It's a horrible design man. So many people copy other people's 'tutorials' that it kills me. I'm not saying this guy does it. A bench supply can be had for 40 bucks on amazon as well. Anyone who builds anything should have one.
I haven't played in the RC sailplane world for over 18yrs....I'm actually looking to get back into it now that I am retired, hence finding this video. Not sure if you're familiar with the original feather cut machine but you can easily mimic the concept, add a wheel to the back of the bow and let gravity make the cut for you. You'll need to add a sliding scale type pulleys on the edge of your table but I can assure you it'll be easier than trying to run that bow evenly by hand. Thanks for sharing your power source!!!
perfect time for me to stumble across this video. As of yesterday I decided to make a hot wire foam cutter and while looking for a power supply I found a battery charger that has a control on it to select 2-6amp 6-12v and was trying to find out if it would be usable for my needs.
Great info! I had all the items but I didn't know they could be used for this! The SS welding wire I used is.025" and a Sears battery charger set on the 10 amp charge section. It cuts 2" foam fairly easily. I set mine up to work with my table saw fence so I can cut long straight pieces. Had to make an overarm clamped to the edge of the table saw, but still built within 4 hours start to finish. Thanks so much for the info!!!!
Nice work, thanks for the explanation, the using more wire in the circuit to vary amperage is so simple its genius. as far as those little variances in the wing... there have been lots of models that flew just fine with WAY worse!
That's a great design for the application. I am curious if you thought of measuring the hot wire heat once you achieved your cutting temperature. I believe the length of the wire dictates the actual resistance. So different wire length will change the resistance which will change the current value needed. If you know the cutting temperature needed for that type of foam material you can use an infrared thermometer to adjust the current until you reach the appropriate temps so no trial and adjust cycles for future use. Either way it's a great design.
Sweet project. Lots of good information there. I suppose if you wanted to make wing taper your outer pattern would be smaller and placed forward to keep the leading edge straight or back for a trailing off leading edge. I can see running the wing through a table saw on an angle to make a dihedral wing. You really got my creative juices flowing. I would build one with a motorized feed table to control the feed rate exact through the foam.
You got it. There are gravity feed designs online, you use pulleys and a scaled bar to adjust the speed of each side of the cutting wire as it's pulled off the table by a small weight. You want the wire to cut through each end of the foam blank at the same speed, so if you have a tapered wing you use the pulleys and some math to adjust where the strings attach to the swing arm. Pretty neat. There's a neat article about it in this old magazine - www.rcsoaringdigest.com/pdfs/RCSD-2008/RCSD-2008-11.pdf
K.I.S.S. right there! The tip with the welding wire is genius, it opens up a wider market if your local home depot doesn't have NiChrome wire. Btw: professional shops are using CNC hot wire machines and controlling temperature & feed so they don't get waves in the surface. I've build a few flying wings made of EPP RG25 and RG30 and the cut wing halfs were always perfect. They are always shipped with the whole block to prevent damage and the wings were cut on one go. I guess they've found out what works through trial & error... ;-)
Just a note about ventilation. The bad smell you talk about is a very dangerous gas. Long term health hazards may result. Suggest you add a note about using your rig in a well ventilated area. Same goes for sanding foam without a mask. Very informative video. Thankyou
I’m currently thinking of building a hot wire cutter. I wasn’t sure what I should use for a power supply. I have a battery charger similar to yours. …. I have found my power supply!
As for the alignment issue; try constructing an arm/lever/guide to restrict the cutter from getting out of side to side alignment. An arm with hinges to allow only front to back and up/down movement? Kinda like a radial arm saw.
Made one the other day. I used a power supply from an old massaging chair cover thingy. Output is 2AMPS and it cuts fine along the length of the wire (8 inches). I'll be using it to make molds to cast knifes and handles. Nothing big like you.
Arnold's Design I reuse old broken hairdryers, if you ask your friends on Facebook, guaranteed one of your female friends will have one. And you would be surprised how many people hang on to broken stuff! I asked once and ended up getting 6 hairdryers lol, enough for a lifetime of cutting 😂
I used stainless steal wire from a 100 yen store (dollar store), it's probably intended for craft working but it has high resistance, so heats up easily when connected to DC power supplies such as charger bricks.
Considering the "professional" ones cost upwards of $300,.. VERY handy video! I have a stack of guitar strings,.. easy wing sections here I come! Thanks very much. :-)
Thanks for the variable resistance trick, I've had sleepless nights wondering if that would work, great to have visual confirmation, gonna make this for some cement moulds I have in mind, any tips on how you can glue polystyrene foam pieces together?
Sweet this uses more things that i have on hand vs other videos that suggest transformers and such. But what did you use exactly in your sliding piece you mention it, but it just looks like wood there on the side...
@@ArnoldsDesign thanks I rewatched it and figured it out. I was glad you mentioned stainless steel, I tried to find other types of suggested wires and that was the only one sold at a store near me.
Great tutorial! You mention covering it with fibreglass - I tried this years ago and it melted the foam! I was using white expanded polystyrene that time, I just wanted to double check what type of foam & fiberglass you use that work well together?
Thanks! You can cover polysterene with fiberglass, but make sure to use epoxy resin. Polyester, and vinyl ester resins will melt the foam. They won't melt urethane foam, but you can't hot wire it, because it releases toxic gas. I has to be cut and sanded (with good respirator). The foam I use in the video is polystyrene, I think 2 lb/cu ft. You can use the green foam too from the building supply, or pink Foamular, concrete form foam, and boat flotation foam. I don't know your application, but I wouldn't use the stuff made of the little balls pressed together. It doesn't have the density and compression strength to safely build an aircraft, unless it's for RC craft. You can get epoxy and E glass cloth at Wick's Aircraft, and Aircraft Spruce and Specialty.
@@cybair9341 I swear someone else had a video with jumper cables and a battery and that's it.... I was looking for that video when I found this one. It's no big deal to me either way, I have both a battery charger and a spare battery+ jumper clamps... I just thought the other one seemed simpler, maybe they used a different kind of wire🤔🤷
@@elisa7joy9 - If you use nichrome wire from hobby shops, it is a resistance wire that limits the amount of current and could be used directly from a battery. You'll have to google that.
Fantastic. This is exactly what I've been looking for to cut out progressively sloping pieces of 3-4 inch wide foam. Do you think polyisocyanurate would be safe or must I use another sheet foam?
Funny how you only now do that. The first wing I did was for a robbe rasant. That was in 1974... ancient tech. We used copper wire, Styrofoam. Gradually changing profiles, simply because we could.
@@ArnoldsDesign there was a little more to it, when you cover the core, even with 1.5 mm balsa, the strength genrate is greatly improved. The planked wing would withstand high g-forces, that plane could take a 6.5 cc engine spinning a prop in excess of 18.000 rpm with a fuel with 30 percent nitro. Instead of a 4cc engine.Those were fun times wondering how far you could go. 😊
You could try it, but it still might be too soft and the wire might dig in or burn. The best I've found is the thing laminate they use to resurface countertops.
What do you mean by compound? I don't know if this is what you mean, but say if I want to make a tapered wing with a twist, you can do that fairly easily, but you have to cut faster on one end than the other, which takes a little practice.
Small world ! I watch your vapor blasting videos. Now I come across your videos when I'm researching foam rc airplane construction.
It's a horrible design man. So many people copy other people's 'tutorials' that it kills me. I'm not saying this guy does it. A bench supply can be had for 40 bucks on amazon as well. Anyone who builds anything should have one.
I haven't played in the RC sailplane world for over 18yrs....I'm actually looking to get back into it now that I am retired, hence finding this video. Not sure if you're familiar with the original feather cut machine but you can easily mimic the concept, add a wheel to the back of the bow and let gravity make the cut for you. You'll need to add a sliding scale type pulleys on the edge of your table but I can assure you it'll be easier than trying to run that bow evenly by hand. Thanks for sharing your power source!!!
perfect time for me to stumble across this video. As of yesterday I decided to make a hot wire foam cutter and while looking for a power supply I found a battery charger that has a control on it to select 2-6amp 6-12v and was trying to find out if it would be usable for my needs.
It works well. The natural resistance of stainless steel also help dialing it in.
What a great presentation you’ve given us. The wing product looks amazing and your explanation was top notch. Thanks so much.
Great info! I had all the items but I didn't know they could be used for this! The SS welding wire I used is.025" and a Sears battery charger set on the 10 amp charge section. It cuts 2" foam fairly easily. I set mine up to work with my table saw fence so I can cut long straight pieces. Had to make an overarm clamped to the edge of the table saw, but still built within 4 hours start to finish. Thanks so much for the info!!!!
I remember my grandfather using dense foam and hot wire cutting back in the early 90's along with vacuum bagging
Nice work, thanks for the explanation, the using more wire in the circuit to vary amperage is so simple its genius. as far as those little variances in the wing... there have been lots of models that flew just fine with WAY worse!
That's a great design for the application. I am curious if you thought of measuring the hot wire heat once you achieved your cutting temperature. I believe the length of the wire dictates the actual resistance. So different wire length will change the resistance which will change the current value needed. If you know the cutting temperature needed for that type of foam material you can use an infrared thermometer to adjust the current until you reach the appropriate temps so no trial and adjust cycles for future use. Either way it's a great design.
This is amazing that you can make such a smooth wing.
My dream is to design a semi glider with STOL properties and a powerful motor.
Thanks for sharing your basic tools.😊
Really impressed with how easy Arnold makes this seem. Great video.....very clear.
Thanks :)
Sweet project. Lots of good information there. I suppose if you wanted to make wing taper your outer pattern would be smaller and placed forward to keep the leading edge straight or back for a trailing off leading edge. I can see running the wing through a table saw on an angle to make a dihedral wing. You really got my creative juices flowing. I would build one with a motorized feed table to control the feed rate exact through the foam.
You got it. There are gravity feed designs online, you use pulleys and a scaled bar to adjust the speed of each side of the cutting wire as it's pulled off the table by a small weight. You want the wire to cut through each end of the foam blank at the same speed, so if you have a tapered wing you use the pulleys and some math to adjust where the strings attach to the swing arm. Pretty neat. There's a neat article about it in this old magazine - www.rcsoaringdigest.com/pdfs/RCSD-2008/RCSD-2008-11.pdf
K.I.S.S. right there! The tip with the welding wire is genius, it opens up a wider market if your local home depot doesn't have NiChrome wire.
Btw: professional shops are using CNC hot wire machines and controlling temperature & feed so they don't get waves in the surface. I've build a few flying wings made of EPP RG25 and RG30 and the cut wing halfs were always perfect. They are always shipped with the whole block to prevent damage and the wings were cut on one go. I guess they've found out what works through trial & error... ;-)
Thanks for you comments!
Just a note about ventilation. The bad smell you talk about is a very dangerous gas. Long term health hazards may result. Suggest you add a note about using your rig in a well ventilated area. Same goes for sanding foam without a mask. Very informative video. Thankyou
Great video. Subscribed so I can come back here and watch it again when I am ready to make my wire cutter.
Admirable craftsmanship. Nice tutorial!
I’m currently thinking of building a hot wire cutter. I wasn’t sure what I should use for a power supply. I have a battery charger similar to yours. …. I have found my power supply!
Cool
As for the alignment issue; try constructing an arm/lever/guide to restrict the cutter from getting out of side to side alignment.
An arm with hinges to allow only front to back and up/down movement?
Kinda like a radial arm saw.
for control the temperature of wire can use a brushed esc with servo tester
Can you help me understand what this would look like?
great video but man, I could really use to know what power supply you used??
Remember he said battery charger.
Made one the other day. I used a power supply from an old massaging chair cover thingy. Output is 2AMPS and it cuts fine along the length of the wire (8 inches). I'll be using it to make molds to cast knifes and handles. Nothing big like you.
best diy foam cutter video
Cool, this technique seems so simple and effective than even I can do it
I have no doubt.
Arnold's Design I reuse old broken hairdryers, if you ask your friends on Facebook, guaranteed one of your female friends will have one. And you would be surprised how many people hang on to broken stuff! I asked once and ended up getting 6 hairdryers lol, enough for a lifetime of cutting 😂
if you make the tamp let 2mm bigger you have a bigger error margin,and nicer surfes in the end after sanding👍,longer sanding block is good to
Interesting! I've got a 4'x5'x12" block of foam that I need to cut in half. I think this might do it.
I used stainless steal wire from a 100 yen store (dollar store), it's probably intended for craft working but it has high resistance, so heats up easily when connected to DC power supplies such as charger bricks.
That is just what I was looking for. Thanks
You have a gift for teaching - subscribed.
Thanks
Great job. Could you please tell us if you were using a LiPo charger to heat the wire and how it's done. Thanx.
It was just a 12v car charger for lead acid batteries.
Considering the "professional" ones cost upwards of $300,.. VERY handy video! I have a stack of guitar strings,.. easy wing sections here I come! Thanks very much. :-)
Thanks!
Hi Arnold, I would like to know the build steps that you followed to build this cutter, can you please share them if so possible. Thank you!
Thank you for explaining in such an easy to understand video 👍
Great cutter and loads of handy information. Many thanks indeed.
Fantastic dude superb explanation
Guitar strings work fine ehehe
You just made my day, GREAT JOB thank you very much ⭐️⭐️⭐️⭐️⭐️
wow cool very interesting thanks for showing the styrofoam hot cutter.
Thanks!
hi great job. how many milli millimeters of nickel wire did you use and what is the voltage. what kind of foam do you use?
.76mm, 12v, styrofoam insulation board. Thanks
Really excellent video. Thank you
Thanks for the variable resistance trick, I've had sleepless nights wondering if that would work, great to have visual confirmation, gonna make this for some cement moulds I have in mind, any tips on how you can glue polystyrene foam pieces together?
Super video!
It's what I was looking for.
Thank you!
i used vaping coil wire. There is a calculator online to configure wire size, length and current.
Thanks for the info friend!
Nicely done.
What type of phenolic for the template? Like Garolite? I've used that for electrical boards.
@@ArnoldsDesign don't know the brand name(s) but yes, the same type of material used for circuit boards.
Sweet this uses more things that i have on hand vs other videos that suggest transformers and such. But what did you use exactly in your sliding piece you mention it, but it just looks like wood there on the side...
There is a stainless wire that goes up the side of the wood. You slide the alligator clamp up or down the wire, and it changes the heat in the wire.
@@ArnoldsDesign thanks I rewatched it and figured it out. I was glad you mentioned stainless steel, I tried to find other types of suggested wires and that was the only one sold at a store near me.
@@elisa7joy9 Yes, it's just .030 inch stainless welding wire for a mig welder. ER308L alloy, but any stainless wire should work.
Like your veritable heat control
Great tutorial!
You mention covering it with fibreglass - I tried this years ago and it melted the foam!
I was using white expanded polystyrene that time, I just wanted to double check what type of foam & fiberglass you use that work well together?
Thanks! You can cover polysterene with fiberglass, but make sure to use epoxy resin. Polyester, and vinyl ester resins will melt the foam. They won't melt urethane foam, but you can't hot wire it, because it releases toxic gas. I has to be cut and sanded (with good respirator). The foam I use in the video is polystyrene, I think 2 lb/cu ft. You can use the green foam too from the building supply, or pink Foamular, concrete form foam, and boat flotation foam. I don't know your application, but I wouldn't use the stuff made of the little balls pressed together. It doesn't have the density and compression strength to safely build an aircraft, unless it's for RC craft. You can get epoxy and E glass cloth at Wick's Aircraft, and Aircraft Spruce and Specialty.
use epoxy instead of polyester resin on foam
One thin coat of pva paint on the foam first then u can put almost anything on it 😉
I have used guitar strings with success along with a 12V 2A battery charger.
Can you just use a 12v battery? Connect clamps to each terminal?
@@elisa7joy9 - No, you can't connect directly to a battery because there is no resistance in the circuit and the wire will become red hot and melt.
@@cybair9341 I swear someone else had a video with jumper cables and a battery and that's it.... I was looking for that video when I found this one. It's no big deal to me either way, I have both a battery charger and a spare battery+ jumper clamps... I just thought the other one seemed simpler, maybe they used a different kind of wire🤔🤷
@@elisa7joy9 - If you use nichrome wire from hobby shops, it is a resistance wire that limits the amount of current and could be used directly from a battery. You'll have to google that.
Nice work. i am using This beekeping make hive. God bless you.
Excellent !
You should put affiliate links to the stuff you used that will bring some income your way and help others find the supplies.
Good idea
Yes. Guitar strings are stainless steel and nickel . Plus I play guitar so it's just available lol
excellent video. Very clear. Liked and subscribed.
Thank you :)
Can it cut furniture foam padding like couch / chair cushion..guess polyurethane 😊
Very interesting and well explained. Simply practical. Thank you.
You can make a sanding block to ride your template. Nice tutorial. Is the wire that you use for varying the resistance, the same as the heating wire?
Yes
Excellent video, thank u for sharing
I never could get it to work so I just tried to wired to a see clamp on the other end of the table and cut tapered wings by pivot from now on
Wow😮 free handing it!
Good show. Which grit number sand paper is recommended for sanding of wings?
I don't recall. I think I just used 150 or similar.
Very clever design! What size stainless wire (resistance) are you using?
Fantastic. This is exactly what I've been looking for to cut out progressively sloping pieces of 3-4 inch wide foam. Do you think polyisocyanurate would be safe or must I use another sheet foam?
I think hot wire cutting polyiso can produce hydrogen cyanide gas. I'd stick to polystyrene.
Very nice!
Great Video!, Have you considered using a light dimmer switch on the input of the battery charger to control the charger's output ?
Thank :) I haven't tried the dimmer switch.
@@ArnoldsDesign don't try it. It will not work. Dimmers work on basics of ac cycle chopping which won't work with DC.
very nice
Thank you!
what kind of the foam is it? Where can I buy? Thanks!!
Great video nice job!
Thanks
Sanding Stick. You can buy them pretty cheap or you can make them yourself even cheaper.
Variable resistor. Ha! Excellent!
Thanks :)
Nice cutter sir
Thank you
Wow absolutely genius, great job, I love it,
Thanks!
Like to see you cut out foam for a rifle case
You did a good job
Thanks
Great video! Will it also work if I use 12v Ac/dc adapter with a 5amp output? Thanks
Yes
Can you cut an airfoil onto a Delta shape design the same way?
LR
Yes, you would have to cut two half spans and glue them together.
Hmmm... okay
please suggest me the material that I can use to laminate this foam after cut-out
Good job.
The BEST way to cut wing cores is with TWO people. one on each end. One of the operators will call out the stations.
Yes, that's what I understand.
How do you put spar in them now ?
What if you weren't near a power source though. How could you modify for a battery?
Connect to a 12v auto battery. Same voltage as charger.
@@ArnoldsDesign thanks. I appreciate the reply!
Funny how you only now do that. The first wing I did was for a robbe rasant. That was in 1974... ancient tech. We used copper wire, Styrofoam. Gradually changing profiles, simply because we could.
Yes, it's ancient and heavy, just like me.
@@ArnoldsDesign there was a little more to it, when you cover the core, even with 1.5 mm balsa, the strength genrate is greatly improved. The planked wing would withstand high g-forces, that plane could take a 6.5 cc engine spinning a prop in excess of 18.000 rpm with a fuel with 30 percent nitro. Instead of a 4cc engine.Those were fun times wondering how far you could go. 😊
great!!🤜🤛
great video sir !
Thank you.
man that work lamp is killing me
Is there any reason you couldn’t use heavy cardboard for your templates?
Like the stuff you get at the dollar store to make posters.
You could try it, but it still might be too soft and the wire might dig in or burn. The best I've found is the thing laminate they use to resurface countertops.
All you need is a dial based house light switch.
yeah
I use no. 1 electric guitar string with success.
And a 15V 1.5A transformer.
Got a question for you Arnold. With a wire cutter can a compound curvature be cut? Is it possible?
What do you mean by compound? I don't know if this is what you mean, but say if I want to make a tapered wing with a twist, you can do that fairly easily, but you have to cut faster on one end than the other, which takes a little practice.
Hot wire was the parent of lazer products.?
where can you buy the blue foam in England
Hardware store.
It's insulation foam called 'xps foam' where I live.
awesome
Excellent , wha size of stainless steel welding wire?
Jim "P"
I think it's just my .030".
What foam are you using?
High density polystyrene.
@@ArnoldsDesign thank you!
@@Decadence1 You bet bro
You can get nichrome in Amazon.com.
How bout a cheaper dimmer switch knob?
Would probably work.
Will not work. Dimmers chop ac waves to be said simple. It will just burn on DC
right, low cost. So R = E / I. What is R ?
I don't know. I flunked algebra, and was high most of the time when we were taught basic dc circuitry in physics. I flunked physics too.
Especially when the wire gets hot.
Cyanide gas? Isnt that what they use for executions?
Well let me get my huffing bag. 😂
man i was cutting polyurethane just yesterday guess I wont do it anymore lmao
@@filippo9185
Its had no effect on me. Why, just the other day I was cutting some polyurethane and
@@AngryHybridApe idk actually I realized that what I cut wasnt polyurethane but It was instead polystyrene
Vape supply shops sell that wire.