Megabar Plug is cut
 

This winter I started a new plane called the Megabar...
The Isobar is ~80 inches long and the Megabar is 90.
The wings will be the same, along with the weight (I hope),
more room inside, very accurate plug for the molds and better fuel tanks.

The pics below are what I did today at the machine shop.
Darren (owner) and I cut the pug for the front hatch from
6 layers of MDF wood. We used 1 inch ball end mill, CNC
mill, 70,000 lines of code (G01s) to get the most accurate
plug possible.

Over the last month, I learned a program call Solidworks
that I used to design the plane. (pic below) From this
drawing Darren ran another program called Surfcam witch
produced the 70,000 lines of machine code.

It took around 4 hours, at 90 inches/min at 7100 rpm with
the 1" ball end mill to cut the front hatches.....

Eddie Weeks
http://www.corpcomp.com/weeks1/

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all the parts that need to be cut

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Its now cutting the finish cut on the right front hatch

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This is what the mill started with...

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Here is the hatch finished....

Solidworks
 

That is cool I have a interactive disk about Solidworks I may buy it soon.

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Halfway into the roughing


More pics at

http://www.corpcomp.com/weeks1/

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Eddie,
Wow, You've come a long way from whittling Isobars out of boat dock pontoons! Keep us posted.

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Hi Eddie, it looks great, but what is worse learning solid works or the dust from the MDF? I will be upgrading to the latest version of solid works but the program still has a lot of dead ends!What type of file are you exporting to your cam program ? Who sells surcam,looks like I may look into it?
Brg,
Don

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Hi Eddie, it looks great, but what is worse learning solid works or the dust from the MDF?

One just takes time and the other takes a large shop vac....
I was really worried about the dust at first but for the
4 hours of cutting I sat there holding the shop
vac right by the cutting head. Next to no dust left the
machine.


What type of file are you exporting to your cam program ? Who sells surcam,looks like I may look into it?

Surfcam reads Autocad, DFX, Solidworks, Parasolid
and a lot more..

http://www.surfware.com/index.htm


Once in Surfcam, you simply pic the tool, depth of cut,
and a bunch of other stuff, and It will tell you how long
it will take, show you the tool path, and write the
machine code... btw.. Surfcam is only $25,000

Eddie Weeks

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Solid works at 6,000.00 seems like a bargin compared to that! Ouch!

Wow...
 

If you look in the dictionary under "jealous", you'll see my picture.

"Sanding is my life".

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If you look for a new COA software, dont look at entry level one i.e : SolidWork, SolidEdge, Inventor. Since about a years the big CAO system Are about the same price(about 1 to 1.5k$ more) and they have alot more to offer. We use CATIA V5R9 with CamPost post-processor and we are very happy with it. I'm about to mill parts for mw54 turbine ( diffusor). My only concerne by now is that i will use 4 axis for the first time ;)

Machining
 

I've been using Inventor and Solidworks for some time now. Surfcam is great too. This is what I been drawing for the past couple of weeks. Will you cut me one of these too.

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Here is another one.

Name ?
 

Great job Eddie - but are you sure about the name ??

I mean - the project looks really cool, and I am envious of the neat tools you have... and all that kinda good stuff ... but the name sounds like some kind of health-food snack that you'd buy at GNC ;) You're not sponsored by them, are you ? :eek:

Gordon

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Nice work! I did that too a 2 years ago from KJ66 plan on Inventor. I'm a CAO teacher and we used Inventor. Now we're on CATIA V5. I'm doing the MW54 by now (i deleted all my Inventor stuff ). I think that Your compressor look better than mine ;) I did one but it is simplier. Now i'm at work so i will post some pics of my work tonight.

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Cool, I dabble with it on occasion. I have a full helicopter drawn in inventor to scale about 1000 parts. The compressor is pretty close to scale. That was the most challenging with that type of sweep. My intention were to do what Eddie is doing, cnc cut some plugs for production. I have a bunch of scale models of jets that would make some great aircraft. Just finding a cnc machine to do it is the problem $$$. I'm working on building my own large scale CNC router.


Barclay

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Yeah the most difficult part to do is the compressor. I did mine in the surface module ( you dont have that in Inventor) My compressor have the real outline but i did the 'impeller' right from my mind ;) ( i dont have one, so i looked at pictures)

Machining
 

I've been using Inventor and Solidworks for some time now. Surfcam is great too. This is what I been drawing for the past couple of weeks. Will you cut me one of these too.

CADCAM
 

Hi All,
If you are lucky enough to have these mega packages available it sure makes life easy. We use Mastercam for solids but I can highly recommend a cheap alternative for 2.5d milling (.dxf) and 3d milling using stereolithograpy files (.stl) from solids. Its only $200 and beats the pants of many more expensive options for ease of use. Check this guy at http://www.deskam.com Also some resources for making your own CNC router. Use it free for 30 days!
Cheers
Andre

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Here's my pics

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Another one of the diffusor

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Lets see if my thumbnails will work this time

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Hi Eddie, looks great.

What finish is the best for an MDF plug? What will give a hard stable surface but thin enough that the accuracy of the CNC cutting will be retained?

Will you just put resin or will you glass it? How thick of glass could you go for before you screw up the outside mold lines?

Scott Black
Montreal

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Thanks for all the great comments..

I have been thinking about the finish for a while
and I really don't know... Maybe someone could
help me out here.. I was just thinking of painting
it with thinned exoxy and then see what I get..
I don't plan on putting glass on it. All this mold
stuff is new to me..

Eddie

Mega Bar
 

When I saw the title to this thread and then saw the author's name I thought that we were in for a new addition to the Eddie Weeks custom trailer----A MEGA BAR where those Louisiana rum drinks flowed freely and all the mud bugs you could eat. I must say....I'm deeply saddened. :cry: :D

Eddie---Good luck with your new project. It's looking great!!!

Kevin

PS---I got the outer case off of the Merc with no problems after your help---Thanks!!

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A friend of mine has built an NC router with MDF as the frame material. He finished it with some sort of clear coat and said that it was incredibly thirsty stuff - it just kept sucking it up. He will try some parts that I have lofted and I personally would go for epoxy resin and hit it with a heat gun. That makes it get really thin so it can soak it, without watering it down which sometimes affects the properties of the resin. I would do that until it stops soaking in, then it it with a good primer - either an automotive 2 part or one of the polyester ones like Featherfill or Duretec which take a catalyst and cure rock hard so as not to be affected much by heat.

Please keep us posted on how it works out.

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Eddie,

If you can rustle it up, it might be worth trying the UltraPoxy Primer. This is the new stuff from K&B.

I have used it and it seems to have a high solids content and cures rock hard. Hard work to sand if you let it sit for more than a week though.

Regards,
Garrett

getting ready to cut formers
 

Eddie Weeks

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Eddy, go to your auto paint store and get some Evercoat Polyester Feather fil Primer. sands like butter. I use it and a comercial product that is the same except you have to thin it. The featherfill is already thinned and all you add is the cataylist. (Mek)

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I starting stuffing the Megabar with parts. I am using
the Isobar Wing plug in system. It took a long time
to get to this point but its starting to pay off.
I design two 67 oz fuel tanks that I know will fit.
(the one in the pic is ~40 oz)

Using Solidworks I was able to make a very smooth
intake, and a bypass that will hold an AMT450.

Eddie Weeks

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I spend all day at the machine shop cutting
the plug for the back hatches today. Here is
a small video of the final cut of the right side
back hatch.

RPM 5100, Depth of cut 0.062
Feed Rate 200 inch/min
Cutter: 2 inch Fly cutter with 4 carbide inserts


www.corpcomp.com/weeks1/movies/Back_Hatches.WMV

Eddie Weeks

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Roughing out the hatches...

0.400 depth of cut...

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Finish cut

Solidworks
 

Hi Eddie

Great project. A few of questions

1.) I assume you are doing all of this on a 3 axis mill. Is this mill special made to do this type of work (ie lighter duty cause all you are cutting is foam or wax or wood...etc.)

2.) Did you think about directly cutting the female molds? I can see how with a 3 axis that might be hard.

3.) Solid works. I assume you used the lofting command a lot. How did you decide where to put the guide points for the loft on each cross section? I keep looking for software that will do this like magic, but it looked to me like with Solid works you have to do it manually.

4.) How did you design that bypass? If you ever want to offset some costs I will buy one from you. What is the inlet diameter?

You really need a P-200 for that :-)


Anyway very impressive work.

Re: Solidworks
 

1.) I assume you are doing all of this on a 3 axis mill. Is this mill special made to do this type of work (ie lighter duty cause all you are cutting is foam or wax or wood...etc.)

No.. the mill is a standard metal cutting mill... When it was
new, it went for ~$100,000... You can get the same mill
now for ~$50,000

2.) Did you think about directly cutting the female molds? I can see how with a 3 axis that might be hard.

yea.. we were going to cut the mold itself, then I got
a price for an aluminum 90"x13"x7' and bout fell out...
and they would be too big and heavy to vacuum bag.
I was told that building a few molds was not that big
a deal...

3.) Solid works. I assume you used the lofting command a lot. How did you decide where to put the guide points for the loft on each cross section? I keep looking for software that will do this like magic, but it looked to me like with Solid works you have to do it manually.

Your right.. Each cross section has 8 points... no more. no less
The #1 point on cross section A must line up with #1 point
on cross section B... There are no guide curves.

4.) How did you design that bypass? If you ever want to offset some costs I will buy one from you. What is the inlet diameter?

I just plan on making a few planes, but with the very
low part count, I may make a builders kit. (builder does
a lot of work)

I drew a AT450 (the biggest turbine that it will fly with)
and then drew a nice smooth curve around it. That's it.
I made sure to leave 0.750" gap.. No big deal..
All other turbines will just have more room.
It will most likely fly with AT400s or P160-P200
if we can get them.

I should be flying the first plane in 4-6 months, I will keep
this thread updated, but you are the first on the list to get one...

Thanks again
Eddie Weeks

Slow down son!
 

I just want one of the giant bypasses not the plane! I don't have room for another kit!!

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I just put this together

~10 meg

its a 55 sec movie of CNC cutting MDF (wood)

http://www.corpcomp.com/weeks1/movie...ck_Hatches.WMV

Eddie Weeks

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Here are two intakes that I designed for the Megabar..

Witch one do you think would work better. ?

One, with more less constant area or one with lots
of area.

Eddie Weeks