My first engine...

[arnoldb]

I've been working on my first one for a while. Building a small steam engine has been a dream of mine for the past 30+years, and it is high time to start turning dreams into reality.

I've been working (very intermittently) on it from the start of the year. First up was the cylinder & piston - both need some more work though. I finished the crankshaft this weekend, but will most likely have to redo it - I think it warped. That I'll only find out once I finish the bearing blocks and mount them on a suitable base though.

Still a lot of work left, but at least some progress ;D

 

[ChooChooMike]

Warm Welcome arnoldb ! Good start on your engine

Do you have plans to share with us so we can see what the engine will look like ??

Mike

 

[cobra428]

Looking Good there arnoldb!!!
So Far Soooo good
TonyR

 

[arnoldb]

Thanks Guys. I have very rudimentary plans, but am improvising as I go along, depending on what material I can find here in Windhoek. I finished the bearing blocks today, and as I thought, the crank has warped - if I spin it in the bearings, there is a small but noticeable wobble, so back to the drawing board

I think my problem with the crank was caused by the HRS I've been using - finding good steel here is a problem. So I've been thinking and had one of those "DUH" moments. Over the years I have collected & stripped a couple of dot matrix line printers - all the shafts & stuff was lying hidden in a corner. Grabbed the thickest shaft I have and cut the end off it, and lo & behold - in the cut mark there are sort of "concentric circles" - indicative of CRS. The steel also cut cleanly on the bandsaw, unlike the rough cuts I normally get from HRS.

The shaft is too thin to turn a crank from in one piece though, so I'll now re-fabricate a multi-part crank and silver solder it together. Also, on the original crank, I made the big-end bearing diameter 12 mm (I only had a 12 mm reamer) - but this won't work well.

Well lucky me - this month, I get my 13th cheque, so I splurged a bit and this morning bought a 6mm reamer, a 4mm slot mill and a couple of 3.3 mm drill bits (for tapping 4 mm threads) on my credit card. Wasn't too bad - N$ 320; about US$ 33 - and all quality items manufactured in South Africa. So the big-end bearing can come down to 6 mm, and I think the new crank will be a lot nicer.

I might have to remake the cylinder as well (also currently made of HRS) - I spent some more time lapping it, but it still seems to eat brass off the piston...

Oh well, all good machining practice ;D - attached some pictures of the warped crank & bearing blocks.

 

[bearcar1]

Oh yeah! ;D My don't they look great when they are all bright and shiny? Good looking bearing blocks and crank. I know what you mean about finding good steel on the cheap. A friend of mine recently ran across a pile of steel rods a contractor had left in the parkway in front of his house. They were .875" diameter and about 4' in length, they had cross drilled holes on the first 20" but the rest was solid. They were a bit rusty but not real bad from being out in the weather for who knows how long. Anyway he gave them to me (a dozen) and I had my doubts about the quality of steel, thinking that they would be either too hard or that they would tearout when I tried to turn them. Low and behold :bow: they cut like butter all the way to the center and would polish up with some emery cloth. I was amazed and happy to get such a find, you just never know what you are going to find lying around in the strangest objects.

BC1

 

[arnoldb]

Thanks bearcar1 . You've got very lucky with those bars!. Nearly ALL work I've done so far was in HRS, and from what I've researched so far, I'm actually fortunate to get "some" sort of finish on it - maybe it's good practice for when I can get my hands on something better. Also, I think my skills at grinding toolbits from HSS is improving, and some manual labour on a fine oilstone afterwards definitely helps

I 'phoned a local engineering company (once again) today about stock. The salesman said they have some CRS in stock, so I'll pop around there tomorrow to see what they have. This specific company' sales people treated me like s...t in the past, but the salesman I spoke to today was a lot more helpful.

Here it's not even about finding materials on the cheap - it's about just _finding_ it!

Regards
Arnold

 

[bearcar1]

I see that you are in the shadows of the AUAS Mountain region of the great continent of Afrika. I can only imagine what locating suitable materials can be like. May I ask what make or model of lathe it is that you are using? Keep up the search and I do so hope you are able to get your hands on the metal you need to finish your project. Good luck.

Cheers
BC1

 

[arnoldb]

Thanks BC1. Yes, I'm surrounded by the Auas Mountains - Namibia is a STUNNING country to live in. I've had many opportunities to emigrate to South Africa and even overseas, but this place is in my blood, so I'm prepared to be a bit inconvenienced to live here

My lathe's a Myford ML7 from 1970. I'll have to get/make a new cross slide nut for it soon, it's a bit worn. I will actually make a feedscrew and nut combination, and add an adjustable index - that's why my avatar is of the acme thread - that was my first ever attempt at it

Regards, Arnold

 

[arnoldb]

Whoo-hoo :big:

I found the metal candy-store in Windhoek!

Racks full of stock - stainless, silver steel, cast iron, and brass ;D
At first this engineering firm only wanted to sell me meter-lengths of metal. I asked the salesman for a walk-about in their store room to see what they've got & spotted their off-cut bin. So I asked him about buying the off-cuts & he agreed :big: - price was not too bad either. Once I explained to the salesman what I wanted the metal for, he was a lot happier (I think they might feel threatened that someone might be taking work away from them), and invited me back whenever I'm looking for stock

Got some 6mm silver steel, a hunk of 120mm diameter cast iron (I'm sure there are 2 flywheels hiding inside ), piece of aluminum, slug of stainless & a small brass off-cut! I have sleep-over visitors for the week so it would be rude to ignore them & go to the shop, but don't think I'm not tempted

 

[mklotz]

Arnold,

I've mentioned it here before but it's worth repeating.

When you go scrounging for machining related items, slip one of your model engines into your pocket. When you inquire about cut-offs, scrap, etc., pull it out and tell the employee that you want the items to make more model engines like this one.

Most folks are astounded that anybody can make anything but they're particularly in awe of engines. I imagine it's the fact that engines are more than static constructions - they actually work. That impresses them.)

This tactic works for more than just obtaining stock. I've used a functioning model engine as a ticket to get into:

several engine rooms in ships
fabrication and repair shop in museums
jewelry fabrication areas
etc.

 

[90LX_Notch]

mklotz, I remembered your tactic too late this past weekend. I probably could have done better at a swap meet I attended if I had brought my Elmer's Tiny at 1/2 scale. Still, I did alright after I explained to the vendor's that I make little engines as a hobby. One vendor let me get an original 1939 South Bend "How To Run A Lathe" book for $2.00 as long as I promised to take care of it.

 

[mklotz]

If you had brought the engine, he would probably have given you the book.

The best "tickets" are engines that run, especially LTD Stirlings and flame suckers.

My favorite sushi chef was so delighted with my Stirling running both on a cup of hot tea and on a saucer of ice that he didn't charge me for lunch.

Stirlings are a bit too intellectual for bars. That's where flame suckers shine - especially dark bars where you can see the flame entering the engine. Always good for a few free beers.

Of course, if you really want to strike it rich in the bar, take your home made martini mixer with you.

http://bbs.homeshopmachinist.net/showthread.php?t=25247&highlight=cement+mixer

 

[arnoldb]

Thanks all - Mr Klotz, great tip. My next build will be a tiny pocket-sized engine that can run on breath power

 

[Kermit]

Whoo-hoo :big:

I found the metal candy-store in Windhoek!

A bit tougher to do than it is in a city like Houston. Well done Sir!

 

[mklotz]

Thanks all - Mr Klotz, great tip. My next build will be a tiny pocket-sized engine that can run on breath power

The Duclos Huff 'n Puff

will unlock any door.

BTW, no need for the "Mr. Klotz". I appreciate the intended respect but "Marv" will do just fine.

 

[arnoldb]

Thanks Marv. That's a nice looking small engine :bow: - I'll keep it in mind
Regards, Arnold

 

[JMI]

The Duclos Huff 'n Puff

Nice! Can plans for that engine be downloaded?

Thanks

Jim

 

[JMI]

Nice! Can plans for that engine be downloaded?

Thanks

Jim

Found the book and ordered it

Jim

 

[arnoldb]

Wow - a lot of LIFE has happened since I last posted - (LIFE happens! )
I've been working 12+ hours a day including weekends at my job most of the time, and was peeking in on HMEM in between server re-boots, and grabbing quick looks in evenings while making some grub. This has been causing some serious "Workshop Envy" , as I could not get around to my workshop!

Well, for a change I got something done. I took stock of what I had done so far, what materials I had available, and what needed to be done. Darn, the answers just did NOT add up. Closely examining the already made cylinder and piston, I could visually see tiny cracks in the HRS cylinder, so "duh" - that's why the piston was being eaten up... (I also think some lapping compound got stuck in there)

Some things are not worth doing, and continuing along my current course _definitely_ was not. So I sat down, and started re-designing for the materials I have. Lots of crap-o-cad, some minor calculations, and then on to QCad which I use for drawings on Linux. Some more fiddling, and I think I have something better, with adequate material available even if I make a couple of mistakes.

First off, a new cylinder: The parts I salvaged from old dot matrix printers contains ~20mm ID ~28mmOD "pipes" from the platten rollers - these are covered in a hard plastic. I have a a couple of those approx 50 cm long..., ideal for a cylinder, with minor honing required.

The storeman at the "metal candy-store" gave me a piece of free-machining aluminum (for free!) 50mm diameter 40 mm long - this would work for cylinder heads. While I was about it, I could just as well make a double-acting engine; not too much extra effort involved.

Last weekend, I finished the cylinder heads, except for the packing gland. I don't drink things out of cans, but when a friend came to visit that drinks a popular soda as mix, I forewent the normal plastic bottles and bought cans - I needed them for chucking workpieces on "finished" surfaces ;D.

Attached some pictures of what I did last weekend:
1. Machining external dimensions on part of the cylinder heads & the packing gland.
2. I used a soda can strip to chuck and center the machined part in reverse in the 4-jaw. Here I drilled 4 holes in the cylinder heads (to be) for pulling them together around the cylinder.
3. Parted a groove to fit the cylinder in the piece that was to become the "blank" cylinder head.
4. Completed cylinder heads & links. There's a couple of pictures missing in between; I'll have to set up a photobucket account to show more ;D

The "links" were also made from printer shafts - salvaged from the tractor feed shafts. I simply drilled & tapped them M3 on each end for the cap-screws.

Bolted together like this, if I suck on the "open" end and stick my tongue in the hole, the whole assembly stays hanging on it, so pretty much a good seal, even without packing .

 

[arnoldb]

Carrying on from previous post...

Thursday was a public holiday here in Namibia as well, so I got some more done

Finished the packing gland and nut - sorry, forgot to take pictures. Not much for a day's work...

I drilled, bored & threaded the cylinder head gland part for M10x1.25 (I chose the metric fine, as it is a finer thread & I happen to have taps and dies for this, as I needed to buy them for making some parts for putting a new engine in my old Toyota Hilux; the Japanese seem to have an affinity to metric fine threads.

I fabricated the nut from a piece of round 3/4" brass, and finished off the hex-head using the dividing head and a threaded arbor I made for machining a new clutch arm pivot for aforementioned Hilux.

Today I made a couple of laps from broomstick to hone the cylinder - one for coarse compound, an an identical one for fine compound. As I don't have a SWBDMO, I rule the kitchen, so I got some aluminum foil to cover the bedways & important parts while lapping. Each lap also has a split sawed in the end, so that I can use a wood screw to turn in to increase lap-size. Turns out, I didn't need that . After finishing with each lap, I used more kitchen consumables - known as cling-wrap, and after marking the lap with the compound used, wrapped it up, "just in case".

Well, things were going too smoothly... With lapping done on the cylinder I had a "Arnold, you're a Freaking IDIOT" moment. I've been carefully planning on how to do everything, but it seems over-eagerness got the better of me...

I was actually planning to first mill a flat on the cylinder for the steam passage connection, and drill the steam ports _BEFORE_ lapping - this makes sense doesn't it? Well, I didn't do it :-[ - so, I have burrs on the inside of the cylinder after milling the flat and drilling the holes. For now, I used a grinding stone in the Dremel to clear that, but if it is not good, I'll have to redo the cylinder. Ah well, LIFE happens ;D

As I don't have a milling machine yet, all milling operations are confined to the Myford and the vertical slide. My plans were to use a piece of 20x16 brass bar to make the steam passages and valve block, but I could not get any - at least not in my current financial bracket. I was thinking of using a steel solid for this, but, fortunately, before I tried to tackle that, I had an idea :idea:. I have a 200mm long piece of brass tube 100mm OD 60 mm ID my dad left me here when he retired. Can't I coax a bit of 16x20x39mm rectangular brass from that? Well, some measuring, drawing and bandsawing produced it :big:. I first sawed of a 50mm long disc from the original. This I mounted on-end in the bandsaw and sawed of a part as in the one attached picture. The left-over piece can be coaxed into more rectangular/square bits, so not too much of a waste - I don't think I'll need the original size too much, except for making flywheel outer rings like Foozer

As the Myford & vertical slide was set up nice & square for milling the flat on the cylinder, I just fly-cut the hacked piece of brass as well. Tomorrow, I'll carry on with cutting the steam & exhaust passages in the block, as well as the valve cylinder if possible.

Pictures:
1. The coarse wooden lap after use.
2. Coaxing a piece of round brass tube to give up a rectangular section :big:
3. Fly-cutting the above brass to a rectangular block. (I made the fly-cutter as one of my first lathe projects. This year, we had far-above normal rainfall which leaked into puddles in my workshop. A lot of my "things" rusted - I'll have to spend some quality time de-rusting everything (Marv has a good solution for that )
4. Where I was tonight - Cylinder assembly,packing gland finished, and brass block for valve & steam passages part-way. Flat milled on cylinder and ports drilled.

Now, I need to make some grub and pacify Shrek the African Grey parrot who owns me, and is insisting on some cheese, potato and apple ;D