Thank you for interviewing David! He seemed shy to begin, but near the end his wisdom shown through like something out of this world! David seems very experienced beyond his years! Great interview!
Thank you so much for this video, guys. My father used to build balsa gliders way back when he was in the Navy. He and I are beginning to explore the RC hobby together, but so much has changed since his day. It would be a tragedy to build a big balsa craft and wreck it on first flight, but building is what he loves. Showing how to use foam core as a medium lets him build a much more durable aircraft. This makes a big difference for both of us getting into things.
That is just plane epic. I have never seen a solution that simple but sophisticated enough to replace a professional soldering jig. You could literally save $100 just by choosing this simplistic yet sturdy design. I could see a whole new revolution in DIY!
11 лет назад+7
They are to scale. Just downloaded them of the site and they are still correct. The wingspan says 700mm so that's a scale you can use.
BTW I use a number 10 Dulcimer string " like a guitar string" hooked to my Weller Soldering gun as a transformer " tip removed and wires hook there" and run the gun from a light dimmer. Has always worked on projects for me. The biggest foam we can get around here is from Lowes or Menards for house walls. 73 Jimmy, ARRL TS, WX9DX
Great! Actually, I was expecting a long time, when David'd share the knowledge on hotwire foam cutting. I have some (working) idea on how to power hotwire with simple components from electric store. Now, I guess, I have to write an article for flitetest
I have a hot foam cutter that is configured like a bandsaw. It has a table, the wire comes out of the table vertically to a frame that goes back to the table. I haven't used it but I loaned it to a friend who uses a handheld cutter and she liked it a whole lot better. Also, we have no trouble getting foam in Miami. In fact we're 30 miles from Miami and that's where we go to get foam.
The good thing about the templates is if you are like me and hopeless with all things electrical you can make your templates out of thin steel or aluminium and use a sanding block / Blocks to sand down to the template after cutting the excess foam away with a small saw or knife.. Thanks Dave and Josh this gives me more confidence to try new shapes that I wouln't have thought possible before.. Regards Vince.
Ohm's Law is V=I*R (Voltage=Current*Resistance) Joule's Law is P=V*I (Watts=Voltage*Current) Nichrome wire with a diameter of .010 is roughly sitting at 7 Ohms resistance per linear foot. You can measure the 2 contact points on the bow with a DMM or use this as a rough calculation entry point for your R value. What current value are you attempting to achieve while you vary the voltage? Great video btw! M~
For those who don't know: I squared R is the power P that is produce and is not necessarily the amount of heat. There is a formula to calculate the amount heat that will be produced.
I have have miles of Nicrome wire if you would like some. However you can use fine piano wire but unlike Davids bow you need more tension to get a good cut. Use a high current transformer and a light dimer or you will just get a fire. The best bows are made of wood and Aluminium, and have an H shape. You use 2 pieces Aluminium at the ends and timber to separate and insulate. Tension with shock cord or a spring & cord/rope. $20 and your cutting. Don't use PVC and don't burn the house down.
also, how about adding mirrors to the sides of the bow so you can see how far along you are cutting on both sides without having to turn the piece over the awesome thing about having the plans made in foam sections is that each of these sections are small enough to be 3d printed ... you could add pins and holes, or slots and tabs, and make it much easier to assemble and give it some added structural rigidity as well
Add Springs to tension the wire. You'll get a better finish and you can turn up the voltage, which will produce more heat and will also allow you to cut faster.
If you put more voltage, more heat, yes. But the heat will "melt" more foam than your template. With a friend, we made that mistake while cutting foam cores for our glider's wings.
You can get big blocks of the blue foam from aircraft spruce and other aircraft/fibeglass supply places. It's not expensive but can be to ship due to size.
I don't even do this hobby, probably due to the fact my first real plane blew up on maiden voyage as a kid lol, that's another story all in itself haha, yet I learn a lot of tricks for other things and strangely I keep watching your vids anyway knowing I could never build the awesomeness you guys do ^^ i love watching you guys and keep up good work.
Hi David, Great quoting the formula for power, I2 x R. We can measure the resistance of the wire in the bow of any length we intend to use, but how much current are you having flowing through the wire of the bow? Fantastic model, second to none! TIA. Kay.
What amperage is the brushed ESC you are using in this video? As you say, they are getting hard to get your hands on, and I wanted to know what would be the minimum needed.
I just made one today. I didn't use the esc or the dimmer. Just some nichrome, wood, and screws. I used a simple 9 volt on 12 inches of 28 guage wire. I plan to step it up to 12 volt as 9 was a little slow. Idk about the AC/DC part though. You can buy Nichrome on Amazon for a few dollars.
If you have any experience with 3-d modelling on computers this is a piece of cake, its a similar concept to skinning between two polygons, in fact I've modelled planes in 3-d doing exactly that
im building the hot wire foam cutter from grant thomsons video. With the templates that flite test showed me how to make in their how to make templates video i can make professional scratch built planes like the ft 3d and other planes built by them.
Thanks for the info guys, I built a foam cutter using a computer power supply which had WAY more than enough power. I will have to revisit that adventure and see if I can't refine it a little bit!
Could you make an aerofoil shaped hot wire cutter and cut the foam side to side instead of a long wire across the width? I think you'd need thicker wire to hold aerofoil shape and more power, but it could the cutting process much simpler!
Excellent 👍 video, it is a great help since it will be my first time working with a foam cutter. I'm into RC cars and drones so I am very familiar with the components utilized, the heat for the wire was my biggest concern and you guys clarified that for me, thanks
So how would you cut a hatch f.ex? I have a plane where the pilot door is cut in an angle, this means that you can't push the door through, and is an excellent for hatches, as they can only open outwards. But how would you cut that with a good looking result?
that servo driver, doesn't need an external power supply or is it powered by internal batteries? I have one that requires to plug in a battery. Does that mean I need one battery for the servo driver and one more for the ESC?
Found out I am very allergic to the off gassing of that foam when i used it around a window installed air conditioner years ago. When home, I had non-stop runny nose. We tested our suspicion of the foam being the cause, confirmed it was, and removed it. I have no other known allergies, so can only conclude the chemicals coming off that foam, cannot be good. The takeaway is: Use natural materials and hone your skills of workmanship with other building methods whenever possible. Enjoy lasting health.
Hi FliteTest this is an awesome piece of work very nice cuts I want to make some shapes cutting a foam but pls tell me what is the name of this foams I know it is a high density foam but there some few other products that are not the best for foam cutting Thank you for your to reply
It's when you're cutting the foam and the wire isn't hot enough to cut it with proper speed, so you push it a little harder and the wire starts to flex a little. That is bowing. Like when you pull back the string of a bow, bowing.
2:53 you can use a 3 phase brushless ESC if you make a rectifier out of diodes ... you will need to hook up a motor in parallel so that it gives a feedback voltage so that the ESC will work
3M77 works, too. Spray both faces, leave until it's only just tacky then press together. Holds well, and the wire goes through the joint no problem. (I learnt that from Phil Barnes dvd on vacuum bagging.)
Hey, sorry for the completely unrelated comment, but could y'all do an episode/walk-around of David's "Quadrone"?? I was looking at it on David's website, and by golly, that design is wonderful! Would love to hear the designer comments on how he came up with the design and how it performs! Thanks!
this is awesome...... but how do people in countries like Nigeria get foams like the ones u use? hv tried a couple of places n hv only seen d soft foams from electric appliance packaging...
Hey HK still sells a brushed ESC! I don't know how to access templates yet. Are you making your own or have you found a source? I'm so new, I am still working on hand launching my foamcore trainers.I have already destroyed three props and two motors will need new shafts installed. I wanted to use extruded SM styro like in the video. You know there are two diff kind 200 & 300 psi test. Blue and pink.Need templates for flying wing. I'll do a rear motor mount to help keep damage from crash minimal
Would your regular old Kanthal wire used in a vape work for this? I know a few shops carry NiChrome, but it'd be easier to just use what I've got around.
Awesome video! I live just by Miami and they always have foam at Home Depot or Lowe's. I too did a hot wire foam cutter but never thought of making it portal like this one. Great job.
Dimmer switch from room light switch?? And how did you force car battery charger to flow current if it is with electronic processor prevents from overload and so..??
Thanks for the heads-up VH, that's what I call team work. Now that I have sorted my first Tricopter build and the associated Firm Ware issues.Whew! I can now try my hand at making an airframe from inexpensive, readily available, easy to cut Foam. BTW I am looking for the "How To Make Inexpensive Hot Wire Templates" ? Or is there another link you found with actual template designs that I can print and cut out?
That depends on 2 things: The type and density of the foam, and the power you want from your wire at a given voltage. If you intend to cut thin sheets of low density foam you can use thin wire, but if you need to cut the sort of stuff they are cutting here then your best bet is to just hit the thrift store and find yourself an old hair dryer, bust it open and use the coarsest heating wire in the thing. The most important practical consideration once you're ready to string a bow with wire is how you're planning on powering it. I like the ease of use of a cordless setup so I recommend powering the setup with a lithium ion battery. Preferably 1 or 2 18650 cells. Using a speed controller like this is a nice touch but not strictly necessary. You want to be dissipating about 0.6 - 1 W/cm of wire so if you have a ~40 cm bow like David you'll need your wire to have a resistance of 0.4 ohm if you want to run it from a single 18650. Ni-chrome would actually have to be excessively coarse to get such a resistance over 40 cm but a good alternative is stainless steel or piano or guitar strings.
Hey! I have created a number of planes completely out of foam (but EPS not XPS) using a similar technique. But, when I do wings, I have issues with the sag of the wire. I get the timing and stuff right, but some of my wings get badly damaged due to the sag if I'm not careful. For now, I just push the bow down on the templates to maintain the tension and keep the string taut, but it is not very effective. What would you suggest I do?. I have a fixed 12vdc source at home. So I can't vary the voltage. So I just use a 60cm long guitar wire.
i tried guitar wire with 12v 8 amp battry charger. it didnt get hot enough to foam. so i started to make wire smaller. it barely work with 20 cm. when i tried 15 cm, the wire wasnt there any more :D. it was just puuffed. Just dissapered. not even smoke
hi, i have tried to make it, but wire didnot get hot. my NICHROME wire is 32gauge. just like a hair.and the output is +12v--750mA. where is i am wrong ?
your bow is too long for your power supply. at 12v and 32gau 400F is 680ma at 20" of wire 500F is 790mA at 17.28" of wire 600F is 900mA at 12.17" of wire Shoot for 18" which should put you at around 470F
NiChrome wire is the stuff you need for this. It's the same stuff they put in hair driers and heaters. Get it from a hair drier without breaking it and a few sticks from the yard later you have a foam cutter if you plug it in to a rheostat like a light dimmer.
David B, you'd want to use SS not flux core. Probably any thickness since it doesn't get very hot. I used Nicrome in a textile mill to cut 5 10 inch rolls of 150 denier polyester at a time on a machine we built. I can't remember the gauge but you can buy it at supply shops. I can see how stainless or a guitar string would work fine on foam though. Our wire had to be a higher temperature or it would melt the tube ends of the rolls together. In that application other wires would sag/break. I admit we only used a hair dryer wire to prove the concept them moved on to thicker stuff. I still have a roll somewhere, maybe 12 gauge or 14.
Thank you for the reply. I have plenty of SS .025in Dia. wire I can try first. I will give that a try first. If it works, I'll let you know. Once again, Thanks.
I'm from Alaska and Dad was raised in Alaska and in his many years of flying up there he had flown over most of the country up there. He learned to fly in the late 30s in SE. I'm just getting back into flying both RC and full sized aircraft.
I got the plans printed off for this on 54 pages using a titled PDF. Going to get foam tommorow and start building this thing. I have never even flown a Rc plane before in my life but I don't even care!
Hey, guys! While David is still there and while You are on topic of blue core foam, maybe make some BEGINNER'S TUTORIAL IN FIBERGLASSING on this plane! You mentioned that it needs reenforcement for air intakes. Nothing major, just tips & tricks in basic fiberglassing - tools, compounds, methods, safety things e.t.c.
You shouldn't need more than 10amp I use a PWM controller instead of an esc, it has a rheostat and will take up to 40V. I use 28gauge nichrome wire (stainless fishing leader also works) and up to 24v (2 car batteries in series) for wings up to 10 feet long. Any longer than that and you have to go really slow or your wire will bend too much (but that can be useful for adding reflex).
Thank you for interviewing David! He seemed shy to begin, but near the end his wisdom shown through like something out of this world! David seems very experienced beyond his years! Great interview!
Thank you so much for this video, guys. My father used to build balsa gliders way back when he was in the Navy. He and I are beginning to explore the RC hobby together, but so much has changed since his day.
It would be a tragedy to build a big balsa craft and wreck it on first flight, but building is what he loves. Showing how to use foam core as a medium lets him build a much more durable aircraft. This makes a big difference for both of us getting into things.
That is just plane epic. I have never seen a solution that simple but sophisticated enough to replace a professional soldering jig. You could literally save $100 just by choosing this simplistic yet sturdy design. I could see a whole new revolution in DIY!
They are to scale. Just downloaded them of the site and they are still correct. The wingspan says 700mm so that's a scale you can use.
BTW I use a number 10 Dulcimer string " like a guitar string" hooked to my Weller Soldering gun as a transformer " tip removed and wires hook there" and run the gun from a light dimmer. Has always worked on projects for me. The biggest foam we can get around here is from Lowes or Menards for house walls.
73
Jimmy, ARRL TS, WX9DX
Health and safety bit: **Wear an M3 Vapor mask**, Gloves, Goggles
and do it outside!
i was thinking the same thing, boy i bet those vapors have all kinds of carcinogens in them
Cutting it is safe, burning it is not.
Great!
Actually, I was expecting a long time, when David'd share the knowledge on hotwire foam cutting.
I have some (working) idea on how to power hotwire with simple components from electric store.
Now, I guess, I have to write an article for flitetest
I have a hot foam cutter that is configured like a bandsaw. It has a table, the wire comes out of the table vertically to a frame that goes back to the table. I haven't used it but I loaned it to a friend who uses a handheld cutter and she liked it a whole lot better.
Also, we have no trouble getting foam in Miami. In fact we're 30 miles from Miami and that's where we go to get foam.
The good thing about the templates is if you are like me and hopeless with all things electrical you can make your templates out of thin steel or aluminium and use a sanding block / Blocks to sand down to the template after cutting the excess foam away with a small saw or knife..
Thanks Dave and Josh this gives me more confidence to try new shapes that I wouln't have thought possible before..
Regards Vince.
We need a laser-cut set of the plywood templates avail in the FT Store right away!! (for this and OTHER planes)
and if have laser who can cut plywood can cut laser all foam too easy.
Building one of these now. Can not wait to try it out. HUGE THANKS TO FLITE TEST GUYS!!
Ohm's Law is V=I*R (Voltage=Current*Resistance)
Joule's Law is P=V*I (Watts=Voltage*Current)
Nichrome wire with a diameter of .010 is roughly sitting at 7 Ohms resistance per linear foot. You can measure the 2 contact points on the bow with a DMM or use this as a rough calculation entry point for your R value. What current value are you attempting to achieve while you vary the voltage?
Great video btw!
M~
hotwirefoamcutterinfo.com/__SupplyCalc.html
Nevermind. I found it.
6.2v @ .92A = 5.7watts and 400F and 8.0v @ 1.19A = 9.52 watts and 600F
Mmm, brings back my unregulated vape mod days. I would turn my own coils.
You could also use an AC transformer and a light dimmer to control the heat of the wire.
"what was it, Vegan?" "Viggen" "Alright, the Vegan..."
its a swedish plane
David is from Sweden i things
Saab 37 Viggen ;)
Saab also made a car called Viggen..
Little factoid for ya ;)
Jan Christian Frodahl m
He kept saying vegan lol
You can buy a whole hot wire cutting set for around $25. However, the one that you made works great as well!
For those who don't know: I squared R is the power P that is produce and is not necessarily the amount of heat. There is a formula to calculate the amount heat that will be produced.
the guy in the red woodsman shirt is mad smart
David windestal?
David windestal?
I have have miles of Nicrome wire if you would like some. However you can use fine piano wire but unlike Davids bow you need more tension to get a good cut. Use a high current transformer and a light dimer or you will just get a fire.
The best bows are made of wood and Aluminium, and have an H shape. You use 2 pieces Aluminium at the ends and timber to separate and insulate. Tension with shock cord or a spring & cord/rope.
$20 and your cutting.
Don't use PVC and don't burn the house down.
You could use a turnbuckle half way up the arms to keep the wire taught,
It's usually better to just use the flex of the bow or a tension spring.
please please please do a flite tip episode about how to extend the flight time of an existing air frame. thanks and keep the episodes coming!
also, how about adding mirrors to the sides of the bow so you can see how far along you are cutting on both sides without having to turn the piece over
the awesome thing about having the plans made in foam sections is that each of these sections are small enough to be 3d printed ... you could add pins and holes, or slots and tabs, and make it much easier to assemble and give it some added structural rigidity as well
One of my favourite channels, other than Flite Test, did that and it was amazing.
Miss this young man. Great video.
Add Springs to tension the wire. You'll get a better finish and you can turn up the voltage, which will produce more heat and will also allow you to cut faster.
If you put more voltage, more heat, yes. But the heat will "melt" more foam than your template.
With a friend, we made that mistake while cutting foam cores for our glider's wings.
You can get big blocks of the blue foam from aircraft spruce and other aircraft/fibeglass supply places. It's not expensive but can be to ship due to size.
I don't even do this hobby, probably due to the fact my first real plane blew up on maiden voyage as a kid lol, that's another story all in itself haha,
yet I learn a lot of tricks for other things
and strangely I keep watching your vids anyway knowing I could never build the awesomeness you guys do ^^ i love watching you guys and keep up good work.
Great video, congratulations, but what are the measurements in centimeters of the saw and Nichrome wire ?
Hi David,
Great quoting the formula for power, I2 x R.
We can measure the resistance of the wire in the bow of any length we intend to use, but how much current are you having flowing through the wire of the bow?
Fantastic model, second to none!
TIA.
Kay.
What amperage is the brushed ESC you are using in this video? As you say, they are getting hard to get your hands on, and I wanted to know what would be the minimum needed.
If you construct the bow like a spanend woodworking saw and use a string spring between the hotwire and frame you will get much better tension.
Thank you for your great video!
Will you be making a video about fibreglass coating the foam?
I just made one today. I didn't use the esc or the dimmer. Just some nichrome, wood, and screws. I used a simple 9 volt on 12 inches of 28 guage wire. I plan to step it up to 12 volt as 9 was a little slow. Idk about the AC/DC part though. You can buy Nichrome on Amazon for a few dollars.
If you have any experience with 3-d modelling on computers this is a piece of cake, its a similar concept to skinning between two polygons, in fact I've modelled planes in 3-d doing exactly that
Nice one bro, thank you very much. But what is the thickness of the Nichrome wire?
I didn’t see a spring to take up the slack when the wire nets hot and expands, how did you handle the wire expansion?
im building the hot wire foam cutter from grant thomsons video. With the templates that flite test showed me how to make in their how to make templates video i can make professional scratch built planes like the ft 3d and other planes built by them.
Thanks for the info guys, I built a foam cutter using a computer power supply which had WAY more than enough power. I will have to revisit that adventure and see if I can't refine it a little bit!
does the hot wire not cut/burn into the PVC? I do not see any insulator on it?
good places to find good foam, craft stores, they have a foam that is excellent for hot wire cutting and it's also very light.
Could you make an aerofoil shaped hot wire cutter and cut the foam side to side instead of a long wire across the width?
I think you'd need thicker wire to hold aerofoil shape and more power, but it could the cutting process much simpler!
Excellent 👍 video, it is a great help since it will be my first time working with a foam cutter. I'm into RC cars and drones so I am very familiar with the components utilized, the heat for the wire was my biggest concern and you guys clarified that for me, thanks
So how would you cut a hatch f.ex? I have a plane where the pilot door is cut in an angle, this means that you can't push the door through, and is an excellent for hatches, as they can only open outwards. But how would you cut that with a good looking result?
You use a real sharp Exacto knife and make the cut in a number of cut passes. Glue some stiff paper or Balsa inside to act as a stop for the hatch.
Great video. What should the template be made of so the wire doesn't damage it? Thanks.
that servo driver, doesn't need an external power supply or is it powered by internal batteries? I have one that requires to plug in a battery. Does that mean I need one battery for the servo driver and one more for the ESC?
The servo tester is powered by the BEC in the speed controller, same way most small receivers are.
I could listen to David say "glue" all day.
Found out I am very allergic to the off gassing of that foam when i used it around a window installed air conditioner years ago. When home, I had non-stop runny nose. We tested our suspicion of the foam being the cause, confirmed it was, and removed it. I have no other known allergies, so can only conclude the chemicals coming off that foam, cannot be good. The takeaway is: Use natural materials and hone your skills of workmanship with other building methods whenever possible. Enjoy lasting health.
I am not into planes anymore but making a smaller ver of you wire former would save me alot of time with my model Railroad!
At around 13 minutes, is the type of foam you are talking about insulation polystyrene? Also, now I know that I can get foam very easily.
Hi FliteTest this is an awesome piece of work very nice cuts I want to make some shapes cutting a foam but pls tell me what is the name of this foams I know it is a high density foam but there some few other products that are not the best for foam cutting Thank you for your to reply
I have a lot of spare kanthol wire around, will that work, or is nichrom a must?
You can also use an adjustable light dimmer to have control over the current to the wire.
Hobby King still sells Brushed ESCs. But they only have two of them. A 20a and a 30a. You have to search "brushed" if you want to find them quickly.
It's when you're cutting the foam and the wire isn't hot enough to cut it with proper speed, so you push it a little harder and the wire starts to flex a little.
That is bowing.
Like when you pull back the string of a bow, bowing.
What's the amp rating of your brushed esc? and resistance of wire? Have you got some guidelines for how much power /cm or /m for a foam cutter?
2:53 you can use a 3 phase brushless ESC if you make a rectifier out of diodes ... you will need to hook up a motor in parallel so that it gives a feedback voltage so that the ESC will work
What an amazing young man!!!
Very well done.
John in MD
That is awesome!!!!
What turnigy tester is that? got a model number?
i find brushed esc on HK, but wat current do i min/max need? i see 20A or 30A ….
3M77 works, too. Spray both faces, leave until it's only just tacky then press together. Holds well, and the wire goes through the joint no problem. (I learnt that from Phil Barnes dvd on vacuum bagging.)
Hey, sorry for the completely unrelated comment, but could y'all do an episode/walk-around of David's "Quadrone"?? I was looking at it on David's website, and by golly, that design is wonderful! Would love to hear the designer comments on how he came up with the design and how it performs! Thanks!
this is awesome...... but how do people in countries like Nigeria get foams like the ones u use? hv tried a couple of places n hv only seen d soft foams from electric appliance packaging...
try it out man, you can make anything fly from most foam
I would really like to see these formers and other formers like them on the store. A C-130 would turn out crazy sharp with this technique.
Hey HK still sells a brushed ESC! I don't know how to access templates yet. Are you making your own or have you found a source? I'm so new, I am still working on hand launching my foamcore trainers.I have already destroyed three props and two motors will need new shafts installed. I wanted to use extruded SM styro like in the video. You know there are two diff kind 200 & 300 psi test. Blue and pink.Need templates for flying wing. I'll do a rear motor mount to help keep damage from crash minimal
Electronic Dimmer used to control lights do the same job and is cheaper. Thumbs up for the great idea of PVC tubes for the bow.
Would your regular old Kanthal wire used in a vape work for this? I know a few shops carry NiChrome, but it'd be easier to just use what I've got around.
It works, I have it. I think Kanthal can withstand higher temperatures and has a higher resistance.
Thank u guys I always wanted to see a edf jet on your channel
Awesome video! I live just by Miami and they always have foam at Home Depot or Lowe's. I too did a hot wire foam cutter but never thought of making it portal like this one. Great job.
I've done this w a dimmer switch wired upstream of a 12 volt car charger. Great temp control.
Dimmer switch from room light switch?? And how did you force car battery charger to flow current if it is with electronic processor prevents from overload and so..??
I'm planning on building this foam cutter, just like to know your wire thickness, working length and how much amp this esc should be able to pull.
did you laser cut the formers? what if i don't have a laser cutter? how do i cut formers? Great plane!!!
Crazy good cutting skills for hand held
"If you live in Miami, you're gonna have a really hard time finding foam."
I live in Key West. Dang it.
I miss David Windestål. He should have been there, when you got 1.000.000 subscribers...
What happened to him
Hi guys great job.were you get the former!
You design them?
I couldn't catch. What wire temperature should be like? Does it smell while cutting?
Thanks for the heads-up VH, that's what I call team work. Now that I have sorted my first Tricopter build and the associated Firm Ware issues.Whew! I can now try my hand at making an airframe from inexpensive, readily available, easy to cut Foam. BTW I am looking for the "How To Make Inexpensive Hot Wire Templates" ?
Or is there another link you found with actual template designs that I can print and cut out?
Hello I really liked these molds for cutting, can you send me the site where to buy? Or where do I get these molds? thank you.
What diameter should the nichrome wire be?
That depends on 2 things: The type and density of the foam, and the power you want from your wire at a given voltage. If you intend to cut thin sheets of low density foam you can use thin wire, but if you need to cut the sort of stuff they are cutting here then your best bet is to just hit the thrift store and find yourself an old hair dryer, bust it open and use the coarsest heating wire in the thing. The most important practical consideration once you're ready to string a bow with wire is how you're planning on powering it. I like the ease of use of a cordless setup so I recommend powering the setup with a lithium ion battery. Preferably 1 or 2 18650 cells. Using a speed controller like this is a nice touch but not strictly necessary. You want to be dissipating about 0.6 - 1 W/cm of wire so if you have a ~40 cm bow like David you'll need your wire to have a resistance of 0.4 ohm if you want to run it from a single 18650. Ni-chrome would actually have to be excessively coarse to get such a resistance over 40 cm but a good alternative is stainless steel or piano or guitar strings.
hey wonderfull video... just wondering whats the correct temp for wire to cut foam without smoke... my cutter smoking :D
Hey! I have created a number of planes completely out of foam (but EPS not XPS) using a similar technique. But, when I do wings, I have issues with the sag of the wire. I get the timing and stuff right, but some of my wings get badly damaged due to the sag if I'm not careful. For now, I just push the bow down on the templates to maintain the tension and keep the string taut, but it is not very effective. What would you suggest I do?.
I have a fixed 12vdc source at home. So I can't vary the voltage. So I just use a 60cm long guitar wire.
i tried guitar wire with 12v 8 amp battry charger. it didnt get hot enough to foam. so i started to make wire smaller. it barely work with 20 cm. when i tried 15 cm, the wire wasnt there any more :D. it was just puuffed. Just dissapered. not even smoke
hi, i have tried to make it, but wire didnot get hot. my NICHROME wire is 32gauge. just like a hair.and the output is +12v--750mA. where is i am wrong ?
your bow is too long for your power supply.
at 12v and 32gau
400F is 680ma at 20" of wire
500F is 790mA at 17.28" of wire
600F is 900mA at 12.17" of wire
Shoot for 18" which should put you at around 470F
Hi, whats the amperage rating of the "Brushed" ESC you guys are using please :)
I read through the comments, but did not find a quick answer. How does one get templates? Happy to buy them if needed.
Craig Corbin sorry for the late answer but they design and laser cut the templates themselves.
do you guys sell the templates at the flitetest store?
NiChrome wire is the stuff you need for this. It's the same stuff they put in hair driers and heaters. Get it from a hair drier without breaking it and a few sticks from the yard later you have a foam cutter if you plug it in to a rheostat like a light dimmer.
+1985cjjeeper Nicrome wire brakes to easy i use stainless steal or a guitar string.... Even mig welding wire works good.
what size mig wire and what kind? SS or Fluxcore?
David B, you'd want to use SS not flux core. Probably any thickness since it doesn't get very hot.
I used Nicrome in a textile mill to cut 5 10 inch rolls of 150 denier polyester at a time on a machine we built. I can't remember the gauge but you can buy it at supply shops. I can see how stainless or a guitar string would work fine on foam though. Our wire had to be a higher temperature or it would melt the tube ends of the rolls together. In that application other wires would sag/break. I admit we only used a hair dryer wire to prove the concept them moved on to thicker stuff. I still have a roll somewhere, maybe 12 gauge or 14.
Thank you for the reply. I have plenty of SS .025in Dia. wire I can try first. I will give that a try first. If it works, I'll let you know. Once again, Thanks.
That should be fine as it won't need to be very hot for most things. Just make sure you never touch it when it's plugged in and you won't die.
This is awesome! Do you have any tips for cutting shapes into the foam without going all the way through?
Lizzy Rose there is like a foam needle? but its a foam cutter but more like a needle and not a wire
I'd like to see a 200% Viggen. 140mm EDF!
Speaking of Alaska, it would be awesome to do a flite test in alaska. we have more planes and pilots than you would know what to do with!
I'm from Alaska and Dad was raised in Alaska and in his many years of flying up there he had flown over most of the country up there. He learned to fly in the late 30s in SE. I'm just getting back into flying both RC and full sized aircraft.
Can we get a parts list for the foam cutter? @flighttest
The Nichrome wire dosnt stretch when its heated so i make my bow as tight as I can especially for wing panels
How many amps are needed for the wire to cut through the foam?
I got the plans printed off for this on 54 pages using a titled PDF. Going to get foam tommorow and start building this thing. I have never even flown a Rc plane before in my life but I don't even care!
You can get foam from Hydroponic shop .great video 👌👍
id pay a lot of money for that EA-6B prowler... if i had a lot of money
prowler/intruder or the De Havilland's vampire
Hey, guys! While David is still there and while You are on topic of blue core foam, maybe make some BEGINNER'S TUTORIAL IN FIBERGLASSING on this plane! You mentioned that it needs reenforcement for air intakes. Nothing major, just tips & tricks in basic fiberglassing - tools, compounds, methods, safety things e.t.c.
You can get it from an old heater heating element. Usually it comes in a coil shape.
You shouldn't need more than 10amp I use a PWM controller instead of an esc, it has a rheostat and will take up to 40V. I use 28gauge nichrome wire (stainless fishing leader also works) and up to 24v (2 car batteries in series) for wings up to 10 feet long. Any longer than that and you have to go really slow or your wire will bend too much (but that can be useful for adding reflex).
Better to work with high density foam? Recommended?
If you don't have a piece of foam big enough can you Hot Glue two pieces together first before you cut it?
Thanks
Jimmy, ARRL TS, WX9DX
Hi David, the plans I downloaded int the website are not in scale? So, what is the is the scale of the drawing?