Rib DXF

[IAflyer]

Hello all! My name is Tim and I just purchased plans for a Bearhawk 4 place. I have built an Avid Mark IV and am now looking for something to fly my wife and kids in. I was able to create DXF files for the airfoil (rib) and was going to have a local shop laser cut the ribs for me so that I don't spend hours with tin snips trying to cut each one identical to the next. In the interest of cost savings, the more parts they cut out, the cheaper my price is. I was wondering if anyone else was getting started with a scratch build and interested in having the rib pieces cut out as well. Depending on the number of responses will determine the cost per person. I will split evenly between myself and anyone interested. Feel free to let me know!

[Dashry1]

Hello all! My name is Tim and I just purchased plans for a Bearhawk 4 place. I have built an Avid Mark IV and am now looking for something to fly my wife and kids in. I was able to create DXF files for the airfoil (rib) and was going to have a local shop laser cut the ribs for me so that I don't spend hours with tin snips trying to cut each one identical to the next. In the interest of cost savings, the more parts they cut out, the cheaper my price is. I was wondering if anyone else was getting started with a scratch build and interested in having the rib pieces cut out as well. Depending on the number of responses will determine the cost per person. I will split evenly between myself and anyone interested. Feel free to let me know!

I am interested however by transposing the measurements what will the accuracy be? I have had plans for about a2 years and am at the point to start construction.thanks Dugan

[rodsmith]

I wouldn't spend much money on getting ribs laser cut when you can buy all the ribs formed from Avipro for $2165 delivered.

[IAflyer]

Dashry1
I worked with a custom engineering and machine shop that has a special scanner. It has an accuracy of about .001 which is much more accurate than anything I could cut by hand. They scanned the mylar rib drawing provided with the plans.

Rodsmith
I appreciate the info but I am wanting to try and do as much as I can myself. I also know that the cost of material and cutting will still be significantly cheaper than the Avipro price (even though they are formed at Avipro).

[S Lathrop]

I would get an expert opinion on cutting the ribs with laser. You are burning the edge of the metal. There is a lot of stress on the edges as you form the ribs and I think you need clean, smooth edges to avoid forming stress cracks.

I cut all my ribs with a hand held router and a wood blank. I was able to cut the ribs, 3 at a time in just minutes and the the edges did not take a great deal of effort to finish. That was a fully cut rib ready tor the forming tools.

I use the services of a water jet cutting company for a lot of aluminum parts I make in my business. And for the same concern about the edges of the material, I did not even think about the water jet cutting process for the wings.

[Mark Moyle]

I would get an expert opinion on cutting the ribs with laser. You are burning the edge of the metal. There is a lot of stress on the edges as you form the ribs and I think you need clean, smooth edges to avoid forming stress cracks.

I cut all my ribs with a hand held router and a wood blank. I was able to cut the ribs, 3 at a time in just minutes and the the edges did not take a great deal of effort to finish. That was a fully cut rib ready tor the forming tools.

I use the services of a water jet cutting company for a lot of aluminum parts I make in my business. And for the same concern about the edges of the material, I did not even think about the water jet cutting process for the wings.

There were DXF’s on the old yahoo site. Pretty sure just the steel parts...I don’t recall creating the ribs drawings as I had purchased quick build wings... and ditto on water jet cutting of the ribs unless you specify the feed rate...as in request the operator calls out the material being something like 1/4” HRPL. That will increase the tool path time and improve the smoothness of the edge...to the point you’ll be doing the same amount of work chamfering and deburring the edges had you used a router and jig.

[S Lathrop]

Look for DWG files posted 1/12/2003; https://groups.yahoo.com/neo/groups/Bearhawk/files

The wing rib files were posted in both DXF and DWG formats. The drawings are for the A model wings.

[mswain]

I’d be interested in getting the DXF from you. I’ve been learning solid works the last year and would like to play around with the wing profile. I’ve built model A wings but if the price is right I might be interested in the cutouts too.

[rodsmith]

Speaking of solid works, I heard that all EAA members can get a free copy of the student version. Our Experimental Avionics instructor told us that but I haven't personally looked into it yet.

[Chris In Milwaukee]

It’s true. I’ve had it for a while and have been dabbling. It’s a different train of thought if you’ve ever done any 2D CAD.

[S Lathrop]

One nice feature of Solid Works is the ability to take a part drawing and convert it to a 2D drawing and then save that file as either a DFX or DWG file. SW will also open those files and import them into a part file.

Draft Sight is a free 2D drafting program from the makers of Solid Works. It is very close to AutoCad and in fact all the commands from AutoCad work in Draft Sight, even the 3D commands which Draft Sights does not list.

[Jpettygrove]

Is there anyway to get the DWG files from the yahoo group? I tried becoming a member but the group is closed.

[Chris In Milwaukee]

They should be public. Do you need to be a member?

[BravoGolf]

Some of the posts are public, but the files are not. As a closed group I was unable to join.

[Chris In Milwaukee]

AH, that's a bummer