CNC cut foam cores

[EZ AHAB]

I recently built a CNC (computer controlled) hotwire foam cutter specifically for cutting foam cores for EZ and Cozy wings. I also digitized the templates for the wings and Roncz canard for the same aircraft. I haven't done the winglets or VEZ templates yet but I certainly could. I have original templates for all 3 aircraft.

 

I originally built this machine to cut my own wings but I was wondering if there would be much interest from others in the community in getting CNC cut cores. CNC cutting eliminates a number of problems inherent in cutting by hand and produces excellent and repeatable results. I haven't yet decided what I would charge for this service but the first 1 or 2 would probably be for only a little more than material costs. That will give me the opportunity to work out actual costs and shipping issues. After that, I'm thinking it will be somewhere around $1000 for wings, winglets, and canard depending on material costs and the actual amount of labor involved.

 

Anyway, right now I'm just trying to decide if there is enough interest to do this at all. Please let me know if any of you would be interested.

 

Thanks

[Jon Matcho]

I'd be interested in what your CNC machine looks like. I was tempted to make one myself, but that was just a daydream while surfing some CNC hotwire web sites. Personally, I have my wing foam.

[tom rodgers]

Color me in for at least a canard core! I think you could provide a valuble service to the canard comunity. we have been losing to many contributors.

Ps. this my first post to this board. I us to post on the ez squadron but it seems to be lost to spam.

Tom

Long ez getting closer at a real 90 percent

[EZ AHAB]

Here are some photos of my machine, some 1/4 scale EZ cores, and a full scale sample of a Roncz core.

[Jon Matcho]

VERY nice! I concur with Tom -- it would be a great service to the community if you could provide. I'm looking forward to doing my own, but I do know that many would appreciate the precision of a CNC machine. Great job!

 

You also reminded me why I didn't want to make a hotwire CNC machine (they're too big).

[jany77]

nice job i m interested in long ez core for wings and canard let us know the availabylity and pricing thank you

[jprock]

You might contact Velocity about your CNC machine. They

may buy or rent it off you. They still cut all their cores

by hand.

 

Jack

[Phil Kriley]

I would be interested! I don't think I could do as good a job by hand! I'm only on Chapter 6, so it will be a while before I'm ready to buy the cores, but when the time comes and if the price is reasonable then I would be interested.

[airwrench]

how much for the canard cores complete?

[EZ AHAB]

I'm not quite ready to set prices yet. Featherlite charges $1685 for a full set of cores and AeroCad charges $1520. I know AeroCad still cuts them by hand and I wouldn't be surprised to find Featherlite does too. I should be able to do it for substantially less depending on the actual amount of work involved and the price and availability of the raw materials. I've never had the chance to look at AeroCad or Featherlite cores to compare but I do know that CNC cutting eliminates a lot of problems involved with cutting by hand. For one thing, it can totally eliminate wire lag problems since the wire speed is precisely controlled. It is possible to cut by radiance alone which means the wire never even touches the foam.

 

If anyone wants to let me give it a shot, shoot me a private message. I'd like to start with a canard. Just order (and pay for) the foam and have it delivered to my address. I'll cut the core, put all the pieces back in the original box and mail it to you. I won't charge you anything. Please just reimburse me for the shipping. The first one to take me up on this gets this deal. After that, I'll work out the real prices.

[EZ AHAB]

Oops, actually AeroCad charges $1930 for a complete set of cores for a Cozy, not $1520. I was looking at the wrong price list.

[Jon Matcho]

The first one to take me up on this gets this deal. After that, I'll work out the real prices.

I can send you a 3-4 billets (however many it takes) -- enough to cut 2 canard cores. How about cutting me two, get extra practice, and you'll have 2 potential positive references. Deal?

[EZ AHAB]

Jon,

 

You're actually the second response I've received so far. I'll cut you 1 or 2 cores anyway but everyone else wait till I get the practice to perfect my work and then I'll set some prices.

[Kraig]

I have a complete set of canard and elevator cores from Featherlite that are still unopened and in the box, (Cozy MK IV). I will be building with them sometime in Jan.

 

If you wanted me to compare yours to theirs, you could ship me a set and I could compare, photograph, and send them back to you, or on to whoever needs them.

 

Put me down as interested in your wing and winglet cores as well.

 

Kraig

 

505-280-5880

[EZ AHAB]

That sounds like an interesting idea. Maybe I'll just cut some short sections and send them to you. That way you won't have to send them back. I'm also interested in knowing how the Featherlite cores come. Are they ready for glass? Are they already cut in half spanwise for the shearweb? Etc.

[bhassel]

The results look great!

 

I was gong to build my own CNC machine for just that purpose. Here's a good starter link for you do-it-yourself-ers

 

http://www.8linx.com/cnc/cnc.htm

[EZ AHAB]

Yes, that's where I started. It wasn't nearly stiff enough to cut big wings with any kind of precision though. You'd also need awfully big drawer slides to to do EZ or Cozy wings. That design may work for models and it's a great way to start but it just isn't a practical design for full scale stuff.

 

Here's a link to my website where I describe my own CNC hotwire saga:

 

http://members.cox.net/ahabsworkshop/CNC.htm

[bhassel]

Nice setup! I knew that the stuff on the cnc link was for model wings but wasn't sure about the translation to real sized cores for our wings.

 

It looks like you've done some great testing already! Well done!

 

Bob

[EZ AHAB]

I decided to do some more testing on cutting full scale canard cores out of the small amount of Wicks polystyrene I have on hand while I wait for a couple of people to send me some more foam for their canards. This is the first time I have cut this type of foam in my machine. I decided to cut a 14" span canard core with a spar trough. This would be like a short section of the center section of the Cozy canard.

 

And the results.....

 

Absolutely perfect! Seriously, I can find no defects whatsoever. There is no sign of wire lag at all; the core matches perfectly with the scale drawing; there are no ridges; there isn't even any angel hair! I see no reason a core cut in this fashion would need any sanding whatsoever.

 

So, what's the next step? Well, a full span set of canard cores to start with, then winglets and wings. Winglets and wings will be more complicated due to the taper involved and a more critical setup but CNC should still excel since it can exactly deliver the correct speed ratio on each end.

 

So far so good!

[Jon Matcho]

Looking good! You definitely have a keeper here. Keep up the great work, and I look forward to the results.

[magnum]

I'll be ordering some cores later after the first of the year! Looks great! :banana:

Press on!

Tom

[velocity dreamer]

Im interested in the wiring details of your machine and which software you use. How do you transpose the plans templates to the machine. Do you have to plot many coordinates or can you scan them somehow.

 

thanks

Lynn

[EZ AHAB]

That's a pretty broad question. I've spent the last 2 years developing all the hardware for my machine, electronics included. I always have to do things the hard way:D If I had been working on my airplane instead of being distracted with CNC stuff, I probably would be flying my EZ and working on a Cozy by now.

 

Here's a link to my website with some photos of me etching the circuit boards: http://members.cox.net/ahabsworkshop/Electronics.htm

 

In essence I have a PC that sends signals to drive the 4 motors and the wire heat via the parallel port. This runs into a breakout board that buffers the PC against power surges in the CNC electronics (something I learned about the hard way:eek:) and breaks the signals out to each individual motor. Each set of motor signals then goes to a separate motor driver that actually runs the motor to the proper position.

 

As for software... after testing a number of different software packages I finally settled on GMFC Pro. It has the capability to do everything I need it to do without being extroadinarily expensive. It was "only" about $200.

 

As far as digitizing the templates goes, this has turned out to be rather complicated and time consuming. I can scan them and make the computer vectorize them automatically but it doesn't do a very nice job. It gets confused easily with all the text and such on the drawings. Instead, I've found the best method is to scan them and trace over them manually in CAD. After I have a vectorized version, I can print it out to compare with the original paper copy. This is a rather tedious process but, with a little tweaking, it gives excellent results. This works well enough for simply making a CAD version of the templates but there is really quite a bit more to it than this when you are building a digital template for use with a CNC machine, especially a hotwire. Then you have to take into account wire progression, kerf compensation for differing wire speeds and temps, wire paths, etc. I had no idea what a complicated endeavor this would turn out to be. The good news is that it works pretty well now. I have been very pleased with the results of late.

[avyator]

Velocity could use some precision. They suffering from a severe case of low tech.

[EZ AHAB]

I received Jon's foam yesterday and cut his canard cores tonight. Let the photos speak for themselves:

 

Bruce, I got your foam today. I'll probably cut the cores this weekend.

 

Steve