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"Titan 60" engine build

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magu

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#1
Hi All!

I bought a set of plans and a kit containing the raw materials and a few castings to build a small "cox" style engine like those used on model airplanes back before brushless took over the market. I briefly began to machine it, but with no real planning and sort of "shooting from the hip" about two years ago. Fortunately, I didn't ruin any of the castings, although I got dykem on a bunch of surfaces that will remain as cast and which I did not want to sand or pain as I like the look of them. Anyway.... one night the wife said "I think I'm pregnant" and that was the end of that.

Last night I finally drug the box of small paperweights out and started messing with it again. This time with a toddler sitting on my workbench trying to touch everything I looked at. That's something I never planned for, but sometimes we don't make the best plans I guess..... (that's a bit deep of a statement but is mainly there to account for the many pictures which contain the odd shoe, small hand, or drool).

I got so far as boring out the journal for the main bearing (a yet to be machined bronze bushing), facing off the back of the engine where the mounting plate will attach, and beginning to bore out the crankshaft cavity. By the time I started that third step my left arm felt like it was going to fall off. My son had grown bored of playing with my drill and turning the feed handles on the mill, and had decided that the only way progress would continue is if I held him so he could watch while I worked.

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RandyM

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#2
Cool, looks like a fun project.
 

magu

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Thanks Randy; I'll be happy, and a lot less nervous when I'm done with the main body. This is the only piece that can't be replaced if I stuff it.
 

larry4406

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#4
Neat project! I used to fly wood planes with the Cox 049! Thought I was really cool when I got the Tee Dee 051!
 

kvt

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#5
The Dykem, Soak it in brake cleaner, may take it out. Another option is beryman b12 chemtool, Both seam to remove a lot of it. I use them to clean it off all kinds of stuff I get it on.

Nice project.
 

magu

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The Dykem, Soak it in brake cleaner, may take it out. Another option is beryman b12 chemtool, Both seam to remove a lot of it. I use them to clean it off all kinds of stuff I get it on.

Nice project.
Thanks, I'll give that a try. If I can't get it off, I might try light media blasting or painting it silver
 

RandyM

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The Dykem, Soak it in brake cleaner, may take it out. Another option is beryman b12 chemtool, Both seam to remove a lot of it. I use them to clean it off all kinds of stuff I get it on.

Nice project.
I find acetone works quite well also.
 

magu

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No Pictures, but I got a little bit done last night. I opened up the crank case ~150 thou for most of its depth. Then my son decided he wanted cheese, so we went back in the house because I am the subject of a small iron fisted tyrant with a fondness for dairy products.

I'm pretty much stuck waiting for my order from shars so I will have a dial indicator to watch my depth with. It was supposed to ship Monday, Wednesday I emailed them and they assured me it would ship that day, nothing yet. I don't know that I will be ordering from them again. They sell the same crap import tools as a million ebay vendors, if they don't have their act together, I don't see the point in giving them my business over any foreign importer with marginally better prices.
 

magu

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Also, thanks Randy, I will probably try the acetone first because there is some in the house I can steal. If that doesn't work I'll try brake cleaner or B12, which I would have to buy.
 

magu

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A couple days ago I finally got my order from Shars and finished the crank case area. I accidentally ran the boring bar in too deep a coupe times, so I just increased the overall depth by ~0.010", and I will make up for it when I sleeve the crank journal.

The pictures came out pretty crappy, but it looks better in person. (Still not perfect though...)

Also shown is the back plate which I turned down from the raw casting way back when I first started this thing. It will need re-visited, but I had it out so I could check the diameter as I closed in.

Next I will need to deck the top of the cylinder and bore it to size so I can sleeve it as well. I'm not quite sure how I am going to locate the CL of the crank axis yet, but I have a thought that I think will work...


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larry4406

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#11
Very cool!

How does the backplate thread to the body? Looks like 4 bulges in the casting for future screws?
 

Cactus Farmer

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#12
Please be careful with B-12. It's vapor is heavier than air and seems to be deadly to small rodents. It is also awesome solvent for stains/dychem.
 

magu

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Very cool!

How does the backplate thread to the body? Looks like 4 bulges in the casting for future screws?
Thanks! Yup, 4 itty bitty countersunk screws. I have been going back and forth on whether I should clamp the parts together and drill/countersink them then thread the body and clearance drill the backing plate, or if I should drill them separately. I'm leaning towards the former.


Please be careful with B-12. It's vapor is heavier than air and seems to be deadly to small rodents. It is also awesome solvent for stains/dychem.
Thanks for the B12 warning, especially with a little one around (the dog is smart enough to generally avoid killing himself, but how the human race has endured I will never understand...) That does also sound like a feature in some circumstances though.
 

magu

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Progress has been made!!!

My next step was to bore the crankcase for the yet to be made cylinder sleeve. In order to do this I needed to be able to locate the CL of the crank so I made this bushing and pressed it into the end of the crank journal:

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Then it was time to do some milling :) well... boring.... but it wasn't boring, it was very cathartic.

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Until this happened... I was cruising along fine and I must have adjusted my boring head to be a little too unbalanced for my given speed. I began cutting and it suddenly began going down hill very quickly. I don't know if I just hit a harmonic node and could have pushed past it, or If I was just going to be unstable from there out, but I backed off the RPM and everything quieted down. Fortunately this was while I was still hogging material out, so no harm done.

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Once the bore was finished, I used the boring head as a single point tool to deck the head. I doubt this is recommended, but it actually worked very well. THe camera makes things look atrocious, but it is an RMS 63 finish or better.

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Next, I drilled and tapped the three holes which will secure the cylinder body and head. This was my first time doing anything meaningful with a DRO, and I must say that they are amazing. Anything a DRO can do can be done by hand, but it just made life so much nicer.... I also milled the exhaust port to "length". No direct pictures of these steps, but here is the final product:

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One thing I didn't consider in my setup and probably should have was chip clearing. It didn't end up being a problem, but I was running out of room:

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Chris Hamel

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#15
Looks good. I fly rc model airplanes and have dealt with glow fuel engines for over 20 years. I am looking forward to seeing how it turns out. Enjoy your son. Trust me the time will fly by.

Chris
 
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