Author Topic: Props first engine - Elmer Wobbler #25 (Read 24210 times)

propforward · « **on:** January 11, 2013, 02:53:47 PM »

I decided to go ahead and just post a few pictures of where I am so far on my first ever engine build.

I haven't got very far with it, but I figure I might as well just start, and use this as a build log, kind of thing.

I started with the crankshaft bearing, mainly because on the day I started it was the only item I had a suitable piece of material for. Here is my first attempt.

It's a bit rough, but it is also my first piece of brass turning.

I therefore called it a successful day on that particular item, and celebrated accordingly

Safety note - beers only come out once all tools are cleaned and put away. No activities in the shop except for pondering and sweeping when the relaxation begins.

Anyhoo, the next item I turned my attention to was the connecting rod.

That is as far as I have got with that item. I need to thread the little end, and machine flats and drill a pivot hole in the big end. Elmers plans call for flats both sides of the connecting rod big end, but am only going to do one, mainly because I think it might be more arty looking. If it looks rubbish then I'll do 2.

It took me three goes to get the con rod this far. I destroyed the other 2 because holding the part and turning the longish, thin diameter were difficult, and after reading Jos thread about her home made follow rest today, will be making one of those for myself for small work. In the end I machined the con rod in 3 goes - three short lengths at a time, so to speak. I managed to get the three sections blended fairly well, so I'm happy enough for now.

By this time I had acquired some larger diameter aluminium and some steel, and so I had a try at the flywheel, and also the jig pin in Elmers plans. I realise a lot of people just make use of their mills to place all the holes accurately on the support frame, but since I don't have a mill yet I thought I would try using Elmers ingenious jig approach for laying out the holes.

This picture shows first flywheel, jig pin and the con rod and bearing.

At the time, I had decided to leave the flywheel as a plain disc as shown in the picture. However, since then I broke a drill bit off in the flywheel attempting to drill the hole for a set screw, so I shall be remaking the flywheel. I have decided that I would rather make it in brass anyway, and I am not going to shy away from attempting a groove each side of it either.

Next up, I had a go at the crankshaft. So far all I have done is the main shaft:

I have yet to make the crank disc for the end of it.

I have also started work on the frame for the engine, and have rough cut it to shape, and drilled the bearing hole, the inlet and exhaust port holes, and the cylinder pivot hole. I need to do some finishing work on it, which will be done the old fashioned way by hand with files, and then various grades of emery paper, and if that looks good I'll post a picture of it.

The engine has taken a bit of a back seat for now while I make some other tooling, plus I have been working on motorcycle maintenance and repair over the winter break, but I should be able to attempt some more work on the engine this weekend, which is exactly what I said last weekend.

Anyway, that's my wobbler so far.

b.lindsey · « **Reply #1 on:** January 11, 2013, 02:57:04 PM »

Those all look great to me!! Given the magnification on the brass bushing, it looks plenty smooth enough too!!! You're off to a good start there and I will be following along. THat first engine when it comes to life is really special.

Bill

arnoldb · « **Reply #2 on:** January 11, 2013, 03:56:37 PM »

What Bill said

Thanks for posting up Prop

Kind regards, Arnold

Don1966 · « **Reply #3 on:** January 11, 2013, 03:59:25 PM »

Looks great to me also Prop, you are off to a good start like Bill said. It will progress faster then you would expect.

Don

rleete · « **Reply #4 on:** January 11, 2013, 05:40:22 PM »

Keep at it, one part at a time. You seem to be doing well so far.

Only three tries at a small part is not a bad ratio. I think the first time is just practice.

ScroungerLee · « **Reply #5 on:** January 11, 2013, 08:15:17 PM »

Looks great Prop, the moment that first engine runs is a great reward for making parts even when you make them two or three times like I end up doing

zeeprogrammer · « **Reply #6 on:** January 12, 2013, 12:06:13 AM »

For a first turning...I'm thinking excellent!
Nice start.

I know what you mean about turning small diameter long pieces. I've done a few using your method...turning a bit at a time keeping as much meat towards the chuck as possible. Another method I've used is turning a part with some sacrificial metal at the end and using a live center. Have to really prepare for that...it's a sad thing when you get close and find out you're going to hit the live center with the tool or the tailstock with the tool post.

I've gotten real good at that. Not preparing...hitting.

propforward · « **Reply #7 on:** January 12, 2013, 12:43:56 AM »

Thanks all, I really do appreciate your encouragement. When you start out, and scrap the first few parts you make it can be a bit of a downer, so a few positive words goes a long way. Hoping to make progress tomorrow! Today I was getting my new toolpost finished up. I will write a post about that elsewhere.

steamer · « **Reply #8 on:** January 12, 2013, 09:32:57 AM »

Looking good from here Prop.....keep at it!

Dave

propforward · « **Reply #9 on:** January 13, 2013, 01:50:44 PM »

Well I spent a little more time on this yesterday, and did some work on the cylinder and piston.

First time working with the 4 jaw is certainly enlightening. It all went "OK" I guess. I'm not super happy with these parts, a big part of me says "make them again", but on the other hand, why not go with them and see what happens?

Obviously the cylinder is unfinished yet. It still needs the port hold drilled, and then chamfers and finishing on the exterior.

The piston:

I am relatively happy with. I screwed up the position of the oil grooves, but I don't think they are critical at this stage. This will only run on compressed air, so I am going to go with this for the time being. It fits in the cylinder without flopping about, so that's a step in the right direction.

Today I think I'll do a bit more work on the con rod and cylinder, and also on the frame.

There are getting to be enough parts that there is the possibility of a complete engine occurring eventually.

Also need to get some brass for the flywheel. Or maybe I'll make it in steel. That 12L14 machines up a treat, and isn't very expensive.

b.lindsey · « **Reply #10 on:** January 13, 2013, 01:56:20 PM »

Prop, those parts all look good to me. Elmer's engines are pretty forgiving in most ways so the oil grooves won't pose any problem and even a reasonably close piston fit will usually work just fine.

Bill

swilliams · « **Reply #11 on:** January 13, 2013, 02:03:14 PM »

Good stuff Prop. I'm enjoying your thread

Steve

propforward · « **Reply #12 on:** January 13, 2013, 02:07:32 PM »

I am actually excited about the fact that I made a flat bottomed blind hole in a piece of metal. It's the little things in life that keep you going!

Like bacon and eggs, which sounds pretty good at the moment.

zeeprogrammer · « **Reply #13 on:** January 13, 2013, 02:25:57 PM »

Quote from: propforward on January 13, 2013, 01:50:44 PM

There are getting to be enough parts that there is the possibility of a complete engine occurring eventually.

Cool. Get a family shot too. It's always neat to see all the parts together before the get together.

ScroungerLee · « **Reply #14 on:** January 13, 2013, 02:28:27 PM »

Looking good! At this point you should be able to feel resistance due to air pressure pushing the piston in and out of the cylinder since the ports aren't drilled yet.

Lee

Don1966 · « **Reply #15 on:** January 13, 2013, 03:45:16 PM »

Quote from: b.lindsey on January 13, 2013, 01:56:20 PM

Prop, those parts all look good to me. Elmer's engines are pretty forgiving in most ways so the oil grooves won't pose any problem and even a reasonably close piston fit will usually work just fine.

Bill

What Bill said, nice work Prop

Don

propforward · « **Reply #16 on:** January 13, 2013, 10:25:00 PM »

Right so, rather a good day today. I made more progress on the piston and con rod assembly, including threading piston and con rod, milling a flat on the big end of the rod, and drilling the pivot hole.

It looks a little beaten up from the extra work - the close up pics really show up the detail and blemishes, but it will polish up OK. In real life it looks much better - damn cameras!

But never mind that - I took the opportunity to test the piston in the cylinder again, and was mighty pleased to feel resistance as the air compressed, per Lees suggestion, and a then hear a little "thop" sound as I quickly pulled the piston out. Yay! It was even better with a light oil coat. I wandered around the shop for a good few minutes playing with that.

After that I drilled the port hole in the cylinder, and did a little dry fit of cylinder and frame. I was pleased to be able to feel pressure in the cylinder again when on the frame, and also pleased to feel the pressure go away as the port lined up with inlet and outlet on the frame respectively - definitely a good thing.

I also turned and drilled the crank disc, leaving over thickness for now, as I will skim it to the correct thickness once it is pressed on the crankshaft. Jury is still out on whether I leave the crank disc as a disc, or cut it out for that "balanced" look. I'll sleep on it.

Here are the frame, crankshaft and crank disc as they stand. Some (plenty) of finishing work needed on the frame. I'll do that during the week after I have drilled and tapped the mounting holes in it.

Moving along - there are plenty of imperfections, but plenty of positives too. Lots of stuff to build on as I progress in the hobby. I am pretty happy about it all.

vcutajar · « **Reply #17 on:** January 13, 2013, 10:42:41 PM »

You'll have it running in no time. Keep it up.

Vince

chucketn · « **Reply #18 on:** January 14, 2013, 09:26:52 PM »

propforward,
I had started on this engine some time ago, but life got in the way...
I've dug out the few pieces I had made and am following you along, so I'll be asking questions. First one, did you use the drill guide and locating pins to locate the port holes in the frame? If not, how did you locate them?

Chuck

propforward · « **Reply #19 on:** January 14, 2013, 09:43:44 PM »

Hi Chuck - that is great. I look forward to seeing pics of your build.

I did indeed use the drill jig and pins. I'll take some pictures of that. It's a neat and simple method for locating the holes, because you can then use the same jig to get the port hole in place on the cylinder as well, just about gauranteeing a good match up.

steamer · « **Reply #20 on:** January 15, 2013, 12:16:14 AM »

Great build Chuck!....keep it coming!

Dave

chucketn · « **Reply #21 on:** January 15, 2013, 01:48:50 AM »

Uh, Dave, this is Propforward's build. I just asked a question.

Chuck

propforward · « **Reply #22 on:** January 15, 2013, 01:55:21 AM »

Don't worry, I'll adopt any name going when the compliments are being handed out, it helps me feel good about myself.

propforward · « **Reply #23 on:** January 18, 2013, 02:50:52 AM »

I'm still working on it. Haven't done much lately, having had to deal with other far more mundane and boring everyday life matters, but I got down the shed tonight, and cleaned up the frame a bit, and made a base for it.

Tomorrow, I plan on making the pivot pin and soldering it into the cylinder, cleaning that whole assembly up, and then making the flywheel (for the third time).

Depending on how it goes I might even have it all assembled tomorrow - I certainly ought to have it complete this weekend.

swilliams · « **Reply #24 on:** January 18, 2013, 03:44:17 AM »

Go Prop. It's going to turn out a beaut

Steve

propforward · « **Reply #25 on:** January 20, 2013, 12:57:36 AM »

Well I've put a bit more time into it. I had a go at cutting the crankshaft disc to shape, but that turned into a hideous failure, so for this engine I'm just going to leave the crankdisc as a plain circular disc. I don't think it will matter. The replacement crank and disc are made, and ready for use. I made little jigs to keep everythig square when pressing the crankshaft and pin into the disc. (I didn't want to use loctite as in Elmers instructions).

I also made the steam connector, and began work on the third flywheel.

Originally I was using aluminum, and making them plain discs, with a hole through from the perimeter of the flywheel, but I don't think aluminum is massive enough for a flywheel really, and I don't like the lock screw right through the flywheel.

So my third attempt is in steel, and I have changed the design to a flywheel with a boss, and the boss will have a set screw in it.

I was also bound and determined to make it look like a flywheel - ie machine a groove both sides. I am giving up on aesthetics on the cylinder and crank disc, in that the cylinder will not have chamfers on the outside edges, and the crank disc will not be cut to look "balanced", so I need to add some interest somewhere, and this seems like the best place.

This is the flywheel part way into machining.

In this picture the groove has been machined both sides. Not to any specific dimensions, but even both sides. You can see some burrs and marks on the flywheel - that's OK, it isn't complete. The next stage is to drill and tap the boss for a set screw, then I will mount it back in the lathe on a shaft, and take the last finish cuts to true it up and clean it up.

It's not the best finish, although the magnification of the camera makes it look worse than in real life (honest). I am actually pretty satisfied. At least it looks like a flywheel, with rim, web and boss. I used a form tool to make the groove, and that is a tricky piece of machining. The bit wants to chatter like mad. Note to self - read your reference works on using the lathe BEFORE starting new to you operations. Turns out that having a rake angle on the form tool was a mistake. It worked much better with no rake, but this time I saved the part and didn't need to trash it.

So progress continues in a two steps backwards, three forwards kind of way. Yesterday, by lunchtime, I had fewer available parts than when I started in the morning.

However, since then things are well back on track.

Don1966 · « **Reply #26 on:** January 20, 2013, 01:10:24 AM »

Starting to shape up nicely Prop, it wouldn't be long now she will be running.

Don

propforward · « **Reply #27 on:** January 20, 2013, 01:14:55 AM »

Thanks Don. Everything takes longer than it is supposed to to make, but I ought to have this running tomorrow.

zeeprogrammer · « **Reply #28 on:** January 20, 2013, 01:18:21 AM »

Quote from: propforward on January 20, 2013, 01:14:55 AM

but I ought to have this running tomorrow.

Tomorrow? Already? Geez I feel so inadequate.

That means a video then! Looking forward to it.

propforward · « **Reply #29 on:** January 20, 2013, 01:25:13 AM »

Heh. I've been working at this model for ages it seems. I have quite the graveyard of parts that have since become "jigs and fixtures"

If it works (and all dry fit testing says it ought to) then I certainly shall post a video! I shall be quite proud of my first little effort. I realise that there are some quite magnificent models on the site, but you have to start somewhere. This is a basic little model, but I'm pleased as punch so far, and shall be very excited when it spins.

zeeprogrammer · « **Reply #30 on:** January 20, 2013, 01:50:51 AM »

Quote from: propforward on January 20, 2013, 01:25:13 AM

I realise that there are some quite magnificent models on the site, but you have to start somewhere.

As they did.

A person's first model is always magnificent.
It's the second one you have to worry about.

ths · « **Reply #31 on:** January 20, 2013, 12:19:54 PM »

Like Billy Bragg's difficult second album.

Hugh.

propforward · « **Reply #32 on:** January 20, 2013, 06:55:53 PM »

This morning I got the pivot pin soldered into the cylinder - thanks to Arnold for the idea on the little jig to hold the pin. I also cleaned up the flywheel a bit, trued the OD and sides, and drilled and tapped a hole in the boss to lock it in place.

Well, at last, after making a small pile of scrap metal, I managed to coax everything to completion. I assembled it all, and gave it a test run - it runs well!

So here it is, my first model engine.

I am just going to say, I am pleased as all get out with it.

I need to shoot some video of it, but first I need a few bits of hardware so that it will run without me holding the air gun to it. It's too awkward to run it and shoot video at the moment, but I will hopefully get that done tomorrow. You'll have to take my word for it for now.

Tennessee Whiskey · « **Reply #33 on:** January 20, 2013, 07:05:38 PM »

Great job and congratulations. The extra attention to the flywheel and leaving one side of the con rod with a radius added your own touch and looks great! Film at eleven? :cheers
Eric

zeeprogrammer · « **Reply #34 on:** January 20, 2013, 07:48:04 PM »

Congratulations! And yes, you should feel pleased. Feels good don't it?

You can try putting some tubing on, wrapping a bit of wire around it, and do the same on the air gun.
Then you have one hand free to work the camera. Or both if you use a foot. (Yes, I've done it.)
Tripod is helpful too.

Careful though. Without a groove for the wire to press the tubing in...it can pop off.

ScroungerLee · « **Reply #35 on:** January 20, 2013, 08:27:31 PM »

Very nice job, a nice clean look. Congrats!

Lee

Don1966 · « **Reply #36 on:** January 20, 2013, 10:12:57 PM »

Quote from: ScroungerLee on January 20, 2013, 08:27:31 PM

Very nice job, a nice clean look. Congrats!

Lee

What Lee said and congrats on your engine. Will we be seeing a video?

Don

propforward · « **Reply #37 on:** January 20, 2013, 10:26:51 PM »

Thanks Fellas! I appreciate the encouragement.

I followed Zees advice, and added a groove to the steam (air) connector, and doing that I was able to add a piece of vinyl tube, and get the engine to run without me holding on to it so I could shoot a few seconds of the engine in action. Just uploading it to youtube now. Since I only have dialup (the curse of living in the sticks) I anticipate in posting the video in just a few short hours.

zeeprogrammer · « **Reply #38 on:** January 20, 2013, 10:31:54 PM »

Quote from: propforward on January 20, 2013, 10:26:51 PM

in just a few short hours.

No such thing when people are waiting.

swilliams · « **Reply #39 on:** January 20, 2013, 10:35:59 PM »

Congratulations Prop. It's turned out great

Steve

propforward · « **Reply #40 on:** January 21, 2013, 12:01:33 AM »

Here it is folks. Hope this works - just 30 seconds or so - no need to gild the lily eh?

It actually runs very well at low pressure and will lope along quite happily - didn't get any footage of the low speed running. I must say, I really enjoyed making this, and learned a lot of fundamentals about machining from it. I know what engine I want to make next - something a little more complex, but not by much - Elmers number 14. But I have to make a couple of tools first. I need a center finder and a backstop for the lathe. So I'll work on those, then get going on engine number 2.

Thanks again to everyone for your encouragement and for chiming in on this thread.

<a href="https://www.youtube.com/watch?v=V6WHIHeielE" target="_blank">http://www.youtube.com/watch?v=V6WHIHeielE</a>

b.lindsey · « **Reply #41 on:** January 21, 2013, 12:47:30 AM »

Great job Prop. Looks and runs great! And now the inevitable question....what do you plan next?

Bill

zeeprogrammer · « **Reply #42 on:** January 21, 2013, 01:19:09 AM »

Very cool Prop. It does sound and run great.

Yep. Looking forward to your next one.

propforward · « **Reply #43 on:** January 21, 2013, 01:53:13 AM »

I think another Elmer, I thought the number 14 would be good, but I am not 100% set on that.

Well, that's it for this one. I'm going to ship this over the water to my Dad in the UK for his amusement, and move on to the next project. Cheers all!

steamer · « **Reply #44 on:** January 21, 2013, 02:54:01 AM »

Sorry Prop.....been a long week....

Dave

propforward · « **Reply #45 on:** January 21, 2013, 02:59:23 AM »

Heh. I have weeks like that all the time. No worries!

arnoldb · « **Reply #46 on:** January 21, 2013, 06:28:04 AM »

Well done Prop

Feels good, doesn't it ? - I can nearly hear you smile

Go on, do the #14

Kind regards, Arnold

Don1966 · « **Reply #47 on:** January 21, 2013, 02:15:00 PM »

Nice runner Prop and a nice job.

Don

vcutajar · « **Reply #48 on:** January 21, 2013, 06:15:53 PM »

A good runner Prop.

Congratulations

Vince

tvoght · « **Reply #49 on:** January 21, 2013, 06:22:08 PM »

Congratulations on your first!
--Tim

Alan Haisley · « **Reply #50 on:** January 21, 2013, 06:56:38 PM »

Great going, Prop

Remember that the misses can be used wherever you just need a smaller part. Only swarf is scrap (unless you have a little foundry, in which case even it can be reused.)

Alan

propforward · « **Reply #51 on:** January 21, 2013, 08:46:01 PM »

Well I must say the response is really overwhelming. Elsewhere I'm afraid I have only had a very little feedback - which is OK, it is after all "just another newbie wobbler", but given the effort it took, the positive replies are really appreciated a lot. I'm looking forward to moving on to a set of castings one day, but one step at a time.

Thayer · « **Reply #52 on:** January 21, 2013, 08:55:52 PM »

That is a nice bit of work Prop.

There is just a moment at about the 4 second mark in the video that gives a sense of how it would run on less air. It is definitely something to be proud of.

Thayer

propforward · « **Reply #53 on:** January 21, 2013, 09:05:15 PM »

I do have another video now, which I may post, showing a little bit of it running on lower air pressure, which is actually a lot more satisfying than seeing it rev itself silly, funnily enough. But I don't want to keep banging on about this build either (like the proud new Dad

). It's time to move on, and number 14 is definitely the next one.

Thayer · « **Reply #54 on:** January 21, 2013, 10:23:55 PM »

I don't think a couple days of posts constitutes "banging on", at least not for your first.

propforward · « **Reply #55 on:** January 22, 2013, 02:50:22 PM »

Thanks Thayer!

Well, proud parent that I am, I can't resist just one more little video. This one just has a better look at it running a little more slowly. Like I say, I just find this a bit more satisfying than revving it silly, it seems to better indicate the fit of everything, maybe?

Anyway, here it is one more time. Thanks again all for your input!

<a href="https://www.youtube.com/watch?v=np9CqTw8ImA" target="_blank">http://www.youtube.com/watch?v=np9CqTw8ImA</a>

b.lindsey · « **Reply #56 on:** January 22, 2013, 03:15:49 PM »

Sweeeeeeeet Prop!! The slower it runs, the better it is made...so you obviously did a fine job on it.

Bill

ScroungerLee · « **Reply #57 on:** January 22, 2013, 10:40:39 PM »

I love the slow running in the second video, that's cool

Lee

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Author Topic: Props first engine - Elmer Wobbler #25 (Read 24210 times)