6 Cylinder Radial

ejcheli · Feb 26, 2014

Well, I'm new to all this but I really have enjoyed starting building model engines. I built my first engine last month and now I am attempted to build a radial based on the design of crueby found:

6-cylinder radial engine build log

I will be receiving a degree this spring in Metal Fabrication so I have a bit of machining experience and have access to CNC and manual lathes and mills making these projects possible. I will post pictures when able.

Eric

ejcheli · Feb 26, 2014

Here is my first motor. Simple and plain but runs really well and has really good tolerances.

ejcheli · Feb 26, 2014

Well here are all the parts I have completed as of today. For anyone who is familiar with crueby's engine, they will note some differences as I am taking the liberty of changing or adding a thing or two here and there but the heart and operation of the engine is entirely crueby's design.

crueby · Feb 27, 2014

Hi Eric,

Looks like a very good start - loooking forward to seeing it progress!

Chris

ejcheli · Feb 27, 2014

Thanks! Here is what I accomplished today.

ejcheli · Mar 4, 2014

Remade my counterweight but used mild steel this time. It will fit perfectly but I don't like the super close pictures as they show every little defect hehe...

Keep in mind the end mill facing cuts across this piece were done with a .125" end mill, so its a really small part!

ejcheli · Mar 5, 2014

Got all the cylinder blanks turned out today. Made a fixture as well which I will put into the CNC mill tomorrow and bore out the piston and valve shafts and also drill all the holes for the cylinder caps. Seems like cheating but I gotta make this a speedy as possible due to a massive amount of official class projects I have to build as well....

ejcheli · Mar 6, 2014

Got all of the piston heads done today and cut out the engine block but its not finished yet obviously.

necchiom · Mar 6, 2014

Very professional work: with compliment!

ejcheli · Mar 6, 2014

I wasn't able to bore out the cylinders today like I thought but I made the previously mentioned parts on the machines that were available. The piston heads were actually all done on a CNC lathe which means they are all perfectly identical to each other with a 0.4975" diameter. I chose this because it was under .500" by 2.5 thousands but I wasn't sure how much clearance I should have for the pistons. I thought a .001" clearance may be too tight so my options at this point (unless I make more pistons) is a cylinder shaft of .499, .500, or .501" so... 1.5, 2.5, or 3.5 thousands clearance. What would you guys suggest for best performance?

ejcheli · Mar 6, 2014

Here are my current plans of all the parts I built and plan on building. While basically the same as cruebys, these include my modifications if anyone is interested. I am doing this because I know how awesome free plans are. I will post higher resolution and cleaned up versions when I have completed this build as these plans have already undergone dozens of modifications and undoubtedly will receive a few more.

ejcheli · Mar 7, 2014

Bored out all my cylinders today, the fixture worked great! I went with a bore of 0.499" and it worked great. When the bottom of the shaft is plugged and I dropped the piston in, it just slid slowly down... beautiful.

ejcheli · Mar 10, 2014

I touched up some parts today and figured out a couple more things resulting in me posting page 1 of my plans in the download section found here: 6 Cylinder Radial. I believe that everything on this page should be 100% accurate.

ejcheli · Mar 24, 2014

Well.... turns out I goofed up the cylinders. I suspected I may have when I finished them weeks ago but I've been on spring break and just got back into the shop today and really checked them out. I noticed some odd sounds during the CNC process and had to tighten the bolts mid way through and thought by some miracle I'd be ok, but it was as I feared... the cylinder bolts had backed themselves out and had become loose enough for many parts of the drilling and boring operations to be off center or worse. So... I spent most of my day today remaking 6 new cylinder blanks. These 6 are absolutely perfect as far as I'm concerned and will be bolted into a new fixture sometime this week. I plan on using some loctite and checking the bolts every step of the way this time.

Anyway, I hope to get this project completed within 2-3 weeks. We shall see...

Eric

ejcheli · Mar 27, 2014

Here are my NEW cylinders... they are nearly perfect and I'm completely satisfied with them. The pistons slide down beautifully and every dimension that matters is spot on. I don't have pictures of the rest of my progress at this point but basically everything is done except for the connecting rods!

johnmcc69 · Mar 27, 2014

I think it's looking great! That's going to be nice.

John

ejcheli · Mar 31, 2014

Thanks John.

Well, today I got quite a few pictures of the progress to date. Its really starting to look like something now!

Btw, the bottom picture of the faceplate is not finished, its just rough cut right now but I wanted to see how it fit and decided to share the pic.