Crazy Herb's 1/2A Cheap Delta
07-22-2005, 04:10 PM
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Crazy Herb's 1/2A Cheap Delta
Has anyone here ever built and flown one of [link=http://www.crazyherb.com/FOAMIEDESIGNS/CHEAPDELTA/CHEAPDELTA.HTM]Crazy Herb's foamie deltas? [/link]More specifically the 1/2 A version?
It's a 36" span model made from 3/4" pink foam board that he flies on a .061 Norvell. I was wondering if full size gear (Futaba S148s / R127DF) would be too heavy for a design such as this. I'd probably use 2/3AA nicads for the RX, a Fuji style fuel tank, and one of the Sure Starts for power. OR.... I do have a OS .10 FP that I could put on, but whatever I do this thing needs to be CHEAP. (My wife is very forgiving of my antics, but I don't want to push my luck!)
Oh shoot, did I use the F-word? Man, I hope CP doesn't read this.
All comments welcome...
-Joe
It's a 36" span model made from 3/4" pink foam board that he flies on a .061 Norvell. I was wondering if full size gear (Futaba S148s / R127DF) would be too heavy for a design such as this. I'd probably use 2/3AA nicads for the RX, a Fuji style fuel tank, and one of the Sure Starts for power. OR.... I do have a OS .10 FP that I could put on, but whatever I do this thing needs to be CHEAP. (My wife is very forgiving of my antics, but I don't want to push my luck!)
Oh shoot, did I use the F-word? Man, I hope CP doesn't read this.
All comments welcome...
-Joe
07-22-2005, 09:14 PM
#3
RE: Crazy Herb's 1/2A Cheap Delta
PBJ, A project that is much more worthy of your talent, and also extremely easy and dirt cheap, would be a 18" x 18" PIZZA BOX FLYER. I made one from 1/4" x 1/4" balsa sticks, and it is a lot of fun! Flat spins, torque rolls, etc. The plane flies with everything from a BABYBEE to a .061. I set the elevon servos on their sides and have pull/pull thread going back to the flaps. I rigged a rudder, but to tell the truth, it doesn't add that much, you can do it all with just 2 servos. I think the foam delta would just kind of flub around, but this PBF is a real GAS!
07-23-2005, 12:11 AM
#4
RE: Crazy Herb's 1/2A Cheap Delta
PBJ --
I've built a few -- 36" is too large. I scaled it to 30" and used 1/2" blue foam. Delta's are real draggy and the SureStart probably won't have enough poop. I'm using NORVEL .061 C/L engines with 6x3 and 5.5x3 props. I may try a 5x3 COX nylon, but didn't have any on hand at the time. In keeping with the cheap theme, I cut 8 blanks and fins from a 4x8 sheet of DOW blue. Control horns and motor mounts are ripped from paint stirring sticks (free). The problem with blue foam is lack of glue penetration -- the surface layer of foam will just pull loose, so you need to have a lot of area.
I used a dremel to route 6" grooves from the nose back and inlaid 3/8" wide strips ripped from the stirring sticks. On the first one, I glued a piece of 3/32" ply to the top of the stringers. On the others, I filled in underneath with stubs of 3/8" sq. motor mount stock and capped the bottom of the nose with 1/16" ply -- keeps from crushing when tightening motor mount bolts. HS-81 MG's were mounted on 3/32 balsa inlaid into the foam. On others, I plunge cut all the way thru the wing with a drywall cutting bit and sunk the servos into the foam. Did the same for the RX and batteries. I use two strips of filament tape running spanwise and one running from nose to tail. Elevon hinges are bi-directional filament tape. I cover them with various packing tape. The black and yellow is covered with very thin packing tape.
Mounting stuff on sheet foam can be a pain, especially if you want to shock mount it or remove it later. I drilled holes thru the foam with 1/4" sharpened brass tubing, pushed rubberbands thru and used bamboo skewers (80 for .99) on the bottom. Everything on the delta is glued with Elmers ProBond. The fin does not have much glueing surface, so after it's attached, I'll cut about 3 2" lengths of skewer, sharpen the tips and drill into the fin from the bottom. Pull out, moisten, add a little ProBond to the hole and push back in. Bamboo skewers are real tough and I've started using them in a number of projects.
Tank is a Fuji canister. Almost all the foam is cut with a very sharp butcher knife and finished with block sanding.
Got any questions, let em rip. These deltas can be built for about $2 - $3 and are a hoot to fly.
I've built a few -- 36" is too large. I scaled it to 30" and used 1/2" blue foam. Delta's are real draggy and the SureStart probably won't have enough poop. I'm using NORVEL .061 C/L engines with 6x3 and 5.5x3 props. I may try a 5x3 COX nylon, but didn't have any on hand at the time. In keeping with the cheap theme, I cut 8 blanks and fins from a 4x8 sheet of DOW blue. Control horns and motor mounts are ripped from paint stirring sticks (free). The problem with blue foam is lack of glue penetration -- the surface layer of foam will just pull loose, so you need to have a lot of area.
I used a dremel to route 6" grooves from the nose back and inlaid 3/8" wide strips ripped from the stirring sticks. On the first one, I glued a piece of 3/32" ply to the top of the stringers. On the others, I filled in underneath with stubs of 3/8" sq. motor mount stock and capped the bottom of the nose with 1/16" ply -- keeps from crushing when tightening motor mount bolts. HS-81 MG's were mounted on 3/32 balsa inlaid into the foam. On others, I plunge cut all the way thru the wing with a drywall cutting bit and sunk the servos into the foam. Did the same for the RX and batteries. I use two strips of filament tape running spanwise and one running from nose to tail. Elevon hinges are bi-directional filament tape. I cover them with various packing tape. The black and yellow is covered with very thin packing tape.
Mounting stuff on sheet foam can be a pain, especially if you want to shock mount it or remove it later. I drilled holes thru the foam with 1/4" sharpened brass tubing, pushed rubberbands thru and used bamboo skewers (80 for .99) on the bottom. Everything on the delta is glued with Elmers ProBond. The fin does not have much glueing surface, so after it's attached, I'll cut about 3 2" lengths of skewer, sharpen the tips and drill into the fin from the bottom. Pull out, moisten, add a little ProBond to the hole and push back in. Bamboo skewers are real tough and I've started using them in a number of projects.
Tank is a Fuji canister. Almost all the foam is cut with a very sharp butcher knife and finished with block sanding.
Got any questions, let em rip. These deltas can be built for about $2 - $3 and are a hoot to fly.
07-23-2005, 12:19 AM
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RE: Crazy Herb's 1/2A Cheap Delta
Vic - I'm ducking and running for cover....
CP - now you go and say sumthin'!
Serisously though - have you seen the videos? Looks like it does pretty good to me. Check 'em out...
http://www.crazyherb.com/FOAMIEDESIG...ELTA/weeds.wmv
http://www.crazyherb.com/FOAMIEDESIG...ELTA/catch.wmv
http://www.crazyherb.com/FOAMIEDESIG...yherbmusic.wmv
Anyway... I appreciate the advice and recommendation, but I've already started on the delta! [X(]
-Joe
CP - now you go and say sumthin'!
Serisously though - have you seen the videos? Looks like it does pretty good to me. Check 'em out...
http://www.crazyherb.com/FOAMIEDESIG...ELTA/weeds.wmv
http://www.crazyherb.com/FOAMIEDESIG...ELTA/catch.wmv
http://www.crazyherb.com/FOAMIEDESIG...yherbmusic.wmv
Anyway... I appreciate the advice and recommendation, but I've already started on the delta! [X(]
-Joe
07-23-2005, 12:34 AM
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RE: Crazy Herb's 1/2A Cheap Delta
Andrew - I must have been writing my post the same time you were...
Nice lookin' FOAM deltas and lot's of good tips in your post - especially with the skewers - I just happen to have a bag of 'em from my SPAD building days! Also, I like the way you mounted your servos - I think it's worth taking the time to make them removable.
As you all can see, I went ahead and made the thing 36" and I'm going to power it with a .10 FP (w/ a hitec HS-55 on the throttle). It looks like it'll come in around 20 oz or so RTF... Gonna play with the ProBond tomorrow (oh wait, that's today) and get the engine mount/servo mounts inlayed. I'll keep you all posted.
-Joe
Nice lookin' FOAM
deltas and lot's of good tips in your post - especially with the skewers - I just happen to have a bag of 'em from my SPAD building days! Also, I like the way you mounted your servos - I think it's worth taking the time to make them removable.As you all can see, I went ahead and made the thing 36" and I'm going to power it with a .10 FP (w/ a hitec HS-55 on the throttle). It looks like it'll come in around 20 oz or so RTF... Gonna play with the ProBond tomorrow (oh wait, that's today) and get the engine mount/servo mounts inlayed. I'll keep you all posted.
-Joe
07-23-2005, 09:04 AM
#7
RE: Crazy Herb's 1/2A Cheap Delta
That looks about right! When you originally described a .049 hauling around a 36" delta, I had a flash back of the time I followed a CHAPARALL race car around town until I could get the guy to stop and let me have a look. This was a real CAN AM race car. He was powering it with a VW engine and trans axle[:'(], instead of the usual big block CHEVY[8D]........all I wanted to say was....[X(]OINK!! I forced out some compliments and went on my way. The .10 should haul it respectably. The part about making these projects as down and dirt simple as possible is hidden in the final details. Fuelproofing. I have covered a lot of foamies with 2" wide clear tape. You want to buy a bulk pack of the thinnest and cheapest stuff that an office supply carries, stay away from 3M. If you ever want to try a 1/2A PBF, let me know. It should really be called the FLYING WINDOW OF PAIN!!
07-23-2005, 10:10 AM
#8
RE: Crazy Herb's 1/2A Cheap Delta
PBJ --
You will be much more satisfied with the .10 -- the 3/4" foam and 36" span is just too much for a .061. I ordered my packing tape from [link=http://www.fast-pack.com/colored_tape.html]Fast-Pack[/link]. They usually run specials on 6 packs, sometimes with mix and match colors. Their colored tape is much thinner than the original clear tape I used.
You will be much more satisfied with the .10 -- the 3/4" foam and 36" span is just too much for a .061. I ordered my packing tape from [link=http://www.fast-pack.com/colored_tape.html]Fast-Pack[/link]. They usually run specials on 6 packs, sometimes with mix and match colors. Their colored tape is much thinner than the original clear tape I used.
07-23-2005, 11:16 AM
#9
RE: Crazy Herb's 1/2A Cheap Delta
That's the stuff, FAST PACK. I also wouldn't be without it at the field of battle. A wipe down with MEK around the damaged covering, and this stuff sticks real good. I can see the attraction that this 3/4" thick foam has, it seems like the easiest and lightest way to throw something together. I haven't tried working with the 3/4" thick stuff yet. It is heavier than white foam though, maybe twice as heavy?
07-23-2005, 04:16 PM
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RE: Crazy Herb's 1/2A Cheap Delta
Nice looking deltas guys!
Maybe I need to get version 3 going....Hmmm....
Too many projects...not enough time....
ANDREW - I love your hold-down method!! Simple light and cheap.
I just use RTV/Clear Silicone (rough the sides of servos/rx up a little with some 80 grit) and they become "one with the plane" and rubber vibration isolated all in one shot.
CrazyHerb
Maybe I need to get version 3 going....Hmmm....
Too many projects...not enough time....
ANDREW - I love your hold-down method!! Simple light and cheap.
I just use RTV/Clear Silicone (rough the sides of servos/rx up a little with some 80 grit) and they become "one with the plane" and rubber vibration isolated all in one shot.
CrazyHerb
07-23-2005, 04:42 PM
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RE: Crazy Herb's 1/2A Cheap Delta
That's pretty much sums up what I thought - even a warmed-over Surestart wasn't going to do much on a 36" hunk of foam. Besides, the throttle on the .10 is going to be nice to have and that's the main reason for leaning towards the bigger planform/engine.
This is my first time using foam for a model so I can't comment too much on the pink stuff's weight. However, I can give you a number of 7 3/4 oz for just the bare, delta shape.... Seems a bit heavy to me.... but.... if I figured it correctly there's 541 sq inches of wing area.... should give me a wing loading in the 6-7 oz/sq. ft area, no? (assuming 22-25 oz AUW) Or is the wing loading of deltas figured differently?
PM'ed Crazy Herb a couple of times and he says that he never bothered to cover the whole model to fuel proof everything - just the important bits. He swears the foam isn't very porus and he just wipes off the goo. From working with this stuff, it sure sounds reasonable.
Spent a little bit of time today getting the engine mount glued in - I went with a 2" x 8" section of 1/8" ply with the forward 2" doubled, w/ 4-40 blind nuts installed. The "Elmer's Ultimate" polyurethane glue expands like crazy and oozes out - so you need to prepare for that. The fin was glued on too, and I perforated the base of the fin and the wing to give the glue some more bite. Once the glue had cured on the fin, I hinged the elevons and started placing components for the proper CG.
Looks like this thread is starting to become a build article!
More later, and as always, comments welcome!
-Joe
This is my first time using foam for a model so I can't comment too much on the pink stuff's weight. However, I can give you a number of 7 3/4 oz for just the bare, delta shape.... Seems a bit heavy to me.... but.... if I figured it correctly there's 541 sq inches of wing area.... should give me a wing loading in the 6-7 oz/sq. ft area, no? (assuming 22-25 oz AUW) Or is the wing loading of deltas figured differently?
PM'ed Crazy Herb a couple of times and he says that he never bothered to cover the whole model to fuel proof everything - just the important bits. He swears the foam isn't very porus and he just wipes off the goo. From working with this stuff, it sure sounds reasonable.
Spent a little bit of time today getting the engine mount glued in - I went with a 2" x 8" section of 1/8" ply with the forward 2" doubled, w/ 4-40 blind nuts installed. The "Elmer's Ultimate" polyurethane glue expands like crazy and oozes out - so you need to prepare for that. The fin was glued on too, and I perforated the base of the fin and the wing to give the glue some more bite. Once the glue had cured on the fin, I hinged the elevons and started placing components for the proper CG.
Looks like this thread is starting to become a build article!
More later, and as always, comments welcome!
-Joe
07-23-2005, 04:55 PM
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RE: Crazy Herb's 1/2A Cheap Delta
Probond is sandable.... once fully cured...
However....
Better yet...I'll usually LET it bubble out, dry, and trim it with a long break away knife (easier if you just dont touch it)...can usually pull the whole "bubble" off in one strip...with a cut down each surface making a nice right angle "L". Just be careful not to cut into your foam too much....or you'll be back to squirting some more glue in there...
My latest craze is low temp hot melt glue....I haven't had a bond give out yet (even though I've heard it can)...and its SUPER fast...heheh...
I'm just using one of those little wal-mart $1.95 guns with the mini sticks...
Could jam another cheap delta out in less than 30 minutes (minus) linkages.
Hmm....maybe I need to get a little "side tracked" by a cheap delta version 3 this afternoon....
This thread is such a tease...
Looking awesome JOE!!
CrazyHerb
once fully cured...However....
Better yet...I'll usually LET it bubble out, dry, and trim it with a long break away knife (easier if you just dont touch it)...can usually pull the whole "bubble" off in one strip...with a cut down each surface making a nice right angle "L". Just be careful not to cut into your foam too much....or you'll be back to squirting some more glue in there...
My latest craze is low temp hot melt glue....I haven't had a bond give out yet (even though I've heard it can)...and its SUPER fast...heheh...
I'm just using one of those little wal-mart $1.95 guns with the mini sticks...
Could jam another cheap delta out in less than 30 minutes (minus) linkages.
Hmm....maybe I need to get a little "side tracked" by a cheap delta version 3 this afternoon....
This thread is such a tease...
Looking awesome JOE!!
CrazyHerb
07-23-2005, 05:13 PM
#13
RE: Crazy Herb's 1/2A Cheap Delta
PBJ --
The perforations will really help. Although you already have your fin attached, if you build another, you might try taping the wing first. I tape first because it's easier without a fin, then draw the outline of the fin base on the tape and cut just deep enough to pull the outlined tape off, then glue the fin. The glue usually fills in any score lines.
The blue foam appears to be completely fuel proof to 25% -- I routed some depressions in a test piece, filled with fuel and left it until it completely evaporated -- no effect. I tape for beauty and visibility, mostly top/bottom contrast.
I found that it doesn't take much ProBond at all -- and it will foam less with less moisture. I'm very impressed with the bonding strength, plus it sticks to a lot of different materials.
The perforations will really help. Although you already have your fin attached, if you build another, you might try taping the wing first. I tape first because it's easier without a fin, then draw the outline of the fin base on the tape and cut just deep enough to pull the outlined tape off, then glue the fin. The glue usually fills in any score lines.
The blue foam appears to be completely fuel proof to 25% -- I routed some depressions in a test piece, filled with fuel and left it until it completely evaporated -- no effect. I tape for beauty
and visibility, mostly top/bottom contrast.I found that it doesn't take much ProBond at all -- and it will foam less with less moisture. I'm very impressed with the bonding strength, plus it sticks to a lot of different materials.
07-23-2005, 06:30 PM
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RE: Crazy Herb's 1/2A Cheap Delta
Just for info -
My best CG was about 22% (11 inches from the tip of the foam)... I'd recommend starting at 18% though....
I love Palos RC Clubs CG calculator:
http://www.palosrc.com/instructors/cg.htm
CrazyHerb
My best CG was about 22% (11 inches from the tip of the foam)... I'd recommend starting at 18% though....
I love Palos RC Clubs CG calculator:
http://www.palosrc.com/instructors/cg.htm
CrazyHerb
07-23-2005, 06:54 PM
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RE: Crazy Herb's 1/2A Cheap Delta
Yea, I've been peeling the ProBond as you describe - it sticks real good to the porous (cut) part of the foam, but with a little coaxing it peels nicely from the rest.
Hmmmm, I suppose I should have taped the wing first, but you live and learn... Actually, you know what? I'll probably only tape the exposed edges and just fly the thing. I have some sign vinyl I'll probably use for accents / orientation help...
Sounds like a good idea to me - I vote for a two inward canted fins. (I would have done the same, but I wasn't brave enough to depart too far from the plans.)
Now if we can just get CP talked into it.... [X(]
-Joe
Hmmmm, I suppose I should have taped the wing first, but you live and learn... Actually, you know what? I'll probably only tape the exposed edges and just fly the thing. I have some sign vinyl I'll probably use for accents / orientation help...
CrazyHerb: Could jam another cheap delta out in less than 30 minutes (minus) linkages. - Hmm....maybe I need to get a little "side tracked" by a cheap delta version 3 this afternoon....
(I would have done the same, but I wasn't brave enough to depart too far from the plans.)Now if we can just get CP talked into it.... [X(]
-Joe
07-24-2005, 02:18 PM
#16
RE: Crazy Herb's 1/2A Cheap Delta
I just had a stupid idea for using probond. Could you cut a chanel like for a spar wet it, pour some glue in, wet it again, cover it with tape, then let it set-up and become a spar?
By Golly I think I am going to try it![sm=bananahead.gif] Maybe I can get an honorable mention in the spad hall of fame
Cut some scallops on the verticals and you will have the DFSOD (delta foamy sword of death). Yeah I am duckin and wearing a helmet.
By Golly I think I am going to try it![sm=bananahead.gif] Maybe I can get an honorable mention in the spad hall of fame
Cut some scallops on the verticals and you will have the DFSOD (delta foamy sword of death). Yeah I am duckin and wearing a helmet.
07-24-2005, 08:03 PM
#17
RE: Crazy Herb's 1/2A Cheap Delta
VICMAN --
My ProBond experience, and I make no claim to being an expert, has been that while it has exceptional adhesive properties on many materials, it probably will not make good spar material. Good joints need to be tight and clamped -- the excess glue will fill voids and foam out of the joint. However, unless clamped tightly, the excess glue is spongy with little structural strength and quite easily trimmed.
You probably could make a decent external spar by cutting a very small groove, adding a .060 or .070 solid carbon fiber rod, covering with tape and weighting it tightly so that the ProBond doesn't foam much at all. You can control the foaming to some extent by limiting the moisture level in the joint. With less moisture, it will take longer to set, but without as much foam.
My ProBond experience, and I make no claim to being an expert, has been that while it has exceptional adhesive properties on many materials, it probably will not make good spar material. Good joints need to be tight and clamped -- the excess glue will fill voids and foam out of the joint. However, unless clamped tightly, the excess glue is spongy with little structural strength and quite easily trimmed.
You probably could make a decent external spar by cutting a very small groove, adding a .060 or .070 solid carbon fiber rod, covering with tape and weighting it tightly so that the ProBond doesn't foam much at all. You can control the foaming to some extent by limiting the moisture level in the joint. With less moisture, it will take longer to set, but without as much foam.
07-24-2005, 08:07 PM
#18
RE: Crazy Herb's 1/2A Cheap Delta
I use probond all the time As mentioned above I use tape to limit the foam out of the joint to make finising easier. I may put a couple threads of unidirectional CF in the mix to give a little more strength.
It will be a few weeks before I try anything tho. But when I do I will let all know.
As mentioned above I use tape to limit the foam out of the joint to make finising easier. I may put a couple threads of unidirectional CF in the mix to give a little more strength. It will be a few weeks before I try anything tho. But when I do I will let all know.
07-24-2005, 10:43 PM
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RE: Crazy Herb's 1/2A Cheap Delta
Well... not much progress last night/today, but any progress is still progress, right?
Got the control horns made up for the elevons, servos inlaid, and linkages installed. (I'll most likely use silcone to hold the servos in the pockets - it holds well, but still is easy to remove if need be.) I'm still trying to decide if I'm going to inlay the RX and battery, or mount them on top like Andrew did (they're shown in the following pictures at the approximate location for proper CG). I'm worried that cutting holes for the RX and batt. may weaken the structure... I was hoping to get away with just adding a couple of strips of strapping tape, but may inlay a balsa spar for a piece of mind
Eagle-eyed readers may notice the elevon mixer in the center of the wing - I don't own a radio with mixing, but had this add-on mixer from the Ladyhawk rocket glider - it's a "Quillen Engineering Micromixer" I've had since about '95. Still works like a charm...
Still need to shape the leading edge, get the tank mounted and do something with the batt and RX - I'm obviously overthinking every little detail, and only have a few minutes a day to work on it. If one would dedicate the time and "just do it" (without thinking too much about it), I don't doubt that one of these deltas could be whipped out in an afternoon.
-Joe
Got the control horns made up for the elevons, servos inlaid, and linkages installed. (I'll most likely use silcone to hold the servos in the pockets - it holds well, but still is easy to remove if need be.) I'm still trying to decide if I'm going to inlay the RX and battery, or mount them on top like Andrew did (they're shown in the following pictures at the approximate location for proper CG). I'm worried that cutting holes for the RX and batt. may weaken the structure... I was hoping to get away with just adding a couple of strips of strapping tape, but may inlay a balsa spar for a piece of mind
Eagle-eyed readers may notice the elevon mixer in the center of the wing - I don't own a radio with mixing, but had this add-on mixer from the Ladyhawk rocket glider - it's a "Quillen Engineering Micromixer" I've had since about '95. Still works like a charm...
Still need to shape the leading edge, get the tank mounted and do something with the batt and RX - I'm obviously overthinking every little detail, and only have a few minutes a day to work on it. If one would dedicate the time and "just do it" (without thinking too much about it), I don't doubt that one of these deltas could be whipped out in an afternoon.
-Joe
07-25-2005, 07:48 AM
#21
RE: Crazy Herb's 1/2A Cheap Delta
PBJ --
It's looking real good!!
If you're using 3/4" foam, I don't think your battery & RX inlays will be any problem. I had wondered about that myself, especially with the 1/2" foam, but just made sure any holes missed the strapping tape. There's a lot of wing area and the holes are a tiny fraction of area. You will probably be more pleased with the battery and RX inlaid -- besides lowering drag, it provides some protection and they won't have a tendency to shift around.
I'm not familiar with the pink, but the blue DOW has a very thin plastic film covering both sides -- I pull that off before any glueing or covering with tape. BTW, the packing tape adds a LOT of stiffness -- I may drop the filament tape on any others if I'm going to tape the entire wing.
It's looking real good!!
If you're using 3/4" foam, I don't think your battery & RX inlays will be any problem. I had wondered about that myself, especially with the 1/2" foam, but just made sure any holes missed the strapping tape. There's a lot of wing area and the holes are a tiny fraction of area. You will probably be more pleased with the battery and RX inlaid -- besides lowering drag, it provides some protection and they won't have a tendency to shift around.
I'm not familiar with the pink, but the blue DOW has a very thin plastic film covering both sides -- I pull that off before any glueing or covering with tape. BTW, the packing tape adds a LOT of stiffness -- I may drop the filament tape on any others if I'm going to tape the entire wing.
07-25-2005, 08:37 AM
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RE: Crazy Herb's 1/2A Cheap Delta
Andrew - I think I am going to go ahead and sink the batt and RX into the foam - I too thought it would be a lot less draggy that way. BTW, the pink foam doesn't have that same thin covering you mentioned, the packing tape sticks good without any "surface prep" - I just made sure the surface is dust free before I stick it down.
Got the washout in the leading edges marked out - now I just have get up the nerve to cut it!
More later...
-Joe
Got the washout in the leading edges marked out - now I just have get up the nerve to cut it!
More later...
-Joe
07-25-2005, 10:03 AM
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RE: Crazy Herb's 1/2A Cheap Delta
OK, I think I know the answer to this one, but thought I'd check with ya'll before I put a knife to it....
The plans call for the centerline of the leading edge's tip to be 1/8" to 1/4" lower than the centerline of the root. When carving (or sanding) washout into the leading edge, should I sweep the tip's top edge forward and the tip's bottom edge back (the same amount as I drop the tip centerline). I'm probably not making sense, so I've included some pictures to demonstrate what I'm taking about.
I drew a line on the front face of the leading edge, starting on center of the thickness at the root, and dropped it 1/8" at the tip. I also drew a guideline (the red line in the pictures) on the top and bottom of the leading edge so as to get my taper straight - BUT, then I got to thinking, maybe, just maybe I'm supposed to sweep the top (and bottom) forward (and back) a like amount (to mimick twist) so I drew the purple line as shown and once I looked at it thought that this is how it should be done.... hence my dilemma.
What do I do? What do I do?
-Joe
The plans call for the centerline of the leading edge's tip to be 1/8" to 1/4" lower than the centerline of the root. When carving (or sanding) washout into the leading edge, should I sweep the tip's top edge forward and the tip's bottom edge back (the same amount as I drop the tip centerline). I'm probably not making sense, so I've included some pictures to demonstrate what I'm taking about.
I drew a line on the front face of the leading edge, starting on center of the thickness at the root, and dropped it 1/8" at the tip. I also drew a guideline (the red line in the pictures) on the top and bottom of the leading edge so as to get my taper straight - BUT, then I got to thinking, maybe, just maybe I'm supposed to sweep the top (and bottom) forward (and back) a like amount (to mimick twist) so I drew the purple line as shown and once I looked at it thought that this is how it should be done.... hence my dilemma.
What do I do? What do I do?
-Joe