here's the latest development for the 33GT. It's in my Delta which I modified in the fall since the 33 is 1/2 pound lighter than the DLE55 I had in there.
Been wanting to try a flight real bad to validate the work. Not exactly stellar conditions but okay so here it is http://youtu.be/GCwgOeArn30. Now I can't wait for spring to get here so I can tune Delta in
Been wanting to try a flight real bad to validate the work. Not exactly stellar conditions but okay so here it is http://youtu.be/GCwgOeArn30. Now I can't wait for spring to get here so I can tune Delta in
#405
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Augie is the field's supervisor and was the key guy to get use approval from the farmer that owns it. Our field is literaly immediately behind Augie's back yard, and we have to drive through Augie's driveway to get to it. We are very lucky that Augie just happened to love toy airplanes.
Here's the second part of the video where I slice and diced the cardboard into skis. http://youtu.be/JWCloA6IoGQ. Courtesy of Augie.
The thing lost in all of this is the fact that these where a simple tape job onto my landing gear. The gear set is my own design and cast in my molds (both struts and pants). There is a single 4-40 screw holding each leg into the fuse. The gear set is light and springy (4 1/2 ounces total, including wheels, axles) and works great on up to 12 pound airplanes.
#406
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Hi Matt,
Love the thread and vids. What is your distance from firewall to thrust washer on your setup? I scanned the thread and didn't see that measurement but it's probably there. This thread has energized me to convert my Pentathlon from glow to electric and now to gas. This should allow more summer flying here in the desert vrs frying my electric stuff in the heat.
maustin
Love the thread and vids. What is your distance from firewall to thrust washer on your setup? I scanned the thread and didn't see that measurement but it's probably there. This thread has energized me to convert my Pentathlon from glow to electric and now to gas. This should allow more summer flying here in the desert vrs frying my electric stuff in the heat.
maustin
#407
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Thanks Mike,
I have both Delta and Aesthesis set- up with GT33s and both set-ups use 1 1/4" stand offs. But their firewall to washer lengths are different. Aesthesis was originally intended to be powered with a ZDZ40 which is about 3/4" longer than the OS. So the mount is much thicker than normal to compensate.
One other thing, I always cut a hole in the center of the firewalls to make space for the carb. Anyway, the length on Delta will be more typical of most set-ups. It is exactly 7". The mount is exactly 1" thick and the stand offs end 6" from the washer. If your set-up doesn't quite have the room, consider a shorter stand off but more carb will need to be tucked inside the soft mount
The OS has very deep fins and cools well but I duct cooling ram air directly over them anyway. Even in narrow pattern fuses, ducting eliminates any overheating worries. Although I've not flown in 110 degrees, more like 95, I think it will work well.
I have both Delta and Aesthesis set- up with GT33s and both set-ups use 1 1/4" stand offs. But their firewall to washer lengths are different. Aesthesis was originally intended to be powered with a ZDZ40 which is about 3/4" longer than the OS. So the mount is much thicker than normal to compensate.
One other thing, I always cut a hole in the center of the firewalls to make space for the carb. Anyway, the length on Delta will be more typical of most set-ups. It is exactly 7". The mount is exactly 1" thick and the stand offs end 6" from the washer. If your set-up doesn't quite have the room, consider a shorter stand off but more carb will need to be tucked inside the soft mount
The OS has very deep fins and cools well but I duct cooling ram air directly over them anyway. Even in narrow pattern fuses, ducting eliminates any overheating worries. Although I've not flown in 110 degrees, more like 95, I think it will work well.
#412
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About ready for a test run to see how the mount holds up. Mount weighs 3.5 oz. Seems pretty robust.
Matt, are you still selling those fancy homemade couplers?? If so I'll buy some from you. Until then I'll bench run with some old aerotrend blue couplers I have.
Mike
Matt, are you still selling those fancy homemade couplers?? If so I'll buy some from you. Until then I'll bench run with some old aerotrend blue couplers I have.
Mike
#413
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It looks fine. Don't forget the extension. The reflector baffle needs to be 27" from the exhaust flange, following the curve of the header. I'm using about a 3 1/2" extension on my set-ups.
For trouble free operation, don't forget to install a couple small button head screws on straight exhaust tubes. Drill and tap for 4-40 x 1/8", at 3 places around the pipes. The header's bump works fine as is.
Yes I make the couplers available to any one or I can explain how I do it for the do it yourselfer. These cost 10 bucks each plus 5$ S+H. I use ceramic fabric (silica or alumina, good to 2000F+). Chances are good fiberglass or carbon would work great too, but I haven't tried it. Once the sealant is burned off inside, only the fabric is exposed and just works great for years now.. The aerotrend might last 10 runs, enough to figure out where the tune is. Start at 1 1/8 turn on the LS needle and 1 1/2 turns on the HS needle. Suggest you have a Dynatron handy until you learn what the beastie needs. Then, it's usually 1-3 flips.
I will post my latest wood carbon hybrid prop I just ran for the first time last Sunday. It's a 20 1/4" x 12" N, hand carved woodie with carbon cloth cladding. It produces a great sound, very subdued. And produces terrific thrust on an engine that isn't broken in yet. I run it at about 6200 rpm tops in flight. It never needs full revs which are about 7300.
#414
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Matt, Sounds great. I'll take 2 and do some experimenting on the side so see what else might work. Let me know method of payment. I plan to run it this weekend so I'll let you know how it goes. The Pentathlon is about ready for the new firewall. Hope to have this in the air in 2 weeks or less. The thought of 13 min flights is music to my ears, LOL. Thanks for all your help!!
Mike
Mike
#415
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Matt, Sounds great. I'll take 2 and do some experimenting on the side so see what else might work. Let me know method of payment. I plan to run it this weekend so I'll let you know how it goes. The Pentathlon is about ready for the new firewall. Hope to have this in the air in 2 weeks or less. The thought of 13 min flights is music to my ears, LOL. Thanks for all your help!!
Mike
Mike
On the length of flights, I've had one local complain vehemently because his e-pattern plane only flies 8 minutes. Hopefully you won't have that issue. Remember, just as we had with glow, it depends alot on the prop you use and rpm you turn. The engine has plenty of torque to turn the lower rpms and larger props. A great all around prop is 20 x 10.5 PN APC.
#417
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Mike, the parts are on their way. I also sent along a length of gasoline tubing I discovered a few years ago. This stuff is so good I actually sell it. I sent you enough to outfit one set-up. If you use a Dubro tank, you should solder rings of wire to form barbs on the brass tubes. The tube ID is 1/8" and it won't hold on the 3/32" ID brass tubes. The gas line will be as trouble free as the OS will be.
If you have a problem with the couplers let me know. Two things to help them stay put...The button heads installed on the ends of the aluminum tubes really help. The pipe should be soft mounted at its approximate balance point. This isn't elaborate. I use a Dave Brown type which I modify to my liking as follows: I epoxy the bracket onto the pipe with a nut inside to hold the Lord mount. The mount is then secured to the fuse externally. Extremely neat, simple and functional
If you have a problem with the couplers let me know. Two things to help them stay put...The button heads installed on the ends of the aluminum tubes really help. The pipe should be soft mounted at its approximate balance point. This isn't elaborate. I use a Dave Brown type which I modify to my liking as follows: I epoxy the bracket onto the pipe with a nut inside to hold the Lord mount. The mount is then secured to the fuse externally. Extremely neat, simple and functional
#418
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Thanks a bunch Matt !! BTW: I ran the motor last night and it started and ran right off the bat. No starter needed - hand prop about 10 times with choke on for the 1st time, switch on power module and started on the 3rd flip after that. Smooth, quiet and low vibes considering no nose ring to steady it up. I'm impressed so far
Mike
Mike
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Hi Matt, Yes, It's a miracle given the postman dropped the box on the ground and a neighborhood kid found it in the street and actually delivered to my door on his bike!! No damage at that. LOL. Couplers look cool and I like that fuel tubing. Firewall being cut tonight. I'll post a pic when I get the motor completely mounted. It's a drop in fit so it should go well. Got my Tech Aero Ibec on the way, just need a battery.
Thanks,
Mike
Thanks,
Mike
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Update: attached pics show we're about ready to go. Waiting on a battery and recommended prop. Installation was not as bad as thought it would be. Just different being gas with the standoffs and linkages. Mount has passed test runs so not worried. I'll update again once flown a few times. Should be cool to compare the gas motor vrs the YS 160 originally installed & flown in the plane.
Mike
Mike
#422
Hello Mike
Which tuned pipe is, is it a carbon ES Composite ?
Do you know max rpm et what is propeller ?
Thanks
Claude
Which tuned pipe is, is it a carbon ES Composite ?
Do you know max rpm et what is propeller ?
Thanks
Claude
Last edited by papaone; 05-21-2014 at 07:19 AM.
#423
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Update: attached pics show we're about ready to go. Waiting on a battery and recommended prop. Installation was not as bad as thought it would be. Just different being gas with the standoffs and linkages. Mount has passed test runs so not worried. I'll update again once flown a few times. Should be cool to compare the gas motor vrs the YS 160 originally installed & flown in the plane.
Mike
Mike
BTW- The early props I used during break in were 18.5 x 9.5 wide blade (I had one so I used it) and then the 19x11. I quickly (within a couple gallons) switched to the 20x10.5 PN apc and that has been a terrific match. Most recently my hand carved 20 1/4x 12 Narrow blade has been working very similar to the apc. Same noise footprint and similar thrust output per throttle setting. But this wood-carbon composite is only 77 grams, shaving 3 ounces from the nose.
Just completed a 22x10 Narrow Blade wood-carbon hybrid for the YS185. We will see how the 185 performs on that prop. We are looking for 7000 rpm which should be doable. I don't think the 33 will turn this much lumber so I won't even try it right now. Maybe later
#425
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Looks like good progress. The 33 puts out about similar power to the YS175. It actually puts out more top end (which we never use) on the same props...but it's the mid range that will surprise you. You simply point the nose and add throttle for effortless verticals.
BTW- The early props I used during break in were 18.5 x 9.5 wide blade (I had one so I used it) and then the 19x11. I quickly (within a couple gallons) switched to the 20x10.5 PN apc and that has been a terrific match. Most recently my hand carved 20 1/4x 12 Narrow blade has been working very similar to the apc. Same noise footprint and similar thrust output per throttle setting. But this wood-carbon composite is only 77 grams, shaving 3 ounces from the nose.
Just completed a 22x10 Narrow Blade wood-carbon hybrid for the YS185. We will see how the 185 performs on that prop. We are looking for 7000 rpm which should be doable. I don't think the 33 will turn this much lumber so I won't even try it right now. Maybe later
BTW- The early props I used during break in were 18.5 x 9.5 wide blade (I had one so I used it) and then the 19x11. I quickly (within a couple gallons) switched to the 20x10.5 PN apc and that has been a terrific match. Most recently my hand carved 20 1/4x 12 Narrow blade has been working very similar to the apc. Same noise footprint and similar thrust output per throttle setting. But this wood-carbon composite is only 77 grams, shaving 3 ounces from the nose.
Just completed a 22x10 Narrow Blade wood-carbon hybrid for the YS185. We will see how the 185 performs on that prop. We are looking for 7000 rpm which should be doable. I don't think the 33 will turn this much lumber so I won't even try it right now. Maybe later
Mike