Next Project

Indulge me guys, this is my next project. When all the extra metal is cut away this will be a Vivell .09 diesel.

Randy, this is really amazing. What would be nice is for you to make a series of photos of the process and share it with us like Al Rabe did with his Snaggletooth Mustang.

OK, I can do that. I am a little reluctant since this isn't exactly CL stunt, but its certainly related. Stay tuned.

We are all appreciative ( and sometimes jealous ) of extreme craftmanship, especially related to models or planes.

Randy,
Thanks for sharing your engine projects. I've been looking at the Motorboys site (http://archive.dstc.edu.au/BDU/staff/ron/)and even started a Little Dragon. Your postings may give me the inspiration to actually finish it.
I was wondering why the majority of published projects seem to be only ignition or diesel? Do you, or you other guys know of plans or casting kits for simple glow engines?

Thanks!

Norm Furutani

Norm,

The only glow engine kit I know of is the Titan .60 by George Genevro, its still available and a steal at $35 with all the materials required to make the parts and a full copy of the original construction article.

As far as why ignition and diesel I think there are 2 reasons. First, it may be the only way to ever own a rare engine, you'll find that most casting/drawing kits are replicas. Second, since there are hundreds of new hi performance glow engines readily available, why bother? That said, I am getting ready to build a AJC .65 Skyburner in a glow version with stunt timing to use on an old timer. AJC stands for Andrew J. Coholic, the designer. While he's not listed in the MBI book list of Motor Boys, he's the latest addition to the group. He designed this engine inpired by the Edco Skydevil. By the way, generally speaking, the only additional part in a diesel is the contra-piston, so they are as "simple" as glow engines.

For me I simply enjoy the building and get the added bonus of having something of value when I'm done. Some I will use, some I will look at. I need another model like I need a hole in the head right now, so engine building I find extremely satisfying right now.

Well I've made some progress only to be put back to square one. Here are a series of shots of the case machining and the near finished product and the flaw. It may be repairable with some JB weld, but that's not really the way to do it right. I've notified the gent that supplied the casting and we'll see what happens. These shots show the fixture I built to hold the work in the lathe. It doubles as a mill fixture as well.

I'll wait for questions rather that go through descriptions.

Wow, Randy!

(where did the case go wrong, and what is that last photo?)

You got me remembering my late friend Ivo, he was a model airplane engine lover.

He didn't care about flying or building (as a matter of fact he couldn't do either one), but he really knew about engines. He had an extra apartment where he kept his stuff, and in spite of our friendship he never let me in there. Nobody knows how many engines he had, but I figure it could be above 200.

He made a couple of engines, his own design. He used a CB .25 crankcase and made the "guts" of the engines.

He told me that the crankcase was the one thing he couldn't make, since it involved the molding technique and it required equipment he didn't have.
If you reallly wanat to develop your skills as an "engine man" you could get some "hollow" crankcases and plan the engine from there.

I'm really amazed by your ability!

There are gas voids in the casting caused by impurities in either the mold or the aluminum. The caster has agreed to replace the casting so I'll start over again when it gets here. Still allot or work can be done so tonight I will start on the main bearing housing.

The last shot is the gearbox of my lathe. This lathe does not have quick change gears, so when I want to cut threads I have to arrange the gears to cut the pitch I need. In this case the gears are set to cut a 32 TPI pitch thread.

I already have several engines I've designed, after all, thats what I do for a living. The purpose of my current efforts is to have rare engines I couldn't own otherwise.

> The purpose of my current
> efforts is to have rare engines I couldn't own otherwise.

I'd say anything you build for yourself is a rare engine indeed,
and worth quite a lot.

I have an old Southbend lathe, but I've never been brave enough
to tackle a project like this. Mostly I use it to make jigs and
such. Last night, I was milling slots in a piece of basswood.
I mentioned to Howard Rush how well the stuff machined.
He replied "There's nothing like a good piece of bass."

Except maybe a good straight man.

Randy,

That looks just great I am not to the point to be able to cool stuff like that yet. So in the mean time I do custom Cox reed valve engines. I do the chrome cylinder and the anodizing all myself too.

Take care,
Tim Wiltse

Neat Tim, I've seen your stuff on the bay.

Well, today I finished the main bearing housing. That entailed turning main bearing from bronze, turning and threading the case end of the housing, pressing the main bearing into the housing and parting off the finished part.

I pretty much look at trees like you look at metal I guess! Couldn't afford antiques, so started building them. Somehow, they pale in comparison. Very neat work! I hope you don't get any hassels over the BOM rule...

In this installment I have the crank blank, and the cylinder (all three trys). The cylinder scrapped it the 2 ended bit. This finished end is too small in diameter below the last fin. The other is too short by .035, both due to my inattentiveness to the prints. I've found when doing repetitious operations like this you have to check back allot. The crankshaft is done on the main bearing end and will be placed in a yet to be made fixture to turn the crankpin. And last, hey, it looks sorta' like an engine!

The smoky shot is hogging the crankshaft.

One last shot, the doomed cylinders.

A few more bits if anyone is interested.

Tonight I got the con rod made and all but finished the crankshaft, if anybody cares.

Randy,
I care. This is great stuff!!! Your pictures of the machining work are terrific. Please keep them coming. Thanks for letting us share in the process.
DennisV

Great stuff... When are the test runs plannend?
Paul, Belgium

>Great stuff... When are the test runs plannend?
>Paul, Belgium

Paul,

I don't have a schedule, but I expect to be finished in a couple weeks, I'll poat a running shot then.

Randy Ryan
AMA 8500
SAM 36
I fly 'em all and love it!

Beautiful work to say the very least.

> That looks just great I am not to the point to be able to
>cool stuff like that yet. So in the mean time I do custom
>Cox reed valve engines. I do the chrome cylinder and the
>anodizing all myself too.

I must say, regardless of what one might think of the engine (_I_ think it's gorgeous, by the way), that is one mighty gorgeous *photograph*. Sharp, great lighting, great depth of field, uncluttered background, shows exactly what you want to show. You should try posting this for comment on http://www.photo.net.

>Randy,
>
> So in the mean time I do custom Cox reed valve engines.
> I do the chrome cylinder and the anodizing all myself too.

I did not know Cox made reed valve chain-saw engines.

Nice work.

Even though I can only see a little of it at a time...

Randy,

STOP IT!!!!!!! You're making me SICK!!!!!!

WITH ENVY!!!!!!!!! It is simply AWESOME. Don't have any other words to describe it.

Bill <><

Well, more progress. As usual I'll let the pictures speak and answer any questions later.

Hi Randy Ryan, All I can say is fantastic! I don't think I am the only one ,speaking for myself, when I say, this is also a part of stunt and modeling in general. One that is not understood either! Love your posts! Keep the Diesels coming! If you ever make a video of you making a diesel, please let me know. PAW's, Olivers, Webers, home made, its all good! Thanks, Mike

I love seeing this sort of thing, especially as my father has turned many a casting kit into a functioning steam engine.

What causes me to take pause is seeing the amount of effort it takes to produce Randy's engines and my dad's steamers.

When we can, for example, buy a rather decent little Magnum 36 and have a highly suitable powerplant for, oh, an ARF Nobler. All for, what are they now? something like 70 bucks.

I'm not saying Randy's roll-your-own engines are better or worse, it just helps once in awhile to calculate how many man-hours each of us must invest in work in order to buy some of the best engines ever available to the modeling public.

If that doesn't set you back some with glee at the current situation, imagine doing it Randy's way. Without the jump-start of a casting kit.

To Randy, I continue to enjoy seeing your work. But how about also showing us some of your disasters? I know Dad has had a few, and not just uncovering casting flaws...

So, its Dan's fault!! So happens I have a disaster to show you tonight. Enjoy the steps to scrapping one of the most important parts of a 2 stroker. Tonight I scrapped the cylinder cutting the bypass ports .05 too high, I could cry. Its time to lay off for a couple days.

To me, building an engine has nothing to do with its value, though it is nice to know it has value even if my time comes out being worth something like .75 an hour. No, the enjoyment is in the building, utility is not necessarily an objective. Just a running engine that was produced by my efforts. I will and do use some, but infact my contest ships all have "bought & paid fer" motors in their noses even if reworked a little by me. I have plans for a stunt engine based on a casting currently available from a friend, Andrew Coholic, so I will eventually fly a model in a contest with an engine of myown making. I may retro fit this Vivell to my Acromaster just for kicks.

So if you're going to look at it in dollars spent vs time and its value, there's no contest, I'm crazy to even think about building an engine.

Hi Michael,

Thanks for you comments. As far as a video I'd never thought of it. In fact, I just got the dig cam I'm documenting this build with. Engine building is a fascinating hobby right along with model airplane building or anything else. My wife used to complain about me building model airplanes and I explained to her that if I didn't build them I'd build something else, boats, ships, musical instruments, clocks. That's what I am, a builder and for me it is both a stress reliever and an expression of myself. She has long ago stopped her complaints and even learned that its part of me. She has even sent me flying when she sees things getting to me. She's a keeper.

Thanks,

Randy.
How was the crankshaft held in the fixture used to turn the crank pin?
I can not tell by the picture if the fixture was tapped for the threads on the crankshaft or maybe a set-screw was used.
Thank you.
John Tate

John,

The fixure was threaded to accept the propnut thread and reamed to fit the bearing journal. It was run in and snugged then te pin turned.

Thanks Randy.
I was wondering how you keep the crankshaft from slipping.
John Tate

You'd be surprised at how little torque is required to hold it in place if the tool is properly shaped and sharpened. With these little bits its easy to over-do it tightening things. When threads are overtightened on something like this the distortions are huge. Yhis is something I must keep myself aware of because I'm a habitual over-doer.

On most of my crank fixtures I just drill clearance for the thread and use a nut. For this one the length of chuck overhang was so great I decided to do it by tapping the fixture.

Randy,

I am reduced to hiding behind the typical defense put up by liberal Democrats when their social engineering goes bad and they get called on it: "I tried to do the right thing; and besides it's not my fault!"

Now if I can just slip God into this thread somehow...

I think we're on the same page here, as a fan of the capitalist system I was only trying to illustrate how much we get for not much money today, and how this ratio of bang-for-the-buck is ever so much better than 10, 20 and 30 years ago.

Of course you enjoy the building and there is no monetary concern. Same deal with my dad, same deal when I am building a new model airframe.

Great pictures, as always.

I understood that Dan, just laying down some logic for some that may not understand it. You'd be surprised, or maybe not, at the people that react to this in a purely monetary vein. I've been told that its pretty stupid to build engines when I can buy them, and even more stupid to build engines that use 1950's technology. Some people simply won't understand.

I don't care though, while they grub for the bucks, I relax in my shop with a satisfying hobby. Money ain't everything (but it sure helps out at times).

Randy,

I understand. I don't call my activities in the shop a hobby, I call it thearepy. I recently asked a question here about setting up my ST 35's for stunt. I thank the people for pointing out that I could buy a new stunt engine for $65 or so and that I could get more than that from ebay for my ST's. I already knew that. What I wanted to know was if anyone was getting good stunt runs from that engine and pass on some tips for doing so. The engines run fine now but I wouldn't want to put them in a stunt airplane as is. I can afford a new stunt engine or two If I wanted one, but it woldn't be as much fun as making something I already have work. I picked up on something else you said and that was if you started doing it for money it wouldn't be fun anymore. Amen brother! Been there done that and learned the hard way. Lest I forget. Your engines look super.

Tom,

You're so right, therapy is a better term. I need to build things to relax and express myself.

Thanks for the compliment, its always nice to have people appreciate your efforts.

Well, tonight I caught up and got the new cylinder made. It was nerve-racking because even though you check and triple check you're still gun-shy. All came out well and I'm back on track to finish up.

First shot, new cylinder in the lather

Second shot, indicated in on mill table to drill head bolt holes.

Third shot, tapping head bolt holes. (3-48)

Forth shot, checking and rechecking the bypass port plunge depth, this is where I blew it before. (.745 off the table)

New cylinder continued.

First shot, shaking like a dog craping peach pits! Cutting the bypasses.

Second shot, trial fit showing exhaust ports.

Third shot, In living color, the base assembly of the engine, the cylinder ready for lapping.

Well, coming down the home stretch. Sorry but my camera batteries gave up about the time I started lapping. In the first shot you see all the engine parts minus compression screw, spinner nut and Gitts filler cap, ready for assembly. You can't see the gaskets because they're white Delrin and they don't show up. Also in the rows you see all the fixtures and tools made during thie engine build to hold and cut various bits. Then you see shots of piston, cylinder and their repective laps.

Lapping is done with specially made tools(by me)and 36 micron diamond paste. In this case I made the cylinder lap from bronze but I won't do that again, aluminum is fine. The cylinder lap is threaded, taper reamed and split so it can be expanded. It really important to understand what relationships here because as you expand the lap it acually expand only at one end give the tool a tapered shape. This is GOOD, if you lap the part correctly and use the taper to your advantage, that is, small at the top and big at the bottom, this cylinder is tapered about .00075". The piston lap has a pinch screw to reduce its ID around the piston as you go. Using the taper normally present in lathes to some degree, I make sure I identify the ends so that when I lap the piston the big end will be at the top.

Laps are "charged" with diamond paste. The cylinder lap is charged by rolling it between 2 pieces of flat tool steel with paste applied, this imbeds the diamond particles into the surface of the softer metal. The piston lap it charged by rolling it over the benchtop with a drill blank as an axle and diamond paste applied to it.