RE: Here's a Simple & FREE First Foam Build Plan! Cool Looking Plane Too...  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
    Search This Thread  
 
Printable Version

All Forums >> Electric Aircraft Universe >> Foamies! - RC Electric Foam Aircraft >> RE: Here's a Simple & FREE First Foam Build Plan! Cool Looking Plane Too...
Page: <<   < prev  2 3 [4] 5 6 7 8 9 10 11   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/2/2006 9:40 PM   
critterhunter



Posts: 2717
Score: 100
Joined: 9/24/2004
Last Login: 8/20/2009
From: Brook Park, OH, USA
Status: offline 		Fisher, just finished reading a huge stack of how to build foam cutters. I'm still at a loss on a few things so maybe you can help. So far I've figured out that I can probably get by with an old car battery charger I have. It will run (I think) .2 to 1.6 amps at 12 or 6V, or has a non-adjusting 6 amp setting (something like that...check back a page or two for the specific amp numbers). I see that most guys are running 12 volts at about 2 amps. However, if I pick up a light dimmer I'm sure this will compensate for the static 6 amp setting (if the variable dial is too low) to get the right temperture. So, so far I've got the charger and a potential dimmer (if needed). Wire, seems to be a choice of stainless or the nichocrome (sp?). Will have to play with those types to find what works...fishing leader, guitar string, etc. My biggest question involves cutting the wings. Seems all the info I see is for making hand bow cutters or vertical stationary (jig saw type) devices. Easy enough to build those too. But, exactly how are you cutting the wing airfoil out? The only idea I can come up with is you print out the airfoil then transfer this to wood or metal. You take two of these and attach them to two ends of a board. I would figure then that you set the wing into the board between the two airfoil templates and run your bow cutter over the setup...touching the curved templates and following the contour of them to cut the foam? Just can't figure it out based on the pictures and slim descriptions given. Can you walk me through this and anything else as I'm drawing a blank here. May try to search for cutting airfoils with cutters and see if more detailed tool builds and methods pop up.


_____________________________

I find in life that if you give people enough rope they often hang themselves, or at least have a mess of knots to undo...

Hide Signatures

(in reply to Fisher)
       Post #: 76

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/2/2006 11:58 PM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		Thanks for the input fisher, I wonder of those are UL listed, I get in trouble with equipment that's not since I have a regular shop, biz license and all and do get inspected from time to time, they look down their noses at non UL stuff due to the liability. When I buy equipment, I always start out cheap, and only when I can justify it's ability to save enough time and improve accuracy and it actually gives me a return, this is why I'm going with just foam cutters, setting up some jigs and of course, doing things in volume, I'll get the same results as any automated process, and in fact, much of the time improve accuracy since all equipment is in the process of degrading, so you gotta go old school style in order to achieve perfect results. My biz url is http://espresso-outfitters.com everything there from the site design and it's marketing "stays on the front page of msn and yahoo nicely" to building and designing the carts from their plumbing and electrical systems to creating them from raw materials are my creations, I let my work speak for itself in this area, and when I build for others I take a much larger consideration any and all details, these guys are paying big bucks for this stuff and have their own inspectors so they have to look and perform flawlessly. The difference between the carts and airplanes, the carts don't have to fly, yet need to carry a ton of weight, yet the planes are a different animal all together since their parts are so small, I can't use the same procedures "will be doing so shortly" to cut out the components. All I'm doing is going from 8' X 4' plywood stock to foam and balsa stock, this latest build is my largest yet at 36", It just passed the threshold of being able to start using some of my jigs and routers, but regardless, I still have to shape the surface of these, which is what makes foam a different animal and is why I'm looking for foam cutters and preferably ones that can handle a production setting, I replace many power tools annually since they just can't keep up with the volume of use I put them through, the same thing eventually will be with the foam cutters, so as I use them, I can justify upgrading.

Along the foam cutters themselves construction wise, you are right critterhunter, the blocks or "jigs" are what the 2 ends of the foam cutter ends rest upon, I use a similar method with my router, and to be frank, the contraptions I've seen in the home made end don't look like they can handle any serious volume, I'd beef up the controls so gravity isn't the only thing keeping it in place, this is also the same type of method used in duplication machines.

< Message edited by Espresso-Outfitters -- 2/3/2006 5:35 PM >

Hide Signatures

(in reply to Fisher)
       Post #: 77

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/3/2006 9:50 PM   
Fisher



Posts: 624
Score: 100
Joined: 9/21/2004
Last Login: 11/7/2009
From: Anchorage, AK, USA
Status: offline 		First of all I worked with Compfoil to get a wing shape based on Foamflyers specs that had a flat bottom. I did not want to cut both top and bottom.

Your general description of attaching the templates to the ends of the foam blank and drawing the hot wire over the templates is exactly how I did it. Just have to keep both ends moving at the same speed and do not stop. I used some small pieces of packing tape to keep the foam from sliding when cutting it with the hot wire. I also put a 3 or 4 baggies of sand or lead shot on top of the blank the maintain consistent pressure as I made the cut. It will all make sense to you when you grab the bow and begin your first cut. I tossed my first two wings because I did not think I had the correct template dimensions. The turned out fine otherwise. Even tossing that much foam I still had enough for to complete planes.

I ended up using a multi strand fishing leader. It is not stainless or nichrome. When I tried nichrome it just was not strong enough. Probably was not thick enough. I tried different wire until something worked well.

Your plan to use a dimmer switch to drop the current to your battery charger should be fine.

Sorry that I did not take more photos as I went along. A whole other skill to develop, documentation.

When I started this I planned to have the attitude "Just Do It" and things fell into place as needed. Not too much planning. I picked the bow design that uses the heavy music wire / spring steel rods to maintain tension on the wire because it was so simple. And I really like clean and simple items.

Espresso-Outfitters,

I really do not think that the CNC equipment sold at Hobby CNC is UL approved. They state right on their website that this equipment is not meant for commercial use. They also indicate that they are re-designing the Foam Cutting package. All the UL approved commercial CNC foam cutters are in the one to two thousand plus dollar range.






_____________________________

I never crash while flying, it''s the landings that get me.

Hide Signatures

(in reply to critterhunter)
       Post #: 78

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/4/2006 4:41 AM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		Simple and nearly free foam cutter system created by yours truly, it's a no brainer guys........

Supplies: Battery charger, 1' x 2' piece of 3/4" plywood, 2' steel fishing line leader, 2 screws, a short lenght of electrical cable, hot glue gun.

Cut a U shaped pattern out of the plywood, burn off the insulation from the leader, cut off the swivels and attachments so you just have 2 simple loops on both ends. Attach one of the hot leads from the stripped electrical cable to one end, attach the other to the other end, mount them to the edge of the board similar to a traditional bow with the 2 screws. Using the glue gun mount the cable around the parameter of the board to make it easy to handle. Connect each lead to the battery charger, turn it on, you have a foam cutter......... I just built it, have it set to the 6v, 10 amp setting, glides through polystyrene well, will kick up the amps next and try other foam densities, you don't need the rest of the extra's, the charger has it's own built in regulator, if it didn't it would be blowing up batteries. Scale it down if you don't have enough leader, PM me for photos, do this at your own risk guys......

This same thing works when you bend plexi, I have a strip that has a little insulation to keep it from shorting out and is something specially built for that purpose, it's the same principal and plugs directly into a 110v outlet, I've used it for many years with zero trouble.



Hide Signatures

(in reply to Fisher)
       Post #: 79

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/4/2006 1:27 PM   
critterhunter



Posts: 2717
Score: 100
Joined: 9/24/2004
Last Login: 8/20/2009
From: Brook Park, OH, USA
Status: offline 		Only enough time for a quick response at the moment. Will get more into detail later. Thanks for the info, both of you. The electrical aspect of a foam cutter doesn't bother me. I can figure things out when it comes to electronics. Have just enough know how to get the job done without blowing the fuses in the house. When it comes to carpentry, however, my skills are limited and I have trouble figuring out the proper way to build things with wood. I'll be back with more questions later...

By the way, I hear that craft supply stores sell a foam cutter for less than $20. It's meant has a hand held tool and runs on two D batteries. It's not meant to cut wing airfoils, of course, but probably works fine for straight lines and such.


_____________________________

I find in life that if you give people enough rope they often hang themselves, or at least have a mess of knots to undo...

Hide Signatures

(in reply to Espresso-Outfitters)
       Post #: 80

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/4/2006 4:38 PM   
Jax_Dorvek


 

Posts: 17
Score: 100
Joined: 2/4/2006
Last Login: 7/31/2006
From: , AUSTRALIA
Status: offline 		Hi all, been following this thread for a week or so and am very interested.
I'm wanting to get into rc planes, and this foamie looks like it'd suit me for a first build.
I'm from Australia and from a smallish town, and unfortunately its hard to get some things here, plus Aus names for things are diff to most the names on here lol.

Anyway, attempted to make a hot wire cutter today, using a car battery charger as the main power source, and initially it looked good, but the charger switces off by itself every 10 seconds or so, so its not much good for the job, so I'm looking around for alternatives now.
AC low voltage adaptors seem to be looking ok (the adaptors that come with things like PC speakers, discmans, etc), biggest I have atm is a 12v, 1amp one, and it works, but it really doesnt heat up enough to cut well. Now I'm looking at maybe an old laptop AC adaptor (12v 6amp), an old model train speed controller (found an old one on ebay the should work), or possibly I've read that a 12v light invertor works well too.
Any suggestions on these?

The bow was the easy bit, just a length of 35mm white PVC pipe for the cross beam, 2x 25mm pine dowling for the upright arms bolted in the middle to the PVC, cutting blade is a 22 guage steel wire (dunno what that is in inches, its about the size of a middle guitar string) and on the opposite side same wire with a 200mm spring for tension.
If I can keep constant power@ 2 amps the steel glides through foam easy as.

http://www.siliconchip.com.au/cms/A_102846/article.html helped, and
http://www.siliconchip.com.au/cms/A_102319/article.html halfway down is a section about simplifying it, if it helps anyone else.

Hide Signatures

(in reply to critterhunter)
       Post #: 81

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/4/2006 8:59 PM   
critterhunter



Posts: 2717
Score: 100
Joined: 9/24/2004
Last Login: 8/20/2009
From: Brook Park, OH, USA
Status: offline 		I can tell you this much....Wire too cold- Increase the amps or voltage. Wire too hot- decrease the amps or voltage. If your power supply doesn't offer this kind of adjustability then you'll need something like a light dimmer switch to go between the power supply and the cutter to do the adjusting. Or, depending on the problem, shortening or lengthening the wire can get it hotter or colder. Seems the magic number is around 12 volts at 2 amps. My supply has a variable rate up to 1.2 or so amps, or a static 6 amp rate. I can set it for 6 or 12 volts. I plan to hitch a light dimmer up to it with the 12 volt 6 amp setting if nothing else works.


_____________________________

I find in life that if you give people enough rope they often hang themselves, or at least have a mess of knots to undo...

Hide Signatures

(in reply to Jax_Dorvek)
       Post #: 82

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/4/2006 11:20 PM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		My charger has a 6 volt, 10 amp setting which is where I started at, it seemed to cut fine, be it a little slow, it also has a 12 volt, 10 amp setting, that worked well and it cut through things pretty fast. It sounds like that hand held foam cutter that runs on 2 d batteries gave away another magic number, just duplicate it's power source, ie. 2 D batteries and it should have enough juice.

Critterhunter, something I keep forgetting to mention along the hinges, I too face cold weather and to be honest, I think bending a piece of plastic makes a poor hinge, it's restance makes it hard to control it also makes the servo's work alot harder. What I'm doing now is using the new nylon encased push rod lines, ie. it's a tube with the wire feeding through it. I'm just cutting it into smaller lengths, imbedding the housing where I need it and connecting them together using only the push rod, there is almost no resistance and it glides like butter.

Here is a simple diagram of one of the connections, I keep it in short lengths so that you don't need to string the entire assembly through the center of the piece, only in the ends where they connect.


Hide Signatures

(in reply to critterhunter)
       Post #: 83

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/5/2006 6:27 AM   
Jax_Dorvek


 

Posts: 17
Score: 100
Joined: 2/4/2006
Last Login: 7/31/2006
From: , AUSTRALIA
Status: offline 		If anyone is struggling on a cutter, I just found the perfect solution (for my trouble at least.)
Find an old computer, get the power supply out of it. these things give you a few diferent voltages, the best being 12v. the lead where you plug a hard drive in is 12v and 2-3 amp, but you can get up to 17v 8 amp if you find a tutorial on how.
I used an old motherboard to plug the supply into (they dont work if you don't plug in a motherboard) but there are a few pages on the net that can show you how to short them out so you dont need a motherboard to turn them on.

Hooked it up to my bow, and vola! clean quick cuts, and thats over a 1 metre bow

Hide Signatures

(in reply to Espresso-Outfitters)
       Post #: 84

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/5/2006 8:37 AM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		thanks new guy for getting involved, I had a rather bleak inception into mine here. This is all good stuff, keep up the good work !!!!!!

I hacked a hacksaw "totally never saw myself doing that one" for its tension strength hardware, ie. feed one end of the heating line into the end, the other into the opposite, it kept the main components in tact ie. you adjust the tension in the same manner as the blade of a common hacksaw..... I tore off the B string from my guitar "have a whole new forum to create as to what I did to that one already........", and it made a decent cutting coil since it was small in diameter and strong under tension. I've found when you are dealing with this gauge of wire, the voltage and amps affect them within much more managable realms. Thanks fisher for the leader starting point in this area, that and just saying "just do it", Thanks critterhunter for pointing out it may be the way to go to take a risk on my decent battery charger. I have a few rigs, so it's not something I take for granted and doing some crazy experiement was never my intention from the start but I'm into low voltage in this area entirely because of safety.

I'd like to see others input upon their own home made, cheap foam cutters, again, this is all good stuff here.

< Message edited by Espresso-Outfitters -- 2/5/2006 10:15 AM >

Hide Signatures

(in reply to Jax_Dorvek)
       Post #: 85

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/5/2006 4:32 PM   
critterhunter



Posts: 2717
Score: 100
Joined: 9/24/2004
Last Login: 8/20/2009
From: Brook Park, OH, USA
Status: offline 		Still too lazy and time pressed to respond to older messages and PMs today. However, just a quick point....DC at under 20 volts with some kind of fuse is "safe", or I should say "safer"...such as a car battery charger, etc. I've read references to people using AC voltage to heat the wire. Don't do it or even experiment with it as you are asking to do a "shock dance" or even worse. I've also read about people using car batteries or other such batteries to heat the wire. Again, stay away from that as while the DC voltage is safe the potential for over amping the battery and getting an acid bath is very real. A DC power source plugged into a grounded AC outlet with a fuse is the way to go. Beyond that, everything in life is a risk and this still is. Don't get the floor wet in the workshop, either. Take a few minutes to pee outside for a change.

< Message edited by critterhunter -- 2/5/2006 4:33 PM >

_____________________________

I find in life that if you give people enough rope they often hang themselves, or at least have a mess of knots to undo...

Hide Signatures

(in reply to Espresso-Outfitters)
       Post #: 86

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/5/2006 10:32 PM   
Fisher



Posts: 624
Score: 100
Joined: 9/21/2004
Last Login: 11/7/2009
From: Anchorage, AK, USA
Status: offline 		Here is a schematic of my cutting bow. I really like the fact that all you have to do is cut the wood base and music wire (steel rod) to length, file a groove around the end of each piece of music wire for the hot wire to hold onto, then drill two holes into the wood base, hammer the music wire (steel rods) into the holes in the wooden base and wrap your hot wire around the ends of the musc wire rods while flexing them inwards and your done. Clamp your battery charger clips to the base of each of the music wire rods and flip the switch.

As you have all discovered, there are many ways to skin the hot wire foam cutter cat. To each his own. Just have fun and be safe.

Attachments
Click to see fullsize image.
Click for fullsize


< Message edited by Fisher -- 2/5/2006 10:34 PM >

_____________________________

I never crash while flying, it''s the landings that get me.

Hide Signatures

(in reply to critterhunter)
       Post #: 87

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/6/2006 8:17 AM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		Hey fisher, I gotta **** your brain on revisions for this, I'm trying to achieve perfection, hoping it falls short enough to at least has something that can produce consistant cuts and am fine tuning things.

What gauge of wire are you using for the cutting line? Are you placing force upon it to get it to cut through the material, how many psi, guestimate. What about the line slacking off when it's under heat and pressure, have you resolved that? Also, what about the armature, I'm finding doing this free hand, just cutting flat sections to be rather impossible to do consistantly start to finish. Have you been able to reproduce parts consistantly, or is this all more of an art and skill with alot of trial and error and "mistakes". I'm thinking I need a heavier guage.

Also, can I see a photo of the real mccoy, perhaps that may fill in the gaps for me.

Hide Signatures

(in reply to Fisher)
       Post #: 88

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/6/2006 4:25 PM   
Fisher



Posts: 624
Score: 100
Joined: 9/21/2004
Last Login: 11/7/2009
From: Anchorage, AK, USA
Status: offline 		Espresso-Outfitters

Look Back at post #16 on page #1. There is a good photo there of the cutting bow. As you will see the music wire rods are flexed quite a lot to keep tension on the cutting wire. I have not had any problems with the wire becoming loose. That is why I locked onto the design, very simple. I have been cutting by feel. I use very little pressure, maybe 2 psi to move the wire through the foam. I am never cutting totally free hand. I have made jigs for all my cuts. Even straight cuts require some type of guide. I just made a 3 sided box to give me a flat surface to guide the wire along. Any time I have tried to cut totally free handed I get a real mess. The wire gauge I am guessing at ~22 gauge not quite sure though since it is a multi strand fishing leader. I tried common steel wire and very thin nichrome. Neither of those worked too well. I am thinking of trying a thicker Nichrome that I saw at the hobby shop but since this is working fine I have not wanted to spend the money. How cheap is that?

Take a look at this site. Another version of the same style of bow.

http://www.tekoa.com/

Check out this page to see a quick jig for cutting straight edges.

http://members.fortunecity.co.uk/slmohr/rcinterest2.htm



_____________________________

I never crash while flying, it''s the landings that get me.

Hide Signatures

(in reply to Espresso-Outfitters)
       Post #: 89

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/7/2006 8:04 AM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		Awsome links you posted, I took the http://members.fortunecity.co.uk/slmohr/rcinterest2.htm
page and used that design for my latest, it works great and is extreemly low tech and simple to construct, it took a whole 15 min to put together from scratch, I even converted my battery charger and the bow to traditional 110V plugs to make it easier to connect the 2, I was literally thinking after the first one that I'd have to be using a bow in the traditional sense as in the ones that shoot arrows, looks like that's the technology you and the other link was about. I'll be buying from those guys very soon as well, their wares are cheap and for the trouble to reproduce, won't bother for the most part, they have exactly what I've been looking for.

Along the wire, I'm asking about what fishing gauge leader you were using, this should narrow this down when I go to the sporting goods store, the original leader I had seemed to work really well on it, at least the the fact that it didn't break, so far have hacked every string except the E string from my guitar since I keep breaking them, hopefully the D will do the job since it's the second thickest string on it, but I can tell, the leader was designed more for strength fighting against a fish then a guitar string which is designed for it's harmonics. That, and this is the first time it has been almost stringless since I bought it 15 years ago and am not happy I can't play, hehe, hitting the guitar store for replacements tomorrow, should have from the beginning since the originals were long overdue for replacement so I can't say 100% they aren't the way to go, just make sure they are new, or unused, or at least not hammered upon by this madman.

I'll take some time out to diagram and break down construction of this one to make it very easy to understand, I think having it all built at once may seem overwhelming to readers, so it's good to break it down into it's basic components more like a kit.

Hide Signatures

(in reply to Fisher)
       Post #: 90

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/8/2006 2:37 AM   
critterhunter



Posts: 2717
Score: 100
Joined: 9/24/2004
Last Login: 8/20/2009
From: Brook Park, OH, USA
Status: offline 		Expresso, look forward to reading your exacting and simplified build plans. Still too lazy to respond to prior messages and I know I owe a few people a PM. Will get to that soon enough...

Hey, I did take a micro step today. Stopped at the local fishing tackle store and found the wire leaders I need in 25' packs. They have five or six different diameter leaders. Couldn't buy yet because I didn't know which size diameter to get? Once I get that rolling with the battery at 12 volts and 6 amps I'll see if it's too hot and thus need a light dimmer switch from Home Depot. Tell me if my thinking is right here....While I may be able to get by with 6 volts 6 amps (static setting), or 12 volts and the variable up to 1.2 or 1.5 amp dial, I'm thinking if I crank her at 12 volts and the static 6 amp setting I'll have more than enough amps...which can then be tweaked down to control the heat via a light dimmer switch? Rather than hoping the variable dial that goes up to 1.2 or 1.5 amps is going to be enough, or that 6 volts at the static 6 amps will be the magic number. I know 12 volts at 6 amps is more than enough to start with and can step down from there.

Like I said, my main blocking point at the moment is building a device to hold the wing, taught the wire, and be able to cut the airfoil out. That's starting to make a bit of sense but for the most part I'm still all thumbs in the head on that one. Then there's the cutting straight lines thing. Just mark the foam line and try to follow it?


_____________________________

I find in life that if you give people enough rope they often hang themselves, or at least have a mess of knots to undo...

Hide Signatures

(in reply to critterhunter)
       Post #: 91

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/8/2006 2:59 AM   
Fisher



Posts: 624
Score: 100
Joined: 9/21/2004
Last Login: 11/7/2009
From: Anchorage, AK, USA
Status: offline 		12 volts at 6 amps will really heat things up. I am using 12 volts at 2 amps to heat a 38" wire. My 24" bow gets quite hot at the same setting. I would go ahead and get the dimmer switch, your going to need it. I think it is the way to go. Gives you the best control over heat. As for wire gage I am using I have no idea. I tried everything I could get my hands on. Guitar strings worked well. Use the largest diameter that is still just a single strand. I stayed with the fishing leader since everything else was breaking on me. This multi strand leader is tough. Just guessing that is is in the 22 to 16 gage range.


Good luck.

< Message edited by Fisher -- 2/8/2006 3:07 AM >

_____________________________

I never crash while flying, it''s the landings that get me.

Hide Signatures

(in reply to critterhunter)
       Post #: 92

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/8/2006 8:40 AM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		I picked up the fishing leader, actually had to buy a big spool, it's stainless steel trolling line rated at 135 pounds, so I'm sure if you duplicate that number, you'll be good to go, did quite a few cuts today with it, no breaks and it worked well on the 25" bow. I'm at 12v 2 amp at that setting, but have more wire strung around the bow so the power did dissipate enough for it to work correctly at that setting.

Along the bow construction diagram, here it is:



You have the electrical end down, so no need to elaborate upon it, you also should reference the http://members.fortunecity.co.uk/slmohr/rcinterest2.htm site for more exacting specifics, I just used one spring instead of the extra wire, which can be used if your spring isn't strong or long enough. The idea behind this, it's like a capitol letter "I" where the top part of the letter is like a teeter totter. The diagrams are all "Top" views. Here are some photo's of the first one I created:

Here it is with the springs off of their track

Here it is tightened up




Once together, all you are doing is tracing the jigs with the wire itself, make any shape, straight, rounded, etc. your final piece will only be as good as your jig and how much control you have over keeping a steady hand while you trace it, here is a 3d view just showing the jigs and wire, the foam will be sandwiched between them obviously:





< Message edited by Espresso-Outfitters -- 2/18/2006 10:55 AM >

Hide Signatures

(in reply to Fisher)
       Post #: 93

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/8/2006 12:12 PM   
Jax_Dorvek


 

Posts: 17
Score: 100
Joined: 2/4/2006
Last Login: 7/31/2006
From: , AUSTRALIA
Status: offline 		From what I have seen around the place, 1 amp is roughly about right per foot of wire, so 6 amps should do a 6 foot plus a bit bow

I found the 22 guage stainless steel wire I got is just a bit too thin to do large foam pieces, so I might have to go to 20 guage instead. I got mine from a local hardware store in the garden department of all places, and is was about $5 (Australian) for 50m of the stuff

Espresso-Outfitters, that is the exact design I used, but I used different materials, works good, few things I could have done to improve it, might make a mk. II later lol.
I found I should have thought of a easier way to attach the cutting wire to the power wire.
( I just have them twisted together) Perhaps an aligator clip on the power wire would make it quicker to replace wires.

Hide Signatures

(in reply to Espresso-Outfitters)
       Post #: 94

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/8/2006 5:31 PM   
critterhunter



Posts: 2717
Score: 100
Joined: 9/24/2004
Last Login: 8/20/2009
From: Brook Park, OH, USA
Status: offline 		Expresso, thank you very much for the simple outline and overview of making a cutting bow. Makes more sense to me now. Also, Jax...thanks for the gage wire info. Fisher, thanks for the finalizing my guess that I should go 12 volts with the static 6 amp setting and run it through a dimmer switch. That, I would guess, would give me total control from small short wired hand tools to huge bows longer than I'll ever need? Anybody have any recommendation on the type of dimmer switch to get? I'm guessing they are probably all about the same in function, with an OFF spot or a variable resistance from near total resistance (no current flow) to a gradual full ON (full current flow)? Since these light dimmers are AC I would assume they have a three wire connection on them? But, I would also assume I'll just be running the dimmer in series with one lead off the car battery charger? IE: Negative directly to hot wire cutter. Positive through the dimmer in series and then to the hot wire cutter? Finally, still a bit confused about the use of music wire. Are you saying you are using it instead of steel fishing leader or as a go between on both ends of the fishing leader? If so, what's the purpose of it...keeping the steel leader taught or some other obscure function? In other words, if I use Expresso's setup I'll be replacing the music wire with the springs, or are you using music wire in place of the steel leader to cut? Clear that up for me if you can.

It's too bad this car battery charger wasn't variable from 0 to 6amps. This would probably eleminate the light dimmer. As it stands, this thing has a variable .1 to 1.2 or 1.5amp dial, or a static 6 amp setting. It also can be switched from 6 to 12 volts. By the way, I also heard somewhere that KMart sells a car battery charger which is perfect for a power source at like $20. Can't remember if it was an amp variable setup or not. I'd also check harbor tool if somebody is looking for one. I've got a modern computerized battery charger that will even desulfer a battery that's been sitting dead for a while to recover it. Love the thing. The one I plan to use for the foam cutter is an old antique that my dad bought from Sears probably thirty years ago. It features glass fuse holder in the front. If the fuse pops for some reason I'll just stick a bigger amp raiting one in there, though with the proper wire resistance there shouldn't be any over amping the charger I would think.


_____________________________

I find in life that if you give people enough rope they often hang themselves, or at least have a mess of knots to undo...

Hide Signatures

(in reply to Jax_Dorvek)
       Post #: 95

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/8/2006 10:48 PM   
Fisher



Posts: 624
Score: 100
Joined: 9/21/2004
Last Login: 11/7/2009
From: Anchorage, AK, USA
Status: offline 		Critterhunter,

The Music wire is not needed at all for Espresso-Outfitter's bow design. Music wire is just the term the hobby industry uses for the high tensile strength steel rod they sell for making landing gears etc. Every hobby shop I have been in has a small rack dedicated to displaying a large assortment of "Music Wire". If you review my diagram on this page you will see that the music wire rods take the place of the bow arms and eliminate the need for a spring to maintain tension because the Music Wire is like spring steel and wants to maintain a straight shape. When you flex the arms in and wrap the cutting wire around the ends of the rods, they keep tension on the cutting wire. No pivot point needed and no spring needed. I just hook my battery charger contacts to the base of the music wire and the current is transfered to the cutting wire. I wrapped the music wire with electrical tape to keep from making unwanted contact with the arms. The arms do not heat up since they create very little resistance due to their diameter. The music wire is ~ 3/16 to 1/4 in in diameter. Not really wire.

Again, I chose this design because it require the fewest parts and is quite clean in appearance. (4 pieces to achieve what the other design needs ~10 items to achieve)

Take a look at my photos on Page #1 of this thread.

< Message edited by Fisher -- 2/8/2006 10:55 PM >

_____________________________

I never crash while flying, it''s the landings that get me.

Hide Signatures

(in reply to critterhunter)
       Post #: 96

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/8/2006 11:35 PM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		Fishers design is nearly identacle to a traditional bow, as in the ones you shoot arrows through, the string is the cutting line, the rest is just to keep it taught. Here is an image of a few professionally manufactured versions of the same thing



As you can see, not alot to them, also take note, at $50.00 is what they are selling them for, it may be the way to go since I'm into mine around $25.00, but on the opposite side of the coin, after figuring out how to get the first one to work, I won't make the same mistakes. Also found out it's going to be better to have different lengths of bows so the pieces you are cutting will take advantage of the full length of the cutting wire rather then binding and cooling in a small area.

Along stringing it, I did solder everything in place, wasn't fun with stainless, will be simplifying that process by just having 2 smaller diameter loops so I can just take off the spring, feel the line through and tie them in knots on each end so when it is taught, it will just stay in place similar to stringing beads through a string, the knot on the end is what prevents them from falling off, so is the same concept. Next upgrade will be to set up a more controlled armature so it is mechanically dragging the wire over the jigs, that and creating a vaccume table to secure the foam down which is the only obstical I'm facing now.

Hide Signatures

(in reply to Fisher)
       Post #: 97

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/9/2006 12:52 PM   
critterhunter



Posts: 2717
Score: 100
Joined: 9/24/2004
Last Login: 8/20/2009
From: Brook Park, OH, USA
Status: offline 		Making more and more sense to me now thanks to the extra details from you guys. I'm the kind'a person who has to see the detail in the design in order to wrap my brain around it. As you've probably seen from my messages here and on other threads, I tend to be somewhat painful in my instructions on how to do something. This is really much less complicated than I had originaly invisioned, especially cutting the wing airfoil. The Challenger & Extreme mods are just about done...just a tiny bit more tweaking here and there, then it's off to this foamie.


_____________________________

I find in life that if you give people enough rope they often hang themselves, or at least have a mess of knots to undo...

Hide Signatures

(in reply to Espresso-Outfitters)
       Post #: 98

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/11/2006 7:43 AM   
Espresso-Outfitters


 

Posts: 196
Score: 100
Joined: 12/24/2005
Last Login: 5/19/2006
From: Tacoma, WA, USA
Status: offline 		I measured the cutting line, it's exactly 1/32" thick, that should help you nail it down.

I took a flight test today, high winds in the middle of the day and all, they gusted 35+ mph at the park I was at, I'm going to wait until the evening before trying any more test flights with new designs, this didn't have a chance since the position of the motor and the rudder were slightly off, and with the winds, no trim could make up for it, so it was impossible to control. I took some vid regardless and ftped it to http://discflight.com/testflight1.AVI This just landed itself most of the time, just the wind was so intense and found out my powersource wasn't able to compensate, the next one will be smaller. I'm getting close, it has to be between 16" and 36" and I should have something that can handle these situations better and still remain acrobatic.

It looks like production is kicking in gear, I don't have the time to be building and/or fixing these and opted to go with a foam jet kit since it's going to just be a given I'll be dealing with these elements on a regular basis and it looks like it's going to be an easy design to reverse engineer, so duplicates will be easily made, this wasn't a cheap one, I figured I'd start with the top and figure out what they put into it in all areas since this is going to be the direction I go when I have people that ask me about dealing with the same things I have which is pretty common. I noticed the foam was rather dense and it's injected it resembles the white stuff, but is not, it had the servo's, speed controller, linkage, etc. already installed, all I did was add the receiver and moded it to handle my battery packs and balanced it, so not alot of work, ie. 10 minutes max and I now have my first RC Jet/Flying wing. Here is a shot of it:



I can convert this to brushless easily, which will be the next upgrade, that and a more powerfull battery pack and it's own dedicated receiver, ie. I had to yank it from the last plane and beleive me, the quest goes on in creating new designs, just for now I have to cool it.

< Message edited by Espresso-Outfitters -- 2/11/2006 11:41 AM >

Hide Signatures

(in reply to critterhunter)
       Post #: 99

RE: Here's a Simple & FREE First Foam Build Plan! Coo... - 2/11/2006 9:50 AM   
Jax_Dorvek


 

Posts: 17
Score: 100
Joined: 2/4/2006
Last Login: 7/31/2006
From: , AUSTRALIA
Status: offline 		That thing looks sweet Espresso-Outfitters, wish I had the $$ to play with that stuff

Guys, I'm allmost done on cutting parts out, once I rigged up a few jigs, but I got a few questions.

1: Glue, what kind to use, I've seen talk of hot glue, is it a certain sort, or just your regular old hot glue sticks from hardware stores?

2: Tail area. Have you guys used the same foam for the fins and tail surface or something a bit stronger like balse?

Thanks all

Hide Signatures

(in reply to Espresso-Outfitters)
       Post #: 100

Page:   <<   < prev  2 3 [4] 5 6 7 8 9 10 11   next >   >>  
All Forums >> Electric Aircraft Universe >> Foamies! - RC Electric Foam Aircraft >> RE: Here's a Simple & FREE First Foam Build Plan! Cool Looking Plane Too...
Page: <<   < prev  2 3 [4] 5 6 7 8 9 10 11   next >   >>  




Jump to:


 
Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America

Kaango.com Classifieds

3.718RCU1