The International Cessna 170 Association

Leroy and I are refurbing the baffle on aour 170A since we are in the mitts of an engine over haul. He hand made new baffle for between the cylinders and looking at the baffles that attach to the top of the cylinders at the upper 3 valve cover screws, asked if I thought we should make new of these. In shock he asked I said yes I'd do it and looking at our collection found the only original one we had for a pattern.

Came home and scanned in my example and proceeded to draw its shape in Sketchup which is the drawing program I use to eventually create G code to feed to my CNC router I built a year or so ago for just this type of job. Here's the finished drawing 2 up, which fits the material I have to cut. Took about an hour to draw then a test cut on one to see how it fit. A minor change and it's ready to run.

Here are two baffles cut. The single one on the top is the original I used for a pattern.

Takes about 15 minutes to load the material and run the cut Very little cleanup of the parts when done. They are spot on with only one adjustment and trial cut last night. All I have to do is find my stock of dzus 1/4 turns to get the retainer hole spacing, drill then and install the retainers. If I had the Dzus to get a measure I could have had the router drill pilot holes. If I find my Dzus stock before I run the last 4, I'll add the missing holes.

I'll try to remember my phone and get some video of the next pieces being cut.

I'm really tickled how well this all worked from building the machine that made the parts to the parts themselves. Many times on jobs like this it takes longer to draw, test and setup and run the machine, than it would have taken to make them by hand. But in this case I think I'm going to be an hour or two ahead of the game and these things are identical as they would have been from the factory.

Any one need some early baffle parts?

Jeez, I'm getting ready to make some of those (and some other baffle parts), as I am also in the midst of an overhaul.
But I don't have a CNC router....

Very nice!

I'm a bit disappointed that CNC can't seem to be a bit more accurate in copying parts, Bruce... The new ones aren't even close to matching the oblong-shape of the original's top hole.



(nice job!)

Bruce Fenstermacher wrote:... All I have to do is find my stock of dzus 1/4 turns to get the retainer hole spacing, drill then and install the retainers. If I had the Dzus to get a measure I could have had the router drill pilot holes. If I find my Dzus stock before I run the last 4, I'll add the missing holes. ...

Very nice work Bruce. The 170A IPC, fig 38-59 calls for Dzus spring S5-200. Wicks gives you the dimensions you are looking for on a S5A-200 spring. Not sure what difference the "A" adds to the p/n -- plating perhaps?

Video cutting the parts
https://youtu.be/oZBcRziO8iA
Cutting part 0550117, the small inter cylinder baffle that attaches tot the valve cover. these fit so nicely on the first try only minor filing was necessary.

https://youtu.be/Lsuo5mqk-MI
In this picture, one is bent into finish configuration and the others are flat. The extra on the bottom left is the paper on card stock sample I cut out of the drawing to test fit.

Nicely done!

CNC cutting... Stirling engines from Coke cans.... ....Isn't there an automobile accident or shooting somewhere you ought to be saving someone?

(I'm always astonished and amazed at the talents Bruce has and hides from us. I'm still dreaming about making a food-barrel blasting-cabinet!

The "Big Blue" blasting cabinet. That was a while ago. I am but one of many in the Association with a interesting wide variaty of talents. Did I ever show off the steam engine I made, that fits in your palm, ran on the pressure of a large syringe, using only the brass and steel I had laying about my work bench?

Bruce Fenstermacher wrote:The "Big Blue" blasting cabinet. That was a while ago. I am but one of many in the Association with a interesting wide variaty of talents. Did I ever show off the steam engine I made, that fits in your palm, ran on the pressure of a large syringe, using only the brass and steel I had laying about my work bench?

PLease post a video.

I'm pretty sure Bruce made cold fusion work, too, but is too modest to show it off in public.

Just for George.

Palm size wobbler steam engine made from scrap from my work bench. Challenge was to make it run on a 50cc syringe. When it was new I could get about 2-3 revolutions with the syringe but it's just not enough volume.

https://youtu.be/iwFe3ZO1Rbg

Running on about 20 lb of air.
https://youtu.be/GVxXRHXVYiw

Nice work....I happen to need some of those for my 48....is it something you would consider making on request......for the correct $ of course....

Hey, Bruce, a question for you.

I am just finishing up an engine overhaul, and haven't got around to making new baffle pieces that attach to the upper three rocker cover screws.
So, for now I am using the old ones.
But imagine my surprise when they won't fit onto the new rocker covers that came with my new Millenium cylinders! They fit fine on my old Continental rocker covers. Tomorrow I will file to fit.

So my question: If you are going with Millenium cylinders, have you gotten to the point of check-fitting your new parts onto the new rocker covers?

I used a Continental cover to check the fit of my drawing traced from my old part. I cut a sample part. I fit it on the Continental cover and it fit. There isn't much play. I then fit it on the covers that came with my Superior cylinders and they fit but where tight. I shaved this area a few thousands before cutting the final pieces but there isn't much to shave before you get into the cover screw hole.

A nice file could be your best friend here.

Thanks, Bruce.
Mine will take a little more metal removal than that. But, it is probably because they are owner produced parts that were made to fit pretty tightly against Continental covers.
I ended up deciding to put the Continental rocker covers on for now. When I make the new set of baffle parts, I will make them to fit the new Millenium covers. Or maybe I should hire you to cut out a set!