Fellow hot wire foam cutters, please feel free to weigh in.

[cyclone3350]

I am currently building a 1/5 Gee Bee Sportster using old school methods with a foam core wing. This is my fourth but most challenging wing to date. I am pleased to say that so far, this cutting method I've used worked out very well. I am sure there R many cutters out there & many more who R interested in doing the same. So I am hoping by posting this thread, others will weigh in with their experiences as well. First, I would like to describe the equipment that I am using & how I would rate them. Being new to this process, all I can say, is, that I am very satisfied as to how these cutters work. The first is my table cutter that I bought from EBay. I cannot remember the exact listing I bought this from, but this one has the same specs as mine. https://www.ebay.com/itm/143610667439?hash=item216fdce1af:g:PWkAAOSwDkVaD1Ie The bow cutter I built using instructions & parts from Jacobs Online. I have it set up to operate a 30" & an 18" bow. I have nothing to compare it to, but I just think that this one is the bee's knee's of amateur cutters. Here is the video

The next set of photos R my first 3 attempts of cutting out foam wings The first 2 R small 24" WS and the last one was 54". For the racer and the pattern plane, pink foam was used. The F5 propjet is Hobby Lobby craft foam. The racer had a wide balsa strips glued to the LE & TE with thin strips in between to simulate ribs. Microlite covering & WB paint for the yellow is what finished it off. This is the method I am going to use on the Gee Bee adapted for a larger scale. The F5 is fully sheeted & the pattern plane is WB topcoat fibereglass over pink foam with WB paint. These wings were fairly easy after a some trial & error. Straight lines for the LE & TE, rib patterns pinned to the sides, & follow through with the bow. The Gee Bee has semi elliptical rounded wing tips. I did this one by dividing the wing into 3 sections. The straight LE & TE as one, & then I did the tips into 2 & made the curves into straight lines for the hot wire cutting. I then taped the sections together & cut the curves back into the wing with an Exacto Long carving blade. U can see how well the sections lined up & the symmetrical step down from the different size ribs to the tips. I hope that @wilmracer has some his experiences to share. He is doing a giant 1/9th B-17. He did his wings using a box method that is just beyond amazing.

 

[Taildragger]

Yes! This thread should be full of good information. Hoping to get into hotwired planes this summer!

 

[Ligbaer]

Yes! This thread should be full of good information. Hoping to get into hotwired planes this summer!

im hoping do it for builduary

 

[Taildragger]

im hoping do it for builduary

my howire projects can't be done in one month....

 

[Ligbaer]

my howire projects can't be done in one month....
View attachment 216079

now i want to see if it could be done in a month

 

[cyclone3350]

For those who want to do the smaller models, I bought this from Hobby Lobby years ago. It does table cutting & is removable for bow cutting. It is small. I did the Cassutt & f5 with it. The little birds had the wings using 4 pieces.

 

[Taildragger]

my howire projects can't be done in one month....
View attachment 216079

Well I made this as a joke but now I'm seriously considering it, Time for a first giant scale

 

[cyclone3350]

Well I made this as a joke but now I'm seriously considering it, Time for a first giant scale

Gotta do a biggie. They fly so well. But be warned, U won't wanna go back to small.

 

[Taildragger]

Gotta do a biggie. They fly so well. But be warned, U won't wanna go back to small.

I don't really intend to, just keep the small ones for fun or cramped spaces
I actually plan on getting my PPL right after graduation from high school
today I was given the offer to buy a part 103 bush plane... so tempting but it was 15k so easy choice because I don't have the funds

 

[cyclone3350]

I don't really intend to, just keep the small ones for fun or cramped spaces
I actually plan on getting my PPL right after graduation from high school
today I was given the offer to buy a part 103 bush plane... so tempting but it was 15k so easy choice because I don't have the funds

Back in the 80's, I was kinda in the same shoes as U when I was 20. I had just finished my PPL & had put away about 5k. I came across this Champ in excellent condition for 5500.00. I was about to buy it, when my current mode of transportation took a dump & decided I needed wheels more that wings.

 

[Bo123]

What kind of things to you guys use for the wire on a hotwire cutter. I have always been wanting to make a cutter, however I didnt want to use that wire that is used in e-cigarettes. I have heard that guitar strings might work, but I'm not sure about this.

 

[Taildragger]

What kind of things to you guys use for the wire on a hotwire cutter. I have always been wanting to make a cutter, however I didnt want to use that wire that is used in e-cigarettes. I have heard that guitar strings might work, but I'm not sure about this.

steel hanging wire, like tkor

 

[cyclone3350]

What kind of things to you guys use for the wire on a hotwire cutter. I have always been wanting to make a cutter, however I didnt want to use that wire that is used in e-cigarettes. I have heard that guitar strings might work, but I'm not sure about this.

This where I buy my wire from. https://jacobs-online.biz/nichrome_wire.htm I've been using the nichrome 60 26 gauge. They also carry kanthal which is suppose to make smoother cuts. I will probably be ordering this sometime in the near future,

 

[wilmracer]

WAY back @willsonman did a class at Fite Fest (they trialed a Flite Fest University thing in 2016 I think). I put together an article, available HERE: LINK on the bows that we built and used, including a materials list. I still use these bows and that charger to operate the hotwire and they still work great. Only had to replace the wire a few times, mostly when the bow sat unused for a long time and the wire corroded.

These are cheap, simple, and work great for cutting just about anything. The scroll-saw versions are really great too, particularly for cutting formers and pieces where you want a consistent 90* cut. I had a commercial one for a while that burned out. These days I just use a scroll saw and deal with the rougher edges and dust. I figure dust vs. fumes... its a toss up which is worse.

Also, while I like using solid cores there is another method (box method) that has some cool advantages.

 

[Taildragger]

I figure dust vs. fumes... its a toss up which is worse.

A good construction mask w/ filter can solve both I believe

 

[wilmracer]

A good construction mask w/ filter can solve both I believe

Agreed. And if possible I'll leave the shop door open when using the bow, and run the air cleaner either way. For those of us with bad allergies it is wise to plan ahead and then go straight to the shower when you're done cutting

 

[Taildragger]

Agreed. And if possible I'll leave the shop door open when using the bow, and run the air cleaner either way. For those of us with bad allergies it is wise to plan ahead and then go straight to the shower when you're done cutting

allergies to what?

 

[wilmracer]

allergies to what?

Me? To long to list... damn near everything. Really sensitive skin as a result. I take meds daily and I'm generally fine but too much exposure to balsa or foam dust and I get eczema and my eyes puff up and look like I've been on a bender for days...

 

[cyclone3350]

WAY back @willsonman did a class at Fite Fest (they trialed a Flite Fest University thing in 2016 I think). I put together an article, available HERE: LINK on the bows that we built and used, including a materials list. I still use these bows and that charger to operate the hotwire and they still work great. Only had to replace the wire a few times, mostly when the bow sat unused for a long time and the wire corroded.

These are cheap, simple, and work great for cutting just about anything. The scroll-saw versions are really great too, particularly for cutting formers and pieces where you want a consistent 90* cut. I had a commercial one for a while that burned out. These days I just use a scroll saw and deal with the rougher edges and dust. I figure dust vs. fumes... its a toss up which is worse.

Also, while I like using solid cores there is another method (box method) that has some cool advantages.

Thank You for weighing in! I've set this up in the hopes that this thread could be a one source wealth of info on foam cutting. BTW, is the Sweet Pea build current or have U made any more progress not listed. For balsa sheeting foam, what is your glue of choice?

 

[cyclone3350]

Thank You for weighing in! I've set this up in the hopes that this thread could be a one source wealth of info on foam cutting. BTW, is the Sweet Pea build current or have U made any more progress not listed. For balsa sheeting foam, what is your glue of choice?

I found my answerer in your wing viseo #3.