Album by John Cronin. Photos by John Cronin. 1 - 116 of 116 Total. 5291 Visits.
Rib/tail shopping list
Outline of the Pietenpol.
Most of the plans fit on the wall.
A couple of Pietenpol's.
Pre-drilled holes for nails. About to cut this up.
All cut up for use on jig to hold sticks. Ones on left with black line have been sanded down for use at gusset locations.
Some gussets will be 1/4 of round pieces. Drilled some out of this piece left over from the Hatz
Grain direction is not specified. I'll angle the grain, so setting up the angle for cutting on the band saw.
45 degree angle cut. About to cut from edge to edge along the ruler.
The angled edge will run along the fence, giving me many 1" wide pieces.
One of the pieces.
Oh, my order of wood for ribs and tail section has arrived.
Wicks' does a great job packing and shipping.
The various components of my order are individually wrapped.
The several items of my order.
Starting to accumulate gussets.
About to cut some round ones in half.
Done.
For cutting triangle pieces, I need to make a notch in a holder for the piece.
The holder has been cut to fit the part, which has been cut in half.
I cut strips using a knife. The strips are then cut to the required size. If the pieces then get cut in half, they go into a holder for another run through.
Starting to draw out the rib jig.
After drawing the rib on the board, I traced the full size rib and placed it on top. A bit of a difference.
I then took the full size drawing and placed carbon paper under it to trace directly onto the board. The circled plots are the exact points from page 5 of the plans.
In the center section, the upper capstrips merged and matched up, but the lower capstrip comes up. Here, the page 5 capstrip bisects the full size drawing.
At the back end of the rib, the lower capstrips match up, but the upper capstrip is a tad lower. Here, the page 5 capstrip bisects the full size rib drawing. Spoke with Andrew Pietenpol about this. Long story short, he said I could build either one…from full size or using page 5 dimensions. I'll use page 5.
Download MPEG4 Video explaining the differences. Full size here: http://youtu.be/KZSTQas6iEA
Capstrip bender in use.
Boiling wood. Then it just soaks for a couple of days. I pour the water out, pour boiling water in, wait 20 minutes, and put them in the bender. Once in the bender, I pour some hot water on them.
Starting to put blocks in to hold the capstrip.
Well, this is what I ended up with.
Lower capstrip in front of the forward spar. Right on the marks I made from the plans page 5.
Closer look.
Immediately behind forward spar. That's 1/32". The capstrip is curving to the high point at the center.
The lower and upper capstrip meet precisely as in plans page 5.
Rear spar: At first, seemed I'd have to sand the back corner to make it fit, reducing from 4 3/4" there. Andrew Pietenpol spoke with me, and was adamant that the entire rear spar be 4 3/4" (don't sand down the rear part). So that block is 4 3/4" and it hits the capstrip at the back right corner.
In making the rear spar 4 3/4", the lower capstrip is slightly lower than on page 5. It starts to dip after the center and at the spar, it's about 1/8" low.
Top of the upper capstrip ahead of the forward spar.
Top of forward spar.
Top of rear spar. Looks like the plans page 5 drawing. My full size drawing shows the top left corner touching the bottom of the capstrip, and the top of the spar going back appears to get trimmed or sanded to fit under the capstrip, but as I wrote, that's wrong.
Bottom of the forward spar.
Download MPEG Completed rib compared to full size drawing. Larger version at YouTube: http://youtu.be/rIYrQKmhiwU
Bottom of the rear spar.
Replaced spar blocks with taller pieces so I can butt the gussets against them.
Made the templates for sticks, nose block and tail wedge.
Added small pieces of balsa to hold sticks in position.
Using templates to mark the sticks for cutting from 5' pieces.
Full size spruce sticks in position,
I soak the lower capstrip in boiling water for 20 minutes before placing it in the jig.
Gusset holders have been installed.
I've placed gussets in roughly the correct locations so I could glue the support end of the arms together.
Sanding to the line.
First rib glued up in the jig.
My wife sanding some sticks. I made that DC-3 wall art you see behind her.
A bunch of sticks and some gussets.
Since I'm using new T-88 (discarded the batch from the Hatz project), I made a V shaped piece to break in order to test the glue. Looks good. Some glue had oozed out and hardened on top of the stick.
I made the second jig for gluing gussets to the other side.
Download MPEG Video of rib jig. Larger version here: http://youtu.be/6M8wl5drp28
My friend came over and watched.
After I trim most of the excess with the bandsaw, I run the gusset overhang against the belt sander, careful to not sand the capstrip.
The belt sander is angled so I don't accidentally sand the capstrip.
Next, I use 100 grit sandpaper to smooth it even with the capstrip.
I round off the gusset edge so it doesn't create an edge when the fabric pulls tight on it.
Sometimes, glue has oozed out. I can easily feel it.
This file takes care of it quickly.
I also have to file the edges which will contact the spar.
I placed a finished rib on the full size drawing for comparison. My spars are built using the page 5 dimensions, and the paper may have shrunk a bit.
My spars are about 1/4" forward of the full size drawing location.
Jig to trim the rear of the ribs.
Back of rib.
Jig to trim the front of the ribs. See video here: http://youtu.be/B2b2-pgHeqk
Front of rib.
Ready to cut full size gussets.
Four full size gussets and the pieces for the aileron area.
Cutting holes for the spars on the scroll saw. I'll cut for brackets later.
First pair in the jigs. The top has mahogany gussets already glued on the bottom side. The lower rib at this point has only the full size birch gusset.
Going to use the router. This rib then goes back in the jig for the normal mahogany gussets on the side facing up. I used birch for the full gusset as I have a few sheets and it seems stronger.
Used this router bit.
The finished 'full gusset' rib. There are four; the inboard rib of each wing with full gusset facing towards the center section, and the outboard center section ribs with the full gusset facing the wing.
To round the rib edges, I first used 60 grit, then 100 grit.
Looking down the pile of ribs.
The last full gusset piece is on top, and the bottom is the rib that'll go next to the aileron. I had to use a weight to hold the large gusset down.
