Author Topic: Enlarged rocking engine build (Read 18705 times)

Ross · « **on:** August 24, 2012, 06:48:45 PM »

Hi everyone,

I started a new project on my lathe today. I'm building a enlarged version of the rocking engine, designed by member NickG on here. His oiginial build:

http://madmodder.net/index.php/topic,1718.0.html

I will be making a few artistic changes to the original plans it won't be a fast build though! Sadly I don't have much time to get to The shed at the moment do bear with me!

I didnt get much done today, I had to make a Gear knob for my dads new car it took longer than expected due to my tail stock failing. I need to strip it tomorrow as the part that extends when you turn the wheel has come loose and is slipping. The link for the knob is below for those that are interested!

http://madmodder.net/index.php/topic,7540.0.html

Anyway, I faced all of my stock and turned the cylinder to length.

I also started on the cylinder cover, I turned it to the correct diameter. It needs to be marked out for the 6 equispaced holes next.

Tommorow I think drill and bore the cylinder and Lap it to size, but I shouldn't get ahead of my self!

Ross

Stilldrillin · « **Reply #1 on:** August 25, 2012, 02:27:26 AM »

Hi Ross.
Nice to see you've made a start, already!

Good luck with the build....

David D

NickG · « **Reply #2 on:** August 25, 2012, 03:30:31 AM »

Hi Ross,

Yeah good luck - will be great to see somebody building one of my engines! If you have any more questions don't hesitate to ask - the others on here may have better advice than I do, I will only be able to tell you how I did / would do it.

Cheers,

Nick

Ross · « **Reply #3 on:** August 25, 2012, 12:03:58 PM »

Hi,

Today I marked out the holes on the cylinder cover and drilled them.

It was very hard to do on my pilar drill and it took some lining up. I think I moved in a bit to far in while marking the PCD I will have to make the bore of the cylinder smaller by 2mm.

Next, I cut the stock and faced to the required thickness and drilled and tapped M5:

I finish turned the cylinder cover, and adjusted it slightly to Make it easier to drill the holes in the cylinder. The only thing I didn't do was put a recess for a seal as I'm not sure of the size of the one I'll use.

Next I turned the outer diameter of the cylinder, turned the majority first.

And then turned it in the chuck and finished all the way.

Next I drilled the bore to 13mm

And then bolted The cylinder plate and cylinder together ready for drilling and tapping.

NickG · « **Reply #4 on:** August 26, 2012, 09:17:47 AM »

That's def the best way to do it, you can use the cover to drill both ends then use it on the frame as well, sure fire way to get them to line up.

Think I just used a paper gasket on mine.

Nick

krv3000 · « **Reply #5 on:** August 27, 2012, 07:28:25 AM »

thats shaping up nice

Ross · « **Reply #6 on:** August 27, 2012, 01:22:44 PM »

Hi guys,

I drilled and tapped the holes in the cylinder, I messed up the centre punches on the first try hence the extra set.

I drilled the bore to the final diameter and lapped.

That's all I got done today due to my lathe having a blip! I made a little start on the piston I'll finish that this weekend hopefuly.

Stilldrillin · « **Reply #7 on:** August 28, 2012, 01:50:59 AM »

Nicely done Ross!

Don't worry about the marking-out glitch. We won't tell.....

Don't mention lathe blips!! I've had enough of 'em, now!

David D

Ross · « **Reply #8 on:** August 31, 2012, 12:56:55 PM »

Hi Guys

Not munch done today, just got myself into a bit of a pickle on the piston.

While roughing out I thought to myself , why the hell did I face it to length? It would have been 10x easier to make then.

Im finding it hard clamp it to turn it to size, so I think I may scrap this and order a new bit of stock and redo it.

The diameters on the far left and right are .0010" off finish size, but I'm left with noting to clamp onto for the middle!

Live and learn!

Stilldrillin · « **Reply #9 on:** August 31, 2012, 03:34:47 PM »

Hi Ross.

Centre drill the small dia end.
Then, hold on piston with revolving centre in conrod end. Finish conrod to size.
Hold on conrod, to finish the piston.

David D

Ross · « **Reply #10 on:** August 31, 2012, 06:35:53 PM »

Not to worry David, I remembered I had another piece of brass long enough so I've just made another!

I made the piston a little bigger on this one so it gives me lots of room to play with for the radius on it.

Brass_Machine · « **Reply #11 on:** August 31, 2012, 06:48:17 PM »

Nice start Ross!

Eric

NickG · « **Reply #12 on:** September 01, 2012, 04:22:12 AM »

Nice one Ross - I told you what happened on mine didn't I ... I got carried away when filing the radius so get to form taking as little off as poss then go very gently trying the cylinder over it all the time.

After my first attempt I cut the piston off the end and threaded the end of the rod / made a disc with a threaded hole for piston so I could have multiple attempts!

You've done a good job doing it out of a solid piece now though.

Ross · « **Reply #13 on:** September 01, 2012, 07:17:45 PM »

Hi everyone.

Today I put the radius onto the piston and made it fit the bore.

It was VERY easy to go undersize, the piston fits and turns in the bore nicely its not as snug as it probably could be but I think it should be good enough I can always adjust when it is all together.

NickG · « **Reply #14 on:** September 02, 2012, 03:16:46 AM »

Good job there, you've done the hardest bits of the project now! However you do the frame etc just remember to have the offset beween crank hole and cylinder bolt ring - otherwise the engine will do one stroke and never exhaust!

Nick

Ross · « **Reply #15 on:** September 23, 2012, 11:22:00 AM »

Hi everyone,

Today I made two crank wheels. They just need the off set hole drilled through the for the crank pin.

I also shortened the bolts for the cylinder plate.

NickG · « **Reply #16 on:** September 23, 2012, 02:59:41 PM »

hang on - 2 cranks? is there something you're not telling us??!!

Ross · « **Reply #17 on:** September 23, 2012, 04:40:14 PM »

Quote from: NickG on September 23, 2012, 02:59:41 PM

hang on - 2 cranks? is there something you're not telling us??!!

It all goes downhill from now on Nick!

Stilldrillin · « **Reply #18 on:** September 24, 2012, 07:54:12 AM »

Quote from: NickG on September 23, 2012, 02:59:41 PM

hang on - 2 cranks? is there something you're not telling us??!!

He's building a twin, Nick!

David D

Ross · « **Reply #19 on:** September 26, 2012, 05:35:57 PM »

Quote from: Stilldrillin on September 24, 2012, 07:54:12 AM

Quote from: NickG on September 23, 2012, 02:59:41 PM
hang on - 2 cranks? is there something you're not telling us??!!

He's building a twin, Nick!

David D

I wish! I don't think it would be done before the end of next year if I did that! I'm just modifying the crank end of the engine slightly.

Ross · « **Reply #20 on:** October 20, 2012, 03:13:19 PM »

Hi everyone,

Finally got back onto this today.

First I made a mandrel for clamping the crank wheels while drilling the offset holes.

I drilled the first hole with no problems. But on the second I over tightened the nut and stripped the thread, I had to put the 3 jaw back on and skim the face.

Clocked and drilled.

Then I drilled the holes for the grubsrews to fix onto the crank. And. Threaded M3.

Ross · « **Reply #21 on:** November 01, 2012, 04:19:30 PM »

Hi everyone,

I ordered some aluminium for the engine frame a while ago, and it arrived today

I had a go at filing the edges of the engine frame square. And being probably the worst filer in the world even using a square and taking off the high spots, I was tearing my hair out! I don't think I can get any straighter than what I've ended up with!

The only problem being is that the rectangles are now 2x1.5 inches they need to be 2x1.25 I don't particularly fancy trying to file the longer edge square but I'm worried that the extra .250" height will dwarf everything else! Ideas?

Ross

Stilldrillin · « **Reply #22 on:** November 01, 2012, 06:47:50 PM »

Ross.
If you're worried about sawing/ filing 1/4" off, accurately.

Do you know anyone with a mill?

David D

Ross · « **Reply #23 on:** November 01, 2012, 08:16:40 PM »

Quote from: Stilldrillin on November 01, 2012, 06:47:50 PM

Ross.
If you're worried about sawing/ filing 1/4" off, accurately.

Do you know anyone with a mill?

David D

Not anyone nearby I don't think, it dosent have to be too accurate but I will need use of a mill to do the part that attacthes to the cylinder so it holds everything sqaure.

NickG · « **Reply #24 on:** November 02, 2012, 07:01:50 AM »

You could leave it as it is Ross, not bother with the turned legs and sink the flywheel into the base? You should be able to get the ends square if you have a vice and just using the top of the jaws as a guide or clamping a known square bit of metal next to it in the vice and using that as a guide?

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Author Topic: Enlarged rocking engine build (Read 18705 times)