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Baffling question

N941WR

N941WR

Legacy Member
I'm just about finished with the baffles on my new engine and this question is for those who have done multiple installations, one with the safety wire and another with the new SS rods.

I never had a problem with the safety wire but if there is a compelling reason to use the rods, then I'll install those.

Which is better?
 
Bill, everyone's quiet on your question. I actually just fabbed one SS rod yesterday and promptly decided to use safety wire instead. I ran out of .041 so I will have to get some more, but my plan is to use a double wrap around a steel hinge pin section then thread the twisted wire through the hole then through a section of vacuum hose then secure with another hinge pin section.

The SS rod sucks and it's hard to get the right tension and still avoid any chafing.

Of course, I have not done this yet so I may change once I get to it.(Tuesday)
 
baffles

Bill,
I'll confuse you a bit.
On my Superior O-320, I opted for a threaded SS rod. I actually used hinge pin, and threaded it 4-40. I was able to bend angles in it to clear the inter cylinder baffles, and it was easy and looks real nice too. I check them every time I have the cowling off, and I have yet to adjust or tighten them.
I have seen quite a few installations with saftey wire, and that appears to work well too, but mine was not a straight shot from end to end, so the rods were a better choice for me.
Hope this helps...
Chris.

PS ....Check your PM's for an Emag question....
 
Tony & Chris,

Thanks for the comments. I might just go with the safety wire because it is less parts to deal with.

On my old baffles, I put a pop-rivet through a small AN washer and then through the hole on the tab. After that I punched the center of the rivet out. This kept the wire from working the baffle. Here's a picture:
 
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PS. Tony, check my post above. I clarified it a little by adding the part about using the pop rivet to hold a small AN washer in place.
 
I installed the SS rods. It took an hour or so to fab them. I am pretty sure they will be disposable when it comes time to remove them. But they look good right now.
 
I used the safety wire for a second time when I replaced my #4 baffle assy (using Vans supplied new design parts) even though I could've used the threaded rod. 'Course then #2 baffle would've needed modification.
 
vans st. steel tie rod material

I attempted to make the tie rods today using the material supplied in the kit- the plans show it, how hard can it be? That is some seriously hard stainless steel rod.

The stuff in my kit measured 0.113" diameter, thus way under the nominal 0.136" diameter for a normal #6 thread. Even so, I managed to destroy a brand new, very expensive US-made high speed steel die by the time I had threaded three of the four rods. I even held everything in alignment on my lathe, which I turned by hand, backed up frequently to break the chips, used high quality cutting oil, etc.

Yes, I know there are easier and possibly better ways to do this, but I was being (extremely) stubborn. Thus pushing my completion date out a little bit farther. Again.

Switching to Plan B...
 
I wonder if one of these would work?

Maybe D, E, or F could be soldered on the bent rod, or the threaded rods in the lower picture could be bent and cut to length and connected with a coupler like G or H. There may be other manufacturers of these with slightly larger sizes.

There are available at lots of hobby shops.

963781013_AvCMz-L.jpg


963786037_VUYdv-M.jpg


http://www.dubro.com/hobby/
 
Used the rods

Since the rods came with my baffle kit I used them. Threading the ends was definitely the hardest part. I really struggled with the first one until I figured out that grinding the end of the rod to a taper was the only way to get the die started.

The rods have held up fine for 200 hrs. Putting those tiny all metal lock nuts on is a real PITA. The washers also have to be ground down on one side.

I pit hard nylon tubing over the rods and put a dab of high temp RTV on the tubing where they run close to the cylinders.
 
I tapered the ends of the rods and had no trouble getting the die to start. It was keeping it going that I found problematic :( On rod #4 the die grabbed the rod and wouldn't let go. Had I been using an adjustable die I might've been able to get it apart and carry on, but it was not to be.

The safety wire in a plastic tube approach as used on the older baffle kits is light, simple and minimalistic. BUT... tie rods appeal to me for some reason, so I'm going to follow the lead of a few others and use 8-32 all-thread inside nylon tube. The aviation department of McMaster-Carr has 24" lengths in st. steel for about $150 apiece, so that's the route I'll take. Gotta build on...
 
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