Rene Schaffers HR27 Ringbom Engine

[fcheslop]

Hi, You should all know by now I cannot stick to one build at a time and as the tractor is on hold until I pass m-machine for some materials for the smoke box I though I would chuck this build into the pile

Started on the uprights first
As you can ee the stock was anything but flat so out with those old fashioned tools and gave it a quick lick over with a file

I just use a marker pen and gently file until the blue has gone. Ok I did check it with blue on the surface plate but don't tell Dave

Then onto the mill after marking out just as a back up as I often forget how many turns Ive moved the handles I know one those fangled digi read out things would be great but I'm tooo much of a tight wads to buy one and often take a perverse pleasure in doing it the hard way

Why two uprights
Well I might as well have a crack at HR???? .Theres no drawings in the book but the hot end and a few other bits are the same so its easy to double up as I go

The uprights were then drilled and tapped before a start on the hot ends of the engines.Although I wont be building HR28 straight away at least a good part will be done.
Then onto the patent pending tapping thingy I know theres no hole in the middle  but drilling that stuff is bad news but notice the nifty chuck key holder it stops me loosing it unless youre posh and have a key less chuck

Well its late and time for a medicinal malt
cheers

[steamer]

Yes I like the tapping stand!.....and no you don't need my permission to check it on the surface plate!

Dave

[fcheslop]

Hi Dave, Thanks but you no doubt noticed I didnt show how poor it was

[b.lindsey]

Nice looking engine(s). Just how does a Ringbom differ from other stirlings though?

Bill

[Don1966]

Hi Frazer, I am in on this one and will be following your progress,

Don

[tvoght]

I'm very interested as my next build is to be a Stirling engine (first cuts were made today). I have built a Ringbom from the book by James Senft but have never gotten it to run. I'm sure you will do much better. Looking forward to the hot cap as that is what I'm working on now.

Bill, for a hint as to what's unique about a Ringbom, look at the book cover and notice no linkage between the crank and the displacer.
The displacer is driven by variations in the internal pressure of the engine.

--Tim

[sco]

Neat tapping stand 'thingy' - I can see one of those going on my job list.

Simon.

[fcheslop]

Many thanks gentlemen
   Hi Don I think Tim has covered the difference in the Ringbom design.
Hi Simon the tapping thingy is very handy and well worth the time in making one.
Its my first Ringbom so we will see how it goes.I have altered the design a little and was going to post the hot end build but for some reason my pics have evaporated from photo bucket I will retake them and show how the test tube is going to be held instead of I think bonded in.There is a bit of guess work as I cannot read the text in the book although the drawings are of excellent quality and well worth the £6.50p the book cost
So onto the flywheel it is 20mm larger in dia than specified as I had some bronze alloy rings left over from my Little Angel build
First I just friction turned an alloy blank



As I dont have any large measuring kit it was a bit suck it and see to get the shrink fit

The blank was then set up and reamed for the center bosses Note to myself I must get a shorter 5/8 reamer but this one was for the best price FREEEEE

Then onto the mill to shot a few holes in I was going to use Steve's what the hell pattern but chickened out

Next up the bearing housing so after a rummage through the swag box I found some bearings near enough if a little larger than specified
I dont have a boring head so the bore was machined on the lathe and then mounted on a mandrel this mandrel will also be cut to make the bearing spacer .So not bad two parts for the price of one.

The housing set up on the rotary to for the round section

The excess was milled of and the bearings glued in. The crank is just again glued up

A little group shot of all the parts made to date

Thanks for looking in.
kind regards
frazer

[sco]

That two piece flywheel looks the business - nice job on the other bits too!

Simon.

[b.lindsey]

That's a lot of progress Frazer...looks very good though. Still following along here with interest.

Bill

[fcheslop]

Many thanks gentlemen.
The hot end has been reworked mainly to make life easier for me in the way I like to machine and build.
The cylinders were reamed for the displacer bearing and then counter bored for the O rings I'm using to make a sealing gland.
The O rings are a light stretch fit over the test tube and the cylinder then bored to a light push fit for the OD of the stretched O ring.




A mandrel was then made to mount the cylinders this made life a little easier as the parts could be swapped from the lathe to the mill and back keeping every thing within reasonable tolerances



The holding bolts and gland bolts were drilled on the mill



This is the completed assy so you can see what I'm babbling on about and not explaining too  well

Next up the burner I tend to make these early on as I'm alazy so and so and would simply pinch onefrom another toy to get it running.
The burner is simply an adapted 22mm to 15mm end feed domestic copper pipe fitting I often use them as they make good little burner for not a lot of effort.

The power cylinder was made from bronze and the piston from mild steel and again I made a yoke for the little end as I believe sooner or later the wrist pin would move and score the bore


The conrod has been modified to take a small ball bearing as I prefer when ever possible to use ball bearings


Next up the base was trued up on the mill and a trial build up

After sorting a few little tight spots I just couldn't help myself had to see if she was a runner

That's all for now
many thanks for looking in
cheers

[Kim]

That's pretty cool Frazer!  It runs really well - Nice video!  I like it
Congratulations on a runner!
Kim

[sco]

Nice job  - and nice runner!

Simon.

[smfr]

Nice one Frazer! It's a runnah! 

Simon

[Don1966]

Oh wow! You made short work of that project. Nice job and nice runner Frazier.

Don