dle's Oz Build

[efwd]

I used a c clamp as well.
The McBeans should have somebody weld up a bunch of those reamers as described above and whenever someone calls about how they are going to accomplish that task he can just say "we have those specially made taps". I hated doing those with a ground off tap and a wrench.
Eddie

[rosslr]

Great Progress Dave! Your descriptions and photos are so useful for others! Interesting to hear all the ingenious methods of pressing those bearings! I used the same method as you did.

You'll be covering before you now it!

cheers

r

[David47]

Yes Steve, those pins are real hard, and I found that unless you have the 1/16" drill bit well into the drill chuck (to stop buckling of the drill under load) and the centre punch top dead centre in the machine vice, the drill will try and slip off all over the place !. It was like a wobbly piece of jelly. And I like the long rod with reamer attached idea. You should patent that !

Jim and Eddie, I tried the "C" clamp idea but my clamps have a ball joint on the adjustable side and I didn't want to buy yet another tool for this job. But that to me would be the best way to do it. The nut and bolt approach I used works ok, just a little slow ..... and can be painful to boot !.

Thanks Ross. I know that by reading other people's posts you can learn a lot about how they went about it. That's why I try to post enough detail to help others along the way and get feedback from others who've been there before. All adds to the experience and knowledge base.

[David47]

Had a slower weekend this week due to family commitments and couple of cars breaking down. Everything happens in three's so not sure what's next. However, I did decide to tackle the often talked about process of applying Hysol 960. I've read many threads, including Builders Tips and Hints and decided to go with John Pitkin's idea of using syringes. I bought a few capable of holding 100 ml and thought that should be big enough. Well, they were too big as it turns out.

The first bonded rib assembly off the rank was the trimmable tailplane. All ribs were sanded and adjusted in length using conical and cylindrical grinding bits attached to the vertical drill press. The angle on the conical bit proved an excellent way of providing just enough taper on the trimmed LE edge of the ribs to match the angle of the front tube spar. Front and rear tubes were roughed up with 120 grit wet and dry and wiped with isopropyl alcohol after scuff and just prior to adhesive application.

I taped everything off with painter's tape and loaded up the first syringe with about 30 ml for attaching the rib stiffeners - I bonded the rib stiffeners prior to loading the ribs into the assembly. I couldn't believe (a) how much heat is generated by the adhesive during the curing process and (b) how quick this stuff cures. The brew I made got me through bonding the stiffeners I made up but I had about 15 ml left over. I cleaned the syringe (a messy job) and let the bonds set overnight. Next day I located most ribs in place on the assembly, did a mix of about 100 ml thinking this would be about right. Way way too much yet again. Loads of heat generated and the mix seemed to go off even quicker. So the lesson I learned here is, if anything, work out what you think you would need, and then halve it. The photo I've included showing the empty and used syringe gives you an idea of how much I've wasted. From my experience I would say mix no more than 30 to 40 ml at a time, unless you work real fast.

I took JP's advice regarding the syringe outlet nozzle. The standard syringes I bought have about 1/8" diameter opening. I opened it up a bit more (5/32") and the adhesive seemed to flow really well. I got quite a good bead of adhesive, probably about 1/8" surface contact on both the tube and rib. When cured, the painter tape was removed and there was minimal cleanup involved. You have to be careful when positioning the tape adjacent to the bond line because it can actually shield part of the tube from accepting adhesive. So there are a few areas I need to redo.

All in all, not as many hours spent this weekend but I learned heaps about bonding. And as Josh said on his thread, you get better at it the more you do.

About 80 hours total "hands-on" into the build to date.

(I've added a few photos which hopefully give people the idea of what I'm babbling about.)

[DesertFox4]

It looks like you are doing a fine job David. Nice and neat and clean.
Moving at a good pace.

[rosslr]

Very neat and tidy Dave! Although it takes time to mask everything up, it results a job that pleases the eye - Hysol can get messy! And I agree about your tip re estimating and then halving - I wasted heaps of the stuff by over estimating the quantities. thanks for the updates - interesting to follow. We are off to the Simpson this week ( as soon as the rain passes!) We might call in on our way back if it is a weekend.

cheers

[David47]

I envy the Simpson Desert trip. Hope you have a great time. Just call and if I'm up there would be great to see you and Gayle again.

[papabear]

Nice work going on here, keep up the good work mate, don't forget the paperwork.

pb

[David47]

So I'm getting into this bonding work with more confidence now. This weekend family commitments meant less time of the project again, but then you really have to strike a balance. So I brought the elevator and rudder inside the house (its starting get cold here in Melbourne now) and commandeered a backroom table as the workbench. With my newfound knowledge of working with hysol 9460 I bonded the ribs to both the elevator and rudder. Using the syringes, I'm managing to get a consistent bead of around 1/8" along most bond lines - sometimes it looks a bit ratty but I'm making sure the bond surface is cleaned with Isopropyl alcohol after roughing up and that the bead is contacting both the rib and adjacent tube. For the Elevator, I used a cutoff section of one of my partners facial cream tubes (photo attached - of the tube segment, not her) as a measure. It's about 1 1/4" diameter and about 3/4" high. This mixed just the right amount for the elevator ribs, although I really had to squeeze the syringe to wring the last remnants out and only then, just made it.

Something I'm unsure of with the base of the rudder. The lower-most rib sits just above the lower tube, so when fabric is applied, there'll be a triangular shape to the bottom of the rudder. Has anyone flattened this section off by applying a sculptured foam block as per the rudder tip ?. Not sure whether this is a worthwhile mod or not. Any input gratefully received.

Photos follow.

[Dave S]

David47,

The first attached photo is how I finished off the bottom of the rudder (not shown, but done before the top coat were the drain holes).....reality - this is an area most people won't notice because of the location, particularly on a tailwheel, so not all that sure most would bother to finish off the bottom.

One part I wanted to finish off more smoothly is the center part of the elevator where the trailing edge tube meets the spar - second photo. This resulted in the fabric having a nice profile on the finished elevator.