Author Topic: LHL-14: A horizontal long-stroke (Read 19147 times)

MuellerNick · « **on:** June 14, 2013, 11:19:30 PM »

Hi!

As a side-project, I have been dreaming about a super-longstroke engine for long. So I finally designed it.
Bore is 45 mm, stroke is 90 mm, 143 ccm 4-stroke. Plan is to have a real slow-runner. Castings are made from my own patterns.
Will be water-cooled. I wanted something long and slender. The base-plate will be about 700 mm long, flywheel-diameter 350 mm. I'll have to recycle the flywheel of an other engine, because I'm not sure wether I can cast cast iron now or not (modified my furnace).

The last pattern (the base) is still in the mill and be ready in about an hour. Tomorrow, I'll do some finishing on the patterns and maybe cast on Sunday. I'll see…

Picture #1: The cylinder. Left and right are sticking out the core prints. I'll cast it around a precision-drawn tube.
Picture #2: Core box for the water-jacket (that goes around the cylinder-barrel.
Picture #3: Bearing covers for the crankshaft bearing and the camshaft.
Picture #5: Core box for the channels in the cylinder head.
Picture #6: Mounting bracket for the camshaft.
Picture #7: Cylinder head, core prints for the channels sticking out.
Picture #8: The base still in the mill.

Nick

steamer · « **Reply #1 on:** June 14, 2013, 11:40:47 PM »

Nice stuff Nick!

Dave

MuellerNick · « **Reply #2 on:** June 15, 2013, 12:32:17 AM »

Last pattern is off the mill.

The cylinder,
All main parts "assembled"
And a detail with the bracket for the camshaft.

Nick

MuellerNick · « **Reply #3 on:** June 15, 2013, 12:39:05 AM »

And a top-view from the CAD:

Nick

ths · « **Reply #4 on:** June 15, 2013, 12:40:55 AM »

Very, very nice indeed, Nick. What is the pattern material?

Hugh.

MuellerNick · « **Reply #5 on:** June 15, 2013, 12:48:25 AM »

Pattern material is block material from Renshape with a density of 0.7 kg/l.
They don't suggest it as pattern material, but I had good experience. The real stuff would cost about 4 times more and would last hundreds of castings. Easy to mill and good for final sanding. But it needs a layer of paint, can't be polished and the sand sticks a bit to it.

Nick

steamer · « **Reply #6 on:** June 15, 2013, 01:05:03 AM »

Gas or Diesel?

Dave

Maryak · « **Reply #7 on:** June 15, 2013, 03:19:15 AM »

Nice Patterns Nick

Best Regards
Bob

MuellerNick · « **Reply #8 on:** June 15, 2013, 09:28:34 AM »

Thanks for the nice comments, ladies!

In the first posting, I forgot the description for picture #4: Pattern and core box for the piston.

Engine won't run on Diesel. Gas or gasoline, I haven't decided yet.

Nick

ths · « **Reply #9 on:** June 15, 2013, 09:47:49 AM »

Ladies? I thought that was only one of us.

steamer · « **Reply #10 on:** June 15, 2013, 09:49:22 AM »

OK so the valve gear is ohV....gear reduced on the side...and then a rocker shaft mid engine.

What's that rocker shaft look like...seems unusual....?

Dave

MuellerNick · « **Reply #11 on:** June 15, 2013, 10:23:25 AM »

Quote

What's that rocker shaft look like...seems unusual....?

Well, unusual. I didn't want to follow too much conventional patterns how things look(ed) like. So the cam went to the base of the cylinder, driven by spur gears (are they called that way?). From there short rockers right in front of the camshaft. They only help to keep the pushrods in place. Pushrods go to conventional rockers. The rocker shaft is on two turned poles.
All this setup to keep the engine slim. Also, I wanted it to be as low as possible, just with the flywheel as the big part. So part of the counterweights of the crankshaft go through the engine's base and the base-plate. And obviously the flywheel. Slightly inspired by the Mery engine, but all shifted down as much as possible.

OHV to keep it narrow and to make it longer. This engine will be very long (if you look at the top view). I also tried to add as many features to the cylinder to avoid having to add external features. -> Few castings, exploiting the fact that I can cast. The head is not water cooled. I could cast that, but it wasn't worth the effort to me. This engine is not a power plant, it's a display engine that runs slow, hopefully very slow. I'd like it to run below 50 RPM.

The camshaft also has an excentric that drives the coolant pump. That pump also is a bit odd, as the pump itself doesn't have any valves. The valves sit in the water inlet and outlet to the water jacket.

Attached, a picture of rocker arms with the shaft on poles.

Nick

steamer · « **Reply #12 on:** June 15, 2013, 10:30:33 AM »

OK....understand it now....I couldn't tell if it was a rocker shaft or rotating cam.....clearly it is a rotating cam....though a rocking cam with big mushroom tappets would be interesting to watch.

Watching along Nick!

Dave

MuellerNick · « **Reply #13 on:** June 15, 2013, 12:15:32 PM »

Quote

though a rocking cam

A rocking cam? No, I never had the idea. But I'll try to remember it!
The gearing would be a bit odd, but interesting to watch.
Also the fact that the cam accelerates when it is lifting and decelerates when it is closing the valve.
Does that setup exist somewhere? Never seen that.

Or maybe, I imagine something different than you do?

Nick

steamer · « **Reply #14 on:** June 15, 2013, 12:24:19 PM »

Nope....but that's what struck me with the picture of your engine....and I agree...it would be interesting!

Still watching....

Dave

b.lindsey · « **Reply #15 on:** June 15, 2013, 12:58:31 PM »

Very nice project Nick, i will be following along with great interest. Doing the patterns and castings yourself certainly adds a lot to it also!!

Bill

MuellerNick · « **Reply #16 on:** June 16, 2013, 01:25:10 PM »

So I made the cores. And there is still time left for today's casting …

#1: Water jacket for the upper half with the pattern behind
#2: Same for lower half
#3: Core for water jacket on the tube (AKA cylinder barrel).
#4: Core for the piston

The water jacket is only 5mm in thickness. I didn't want the cylinder to be clumsy. But that didn't make things much easier. I had a few failures ramming the core sand into the core box (with the tube as part of the box). But that's normal, tricky cores take a few trials to find out where and how to ram. And where and how to rattle on the core box to get the core back out.

Edit:
The pattern for the piston looks a bit strange to some, I guess. The useless round on the right is for clamping. Clamp on the piston and turn the clamping round smooth, then clamp on the clamping round and finish all the OD work, bore, cut piston ring groove. And then part off to length.

Nick

steamer · « **Reply #17 on:** June 16, 2013, 02:08:23 PM »

Looking forward to some chips!

Dave

MuellerNick · « **Reply #18 on:** June 16, 2013, 04:19:51 PM »

Quote

Looking forward to some chips!

Dave, first you need to learn how to spell "patience" and what that is.

It's Sunday, sun is shining and I had a walk. Then glued together the cores. Then made and drilled the alignment pins for the patterns. And cut the thread for pulling them out.

Nick

steamer · « **Reply #19 on:** June 16, 2013, 04:23:58 PM »

I don't recall being impatient Nick...

Just that I am interested in the subject and your build of it.

Dave

MuellerNick · « **Reply #20 on:** June 16, 2013, 09:47:53 PM »

So this is todays harvest:
Piston, camshaft-bracket and the three bearing covers.

The cylinder head was a failure, I almost expected that. Shrinkage! I already was casting it quite cool at 660 °C. Next time, even cooler at 650 °C And a raiser, maybe even an exothermic one.

The cylinder didn't want to stay in the cope and always fell out, ruining the mold. I had the same problem with a similar casting and I have a solution for it. But not today.
So tomorrow, three castings to go.
And a bigger crucible to be welded. Not enough volume for the base. And I don't want to fire up the furnace outside with the big crucible.

Nick

MuellerNick · « **Reply #21 on:** June 17, 2013, 01:45:51 PM »

So I have the cylinder head!
Pouring temp lowered to 650 °C, two risers added and added some exothermic powder on top of the riser (on the left in the picture).

And the cylinder!
First try went quite bad. In gate was too small. When pouring, the melt went directly into a venting hole (my fault) and the melt was too cool (680 °C).
So, next try 690 °C, better in gate, paying more attention to the venting hole. When the melt came out of the hole, I've put a load of exothermic powder on it to keep that part liquid . A lot of bubbles escape from there. That venting thing can be seen on the right of the second picture. Also had a cold run in one portion where wall-thickness was minimal and the melt had contact with the steel tube. Isolated that region with a wash, worked like a charm.

Had some sand breakage, but that's nothing to be upset. Can be repaired on the casting and avoided with the next pour.

Now to the crucible …

Nick

MuellerNick · « **Reply #22 on:** June 17, 2013, 09:47:48 PM »

And here is the base:
It is 370 mm long. Casting went quite well. There's a fault in one of the crankshaft's bearing blocks, but it is within the finishing allowance and where the ball bearing sits.
Only thing was, that I decided to have a few beer afterwards.

But these went well too!

So tomorrow, I can start making chips. Just have to decide where to start. I guess it will be the base.

Nick

b.lindsey · « **Reply #23 on:** June 17, 2013, 11:51:02 PM »

Nick, sorry to hear about the few false starts, but those are really some fine looking castings. Someday i hope to try some casting, but for now i'll settle for admiring your impressive work!!

Bil

MuellerNick · « **Reply #24 on:** June 18, 2013, 07:56:10 AM »

Quote

Nick, sorry to hear about the few false starts,

The cylinder head was just a mishap, as I already expected that.
The cylinder was a great success. Even with the first fail. The water jacked has no connection to the outside, so every caster will tell you that this won't work. The core sand will start to gas, no matter what you do. There just needs to be a way for the gas to escape. It worked, I'm happy.
Yesterday, I had so many victories (with other things too), that it was a really great day!

I'll put the cylinder and cylinder head in the furnace to bake out the sand binder, while milling the bearing caps and the base. Pictures this evening …

Nick

gbritnell · « **Reply #25 on:** June 18, 2013, 12:01:34 PM »

Great looking castings Nick. I can't wait to see some machining progress.
gbritnell

ths · « **Reply #26 on:** June 18, 2013, 12:39:20 PM »

Very nice castings, especially the base, which has come up well.

Hugh.

MuellerNick · « **Reply #27 on:** June 18, 2013, 01:16:57 PM »

I just went to the temperature-controlled oven, where the cylinder head and the cylinder were in to bake out the binder of the core sand. Display said 480 °C, that's what I programmed.
Opened the furnace and … a sea of molten aluminium! I guess the sensor went kaputt.

I quite feel like having to cry.

Nick

b.lindsey · « **Reply #28 on:** June 18, 2013, 01:27:42 PM »

Oh wow Nick....how discouraging after those parts turning out so nicely. Man...I feel bad for you...what a bummer!!!!

Bill

steamer · « **Reply #29 on:** June 18, 2013, 02:10:54 PM »

Sorry to hear that!.....

Dave

ths · « **Reply #30 on:** June 18, 2013, 02:29:50 PM »

Very sorry to hear that, so terribly disappointing.

Hugh.

MuellerNick · « **Reply #31 on:** June 18, 2013, 06:58:18 PM »

Hi!

Base is milled and finished (except two small bores).

Now, I'll have to make a few more cores and do two castings …

Nick

b.lindsey · « **Reply #32 on:** June 18, 2013, 07:36:06 PM »

That is just pretty Nick!!! Those castings look as good or better than most of the comercial ones I have seen...as I said before....most impressive!!

Bill

MuellerNick · « **Reply #33 on:** June 18, 2013, 07:52:52 PM »

Quote

Those castings look as good or better than most of the comercial ones I have seen

But not all of them!

That's the remains. In the left front, you can clearly see the cylinder head. Looking from the bottom, one can even see the channels. Must have been by about 50 °C off. I'll check and see wether the control just overshot. Because the last run was 2.5 kg aluminium with the crucible. And the temp-controller has an auto-tune. Maybe he remembered the mass from the day before and was just too enthusiastic.

Last year, at one of my casting-parties, a friend took along a relative of him. He is working in the QC-department of a foundry. Global player! He didn't believe that someone can cast in his backyard (well, many do so). When he saw my castings, he could not believe. He said, mine are better quality than theirs. He couldn't understand how I make better cores than they do. He said, he'd like to send their apprentices to me, so they can really learn something.
I didn't learn that trade, I just experimented a lot of time and observed and analyzed all my mishaps (there are a lot of them).

Nick

NickG · « **Reply #34 on:** June 18, 2013, 08:08:23 PM »

Nick, brilliant patterns and castings. Sorry to hear about the temp sensor. Like the engine concept, would be nice to see a really slow runner.

MuellerNick · « **Reply #35 on:** June 18, 2013, 09:31:15 PM »

Checked the furnace, and it actually is off by 50 °C. So I had 530 °C in it. You can go up to 520 °C, but then the parts need a support, or they will sag. I baked the binder at 500 °C already, but somewhen decided to go to 480 (just takes longer, but is more secure).

Looking back, I always had a layer of sand in the furnace, but not this time. As I need to bake out the binder (don't want to machine sand), next time, I'll cross-check it with an external sensor and keep well away from the evil temperature.

Too late to cast today, I'll do that tomorrow morning. But I have prepared the cores. Then, I'll make the crankshaft.

Nick

MuellerNick · « **Reply #36 on:** June 19, 2013, 11:36:47 AM »

Got two new castings to ruin once more.

Head went "as usual".
Cylinder, I improved the runners. Now it looks like, as if I can go down by 10 °C with the casting temperature. Surface finish in the upper half is getting rough and matte, that's a sign for too much temperature. Overall, result is better than the previous one.

Nick

b.lindsey · « **Reply #37 on:** June 19, 2013, 11:42:33 AM »

Nice results (again) Nick!! From the last pictures, it doesn't look like you used the exothermic powder this time. Does it just not show up in the pictures or did you make some changes to avoid having to use it?

Bill

MuellerNick · « **Reply #38 on:** June 19, 2013, 12:06:40 PM »

No, I used the powder again. You might see that at the left riser (of the cylinder). Also used it with the head.
Maybe I'll risk leaving out the exothermic with the cylinder. There are coming out just two bubbles *blubb* *blubb* and then the melt rises and it stops bubbling. It takes 3 seconds for me to put away the ladle and grab the powder. But at that moment, all has already happened.

With the head, it makes more sense. But I think I can leave that out too. For the first castings, I want to reduce risk. When I got all settled, I can simplify the process.
I have a casting (different engine), that takes half a day to assemble and make. I had 4 failures until I found out the right procedure.

And a quick mockup, before they magically disappear once more.

Nick

NickG · « **Reply #39 on:** June 19, 2013, 03:58:52 PM »

Love it, great stuff.

steamer · « **Reply #40 on:** June 19, 2013, 04:37:43 PM »

Nice Castings Nick!

Dave

MuellerNick · « **Reply #41 on:** June 21, 2013, 09:34:14 AM »

Quite a few delays ...
The day before yesterday, I wanted to start with the crankshaft's web. Went to my stock and wanted to grab the ø140 mm material. But it turned out to be 120 mm. 20 mm too little.
So I asked a friend wether he has some, and how I could get it fast. So he cut 4 disks with ø150 and, as his wife was nearby, asked here to bring the material to my door. DAMNED nice people!
Only drawback, there was a note saying "material unknown". Already being conservative with the cutting parameters in the lathe, one insert didn't survive too long. Going down a bit more, it machined really nice. But it was tough! Picture of a disk in soft jaws.
Milling was even tougher, the carbide endmill started to glow with coolant. Bores were circular milled, and all went well. Diameter of the web is 135 mm.

Started some periphery work, but nothing finished, like the crankshaft. I'll have to harden and grind the pins for the crankshaft. But as I will leave this evening to Austria for an engine fair, there won't be enough time. If I rush the job, the risk of ruining it will just increase. And I won't finish anyhow. Still enough half-finished for a nice mockup.

So, 'till next week …
Nick

steamer · « **Reply #42 on:** June 21, 2013, 11:23:57 AM »

Sounds like 4150 HT or some other Chrome alloy...ouch!

Sure turns well! Nice work Nick!

Dave

MuellerNick · « **Reply #43 on:** June 21, 2013, 12:59:20 PM »

Quote

Sounds like 4150 HT or some other Chrome alloy...ouch!

That would be 42CrMo4-QT. Might well be, have turned that already. Or C60 (1060), but he simply didn't know.
Anyhow, nicer surface than leaded steel.

Nick

ths · « **Reply #44 on:** June 22, 2013, 06:57:17 AM »

Is that a blasted finish Nick? I wonder what happened to the saw blade that cut the discs?

Hugh.

MuellerNick · « **Reply #45 on:** June 23, 2013, 08:25:48 PM »

Quote

Is that a blasted finish Nick?

No, not blasted (nothing to cover). Pictures didn't get the nice finish (with the changing colors). They have to cut more material like this, so they should have a good sawblade for that. They have a bandsaw, AFAIK and how it looked like.

So I'm back from Austria! Was a nice weekend, with at very well caring organisator. If anyone form Germany/Austria is reading here:
Next year, visit the "Pfaffing macht Dampf"! We had a "Sonnwendfeuer" (big fire in the field at night; an old tradition when the sun has reached his highest point) and a few beer extra. Nice people, lots to talk about and see. New interesting contacts and some already asked for castings of my LHL-14!

Nick

MuellerNick · « **Reply #46 on:** June 25, 2013, 08:53:10 PM »

Made the rocker-arm posts and the axle. Maybe I'll add a bit of decoration to the axle's end, so it is longer than necessary.
Also prepared the missing parts for the crankshaft for cylindrical grinding. Here, they are hardened.

Nick

smfr · « **Reply #47 on:** July 23, 2013, 04:50:51 PM »

I missed this thread, and there's some intersting stuff here. I'd love to hear about the hardening and grinding process; that's something that I haven't seen documented on MEM yet. If you done it already, how did it go?

Simon

MuellerNick · « **Reply #48 on:** July 23, 2013, 05:21:52 PM »

I have no news, as I do have other stuff to make. And then, the servo-amp of my mill broke down. I have to repair that (but I have no clue about power electronics).

But I know how to harden.

Material is C45 (1045). Put in the oven at 840 °C, soaked and then quenched in water. C45 doesn't get too hard, so I left out tempering (would do it at 200°C).
Parts will be ground on my Myford MG12-M cylindrical grinder (that I reconditioned from scrap).
I intend to have a plain bearing at the pushrod with a bronze bushing. So to avoid galling, the pin has to be hardened.
The crankshaft axes don't necessarily need hardening. But they grind nicer when hard.

Right before the mill went kaput, I improved the process of making helical gears that will be needed for the cam shaft drive.

Nick

NickG · « **Reply #49 on:** July 24, 2013, 11:38:19 AM »

Looking good Nick, will look forward to the next installment.

News:

Author Topic: LHL-14: A horizontal long-stroke (Read 19147 times)