spar replacement

[richardfci]

I'm replacing the front spar on my kf2. It was the Ibeam type, the new one has a stiffener, does anyone have a pdf of how to insert it and secure it in the spar?

[Peter_SE]

I’m about to build new wings for my kf2 and is wondering the same, have you any Moore info on how to do it?

There are a few blogs online showing the procedure but the manual is needed for sure...

This is my new spars with inserts
https://uploads.tapatalk-cdn.com/20201225/a20dbef0357b8d7d32ee8448afb6066f.jpg


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[patrick.hvac]

Disclaimer: I know nothing about a KF2.

I would think that if you are retrofitting the spars with I-Beams there will not be a manual that applies as a cross-over so you will be on your own for the differences.
The KF7 manual has clear instructions in the wing assembly supplement on how to install the inserts.
You could use those as a general guide and translate intent to the KF2 which would allow you to determine insert setback and locations for struct attach points etc..
The inserts themselves are not difficult really. Make very sure they are rounded and polished perfect as well as lubed. Getting them stuck in the spar would be a very bad day.
You could pull the pages you need from the online manual on the KF site. Send me a PM if you need something specific.

[maplebud]

The manual shows clamping the spar gently between two 2*4 and sliding the stiffener in, when it's ready.

[alexM]

I just did this job a week ago. Clean the **** out of your inserts and also drag an acetone rag through the inside of the tube (long piece of parachute cord with a weight on the end to get it started. Debur the inserts really, really well.

As per the manual instructions, DO NOT FORCE the inserts in. If they don't go with just finger pressure and a push stick then stop and pull it out. The factory suggestion is a light coat of baby oil if needed to assist in the insert sliding in. I don't have a baby but I do have some LPS so that is what I used.

You'll get it, just take your time and STOP if it's not going well.

In my case I'm building up all new spars. Two of them went together easily and two didn't. I went over the mating surface with a scotch brite pad on the two that didn't go in. That, along with the deep clean and lubrication was all it took.