highfly3D

Keith awesome precise job......

klhoard

My Feedback: (10)

Thanks!!
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Design it on a Pentium, Measure it with a Micrometer, Mark it with a Grease Pencil, then Chop it with an Axe!!!!
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klhoard

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I got to make some progress on the front of the fuselage today. After marking up the huge block and making my plan of attack, it took me about an hour to to whittle this thing down to size. I started with the coping saw, then went to the power planer. A trip to the band saw. . . flip it over and begin making a cloud of balsa dust with my Dremel in router mode. . . . then just carving out huge chunks with a big square X-acto blade . . . finish up with 80 grit glued to a piece of pink foam. While it was fun hacking into this big block of wood with all of my toys, if I had it to do over again I would just get out some 3/8" and build the top front of the fuse.. .
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Yes, I went a little OCD on the inside of the tank compartment. . .

klhoard

My Feedback: (10)

Between pictures #2 and #3 above, I was waiting for the polyurethane glue to cure. I decided to go ahead and glass the center section of the wing.
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The first thing I did was mix up some epoxy and add a little acetone to get it going and thin it out. Yes, I know I got the wrong kind of hardener (209 instead of 205), I can never remember the correct number of what I got last time when ordering. I think this will work, just takes longer to cure. I then measure out and cut my fiberglass with a rotary cutter. I like the rotary cutter since it doesn't mess up the fabric. The next step I do is mask off the areas around where I'm going to apply the glass and spray a light tack coat of 3M 77 spray. I then carefully lay down the fiberglass cloth and smooth it out with the plastic scraper. This keeps the cloth in place while applying the resin and keeps any wrinkles out after I get it laid down.
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Once the cloth is in place I liberally apply the resin. I make sure the glass is wet all the way thru to the wood. If your shop is cold, you can also enlist the help of your wife's hair dryer to warm it up and help it flow. Once the resin is soaked into the cloth and balsa, take your plastic scraper and carefully scrape the resin. I practiced this on a couple pieces of scrap balsa before trying it on my model. Once you get the right combination of angle, pressure, and speed, you can remove almost all of the excess resin and leave only a little that has soaked into the wood and the glass. The surface will look dry. If you work your way from the leading to trailing edge, your last glob of resin will slide right off the trailing edge and drop onto your paper towel. A little technique I use is to soak the top half of your paper towel with denatured alcohol to help wipe off your scraper and finger. I tried acetone, but it evaporated too quickly.

viva_peru

Keith,

I am really enjoying this thread, specially how you got it started. I have been keeping an eye on the XLT for a very long time (I still have the 1982 FM issue in which Bob Hunt reviewed it) and I think that I would like to build one at some point. I was wondering if you have an estimate of how much the plane will weigh when finished. I converted over into electric a few years ago and kept thinking that maybe the old Birdi planes were simply too heavy to convert. If I were to do it, I would change it into a tail dragger and possibly skip the retracts in order to save weight...

Thanks,

Teo

klhoard

My Feedback: (10)

Teo,

I edited my last post to add my current weight chart, it is the .pdf file that's hard to see below the pictures. Some of the engine components are guesstimates, but right now I'm at 6.93 pounds, before finishing. I haven't updated it in a few days and need to re-weigh and combine a few items. I'll try to get that done tonight so I can post it with today's progress.

There is alot of "thick" wood on this plane that I have thinned out by using my Dremel tool with routing attachment. I've also replaced several bulkheads with composite honeycomb. If you were going to try one of these electric, you could save some serious weight in the nose by going with 1/8" lite ply for the firewall. Using fixed gear would easily save several ounces along with some of the other changes I mentioned earlier. The canopy came pretty thick and heavy, so I'm going to try to shave it down from the inside with my Dremel and cutting wheel. We'll see how well THATworks out. . . If I had the skill and equipment, the obvious choice would be to make a canopy out of carbon fibre using the supplied one as a mold. I've been trolling the composite forums. . . maybe if enough guys are interested I may take a stab at molding a few.

grcourtney

My Feedback: (1)

If you have any flex in the wood for the fire wall you may need a nose ring. I ran into this with my p-8 i could grab the spinner and had a little to much movement.


gary

klhoard

My Feedback: (10)

Gary,

I cut a new firewall out of 1/4" endgrain balsa / carbon stuff that ACP Composites sells. It seems to be very stiff and tough, I couldn't even crush it in my vise. I am using the YS110 Hyde mount and Merle says that this mount doesn't require a nose ring. Between those two components I believe that the mount would be the part that would allow the engine to move around, so we'll see. I plan on bench running the engine while mounted to the Hyde mount. . . we'll see how much movement I get then. There is certainly enough beef forward of the firewall to mount a nose ring if necessary. . .

viva_peru

Keith,

Thanks for the info. It definetly seems do-able as an electric.

Teo

JHays

Hello
I have a new XLT from Blue Jay as well. I am planing on starting on it soon. Question how and what tool did you use to cut the retract and servo holes in the wing.
Thanks

klhoard

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The Dremel w/router attachment. . .there is a picture of it back on post #36. . .
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Gotta be careful, it is really easy to "get happy" and cut out too much. . .
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klhoard

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Only got to work on the plane a couple hours today. Installed a structure to hold the tank in the nose, and then installed a couple more pieces on the nose. . .
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I also updated the weight spreadsheet and attached it to this post.
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doxilia

My Feedback: (3)

Keith,

you probably mentioned it in another post but... what is going to be powering this puppy? What are you using for retracts?

David.

klhoard

My Feedback: (10)

I have a Jett - FIRE 90L that is scheduled to ship on 3/2 that I'm going to use as the "motivator". For what guys are asking for used Hanno's, I figured I could get a new engine with more grunt. The only thing I'm giving up is the pump, but I couldn't put the tank on the CG of this plane anyway - not enough room over the wing.
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I've never owned a Jett engine before so I'm looking forward to the experience. Dub says on his web site that this motor can turn an 12 x 6 at 14.5, and the guy in the testimonial got 16.0 out of a 10 x 10 APC prop. I don't think I've ever stood next to an engine turning those numbers, so it should be fun!!
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Retracts are the standard Robart air up / spring downs. I've seen other posts where guys had to return them for air up / air downs, so we'll see. . .
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grcourtney

My Feedback: (1)

about a 1/4 of my tank is over the cg. slimline.. not much you can do.

gary

glowplugboy

My Feedback: (17)

You'll enjoy your Jett. I own four..... 2 BSE .25's, one Sport .46, and a BSE .90 SE. You truly get your money's worth; nothing else compares. In a couple of generations, these will be the next collectibles...... I'm putting my .90 on my Great Escape.

doxilia

My Feedback: (3)

Keith,

nice setup. If you've never stood beside a Formula 1 40 engine turning at 20K +, its something to behold. I'm sure you've seen the 250 mph pylon racers on You-tube... I just don't understand how the pilots know where the heck the plane is!

There an interesting video of a guy who built a GP Revolver with a en electric 1.6 equivalent on 12s... [:-] The model easily exists the stratosphere and returns and flys at 160 mph on a level pass. It also requires a jet sized runway to land... I think it weights 10 lbs. [&:]

David.

klhoard

My Feedback: (10)

All right. . . got back from my trip early this morning, but couldn't wait to get back to work on the plane. I started by gluing in the bottom sheeting under the firewall. After I got it in, I realized that I hadn't finished putting in all of the triangle stock to back up the firewall - ugh!! Not impossible to overcome, but I couldnt clamp them in while they cured like I wanted. The downside of having to take a pause in the middle of a project. . .

klhoard

My Feedback: (10)

I decided it was time to get the horizontal stabilizer mounted to the fuse. I began by securing the fuselage to the building table. The next step I do is to make sure that the hole in the fuse for the stab is slightly larger than the stab so I'll have some "wiggle room" while I get the stab set to zero degrees.
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To get the stab perfectly square with the fuselage, insert two T-pins in the stab at symmetrical points as far away from the centerline as you can get. I used the intersection of the leading edge stock and tip block. Then find a point on the centerline of the fuselage as far away from the stab as you can get. The larger you can make this triangle, the more accurately aligned your stab will be. I tried to use the centerline of the firewall, but my measuring stick wouldn't reach, so I moved back to the wing cradle. Using a string to hold the stab in position, I adjusted the stab until the tips were equidistant from the T-pin on the fuselage.

klhoard

My Feedback: (10)

Now that I had the stab aligned perpendicular to the fuse centerline, I started to align it for zero degrees incidence. With the fuse still secured to the table, I inserted four T-pins on the centerline of the leading and trailing edges of the stab an equal distance from the centerline of the stab. I then cut up four wedges of pink foam to suspend the stab inside the hole I cut in the fuse. You want to start with the stab in a position where it doesn't touch the fuselage.
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Now comes the fun part. Using some sort of measuring device, start working your way around all four T-pins making teensy-tiny little adjustments until all four pins are an equal distance from your building table surface. Assuming that your table is flat, and the fuselage is secured at 0 degrees incidence, your stab will now be perfectly aligned with the fuse. Ideally, the stab is still "floating" inside the hole you cut in the fuse.
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To secure the stab permanently, take little pieces of balsa and CAREFULLY insert them inside the fuselage so they touch both the stab and fuse side. Secure the balsa with a couple drops of CA. Do this enough times so the stab is now fully secured from inside. This can look ugly since later you'll seal the gap with your favorite fillet material and they will be hidden forever. (Unless you're doing a build thread, then everyone will see them.)

klhoard

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Once I got the stab installed, I couldn't help but take a quick progress photo. . .

highfly3D

Very GOOD.. what will be the color scheme..?

klhoard

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That's always the tough part for me. . . I have four colors of Klass Kote - White, Black, Red, and Yellow. I'll have to work something up in a week or two. . .

hrrcflyer

Keith,

Great job so far... Keep up the good work.....[sm=thumbup.gif]

You may want to consider adding some additional reinforcing to the tail of this bird. I'd hate to see that Jett 90 rip the tail off in mid flight....[X(]

klhoard

My Feedback: (10)

Well, its that time in every build that I realize I messed something up and need to engage in some "creative engineering". . Luckily my wife is out of town on a business trip because as a professional project manager she has an uncanny ability to detect when I have resorted to any major "project re-work". The worst part is having to document the whole incident and submit a report to her explaining how this affects the project end date and assigning blame . . . (just kidding). . .
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Back whenI started, I decided to mill out alot of the parts to try to shave some weight off the plane. When I milled down the right fuselage side, I was able to leave a respectable 1/8" of wood. However, when I routered the left fuse side, somehow I managed to shave it down almost paper-thin. I have been looking at it throughout the build thinking it would be OK, but when I began taping down the bottom sheeting I realized that the side was bowing out and almost had the consistency of Monokote. In one of the pictures you can almost see the wood bowing in to finger pressure. I've been thinking about this for a couple days, to include hrrcflyer's comment, and decided that it may be a good idea to stop here and try to fix this before proceeding any further. . .
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They say there are five steps to the Grieving Process. . .
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The first step, of course is Denial. . . "Well, it should be OK, I have alot of planes with Monokote sides. Besides, I have already sheeted the bottom and can't get to the inside of the fuse."
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Then comes Anger . . . "(~%($%#$^*()_+%##$%@%!!!!!!!!!!!!"
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The next step is Negotiation . . ."I'm going to glass and paint the fuse so that will add alot of strength, right?"
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After that is Depression . . . "Man, this is going to take forever, add weight, and end up being a kludge fix. . .."
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The final step is Acceptance . . . "Well, its better than having to rebuild the whole thing if the tail rips off. . . where's that razor saw?"