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Old Nov 19, 2012, 02:18 PM
Just call me crash for short
Quick61's Avatar
United States, OH, The Plains
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Originally Posted by HerkS View Post
Hi Mark, I've tried to rationalize your wing with straight lines and multiple panels. It looks pretty reasonable. Anyway - based on what I've been able to do, it does look as if you can get some elevator effect from the pitcheron panels.

Have you decided where you are going to locate the starting CG???

Do you happen to have the pitching moment data for that airfoil? If you don't have published data, but you have run it on XFLR5, then it would be the point on the CM curve where CL = 0.
I just did a quick and dirty comparison on thickness and did not save the data once I settled on 12%. I'll re-run the wing through XFLR5 again and post the results, maybe later this evening. It would be shiny to have the tips do all the work, but if not, a FFA/E (Full Flying Aileron / Elevator ) setup will be OK.

Mark
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Old Nov 19, 2012, 03:00 PM
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Knoll53's Avatar
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One thing is clear......this will be the first Pitcheron type plane without the benefit of a conventional horizontal stabilizer.



Kent
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Old Nov 19, 2012, 03:24 PM
Just call me crash for short
Quick61's Avatar
United States, OH, The Plains
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Quote:
Originally Posted by Knoll53 View Post
One thing is clear......this will be the first Pitcheron type plane without the benefit of a conventional horizontal stabilizer.



Kent
Flies of rekits, maybe your correct. We'll give it a go at any rate. It would be nice to get this one to fly and work it up to a 2-3 m span. Maybe try one of those shiny box spar setups.

Mark
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Old Nov 19, 2012, 03:44 PM
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Who knows....if the pitcheron tips work as elevators, then you'll be able to create a Crow function between in the inboard conventional plank elevator and the pitcheron tips... Which would be handy for the larger sizes.

My vote is still for the pitcherons being effective for pitch control.....at least to some degree.

Kent
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Old Nov 20, 2012, 12:08 PM
Just call me crash for short
Quick61's Avatar
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Got the "sub-assemblies" and the 2 formers / firewall on the fuse glued along with the wing tips. Dry fit one of the wing tips on a piece of CF tube stock to check fit and function after assembly. Very nice. Foam fit like a tight glove into the spaces on the fin and they have now been glued in. The fuse, for as much as I don't like the way it looks, almost built it's self and only one very slight tweak was needed after the glue and bands were applied to get it into square.

I should note that I am very pleased with the quality of parts I was able to turn out with the CNC router. Being that it's my first real run, I really did not expect everything to come out as nice as it did. I do have some flexing in the tool head / Z axis (a few 100's at the tool tip) and parts on on the way to fix the trouble. Being the machine was built from scratch and that being the only real bug in the design so far, think maybe not so bad of a job.

Anyway, a few more pics below. Next are the wings. I did the tips "free-hand" but think I'll jack up the wing halves on a board to make it easier setting up the elevator section.

Mark
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Old Nov 20, 2012, 06:30 PM
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Freaking cool !

I wish I could make parts like that at home.....Nice.

Kent
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Old Nov 21, 2012, 11:06 AM
Just call me crash for short
Quick61's Avatar
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After a bit of mucking about with some odds and ends and a bit more dry fitting, just to make sure, the first wing panel is under way. I decided to assemble the wings in stages. First I marked off the rib placement on the LE and TE, then jacked them up off the plan with some scrap 1/4" balsa and pinned them down. Next, glued all the one piece ribs in place on the outboard side. Once these are set up, I will insert the 5mm CF tube and use it for support in fixing the rib set that integrate the elevator flaps and the root rib. Once those set, the hinge tube will be used to hold the elevator ribs in place. Last, the TE will be cut to free the elevator. pics will explain it more as i go along so for now, here are the first 2.

Still very pleased with the way all the parts fit and everything lines up. fitting is ALMOST as nice as the parts fit in the computer. I say almost as I mentioned before, I had a bit of flexing in the tool head and a few swipes with the sandpaper here and there is needed to get it just right. Haven't checked the mail yet today so maybe the parts for solve that little bug are already here.

Mark
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Old Nov 21, 2012, 11:10 AM
Just call me crash for short
Quick61's Avatar
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Originally Posted by Knoll53 View Post
Freaking cool !

I wish I could make parts like that at home.....Nice.

Kent
Oh, but you can Kent. All you need do is want to bad enough. You already have the CAD skills, and that is more than half the "learning curve" out of the way. The hard half at that.... The rest is easy in comparison.

Mark
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Old Nov 21, 2012, 12:36 PM
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I have a million dollar idea for you.......

In order to label the parts, could you remove the bit in the router, and install a ball point pen shaft, then run the label file? Ah, Er, leave the router off. Or try a felt tipped pen as in the old plotters.

Some pens have a spring loaded tip, such as "space pens".

You could mark layout lines too. For that matter, you print most any design, panel lines, ect. on a sheet of 1/16" balsa and use it for wing sheeting.

Kent
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Old Nov 21, 2012, 04:25 PM
Just call me crash for short
Quick61's Avatar
United States, OH, The Plains
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Quote:
Originally Posted by Knoll53 View Post
I have a million dollar idea for you.......

In order to label the parts, could you remove the bit in the router, and install a ball point pen shaft, then run the label file? Ah, Er, leave the router off. Or try a felt tipped pen as in the old plotters.

Some pens have a spring loaded tip, such as "space pens".

You could mark layout lines too. For that matter, you print most any design, panel lines, ect. on a sheet of 1/16" balsa and use it for wing sheeting.

Kent
Good idea Kent. and one that I have considered. Here's the but...

This would require a physical "tool change" of some sort and later on if / when I design and build a quick change tool holder, this would be no big deal as I could switch from spindle to marker and back again and have the spindle be right where it was before it was removed. With the laser, it can be mounted right along side the spindle and only require a software tool change, nothing more than a mouse click and not have to remove / replace the tool bit. Also of note, above all else, using a pen to mark the material removes the major fun factor of being able to play around with potentially vision disabling hardware!

You are correct in your thinking that the pen should be spring loaded and unless one wants it to look like a 4 year old marked the parts that spring loading needs to be coupled with a linear slide with very tight tolerances so there is no backlash when the pen changes directions. I've actually built one of these plotter heads some years back when I had a nice 9x20 lathe sitting in the garage, but that was sold around the time I got rid of the bit... er ... um wife. Looking back, I guess I got it half right, never should of sold that lathe.

Mark
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Old Nov 22, 2012, 02:15 AM
Just call me crash for short
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One wing fresh off the board. Shot a quick video of the parts moving. The elevator is a bit sticky but that's OK as I only cut it lose and have not sanded anything, nor are the ribs actually glued to the hinge tube so the thing shifts a little. Still, it's coming out nice. One thing I would do slightly different is I would give more clearance in the pocket, maybe another 100th or so.

I sanded the LE &TE on one of the tips, and after a few swipes, I'm thinking the airfoil shape is close enough.

Mark

Moving Parts (0 min 42 sec)
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Old Nov 22, 2012, 02:43 AM
I don't like your altitude
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Now that I like! Not a horny/clevisy/linky thing in sight!
How are you covering,fully sheeted?
Regards Stuart
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Old Nov 22, 2012, 03:32 AM
Just call me crash for short
Quick61's Avatar
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Originally Posted by Stupot46 View Post
Now that I like! Not a horny/clevisy/linky thing in sight!
How are you covering,fully sheeted?
Regards Stuart
Oh. heck no, no sheeting. I was even thinking about just using Doculam, seeing how I have a little left, (about 300 foot), but I think I'll get some color on it. Those bays are only 1" (~25mm) apart so I'm not really concerned with sagging.

Yea, I like how clean it all is too.

Mark
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Old Nov 23, 2012, 03:14 PM
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I just realized that that fuse is going to be one busy little section of real estate. Be sure to snap a few piccies to show us how you squeezed all of that equipment in there.


Kent
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Old Nov 23, 2012, 04:14 PM
Just call me crash for short
Quick61's Avatar
United States, OH, The Plains
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Quote:
Originally Posted by Knoll53 View Post
I just realized that that fuse is going to be one busy little section of real estate. Be sure to snap a few piccies to show us how you squeezed all of that equipment in there.


Kent
Yes, it is going to be a bit active in there. In fact, I am thinking of making almost the entire top of the fuse out of removable panels for easy access 3 hatches with little cross patches in between. Still need to figure out the placement of the elevator servo. Maybe I should of planned all that out a while back , but such is the life of a prototype.

Mark
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