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Builder Name:Jeff Seaborn   -  
Project:   Dalotel DM165   -   VIEW REPORTS
Total Hours:653
Total Flight Time:
Start/Last Date:Nov 06, 2019 - Nov 06, 2019
Engine:Originally Continental IO-346 A what? Yep, an IO-346 as used in Muskateers of the same vintage
Propeller:A Regy Wooden Fixed Pitch What the heck is that? A French prop from that era
Panel:Steam gauges circa 1969. In French and in metric. Yikes!
 
Friendly URL: https://eaabuilderslog.org?s=jseaborn

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Apr 06, 2020     Ribs epoxied into place - (4 hours)       Category: Wings
Today was another big day. Four hours and it looks exactly the same as yesterday. Except that all the ribs on the RH wing are now set in place and are waiting for the epoxy to dry.

Today was a lot of measuring, fitting and adjusting, more measuring, some shimming, more adjusting, a lot of sighting, and then when confident that all the ribs were in the correct position, mix up some epoxy and start gluing. Of course, as you're gluing, you have to move the ribs to get epoxy into the joint, so more sighting, shimming, and clamping. Then more gluing. And then, double check the measurements. As the saying goes, measure twice, cut once. Since I'm gluing about 50 glue joints, it's imperative to get everything in the right position before the epoxy sets.

The first real measurement was to ensure that the RH wing had a sweep to match the LH wing. Measuring from the tail post to the tip of each spar, I made sure that the RH wing matched the LH wing. Ultimately a mismatched sweep will have negligible effect on the performance of the plane but it needs to right. Just because. The next big step was to set the correct incidence of the tip rib. The root rib incidence is easily set by the matching the position of the root rib on the LH wing and how it sits relative to the fuselage. The tip rib has 2 degrees of washout, that is, the tip rib has 2 degrees less incidence than the root rib. This washout is to reduce the likelihood of tip stalls and the corresponding potential for a spin. Of course, is only effective when the plane is upright. When it's inverted, that washout will mean the tip is at 2 degrees GREATER angle of attack, making the tips more susceptible to stalling. The net effect is that the plane will be prone to stall/spin effects when inverted. This a bit of an oversight on Dalotel's part considering that the plane was intended to be flown inverted at times. (Dalotel went to a great bit of effort to design an inverted oil system for the plane, and it has an inverted fuel system. So it wasn't like he didn't expect it to be flown inverted.) Regardless, since the LH wing has 2 degrees of washout, the RH wing needs to match. The correct incidence and position of each ribs IS important to the performance of the plane.

The actual measurement of the incidence isn't important during the build since it's dependent upon how it's sitting in workshop. What's important is the difference between the root rib and the tip.


 


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