Yellow P-38 build thread
05-23-2016, 04:47 PM
#401
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Pull,
Guess my eye isn't as good as it used to be but I don't see a whole lot of difference between the Biela and the Xoar. They may be a little wider. At least the Biela's are composite and cheaper. Think I'll stick with the Biela's and paint them. Thanks for the info on the mufflers.
RVN
Guess my eye isn't as good as it used to be but I don't see a whole lot of difference between the Biela and the Xoar. They may be a little wider. At least the Biela's are composite and cheaper. Think I'll stick with the Biela's and paint them. Thanks for the info on the mufflers.
RVN
05-24-2016, 08:39 AM
#402
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RVN,
You are right they are very close. I think the Xoar blades are a bit thinner at the hub and more tapered so that's the way I'm going. At this point I'm in so deep with $$$$$ a few more bucks doesn't matter...
You are right they are very close. I think the Xoar blades are a bit thinner at the hub and more tapered so that's the way I'm going. At this point I'm in so deep with $$$$$ a few more bucks doesn't matter...
05-30-2016, 04:10 PM
#404
Brought the P-38 out to the field today to get the engines running. Had an issue last year with the left one stumbling on the low end. Turns out it was the servo not the engine so that was a relief. Using Hitec's servo programmer I flashed it and tested it and it worked like normal again.
I programmed the plane all over again on a DX18 and I'm not impressed with how this radio handles twin engines. I made two TH channels and you have to use subtrim to dial the other engine in so they are in sync. Your not given the option to have the upper digital trim assigned to this channel.
Anyways, pain in the neck but it works.
The DLE 35RA's are awesome, one flip starts once warm, pull up to 7400rpm on 18x10's. I'm looking forward to flying this season!
I programmed the plane all over again on a DX18 and I'm not impressed with how this radio handles twin engines. I made two TH channels and you have to use subtrim to dial the other engine in so they are in sync. Your not given the option to have the upper digital trim assigned to this channel.
Anyways, pain in the neck but it works.
The DLE 35RA's are awesome, one flip starts once warm, pull up to 7400rpm on 18x10's. I'm looking forward to flying this season!
07-14-2016, 10:53 AM
#405
PM,
Got the plane out for some PM and the right engine would get up to 6900 rpm's and then sag and surge. I got another G-38 out that has a DLE-30 carb on it and put it on the engine and both are now running nicely at 6900 rpm's. I rebuilt both carbs but must of done something wrong. Ordered two more carb kits from B&B specialty.
ps: got lucky as the picture got posted, correctly.
Got the plane out for some PM and the right engine would get up to 6900 rpm's and then sag and surge. I got another G-38 out that has a DLE-30 carb on it and put it on the engine and both are now running nicely at 6900 rpm's. I rebuilt both carbs but must of done something wrong. Ordered two more carb kits from B&B specialty.
ps: got lucky as the picture got posted, correctly.
08-17-2016, 03:32 AM
#409
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Finished. Using a flex-pipe for exhaust I got from Chief. I had Scott Raines paint it in the 'California Cutie' scheme. Just couldn't hack up those cowls... Amazing work. Setting up DMSS Xbus now, flaps are a bit tricky! This also has a OSA Microsynch Pro and a Sparkswitch installed. Maiden in a month or so.
09-28-2016, 06:47 PM
#412
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Best bet it to post a couple want ads. Feel sure they are some kicking around, or go with disk as Sam said
If you do end up getting a set of Yellow brakes, couple tips. I use a separate air tank. Simple on off spring air style valve to apply the brakes, one time ground testing to fine pressure just below where they want to lock up. Set tank pressure a few pounds below that, and that what you fill tank to each time you fly. Works great, and have never had a problem
I wouldn't recommend trying to use a proportional valve with fuel tube brakes, will just end up spinning your wheels
If you do end up getting a set of Yellow brakes, couple tips. I use a separate air tank. Simple on off spring air style valve to apply the brakes, one time ground testing to fine pressure just below where they want to lock up. Set tank pressure a few pounds below that, and that what you fill tank to each time you fly. Works great, and have never had a problem
I wouldn't recommend trying to use a proportional valve with fuel tube brakes, will just end up spinning your wheels
02-28-2017, 11:59 PM
#413
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After several months of back and forth, Slimline produced a set of muffs for me that are completely contained within the cowl. Just 2 exit pipes on the bottom, looks pretty slick.
Worked on CG earlier tonight. Weight came in at 35.2 lbs. 15.2 on right main, 15.4 on left main, and 4.6 on nose. CG is right on front aluminum wing rail spar - should I add some weight to the nose to move it up a half inch? The aluminum wing rail spar attaches to the rear of the wood spar in the booms.
Thanks!
03-03-2017, 04:04 AM
#418
Keith,
I use to balance all of the ones i ever built just behind the front spar. I never had to add any weight to the nose or tail with this setting and the plane flew great. That was done with the gear in the retracted position. So when the gear was out it was still slightly nose heavy.
I use to balance all of the ones i ever built just behind the front spar. I never had to add any weight to the nose or tail with this setting and the plane flew great. That was done with the gear in the retracted position. So when the gear was out it was still slightly nose heavy.
03-17-2017, 06:26 AM
#421
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Maiden went OK, but not great. Despite a flawless run-up test, the right engine loaded up on takeoff roll. I had to jink to the left and sheared the right main. Despite that, got her in the air and flew for 10 minutes. Needed a dozen or so clicks of left aileron and noticed a significant right yaw in level flight. This could have been due to asymmetric thrust? Airplane is straight and laterally balanced. Landed her wheels up, power off, 50% flaps in the grass. Lost the props but otherwise she's fine. Some scale scratches on the bottom now... Had a spare shear pin so she's back on her feet.
03-17-2017, 05:06 PM
#423
Glad you saved it Keith.
On mine with twin DLE 35RA 's I did baffle the cowls, checked temps and RPM's on the ground. I did a lot of testing prior to the maiden and come to find out I had a bad throttle servo not an engine problem. I flashed the servo and it works fine now but I had a couple of flights on it.
My advice is to check temps and set the carbs, as you have no don't done, but match the engines best you can. I was seeing about 168F at idle after a few minutes at idle with the nose pointed into the wind.
Im looking forward to this season. I'm going to go thru all the details and preflight it soon. I did find the right engine fuel line chaffing against the intake velocity stack so that will be addressed.
On mine with twin DLE 35RA 's I did baffle the cowls, checked temps and RPM's on the ground. I did a lot of testing prior to the maiden and come to find out I had a bad throttle servo not an engine problem. I flashed the servo and it works fine now but I had a couple of flights on it.
My advice is to check temps and set the carbs, as you have no don't done, but match the engines best you can. I was seeing about 168F at idle after a few minutes at idle with the nose pointed into the wind.
Im looking forward to this season. I'm going to go thru all the details and preflight it soon. I did find the right engine fuel line chaffing against the intake velocity stack so that will be addressed.
03-26-2017, 08:58 AM
#424
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Thanks Guys, always appreciate feedback!
Checked Booms for cracks; lucked out, no cracks just small scratch on bottom left rudder. Right rudder was slightly out of trim.
Second flight went much better yesterday. Used Menz 2-blade props without spinner covers. Taxied into position and held while doing a run-up and sync. Takeoff was awesome. With rudder trim correction, flight was straight and true. One click of left aileron and she was flight trimmed. Going to ditch the Microsych Pro; constantly pulsing during flight in mid-range. Going to set up a separate channel and sync with transmitter. Surprisingly floaty on landing with full flaps in ground effect. Might have been a bit tail heavy without the 3-blades and spinner covers.
I'm going to make up some spare shear pins. Anybody know what alloy they are made from?
Checked Booms for cracks; lucked out, no cracks just small scratch on bottom left rudder. Right rudder was slightly out of trim.
Second flight went much better yesterday. Used Menz 2-blade props without spinner covers. Taxied into position and held while doing a run-up and sync. Takeoff was awesome. With rudder trim correction, flight was straight and true. One click of left aileron and she was flight trimmed. Going to ditch the Microsych Pro; constantly pulsing during flight in mid-range. Going to set up a separate channel and sync with transmitter. Surprisingly floaty on landing with full flaps in ground effect. Might have been a bit tail heavy without the 3-blades and spinner covers.
I'm going to make up some spare shear pins. Anybody know what alloy they are made from?
03-27-2017, 04:56 AM
#425
Thanks Guys, always appreciate feedback!
Checked Booms for cracks; lucked out, no cracks just small scratch on bottom left rudder. Right rudder was slightly out of trim.
Second flight went much better yesterday. Used Menz 2-blade props without spinner covers. Taxied into position and held while doing a run-up and sync. Takeoff was awesome. With rudder trim correction, flight was straight and true. One click of left aileron and she was flight trimmed. Going to ditch the Microsych Pro; constantly pulsing during flight in mid-range. Going to set up a separate channel and sync with transmitter. Surprisingly floaty on landing with full flaps in ground effect. Might have been a bit tail heavy without the 3-blades and spinner covers.
I'm going to make up some spare shear pins. Anybody know what alloy they are made from?
Checked Booms for cracks; lucked out, no cracks just small scratch on bottom left rudder. Right rudder was slightly out of trim.
Second flight went much better yesterday. Used Menz 2-blade props without spinner covers. Taxied into position and held while doing a run-up and sync. Takeoff was awesome. With rudder trim correction, flight was straight and true. One click of left aileron and she was flight trimmed. Going to ditch the Microsych Pro; constantly pulsing during flight in mid-range. Going to set up a separate channel and sync with transmitter. Surprisingly floaty on landing with full flaps in ground effect. Might have been a bit tail heavy without the 3-blades and spinner covers.
I'm going to make up some spare shear pins. Anybody know what alloy they are made from?
Keith,
I use to make spare pins out of the unthreaded shanks of a grade8 1/4x20 bolt.
They would usually bend and not break if you had a really bad landing.
The pins that were original to the gear were just to brittle.