Unless the farside part of the jig is somehow pre-aligned by a pin in a pilot hole or something it is redundant and does not do anything; by the time the drill reaches it the dirty deed is already done to the parts than matter.
For a jig to work it has to first clamp in some repeatable way to the parts that need to be drilled, then it needs to have bushings to center AND ALIGN the drill to the parts that are fixtured.
Hope that helps?
...Chrissi
Hi.
I am the guy who built the jig in question. You are absolutely right about pre-aligning the hole before drilling through. What the photo does not show is that 4130N steel WAFs (wing attachment fittings) are used to join the inner and outer spars. These WAFs have holes drilled and it is these holes that the jig aligns on either side of the spar. Whilst the WAFs are not 100% complete, you may get an idea of what I am talking about here http://www.kr-2s.com/wafs.html
To align the jig, you pass a same size drill bit (3/16") through the opposite side and poke it into a WAF drill hole. Hold another WAF on the opposite side of the spar and start drilling through the jig and matching WAF hole.
Unfortunately, I have had to place a ban on people linking directly to pictures on my site but you can see the jig at the bottom of this page. http://www.kr-2s.com/spar.html
Nose Gear Screwup - Please advise
in General Construction
Posted
Hi.
I am the guy who built the jig in question. You are absolutely right about pre-aligning the hole before drilling through. What the photo does not show is that 4130N steel WAFs (wing attachment fittings) are used to join the inner and outer spars. These WAFs have holes drilled and it is these holes that the jig aligns on either side of the spar. Whilst the WAFs are not 100% complete, you may get an idea of what I am talking about here http://www.kr-2s.com/wafs.html
To align the jig, you pass a same size drill bit (3/16") through the opposite side and poke it into a WAF drill hole. Hold another WAF on the opposite side of the spar and start drilling through the jig and matching WAF hole.
Unfortunately, I have had to place a ban on people linking directly to pictures on my site but you can see the jig at the bottom of this page. http://www.kr-2s.com/spar.html
Happy building.