BearHawk 5 school of construction

[Sir Newton]

Good day BearHawkers, Just some more cheerleading going on here. Uploaded a few pictures of my spars in various stages of riveting. I am trucking right along with the project. Ordered up all the tubing for the fuselage. Hit that like button so I know someone is actually looking at these posts! or don't.

[Sir Newton]

You know the saying "Paint that Gold" Right hand rear spar is back on the jig & completely reassemble ready to install RIVETS!

[geraldmorrissey]

Looking good Sir Newton. Love the photos. Keep them coming.
Gerry
Patrol #30

[Sir Newton]

Bearhawk 5 model B wing spar photos after being cleaned & alodine treatment applied.

[Sir Newton]

Corrosion protection & Paint Preparation of wing spars. I used 6" sc40 PVC pipe cut in half. One tank for alodine, one tank for cleaner and to wash water tanks. Over all it work ok, the end result was very good, and the procedure to work with the chemicals was safe. However alot of work to complete.

[N3UW]

Sir Newton. Great work you are doing. I completely agree with all you are doing to cut AL. I had to buy those overly expensive cap strips because I did not discover the circular saw cuts early on. I did help a friend cut his from sheet material. Quite easy. You may want to consider making yourself a cutting guide for your saw similar to a track. Back a few year again I posted about what I did and a link to a video for making it. Here is the body of the message.
I have cut a bunch of aluminum with a circular saw. All you need is a good carbide non-Ferris blade and a long enough straight edge. I use a festool tracksaw but a regular circular saw will work well. A while back i cut all the cap strips needed for two patrols in under an hour. . Very little cleanup needed on the pieces. Bob says this is how he does it himself. Here is what you need.

first you need a saw setup. Making a track saw is easy. Here is a video from this old house that shows one way.

https://youtu.be/rbTvzViDZmo

then you need the circular saw, the proper blade and a table.

For the table, make a table long enough that you can hold the full sheet of aluminum. I used a couple of pieces of OSB on top of saw horses with 12’ 2x4 under for support. The osb will be used hold the AL sheet and also allow the saw to cut about 1/16” into the osb so the cut is clean on the AL and will also prevent the saw from catching on the AL.

Place the AL on the table so that where the cut is will be over the OSB. You want to make sure you cut into the OSB. Now mark the AL and setup the track and clamp down. Set the saw depth so that it cuts through the AL and only about 1/16 or so into th OSB. You do not want to cut all the way through the osb. If you have the ability to hook a shop vac to th circular saw, it makes less flying AL chips. No simply saw through it. For me I cut through the entire 12’ length in under 30 seconds. Cuts like I was cutting through hardboard. Make sure you are wearing eye protection. I just ran a vixen file done the edge once to take off an stress risers,

I use the same method to cut all wing skins also.

If you use the OSB subsurface, track for the saw and proper blade, you will be surprised with how easy and clean cutting this method works. There is actually less cleanup with the saw cut than with a shear. I have cut a bunch of aluminum with a circular saw. All you need is a good carbide non-Ferris blade and a long enough straight edge. I use a festool tracksaw but a regular circular saw will work well. A while back i cut all the cap strips needed for two patrols in under an hour. . Very little cleanup needed on the pieces. Bob says this is how he does it himself. Here is what you need.

first you need a saw setup. Making a track saw is easy. Here is a video from this old house that shows one way.

https://youtu.be/rbTvzViDZmo

then you need the circular saw, the proper blade and a table.

For the table, make a table long enough that you can hold the full sheet of aluminum. I used a couple of pieces of OSB on top of saw horses with 12’ 2x4 under for support. The osb will be used hold the AL sheet and also allow the saw to cut about 1/16” into the osb so the cut is clean on the AL and will also prevent the saw from catching on the AL.

Place the AL on the table so that where the cut is will be over the OSB. You want to make sure you cut into the OSB. Now mark the AL and setup the track and clamp down. Set the saw depth so that it cuts through the AL and only about 1/16 or so into th OSB. You do not want to cut all the way through the osb. If you have the ability to hook a shop vac to th circular saw, it makes less flying AL chips. No simply saw through it. For me I cut through the entire 12’ length in under 30 seconds. Cuts like I was cutting through hardboard. Make sure you are wearing eye protection. I just ran a vixen file done the edge once to take off an stress risers,

I use the same method to cut all wing skins also.

If you use the OSB subsurface, track for the saw and proper blade, you will be surprised with how easy and clean cutting this method works. There is actually less cleanup with the saw cut than with a shear.

[Sir Newton]

N3UW, 100% agree. The saw I used is defiantly over kill for the job of cutting cap 0.125 strips . I had the saw laying around is all. The main reason I even posted about how I cut the cap strips is actually in PROTEST to the outrageous price of 2024-T3 flat bar!

[way_up_north]

Great progress ...thanks for posting detailed photos ... can really zoom in on the parts.. brings the plans to life

[N3UW]

For cutting aluminum, you can use a good quality standard circular saw with a good carbide blade designed for aluminum (just a different tooth layout than a standard wood crosscut or rip blade). I used a festool track saw to cut all my skins to rough and final dimensions. Works much better than snips or shear. I cut on top of a piece of 1/2 MDF, OSB or 2” foam cutting cutting through the AL and into the backing board 1/16-1/8”. I use a vac connected to the saw to suck up chips. Very clean cut that needs very little clean up. The circular saw to cut the cap strips was recommended by Bob. I also use a chop saw with AL blade to cut all the bar to length. With a chop saw just make sure you use a zero clearance fence, made of some scrap plywood, to keep cutoffs from getting caught by blade and flying around.

[Sir Newton]

General cheerleading! All wing spars have been fit up & are being deburred right now. As well builting a Alodine holding trough out of 6" sc40 PVC pipe. To clean & treat all the spar parts in. It took me basically 200+/- hours to fit out all 4 wing spars.
​​​​I very happy to be moving forward.

[Sir Newton]

General cheerleading! RH main spar fit out!

[way_up_north]

a few more questions for you about the Evolution saw

there does not seem to be many retailers selling the saw in Canada, on the Homedepot.ca site they have a saw but its an orange version that does not seem to have the guide like your model has. Did you buy it directly from Evolution?...Amazon.ca does have it but I thought id ask you to see if there was a Canadian seller I could support...the amazon model looks like an similar version of yours

https://www.amazon.ca/Evolution-Power-Tools-STEELSAW2-14-Inch/dp/B003TX1UPO

did you cut all you spar C channel with that saw also...I was wondering if it could handle that thin material if it was supported and the guides go that wide....or did you use a shear or other method to make those

does your evolution saw have 2 parallel guides for the front and back...or one guide the whole saw length..it looks like there is different guides between models..

Thanks

[Sir Newton]

The saw comes with everything required to get the job done out of the box. before you start cutting on the sheet ! draw square reference lines just incase you get out of square as you cut. Something to get you back to a straight & square to the sheet again. I only used the fence to make the cuts. I was careful to make sure I stayed straight & square with the saw & fence as a guild. It worked great. All strips measure 1.265 ish very uniform.
If you are uncomfortable using the fence as a guild. When ordering your 2024 sheets include a piece of 1/4 x 1.5 X 1.5 6061 angle. This material is straight as an arrow when it comes off the rolling mill & makes a super straight edge OR in this case with a set of clamps a straight edge guild for your saw.

There is enough material in a 0.125 x 4' x 12' sheet for two airplanes.

[way_up_north]

looks great....

what source you using for your bending formula? what you found in the build manual or Tony Bingelis...ect.....the bend looks great and your work very professional...

[Sir Newton]

I double checked my interpretation / calculations of the dimensions from the drawing. I am correct. However there's interference on either end of the aileron with the aileron skin 0.020 pocket rib stations on the rear spar.
Resulting in my decision to relocate to the lightening holes.