Suggested engine for beginner in the UK

[MattB]

Eventually I would like to build some more complex engines, possibly steam but more likely IC and very probably a stirling engine but I'm a bit stumped as to where to start.

It looks like an oscillating engine is probably going to be the best place to start but being new i don't like the idea of just going off plans and having to trust myself to order the correct grades of materials so I'm drawn in by the idea of a kit that has everything in it, including fasteners/springs/whatever else i might need.

So after some searching I've found a couple of options, it seems the littlemachineshop kit would be perfect

http://littlemachineshop.com/products/product_view.php?ProductID=2594&category=386435363

but I'm not gonna pay to have something weighty shipped half way round the world! In the UK i could only find the Stuart oscillator

http://www.stuartmodels.com/inprod_det.cfm/section/casting/mod_id/51

but i don't like the idea of ruining castings? unless they're easy to get replacements should i mess something up?

the other concern is tooling, all the plans I've looked at assume you've done some machining and will know what tools you'll need to do which operation but i am new to machining so don't know what I'll need, in particular I'm thinking specific things like reamers and taps.

To give some background I run a bike shop and as part of that we a starting to build our own frames, so i am competent as a fabricator (cut/file/weld) type stuff. It is the business workshop i will be using which consists of a Harrison L5A lathe (which is used for mitring the bike frame tubes and making spacers/drifts etc), pillar drill belt sander plus hand tools. The lathe has a bit of tooling but what I'm really lacking is milling capability (which will obviously affect engine choice) the lathe has a limited vertical slide that i have played with a bit, but can really only be used on parts up to 100mm square and for very light cuts.

so, after all that (sorry for long post) what would people suggest?

thanks in advance

Matt

 

[cobra428]

Hey Matt,
First let me say wEc1. There is great help here to get you started in this hobby. The Little Machine Shop Osc is a good start. The plans for it are right there for you. Pick up some bar stock and have at it.

Click on Chris' tips and there are the plans

Tony

 

[tmuir]

Steer away from castings for your first engine.
If you just want to make an oscillator, material selection or even tolerances are not super important.
Just have a look at the toy Mamod and Wilesco steam engines in a model shop to see what you can actually get away with and still have it work.

Get yourself a copy of Tubal Cains book 'Building Simple Model Steam Engines' (book 1 not 2) have a read of it and decide where to go from there.
Even if you don't build any of his engines it gives some good tips and best of all its cheap.
This book is easy to get from a number of online shops.

 

[mklotz]

Build a simple oscillator from bar stock. You don't need a kit for materials. For these simple engines, material choice is seldom critical and there are lots of folks here to give you advice on what materials to use.

A good first engine would be Elmer Verburg's wobbler...

http://www.john-tom.com/ElmersEngines/25_26_WobblerBoiler.pdf

Avoid castings until you've had a chance to develop your skills a bit. While they appear simpler to the novice, the reality is that they're harder to build than building from bar stock.

 

[MattB]

Wow, that was fast. that was the conclusion i was coming to, if i just buy "steel" and "aluminium" and "brass" without any regard for grades will i run into problems? or are there certain grades i should avoid at all cost? I'm guessing these small engines don't require any special taps or reamers then?

thanks again

Matt

 

[CrewCab]

Matt,
Dave Goodfellow has a good selection of simple engine's on his web page Click Here and scroll down the page about 1/2 way, "Brassy Babe 2" is nice and simple and it doesn't all need to be brass ;D ............. I used aluminium for the piston and delrin (plastic) for the cylinder.

As long as you can work to a reasonable tolerance these little engine's are quite forgiving, you should easily manage one with the tools at your disposal. .................. and if you want help or advice, that's what this site is all about.

CC

 

[arnoldb]

wEc1 Matt

Tony, tmuir and Marv gave you good advice as to engine selection.

I'm pretty new to building engines as well, but from my fresh, but limited experience:
For aluminium, I'd suggest free-machining aluminium. It's got some fancy code name that I still need to figure out
For steel, CRS (cold rolled steel) should work - also get some silver steel(Drill Rod) of a couple of different diameters.
My experience with brass stock is a bit limited - I get all kinds of different off-cuts from a local supplier.

I'd suggest you get a design you'd like to build, and study the plans carefully. From that you will see if you need any taps/dies/reamers/drills etc. Then buy what you need as you need them - when you do buy machine bits, buy good quality; it will save you a lot of frustration.
Also, when studying the plan, try and get a "feel" for the size of the engine you are going to build, and try and think through all the machining processes involved with each part, i.e. how you are going to clamp the part, what tool(s) will you need for doing the machining and the sequence of machining, and what material the part is. One of the first surprises I got when I started making the engines from plans, is that sometimes the parts can be really small - smaller than you'd think from just looking at the plans

I invested in a couple of different reamers(also as & when I needed them), but that's not essential; you can make your own "D-Bit" reamers from silver steel if needed; I made my first such reamer last weekend and was surprised at how easy it was to make and how well it works.

And yes, the members of this site is always helpful - as CC pointed out while I was typing this lot up ;D

Regards, Arnold

 

[kuhncw]

Lots of good advice so far. For the steel, 12L14 leaded steel is a good choice as it is much nicer (easier to get a good finish) to machine than the more common 1018 steel.

Regards,

Chuck

 

[Tin Falcon]

12L14 is the standard for machinable steel
alloy 360 is considered ultra machinable brass
Alloy 2011 for aluminum
These are easiest to machine grades.
If you see screw machine grade of metal it is very machinable.
there are other good choices that will work . Stay away from mystery metals when getting started. They can be a challenge for the experienced.
Any good metal supplier should have a guide as to what grade(S) will work for your needs.
As far as engine plans here are a couple more that are good firsts

http://npmccabe.tripod.com/mccaberunner.htm

http://www.john-tom.com/MyPlans/SteamPlans3/RockingSteamEngine/ROCKING%20STEAM%20ENGINEs.pdf

If you already have some fabrication /silver soldering skills you may want to pick up a copy of "Making Simple Moel Steam engines by stan bray isbn1-86126-773-8
Tin

 

[deverett]

MattB

You have been given good advice from some very knowledgeable people here.

Just a warning for you. Many of the designs you will find on the intenet originate from the US or at least use US threads. There is no need to use these threads - the taps and dies for them in the UK will be more expensive than native threading tackle.

Convert the US threads to imperial or metric - there are charts on this site for conversion to the nearest equivalent size. This brings up another consideration: are you happier with metric or imperial measurements? Gradually metric is taking over from the BA sizes, so give that system serious consideration. And that is from one who prefers the Imperial system.

Suppliers of tools. A good source in the UK for most stuff you are likely to need at the outset can be got from
Tracy Tools http://www.tracytools.com/
or RDG http://www.rdgtools.co.uk/

You have been advised to get the sizes of taps, etc as you require them, and that generally is good advice but certainly from Tracy Tools it would be more economic to buy their sets rather than individual tools.

Do you intend to go to any model engineering exhibitions? You can pick up some good bargains from the dealers there and also drool over the works of art that the exhibitors have made. The next major one is the Midlands Model Enginering Exhibition from 16 - 20 Oct. near Hinckley, Leics. http://www.meridienneexhibitions.co.uk/our-events-detail.php?id=0000000007

Dave
The Emerald Isle

 

[kvom]

All of the aluminum I have used thus far is 6061; it's very machinable and takes a good finish. Likewise 360 brass.

 

[Tin Falcon]

Yes 6061 is probably one of the most common aluminum alloys IIRC it is 6060 in your part of the world. also may be called Dural.
And if you come across some jig plate aluminum that is good stuff also.
in brass engravers brass and muntz metal are common names to look for and they machine well.

What you want to avoid

pre hardened Hi rock steel.
I have some steel I got free or cheap but it laughs at me and the machine when I try to cut it. if it does not file or cut with a hack saw it is likely too hard for the home shop.Your lathe you may be ok. I probably have a hundred weight of steel from a place I worked .machined it every day on a 5 HP cnc with carbide tooling and flood coolant . IIRC it is a 4150 prehardened to a rockwell of 34-38 I also have a nice handfull of high carbon low alow tool steel rod beautiful stuff and a good price but wen to wack off a piece with the hack saw an the carbon steel blade barely cut into it. Guess I need to get some bi metal HS blades.

As far as aluminum 1100 series is nearly pure and does not machine well.

I would probably steer away from formable brass. Have not tried to machine it but suspect the properties are not best for machining.
Tin