Author Topic: Designing and building my own .049 (Read 3942 times)

Dane Martin · « **Reply #50 on:** May 31, 2020, 09:07:57 AM »

Power or RPM may be a little down. But it is an 061 that barely flew a light baby ringmaster. It's not as good as it was. But .... I pulled it apart to see if I see any shiny siezy parts. And I found this. So my stroke ended up slightly taller than the original! Let me fix this and clean up a little and we'll see what's up.

Great suggestion on the finished size though. That makes sense.

Oldenginerod · « **Reply #51 on:** May 31, 2020, 04:41:18 PM »

Quote from: Dane Martin on May 31, 2020, 09:07:57 AM

Power or RPM may be a little down. But it is an 061 that barely flew a light baby ringmaster. It's not as good as it was. But .... I pulled it apart to see if I see any shiny siezy parts. And I found this. So my stroke ended up slightly taller than the original! Let me fix this and clean up a little and we'll see what's up.

Great suggestion on the finished size though. That makes sense.

Well that's not good.

If BDC is lower then TDC must be higher. At least that may give a little more compression

. Is that the original backplate? Or did you make it?

bob whitney · « **Reply #52 on:** May 31, 2020, 07:12:17 PM »

I have about 20 bank brass sleeves left over from waynes work u are welcome to them .will include a completed chromed sleeve to see how he did his if u are interested RAD

Dane Martin · « **Reply #53 on:** May 31, 2020, 08:06:34 PM »

RAD, I would definitely be interested!

Rod, yeah i put a stroker kit in it!! Haha. That it's an original CS backplate. My crank pin ended up a few thou farther out on the flange than the oem.

I cleaned up the piston bite on the backplate. There was a gouge on the liner top where it contacts the head. It was all the way across the face, so I figured I'll fix that while I got the engine pulled apart. I also lengthened the intake window in the crank so it fills the venturi area. Not wider, it just wasn't centered fore and aft correctly. Best run yet. Got 2 minutes.

Dane Martin · « **Reply #54 on:** May 31, 2020, 08:08:17 PM »

Here's the 2 minute run. Checked temp with the super scientific finger on the case method. Not any warmer than a normal engine. Still terrible on the needle. There's about a 1/4 turn total sweet spot. Balsa in the venturi didn't help

Dane Martin · « **Reply #55 on:** May 31, 2020, 10:10:24 PM »

It's hard to say, but it didn't look like it's twisting.
Also however, the piston kissed the back plate again. No where near as bad, but I can't imagine any at all is ok.
And... the con rod fit is noticeably looser than what it was. It's getting to the point I'd say, I need to stop and analyze. It looks oblong. Maybe from hitting the plate and pulling up. Maybe my crank pin sucked. Maybe both.

And in addition to all that... the compression is, and has always been terribly low. So should I start over on the crank, but this time also make a rod and piston?

Yes, I already know this is entirely too much work for an obsolete .061. But I'm getting a great experience and a lot of practice.

Tim Wescott · « **Reply #56 on:** May 31, 2020, 10:16:48 PM »

I suspect that letting the backplate try to pull the piston off of the rod was what did that in.

What's the liner made of? I'm not sure you can do anything other than steel & cast iron DIY, unless you have a DIY chrome or anodizing setup.

Dane Martin · « **Reply #57 on:** May 31, 2020, 10:35:31 PM »

Quote from: Tim Wescott on May 31, 2020, 10:16:48 PM

I suspect that letting the backplate try to pull the piston off of the rod was what did that in.

What's the liner made of? I'm not sure you can do anything other than steel & cast iron DIY, unless you have a DIY chrome or anodizing setup.

I'm thinking possibly this to make a matched cylinder and liner set?

https://www.ebay.com/i/283843231040?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=283843231040&targetid=884131384999&device=m&mktype=pla&googleloc=9030753&poi=&campaignid=9426356364&mkgroupid=96480183780&rlsatarget=aud-412677883135:pla-884131384999&abcId=1140476&merchantid=6296724&gclid=CjwKCAjwq832BRA5EiwACvCWsR8NztE6ckeTTfj22ZWDfUgSWGlEiO_r3sgfQhLuMOMsjgC6slQw9hoCaDEQAvD_BwE

Dave Hull · « **Reply #58 on:** May 31, 2020, 11:18:37 PM »

Danish,

Looks like you having more fun per oz. of chips than is legal--even in the Silver State!

You might want to look at the P/L material combinations used on older production engines as a way to gauge longevity.

1. Liner or integral fin sleeves made from Ledloy or something similar to your 12L14 alloy. Often used with fine grain cast iron (Mehanite) pistons and using a lapped fit. Taper is recommended.

2. A steel liner as in (1) above, but with an aluminum alloy piston and a compression ring. This makes the running fit achievable since there is initial clearance that is sealed by the ring.

3. A steel on steel setup as you mentioned. Perhaps more like a Cox setup? But I'd bet they were using different alloys. I'd have to go figure that out.

4. More modern stuff that we all prefer nowadays that generally requires plating for longevity.

I'm sure guys can fill in details on these, and other variations. There actually was a great deal of experimenting using different materials and platings to try to find a magical pair. I think I read a few articles by Don Jehlik and John Kilsdonk about some of them. I would worry about galling with a lapped fit of identical materials.

The Divot
"Leaving distinguished holes in the ground wherever my airplanes may fly"

PS--I'm late to the discussion on the collet design, but take a look at tool tapers, such as on your lathe tailstock. Most of these are around 3 degrees and are self-seizing. Somewhere around 7 degrees of taper on a precision ground steel shaft is considered self-seizing limit if in good condition and clean. Increasing the amount of taper more would be better for a crankshaft hub application. The old Mickey Red Heads probably exploited(?) the far end of that feature. They were really blunt--but worked.

Dane Martin · « **Reply #59 on:** June 01, 2020, 08:08:44 AM »

Quote from: Dave Hull on May 31, 2020, 11:18:37 PM

Danish,

Looks like you having more fun per oz. of chips than is legal--even in the Silver State!

You might want to look at the P/L material combinations used on older production engines as a way to gauge longevity.

Good day sir! I am in fact, having loads of fun. To hear that thing pop off and continue to run left me wanting to try more!

So, in my "research" I found some fellows saying EN1A was a good material to use, but replies and more reading on "practical machinist", and other sites, lead me to believe 12L14 was possibly the way to go. I didn't research Cox too much, but what I did; they just kept saying leaded steel.

I am not at all opposed to the idea of plating. I am simply not set up for that, so it's all things I'm weighing the options on.

bob whitney · « **Reply #60 on:** June 01, 2020, 09:35:14 AM »

if I am not mistaken the cox pistons are hard plated

I need your address I will send u some odds and ends to look at,plus the sleeves

Oldenginerod · « **Reply #61 on:** June 02, 2020, 05:24:32 AM »

Quote from: bob whitney on June 01, 2020, 09:35:14 AM

if I am not mistaken the cox pistons are hard plated

Hardened rather than plated I believe. The inside and crown of the piston was copper plated so that the chemical hardening didn't prevent the rod being swaged into its socket. So, only the outside surface (sides) of the piston was hardened and ground. In time the rod socket work hardens.

Dane Martin · « **Reply #62 on:** June 02, 2020, 07:33:01 AM »

Quote from: Tim Wescott on May 26, 2020, 06:54:21 PM

Based on all that -- I'd suggest finding some plans for an engine (there's a few "beginners engines" on modelenginenews.org) and just building to plan. Or grab a clapped-out engine and make some new bits (unless you've done that). Once you get that working, even if it's not strong enough to get the skin off of hot milk, then go and build an engine.

Tim,
I may have dismissed the idea of a beginner level engine earlier... but it was purely an aesthetics concern. I will also eat my words here again (twice in the same thread) and look more into that. But also... I'm thinking of making a "bench test case" , where it will be the internal dimensions of this CS... but just a dumpy little blocky thing. Something super easy to make accurate with what I have.
As it turns out, making parts and then hearing them run is pretty fun anyway!

Tim Wescott · « **Reply #63 on:** June 02, 2020, 08:05:08 AM »

Quote from: Oldenginerod on June 02, 2020, 05:24:32 AM

Hardened rather than plated I believe. The inside and crown of the piston was copper plated so that the chemical hardening didn't prevent the rod being swaged into its socket. So, only the outside surface (sides) of the piston was hardened and ground. In time the rod socket work hardens.

What would it have been hardened with? Nitride? Or plain old case-hardened with carbon?

Dane Martin · « **Reply #64 on:** June 02, 2020, 08:24:26 AM »

Quote from: Tim Wescott on June 02, 2020, 08:05:08 AM

What would it have been hardened with? Nitride? Or plain old case-hardened with carbon?

From my research (but I don't actually know) nitride was the most consistent answer

Tim Wescott · « **Reply #65 on:** June 02, 2020, 09:17:14 AM »

Quote from: Dane Martin on June 02, 2020, 08:24:26 AM

From my research (but I don't actually know) nitride was the most consistent answer

Now that's interesting -- because my understanding is that nitriding is something that can be done in a small shop.

But then, the gist of the passage that I read was that it would harden your steel, but it would warp it enough that you'd need to do a final grinding pass, and if you're building motors for fun it's easier to just go with 12L14 cylinder and cast pistons. I think the author's opinion was that long before you wear out an engine, you'll have another one freshly built that wants to fly something.

Dane Martin · « **Reply #66 on:** June 02, 2020, 12:53:00 PM »

So according to other successful small engine hobbyists, I've come to a conclusion for now. 4140 for the liner and 6061 for the piston. There's a machine shop in AZ that sells excess material on Ebay for a very good price with combined shipping, so I ordered a few pieces of each. Now, if this leads to low run time, so be it. Like you say Tim, I'll have some extras!
Maybe if I can see some continuous success in small batches, I can work towards a goal of plating and what not. Get a little more modern as I develop my skills

Tim Wescott · « **Reply #67 on:** June 02, 2020, 01:35:24 PM »

Quote from: Dane Martin on June 02, 2020, 12:53:00 PM

So according to other successful small engine hobbyists, I've come to a conclusion for now. 4140 for the liner and 6061 for the piston. There's a machine shop in AZ that sells excess material on Ebay for a very good price with combined shipping, so I ordered a few pieces of each. Now, if this leads to low run time, so be it. Like you say Tim, I'll have some extras!
Maybe if I can see some continuous success in small batches, I can work towards a goal of plating and what not. Get a little more modern as I develop my skills

If you use 6160 for the piston you'll need cast-iron rings, with all the hassle that brings. I don't think that 6061 running on steel will last for any time at all.

Dane Martin · « **Reply #68 on:** June 02, 2020, 01:50:44 PM »

Quote from: Lauri Malila on June 02, 2020, 01:48:58 PM

I suggest that you read Robbies article about their TR engine. Just google "FMV story". The metallurgy is explained well there.
I allready offered you some Mahle #138, it's good enough for your purpose. L

I will gladly accept your offer! Thank you. I'll look up that research material also.

Dane Martin · « **Reply #69 on:** June 02, 2020, 02:40:57 PM »

Quote from: Lauri Malila on June 02, 2020, 01:48:58 PM

I suggest that you read Robbies article about their TR engine. Just google "FMV story". The metallurgy is explained well there.
I allready offered you some Mahle #138, it's good enough for your purpose. L

Also, can you help explain some of the statements made?

It shows also that an 18% Si-Aluminium alloy should be good for brass or a 12% Si-Aluminium alloy cylinder.
The mentioned alloys can for instance be obtained in bars through dealers of Mahle-Germany. (Mahle 138 and
124 alloys respectively).

When they mention a brass cylinder, is that a chrome plated brass cylinder?
And is the second part of the statement using an 18% si piston in a 12% si alloy liner, and would that be plated or without?

Thanks for your time everyone

Dane Martin · « **Reply #70 on:** June 02, 2020, 04:34:06 PM »

Quote from: Motorman on June 02, 2020, 04:27:13 PM

btw speaking as someone who has done chroming in my home shop, I would avoid attempting any kind of plating operation unless you are highly versed in industrial hygiene.

Motorman

I am versed in industrial hygiene because of my career, and our strict safety practices. And because of that, I know enough to know that I don't want to get involved in that with my young kids and my active household!
When I get to the ABC or AAC side of the experimentation, i would farm that out, knowing it would be expensive...

Thanks for all the notes guys. I'll keep reading up on the FMV steel / iron experimentation.

Tim Wescott · « **Reply #71 on:** June 02, 2020, 06:48:47 PM »

Quote from: Dane Martin on June 02, 2020, 04:34:06 PM

I am versed in industrial hygiene because of my career, and our strict safety practices. And because of that, I know enough to know that I don't want to get involved in that with my young kids and my active household!
When I get to the ABC or AAC side of the experimentation, i would farm that out, knowing it would be expensive...

Thanks for all the notes guys. I'll keep reading up on the FMV steel / iron experimentation.

What, you have a problem with hexavalent chromium in your basement? Wimp.

If I ever build a home-grown "modern" engine, the furthest I intend to go is a hard anodized cylinder for an AAO combination, because sulfuric acid scares me less than chromium in solution. But I suspect I'll pass away before I get to that check mark on my bucket list.

Dane Martin · « **Reply #72 on:** June 02, 2020, 06:56:18 PM »

Quote from: Tim Wescott on June 02, 2020, 06:48:47 PM

What, you have a problem with hexavalent chromium in your basement? Wimp.

I fear my kids may get into chroming parts for harleys and get in with the local biker clubs. Then dad ain't so cool anymore....

Tim Wescott · « **Reply #73 on:** June 02, 2020, 07:07:16 PM »

Quote from: Dane Martin on June 02, 2020, 06:56:18 PM

I fear my kids may get into chroming parts for harleys and get in with the local biker clubs. Then dad ain't so cool anymore....

Yup, that's worse than any chemical damage...

Chrome plated bongs. Hmm.

Dane Martin · « **Reply #74 on:** June 04, 2020, 08:52:16 PM »

I Successfully made a spray bar for the wasp 049 today. Pretty faithful replica, I think. Drilled and tapped for 1-72. I ordered some 1-72 screws to make the needle easier. Lol I know, I cheated. But I'm happy I got the hole centered in the spray bar. That came out classy. Main section was 0.111 and the step down / minor diameter of the barb is 0.100. Barbs are 0.125

Great practice for making my own

Tim Wescott · « **Reply #75 on:** June 05, 2020, 09:47:47 AM »

Quote from: Motorman on June 05, 2020, 09:28:46 AM

Good luck making the point on the needle.

Tool post grinder on the compound.

Dane Martin · « **Reply #76 on:** June 05, 2020, 09:56:17 AM »

I'm feeling lucky these days. Ha!

Check this little sweet heart out

https://images.app.goo.gl/TNv7JUWcr3AG7V8Z6

Tim Wescott · « **Reply #77 on:** June 05, 2020, 10:02:07 AM »

Quote from: Dane Martin on June 05, 2020, 09:56:17 AM

I'm feeling lucky these days. Ha!

Check this little sweet heart out

https://images.app.goo.gl/TNv7JUWcr3AG7V8Z6

If you want to grind tapers it'll need to go on the compound. I'm not sure which Smithy you have, but that grinder looks like it'll go on the cross-slide directly, but not the compound.

I've heard stories and maybe seen a picture at some point, of folks mounting a Dremel tool on a lathe as a tool post grinder. A real true Dremel won't be as accurate, and won't do heavy stuff -- but for that task it may work.

Dane Martin · « **Reply #78 on:** June 05, 2020, 10:07:56 AM »

Quote from: Tim Wescott on June 05, 2020, 10:02:07 AM

If you want to grind tapers it'll need to go on the compound. I'm not sure which Smithy you have, but that grinder looks like it'll go on the cross-slide directly, but not the compound.

I've heard stories and maybe seen a picture at some point, of folks mounting a Dremel tool on a lathe as a tool post grinder. A real true Dremel won't be as accurate, and won't do heavy stuff -- but for that task it may work.

Oh, didn't notice that. Ok well no prob. I'm sure I can whip something up. May take some trial and error, but that's half the fun

Tim Wescott · « **Reply #79 on:** June 05, 2020, 10:53:50 AM »

It may be easiest to get that grinder and modify it. You would have to check spacings, but you might be able to cut that foot off and braise one on that is right on the housing.

pmackenzie · « **Reply #80 on:** June 05, 2020, 04:01:42 PM »

This sort of looks like a needle valve, no grinding required.

Dane Martin · « **Reply #81 on:** June 05, 2020, 04:03:49 PM »

Quote from: pmackenzie on June 05, 2020, 04:01:42 PM

This sort of looks like a needle valve, no grinding

Awesome! I've been watching a lot of Joe Pie's videos. Trying to get educated

Tim Wescott · « **Reply #82 on:** June 05, 2020, 04:27:40 PM »

Quote from: pmackenzie on June 05, 2020, 04:01:42 PM

This sort of looks like a needle valve, no grinding required.

Nah, that looks like a push-pin.

pmackenzie · « **Reply #83 on:** June 05, 2020, 04:43:12 PM »

Add a thread and knurl and it is pretty much a needle valve.

The point was to show how you can cut a small diameter taper without having to grind it.
He has lots of good tips in his videos.

Tim Wescott · « **Reply #84 on:** June 05, 2020, 04:47:53 PM »

Dane, if he's using the technique of machining the cylinder (or point) a bit at a time, then with your 1-72 screw, you'll need to make a block that's threaded through with a jam nut at the end -- and hope that it holds your screw accurately enough.

Tim Wescott · « **Reply #85 on:** June 06, 2020, 02:35:33 PM »

Quote from: Motorman on June 05, 2020, 09:21:36 PM

That's funny. I got some drill rod the same diameter as the needle stem and tried to put a point on that LOL. I ended up just using a bench grinder by hand to make the taper. It works ok....

That's exactly what I've done for needles. "OK" is about the best I've attained -- for me the point is never quite on center, so as you're adjusting it there's a quadrant of the turn where the needle doesn't make much difference, or even works backwards, and then it's back to working normally.

Dane Martin · « **Reply #86 on:** June 09, 2020, 11:54:11 AM »

I ordered a set of 7, 8, 10 and 12mm Boring bar with replaceable tip inserts. I also got a 3 piece set, right left and center turning tools. I built a table for my grinder so I can start using it properly. Not it's final resting place, but it's made of 1.25" steel tubing and a stainless tool box top.
I'll be building a nice work bench for the lathe tonight.
Then on to organizing the garage to be able to make stuff successfully

Tim Wescott · « **Reply #87 on:** June 09, 2020, 12:33:56 PM »

Quote from: Motorman on June 09, 2020, 12:10:53 PM

Nice grinder, I put little sheet metal trays under mine to catch most of the dust.

I have a workbench that does that

Christopher Root · « **Reply #88 on:** June 11, 2020, 11:12:09 AM »

How are cast iron pistons made? Cast? Machined?

Dane Martin · « **Reply #89 on:** June 11, 2020, 11:24:47 AM »

Quote from: Christopher Root on June 11, 2020, 11:12:09 AM

How are cast iron pistons made? Cast? Machined?

I bought some class 40 grey cast in rods. The material spec sheet says its easy to machine but has poor welding compatibility... lol

Tim Wescott · « **Reply #90 on:** June 11, 2020, 12:44:48 PM »

Quote from: Christopher Root on June 11, 2020, 11:12:09 AM

How are cast iron pistons made? Cast? Machined?

For home-built engines, you buy high-quality cast iron stock and machine the piston. The point isn't so much to cast a piston -- it's to have dissimilar metals at the piston to cylinder interface.

Christopher Root · « **Reply #91 on:** June 11, 2020, 01:35:43 PM »

So is the engine case the only cast part? Everything else is machined?

Dane Martin · « **Reply #92 on:** June 11, 2020, 01:50:23 PM »

Quote from: Christopher Root on June 11, 2020, 01:35:43 PM

So is the engine case the only cast part? Everything else is machined?

Not always. The case can be machined also. Mine will be. I'm just making something that can fly a little 1/2a plane that is 100% from my garage

Steve Helmick · « **Reply #93 on:** June 15, 2020, 04:10:55 PM »

Dane's crankshaft is probably every bit as good as the original CS crank, if not better!

What sort of lathe is that? Mine is a 3" x 14" Grizzly....they don't sell it anymore. It's a lot like the HF equivalent, but longer between centers. The Chinese factory apparently offers options and quality choices like a Chinese restaurant. Choose one from column A and two from column B sort of thing. I put a 1/2 dowel pin in my 3-jaw and was pleasantly surprised by how little runout it had. It's fine for fiddling with heads, adapting spinners, and making venturi/restrictors. I also modified a pendant light fixture part awhile back, for our bathroom remodel.

Steve

Dane Martin · « **Reply #94 on:** June 15, 2020, 04:17:37 PM »

Hey Steve.
Thanks for the vote of confidence. Here's what I did... Bill Hughes sent me all new parts for this CS engine. Comparing the crank, I have found no difference in the run quality between mine and the factory. So that's kinda cool.

My lathe is this one

https://smithy.com/Smithy-Combo-Lathe-Mill-Midas

Dane Martin · « **Reply #95 on:** June 17, 2020, 05:37:34 PM »

Getting my work station together. The bench is new, to me anyway. Painted and sanded and cleaned up real good. Then my friend came over today with the cherry picker so we could put the lathe on the new bench.

Dane Martin · « **Reply #96 on:** June 17, 2020, 05:41:10 PM »

Also got a few new turning tools. Bore bars down to 7mm and a variety of turning tools

Dane Martin · « **Reply #97 on:** June 26, 2020, 07:44:30 PM »

This might sound pretty basic, but it was good practice. I made some sleeves for some venturis (venturii?) today. These were 0.281, so I sleeved them down to 0.256.
I had a tube that was 0.256 ID and 0.390 OD. I turned them down to an interference fit. So the practice was getting back into reading a mike properly.

Dane Martin · « **Reply #98 on:** June 27, 2020, 06:29:54 AM »

Easy in the mill with new center drills