Polecat wind dancer???

[j.m.]

Can this plane be used non-electric?

(or does the fuse already have a gaping hole in the front? :rolleyes: )

Looking for a 2m to play around with, but It needs to be pretty cheap. Not necessarily trying to go built up, but I'm not going to pay more that $200.

Great performance is a necessity.

[FrogChief]

I'd say that it doesn't look equipped to handle the stresses of a winch / histart. :confused:

[lincoln]

It looks a lot like the Allegro Lite. If the spar is anything like the Allegro Light's, you'd need a strong winch line to break it. Watching an aggressive launch with the Allegro Light is like watching a film played at double speed. Suggest you ask Denny.

I'm sure that if the nose has a gaping hole you could put a nice wood block there and carve it down in little time. Might take you less than an hour. Maybe less than half an hour. Suggest if it needs a bit of nose weight that you use poplar, as it's very nice to work with. Just don't be afrait to start with 50 grit, or perhaps even a big knife or a Surform, belt sander, etc. and work your way down to finer grit as you get close.

People in our club say they fly nicely, but they use them as electrics.

[j.m.]

The reason i'm looking at a 2m is so I can fly at my local soccer field with a short field hi-start I made for my 3m ship. It's a little on the weak side for it though. And I don't think that a 120" glider is the best to be flying at a soccer field. I do want a floater though, so if I have to add a bunch of nose weight, I don't think it would do that great.

[FrogChief]

The reason i'm looking at a 2m is so I can fly at my local soccer field with a short field hi-start I made for my 3m ship. It's a little on the weak side for it though. And I don't think that a 120" glider is the best to be flying at a soccer field. I do want a floater though, so if I have to add a bunch of nose weight, I don't think it would do that great.


If you're not running any power system, I'm sure the weight of a nosecone is negligible. You'll still be MANY ounces lighter than an E-powered one.

I'm sure it'd be a floater.

[Resurgam]

On my Winddancer (which is an early model - Denny may have subsequently changed the design) the spar is something like a 1/4 inch carbon tube, with balsa sheeting over foam forward of the spar. The sheeting isn't bonded to the spar. I wouldn't trust it on anything more than a light histart in calm conditions.

Of course, you could strengthen the structure relatively easily, if you got the kit version rather than the ARF.

[rdwoebke]

(or does the fuse already have a gaping hole in the front? :rolleyes: )


:rolleyes: right back atcha, the WD's fuselage does come with the firewall setup for electric. You know, if you fly from a park, it would be pretty darn convenient to put an outrunner ($20.00 from United Hobbies) a 12x7 folder ($15 from aircraft world), a $35 ESC from United and a 2S lipo (from United or AC World) and for like $100 you have a nice gliding setup and don't have to worry about the HS getting on the soccor goals.

How do I know this? I have a very similar plane to the WD, the Allegro Lite, setup that way.

Linc, the spar on the WD is not like the Allegro. It is a tube spar that kind of just goes through the ribs. Not sure how that would handle high starting, probably OK on that high start that JM has that he thinks is weak for 3M planes. Denny would let you know if you asked though.

So far as the ballance goes, on my Allegro I have the servos in the nose. I have my Allegro setup so that I can take the motor, ESC, and 2S lipo pack out (the motor pack goes under the wing) and replace that with the receiver and a 400 mah nicd pack up at the very front and then add on a nose block exactly like Lincoln suggests and perhaps a half ounce nose weight and then I go high starting. Takes my Allegro from about 22.5 ounces in E mode to about 19 ounces in glider mode.

Ryan

[j.m.]

I am pretty interested in making an Aegea II, so I might just go for that instead.

But before I do that, I need to make a CNC hotwire cutter...

So many projects this summer :(

(if you don't already know, I'm 16 and a junior in high school :cool: )

[rdwoebke]

I am pretty interested in making an Aegea II, so I might just go for that instead.

I built one of those two. Mine turned out just kind of so so, but that is my fault since it was my first bagged cloth wing job.

I'm sure a CNC cutter is nice, but you can cut the cores by hand with a very simple/inexpensive bow. Probably not quite as nice/accurate as the CNC, but it would get you going a lot quicker.

Ryan

[j.m.]

Seeing as how I would have to build a new workbench and find somewhere to put it if I made a gravity drop cutter, I might as well make a CNC cutter, because I want to start selling a few planes this summer.

[rdwoebke]

I actually don't have mine setup as gravity drop, I'm doing a two person one on each side side cut method. Probably not quite ideal, but it has worked for me.

Ryan

[Ralph Weaver]

I have a Feather Cut (gravity) and a CNC. The Feather Cut is as accurate if your templates are good and easier to set up. The only advantage of the CNC is you don't have to make templates and you can cut other shapes like circles that gravity cutters can't. CNC takes a lot longer to get set up and adjusted for kerf.

[j.m.]

If I did make a CNC cutter, I would sell custom cut cores. It's just a LOT easier to use a CNC cutter for this, and I HATE making templates. To get all the templates I would need for the planes I want to make, I would be half way to a CNC cutter.

Making a gravity system would be a ton better for me. I tried the "do it by hand" method, but it didn't work so well.

I'm looking for absolutely perfect cores that only require a light sanding before I bag them.

Also, with a CNC, I can cut spar slots very easily.

And wash out is more accurately controlled.

The only problem I would encounter would be trying to find a place to put the beast.
(CNC or gravity)

[soholingo]

CNC vs Gravity,

I am definitely in the gravity camp. The biggest advantage is that it packs away when not in use, which is 99% of the time. Making templates is easy, if you have a bandsaw, sander, and profili. Lastly setting up the gravity is VERY easy.

I saw Phil Barns, unpack his feather cut, cut the foam to shape, slap the templates on the side, and cut a core with a spar slot and put everything away away in less than 10 minutes. He did that to show me how to cut a spar slot but had no cores so cut one on the spot.

If I can set up, and get a set of cores within an hour that's worth it.

Regarding quality of the cuts, I have seen Les' cores and Phil's cores and MY cores, and there is not a lot of difference between them. Granted I might need to cut 3 cores to get one on the level of Phils and Les', but I can use the practice, and the subsequent cores end up being something like 4 good 1 bad.

Its worth while to learn the feather cut and making templates if you are small plane maker.

[j.m.]

Well, I don't have a band saw, profili, or a power sander.

I have a bench grinder, but that don't work on anything except metal.

[soholingo]

Well, I don't have a band saw, profili, or a power sander.

I have a bench grinder, but that don't work on anything except metal.

I understand. The band saw and sander can be used for more than just cutting cores.

If you are going into business a CNC machine is a good idea, if you are joe hobby, its hard to beat the advantages of a gravity feed.

I cut my cores in my family room on a foldable card table. So space the space need is temporary.
j

[T.D.]

One can make extremely accurate templates by hand with an Exacto knife, flat file and two grades of sand paper...I do it all the time. It just takes a bit of patience and practice.

Last year a building buddy and I spend a lot of time building a CNC wire cutter and after all that work and messing around to get it done I am back to gravity cutting cores and I am convinced my FeatherCut cores are as good as(sometimes better than) CNC cut cores. The big advantage with CNC is the leading edge but careful sanding can get me just as good a LE with hand cut cores.

The CNC machine took up almost my whole building area and there is no way to break it down and put it in a closet like a FeatherCut...way too much hassle IMO.

Also there was not as much time saved with the CNC as I thought there would be, you still have to skin the foam, block it out, position correctly and set up the cut file etc.


T.D.

[j.m.]

All you have to do by hand is the root and tip. You can get the machine to do the rest.

I was planning on having the surface of the CNC cutter have a 1/8" grid on it.

And I was also goint to make a drop cutter to accurately cut dihedral angles.

Like this:
http://www.utahflyers.org/images/CutterInst/cutter11.jpg
Wire slides up and down between the metal "tracks" If you could adjust these with precision, making dihedral cuts (or any other vertical cut, for that matter) would be VERY simple and easy.

[T.D.]

"All you have to do by hand is the root and tip. You can get the machine to do the rest."

Yes, but that doesn't change the fact that you still have to go through all the steps I mentioned in my post and having the machine do it still requires time/work, it's not like the CNC does everything automatically...not to mention that positioning the foam for the cut is just as finicky on a CNC as on a FeatherCut, perhaps more so.

CNC is good for people who want to cut large quantities of cores but IMO for the average builder it's a waste of time and money.

For dihedral cuts I use two aluminum swing arms that screw into the end of the cutting table with butterfly nuts, they are small, accurate and allow any angle from zero to 90 degrees.

We ended up giving this foam cutter set up away to a fellow club member, more trouble that it was worth.


T.D.

[soholingo]

TD
How do you make your templates? And what do you use for template material?

Thanks,

Jay

[ozmo01]

formica scraps fom any cabinet shop work very well for foam cutting templates. free...thats hard to beat. easily smoothable edges, VERY important for good cores. and heat resistant, also a handy feature.
Formica has been the GO TO material for a long time.

Oh yeah did I mention FREE :D

[ozmo01]

Get your air foil printed out to scale. use a litlle 3m77 type spray adhesive to adhere it to your Formica. Cut it out on a scroll saw with a FINE tooth blade.
Cut + or - 1/8 " out to far and sand ( clamp both templates together to sand to keep them equal) to the line with FINE sand paper.
OK here is the real skinny....Craftsmanship counts ten fold on patterns.
You may use this pattern over and over. You can NOT make a nice wing from a POS pattern. The smoother the edges of the pattern the easier the wire passes and the smoother the foam wing turns out. Also it goes better if you have a buddy to help. Especially on longer wings. Devide each template with numerous pencil marks. I do ten numbered marks on each top and bottom with both patterns exactly equal then as we cut one person calls the numbered mark outload so the other can keep an equal pace. never pull the wire much as a bowed wire cuts crookedly. arive at the leading edge at the same time or it will be crooked. cut more blanks than you think tou will need because usually the first couple suck. Learning curves apply. A still wire makes an ugly groove. A little tab at one or botth ends of the template for the wire to rest on before heat is turned on helps. semetric foils can be cut in one continuous pass and only need a rest tab at the TE.

[lincoln]

You could use the grinder to make aluminum templates.

Think hard about that CNC cutter. You would probably be able to build a glider or two at least with the effort that would go into a homebrew, I'd guess.

Fastest might be to pick up an odd job to earn enough money to buy a set of cores, though of course it's more satisfying to cut your own.

[lincoln]

If he gets the built up kit, I'm sure that beefing up the spar would be fairly easy, after a little homework to figure out the best way to do it.
snip
Linc, the spar on the WD is not like the Allegro. It is a tube spar that kind of just goes through the ribs. Not sure how that would handle high starting, probably OK on that high start that JM has that he thinks is weak for 3M planes. Denny would let you know if you asked though.
snip
Ryan

[T.D.]

Jay, I use the thin grade of arborite (formica). The thick stuff is harder to work with and has more wire drag.

I use the tools in the photo, the small file has a rounded cross section and tapers nicely for fine work on leading edges and under-camber.

I use .5" ramp front and back on the airfoil printout, cut the arborite .25" over size of the airfoil printout front, back and top, make sure the bottom of the arborite is very flat. Spray the printout and the arborite with 3M77, CAREFULLY attach the printout to the arborite using the bottom line of the template printout (which you have accurately trimmed with a ruler and razor knife) and the bottom of the arborite which you have accurately made flat and straight.

For the leading edge I take a pencil and mark a ramp on the front of the template that is shallower than the printed leading edge, this allows the wire to climb nicely and you can sand the true leading edge in later.

Using the razor knife I make several passes using medium pressure just above the printed airfoil shape which scores the arborite and allows you to then snap the excess arborite off.

To finish the surface I start with 100 grit sandpaper, bring it down a fair amount then switch to 220 grit, bring it down closer to the line and switch to the medium coarse file, work it down and switch to the oval profile file on the LE and near the TE lead out.

When you are just about at the template airfoil line switch to 400 wet and dry for a bit and then go to 1500 wet and dry. Sounds like a lot of work and messing around but it is really very fast and accurate...just takes practice.

If you want photos' let me know.


T.D.

[flyonline]

Sounds like a lot of work and messing around but it is really very fast and accurate...just takes practice.

And once you've cut the templates, they can be used as many times as you like. If there are a few of you in the same area, you could even build up a template library to swap.

[j.m.]

In my area, ther is me and my friend. We were going to split the cost of the cnc cutter.

Also, I was going to build a "kit" CCNC cutter. Not quite a homebrew.

It's a VERY proven design.

Here's a link to the finished product:
http://www.foamlinx.com/fc2913.html

[soholingo]

Jay, I use the thin grade of arborite (formica). The thick stuff is harder to work with and has more wire drag.

I use the tools in the photo, the small file has a rounded cross section and tapers nicely for fine work on leading edges and under-camber.

I use .5" ramp front and back on the airfoil printout, cut the arborite .25" over size of the airfoil printout front, back and top, make sure the bottom of the arborite is very flat. Spray the printout and the arborite with 3M77, CAREFULLY attach the printout to the arborite using the bottom line of the template printout (which you have accurately trimmed with a ruler and razor knife) and the bottom of the arborite which you have accurately made flat and straight.

For the leading edge I take a pencil and mark a ramp on the front of the template that is shallower than the printed leading edge, this allows the wire to climb nicely and you can sand the true leading edge in later.

Using the razor knife I make several passes using medium pressure just above the printed airfoil shape which scores the arborite and allows you to then snap the excess arborite off.

To finish the surface I start with 100 grit sandpaper, bring it down a fair amount then switch to 220 grit, bring it down closer to the line and switch to the medium coarse file, work it down and switch to the oval profile file on the LE and near the TE lead out.

When you are just about at the template airfoil line switch to 400 wet and dry for a bit and then go to 1500 wet and dry. Sounds like a lot of work and messing around but it is really very fast and accurate...just takes practice.

If you want photos' let me know.


T.D.

Thanks TD,

Photos are always good.

Jay

[soholingo]

In my area, ther is me and my friend. We were going to split the cost of the cnc cutter.

Also, I was going to build a "kit" CCNC cutter. Not quite a homebrew.

It's a VERY proven design.

Here's a link to the finished product:
http://www.foamlinx.com/fc2913.html


JM,

Keep us posted on your cnc progress.

Jay

[j.m.]

So yeah, As I was saying earlier(i had to close the window fast. My teacher was walking over) the actual CNC kit cost is $250. (no, that's not a typo) and with everything else(minus software), the total comes to about $550-$600. REALLY great deal.