Flite Test - Hot Wire Foam Cutting
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- čas přidán 30. 04. 2013
- Hot wire foam cutting using a homemade hot wire cutter and custom made balsa templates.
More details and links available in the article here:
flitetest.com/articles/hot-wir...
Watch the JA 37 Viggen Review here:
flitetest.com/articles/ja-37-v...
Watch the Skywalker X8 Review here:
flitetest.com/articles/skywalk... - Zábava
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.
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
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!
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
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.
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
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.
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 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.
Building one of these now. Can not wait to try it out. HUGE THANKS TO FLITE TEST GUYS!!
One of my favourite channels, other than Flite Test, did that and it was amazing.
Thank you for your great video!
Will you be making a video about fibreglass coating the foam?
You could also use an AC transformer and a light dimmer to control the heat of the wire.
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.
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
You can also use an adjustable light dimmer to have control over the current to 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 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.
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 can buy a whole hot wire cutting set for around $25. However, the one that you made works great as well!
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.
Miss this young man. Great video.
Great video. What should the template be made of so the wire doesn't damage it? Thanks.
i find brushed esc on HK, but wat current do i min/max need? i see 20A or 30A ….
Nice work guys, thanks for the help.
I love this idea, i just thinking about how to cut the foam, and its just awsome (: !
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.
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.
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!
Yes!!! Would love to build one of these too
Great job on the video! Thanks for the tutorial. It makes me wanna go out and build something!
Thank u guys I always wanted to see a edf jet on your channel
That is awesome!!!!
What turnigy tester is that? got a model number?
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
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.
What an amazing young man!!!
Very well done.
John in MD
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.)
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.
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.
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!
Another amazing diy idea. Thank you so much!
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
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.
Go to the Flitetest site and they have the templates there, Thanks guys!
hey wonderfull video... just wondering whats the correct temp for wire to cut foam without smoke... my cutter smoking :D
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'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..??
can use tungstun wire which can be easily found in electric iron
Great video, congratulations, but what are the measurements in centimeters of the saw and 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?
Hi, whats the amperage rating of the "Brushed" ESC you guys are using please :)
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?
Very clever. Lots of great info. Fantastic.
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.
where do we get the plans/stencils for the Viggen
You can get it from an old heater heating element. Usually it comes in a coil shape.
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!
Nice one bro, thank you very much. But what is the thickness of the Nichrome wire?
does the hot wire not cut/burn into the PVC? I do not see any insulator on it?
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.
a foot pedal like a tig welder would be great for start and restart and speed control
Hello David, I have been watching your nicely build planes and videos of flights. Good job. Can you share some drafting of profile shapes for profile cut sectioned planes so we can experience as you did. That would be awesome if you can. Thank you
The Nichrome wire dosnt stretch when its heated so i make my bow as tight as I can especially for wing panels
the guy in the red woodsman shirt is mad smart
David windestal?
David windestal?
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?
Would 9V be fine for about a meter of NiChrom wire?
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.
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.
Could you please do a review of the Durafly Spitfire.
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.
maybe we can get a demonstration on urethane foam casting?
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!
Can u tell me what the piece the sets the pulse
You can still get a brushed ESC at Hobby King. Check it out. Just type in search for them at the top of page and you'll find 20 and 30A there.
how about figuring out templates for the versa wing, so i can hot wire wings for that. maybe you could lazor cut them and we could buy them from flitetest. you could start a new series on aircraft with cut wings.. that would be awesome..
thanks
Kevin
hye!guys im using cheap guitar string and a power supply source of 3 amp and 12v to 14v of voltage. i cant get nice surface finish.it is due to the wire type i used or the technique?please help me.
Just built this. Awesome!
you said in the video you would show a diagram of how to make the hot wire bow
where to get the drawing templates plane?
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.
I have a lot of spare kanthol wire around, will that work, or is nichrom a must?
what is the thickness of the styrofoam?
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
How can i get these plans printed?
The pink foam in made by Owens Corning witch is in Toledo, OH.
That was a helpful video about hot wire... Thank you guys....
Hi I new to the art.. where can i buy foam core - Thanks
They were using extruded polystyrene foam board like you would use for extruded polystyrene like Dow Blue Board or Owens Corning Foamular. You DO NOT want to use expanded bead polystyrene foam board it is to frail, unless the part is real thick. Any good lumberyard should have the thick foam depending on where you live but you are going to need to buy a 4x8 foot sheet of it.
I couldn't catch. What wire temperature should be like? Does it smell while cutting?
can you use that foam that you get your rc helicopter in that foam thx
I use a screw attached between the wire and the holder to tighten the wire
Josh / David where did you get the templates for the Viggen pls I want to scale it up with bigger propulsion.
hye!its me again may i know what is the specific name of that blue foam?because i usually use white foam and im not satisfied with its end result.any one please help.thank you!
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
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.
yes, ille say 4 foot foam cutting bow is ok .. but how a bout a 7 to 8 foor one ? (mine is 2.4 meters) for cutting windturbine blades.
i know those are not, but why cut the whole plane out of blue foam with very close to ideal shapes, and then just use flat wings? that only works well for small park flyers. i like to use real naca 4 digit foils for low reynolds numbers. would love to see a good tutorial on how to cut real airfoil wing sections from foam.
Omg I just built the ja 37 and it is amazing
hay guys I bought a Cessna micro rc air plane and can you do a review