A BEAM ENGINE

[firebird]

Hi

Thanks Nick and Carl

Here's some photos of the steam chest being made from a piece of 3/8 thick aluminium bar. Note it includes a foot that the cylinder will be mounted on.



The steam chest being cut out.



And after a little more machining.



After parting off matching stud holes have been drilled. In this photo I drilling through for the valve rod.



Cheers

Rich

 

[Blogwitch]

Just a little idea for you Rich.

It is a little late now as you have already done it.

Instead of using bevel gears, you could have used a Hobson's coupling to turn it thru 90°.

What is a Hobsons coupling you may ask?

Well you know all the elbow engines that have been made, that is a Hobsons coupling, but is used in a different context as the coupling has been turned into a motor. It was originally designed to allow a drive to be turned thru a right angle, but also allow the upper part to rotate around the input shaft, just as a bevel gear does.

I made a very rough and ready coupling a couple of years back, just to see if it works, and it does, and isn't as critical as the engines are to having everything spot on square and tight fits. I can't find it at the moment, but if I do, I will take a piccy.

Below is a very, very, very roughie C-o-C.


John

 

[firebird]

Hi John

I'd like to have a look at one of those.

Cheers

Rich

 

[firebird]

Hi

A few more pictures from the early stages.

I made this raised platform so that I could mount some of the components to get an idea what it would like. It's 4mm alluminium on 6 alluminium legs.



This shot shows an early mock up. I have used 2 con rods with the beam in between the 2. The boiler (not yet made) in the back ground.



Here I have started to make the crankshaft bearings from brass.







Drilling and reaming for the crankshaft.





Cheers

Rich

 

[firebird]

Hi

It seems ages since I had a bit of shop time but managed a couple of hours yesterday. I have done a bit more to the flyball governor, starting with the pulley. Its a straightforward bit of turning from 3/8 brass.



With a grub screw.



Followed by a brass spacer that fits behind the bevel gear and 6 pins made from 1/16 stainless steel threaded 10 BA each end with a brass nut on each end.





Cheers

Rich

PS

How doe's a flyball governor actually work ??? ??? ???

 

[Jasonb]

You need a lever from just under where the lower arms mount that is linked to a butterfly valve in your steam supply. As the engine speed gets faster the balls will lift the linkage and shut off the steam, as it slows (put under load) they will drop and increase the steam.

One of teh problems with small models is the mass of the balls does not always overcome the friction in teh linkage so they don't work too well, you will need to play about with the spring tension to get it near enough right. But you need to fit a spring first!! It helps to have a threaded portion to make adjustment easier like this

Jason

 

[b.lindsey]

This project is coming along nicely Rich...gosh, the governor is a project of it's own but looks great.

Bill

 

[firebird]

Hi

Here's a bit more from early on.

This is the start of making the crankshaft webs from a piece of mild steel.





Milling away the webs, you can see where I ran the cutter into the end by mistake so I had to face it again.



Here's the two webs after parting off along with 2 pieces of silver steel.



Loosely assembled.



And after silver soldering. I was a bit heavy handed with the silver solder so it needed quite a bit of cleaning up.



In this shot you can see I have now decided to use just one con rod. I have milled a slot in the top and made a bush to attach part of a wiper blade. I was never happy with the way it looked so changed it later.



This is how it was starting to look.



Cheers

Rich

 

[arnoldb]

Thanks for the update Rich - It's nice to see the bits coming together :bow:

A question if you don't mind - What parting tool do you use ? I still occasionally struggle with parting off mild steel, and doing it on an interrupted cut like on the webs would be a sphincter pulsing operation...

Thanks & Regards, Arnold

 

[cfellows]

Looking real good, Rich.

Chuck

 

[firebird]

Hi

Thanks Chuck.

Arnold, I use a rear mounted parting tool on my Myford. Its 2mm wide. It is one of the best things I have bought. Parting off is easy. I bought the tool post at a show for £20.00. Its not genuine Myford but but works just as well. The parting tool I also bought at a show for £30.00.



Cheers

Rich

 

[Brian Rupnow]

Nice work. I'm going to build my next crankshaft that way. However, since I have had a couple of crankshafts fail due to my skill (or lack thereof) in silver soldering, I will drill and pin them as well. I had a silver soldered joint on the crankshaft of my twin horizontal engine fail right in the final stages of run-in, and was fortunately able to resolder it "in place". I had a similar failure in the crank on my Webster engine. I doubt that my silver soldering is going to get a whole lot better, so the pinned joints will give me that extra bit of insurance.----Brian

 

[b.lindsey]

Rich...still coming along nicely. Was curious as to why the center hole in the crank webs wasn't located in the center of the circle. Won't it tend to make the rounded portion of the webs "lope" as they go round. They will surely work just as you have them...more as asthetic question I think. I love what you used for the beam

Bill

 

[arnoldb]

Thanks very much Rich

I'll have to start looking for a nice thin parting tool like that!

Kind regards, Arnold

 

[firebird]

Hi

Bryan, later on after cleaning the crankshaft I did drill and pin just to make sure. I'm not certain if I have any photos of the operation but from memory I used 1/16 brass rod (brazing rod) and drilled the holes slightly under that size so that the pins were a tight hammer fit.

Bill, this was my first crankshaft made while I was still a bit wet behind the ears. As you say it may have looked better drilling in the centre but it works OK. The idea behind this beam engine was to use as many scrap car parts as possible. I was struggling to find something suitable for the beam so that's why I used the wiper blade. I was never happy with the way it looked but stuck with it while the engine progressed until much later when I changed the beam for one made out of 2 con rods joined together.

Arnold, I can't remember where I saw it now, maybe a magazine article, where a tungsten carbide tipped 10 inch circular saw blade was cut up to give about 6 parting blades complete with brazed in tips. I haven't tried the idea but circular saw blades can often be bought quite cheaply. It might be worth investigating.

Cheers

Rich

 

[firebird]

Hi

Some more photos from earlier.

This first shot shows some work being done on the slide valve links. The fulcrum is made from 1/8 brass with a small boss silver soldered on. I drilled and tapped a new stud hole in the steam chest and drilled a matching hole in the cover and made a stud to suit.



Here I am making the bit that joins the slide valve rod to the link. it is silver soldered to the slide valve rod and has 2 nuts on the link for adjustment



Using a couple of steel buttons as a guide for filing the end round.



Here I am drilling and tapping a big end cap that will be the mounting for the crankshaft.





Moving on to the eccentric, here I am setting up the offset.



In the mill I drilled for the crankshaft and a central stud. The holes are drilled fairly deep so that I can part off an end plate as well.



Having parted of the eccentric I drilled and tapped for a grub screw.



Here's the eccentric with its end plate.



This is a phosphor bronze bush out of the scrap bin having a piece parted off. The eccentric has been machined to suit this bush.



The eccentric link being machined.



This photo shows where I will silver solder the bronze bush to the link.



Cheers

Rich

 

[firebird]

Hi

In this shot you can see the phosphor bronze ring has been silver soldered on. I have drilled and tapped the end 1/8 x 40 for the rod to screw into. I have also drilled and tapped the eccentric and made a stud to bolt the end plate on.



I said earlier I was never happy with the wiper blade as the beam so here's my next attempt. Two con rods have there big ends cut off and machined to equal length.



I made a block of steel to fit between the two and clamped it all up.





Con rods are cast iron so don't weld particularly well but with care I stuck them together.







Cheers

Rich

 

[firebird]

Hi

The mock up has been moved from the ally stand onto a larger box made from a piece of ply. Its beginning to look more like the final layout now.



Turning down a piston to use as the column pedestal.







Moving on to the con rod. I made a bit of a mistake here. My intention was to drill and ream the brass to 1/4 inch but somehow managed to pick up the wrong drill and drilled it over size. I recovered by making some big end shells from phosphor bronze.



Here the piece of brass is being drilled through before cutting in half.



The two halves being machined to size.



One half is tapped and the other half is drilled clearance.



Which gave me this.



I then drilled it too big, 5/16 I think it was but carried on with a different plan. here it is held onto a bit of bar with card board packing.



Being faced to size.



Turning a big end shell.



Testing with a big end cap.



With half the shell machined away.



I had to carry out this operation twice to get two shells.

Trial fit on a piece of 1/4 bar.







By lightly sanding the faces of the big end and its cap on wet and dry I got a really good fit on the crank pin.

Cheers

Rich

 

[firebird]

Hi

The flywheel (ex camshaft drive gear) is reasonably heavy so the crankshaft needs some outer support. For this I used a big end cap with an aluminium bearing housing on top.







The brass bush is a straight forward turning job. The groove is an oil way and the hole in the groove allows oil to get to the crankshaft, also the grub screw locates in the groove. The hole in the outer boss is for adjustment.



The central hole is drilled and then reamed off centre.



This shows how the bush can be adjusted to gain perfect alignment



The side of the bush housing has been drilled and tapped.



Cheers

Rich

 

[metalmuncher]

Hi I don't know if its just me or is everyone not seeing the pictures. I can see them in all the other posts on the forum. Regards Metalmuncher.