Tiny Vertical Based On G. Britnell's Design

[sbwhart]

I'm get very very close to steaming my loco (honest) its been a bit of the trial and may still jump up and bite me, but I've been getting very itchy to design and build an engine.

This one is not all my design I've based it on Georges' design that you can follow her  http://www.modelenginemaker.com/index.php?topic=570.0 but as I'm on the metric side of the pond I've been converting Georges' drawing to metric friendly sizes, I've also designed it with a piston valve instead of the slide valve George used as I hope that will be easier to make:- we will have to see on that one.

I've attached the drawings for those who are interested

I made a start on it this morning, but the first thing I did before starting to make parts was to get a bit of kit together that I thought that I may need.

I use an ER32 collet on my mill which is fine for normal work, but I've found that with small parts and cutters it tends to obscure the job so I got a set ER16 collets and straight shank holder that I will piggy back on the ER 32



I shortened it by 40mm using a dremell cut off wheel it was too had for a hacksaw.



I made a tap wrench to fit in the chuck and a small die holder for the lathe, I also drilled and tapped few practice holes M1 and turned and threaded a male thread, as you can see in the chunk of ally in the shot

First up the base:-

Square a bit of ally to size.



When making small parts you need a small helper.



 

Mill the pocket in the base



Then mill the middle out and mill the steps



Then drill and tap the M1 holes





No broken drill or taps  :whoohoo:

Then profile around the outside



That's the first bit done



Stew

[DavidA]

Nice to see someone tackling small jobs.

I hope your paying that little guy a fair wage.

Dave.

[SwarfnStuff]

Well I will be watching with interest to see how the little helper gets on. This project is way beyond my limited skills so I plan on being inspired. Thanks for posting, also for the pictures.
John B

[sbwhart]

Thanks for your support Chaps

I scrapped a base and I scrapped a support  before I got one right 

To make the support first I turned up a blank on the lathe



Then I mounted it in a ER32 square index block

zeroed the DRO on its centre line and front face then proceded to mill out the fillets it was just a mater of indexing it round and repeating what I did to one side to the other.



When it came to doing the angle I just swivelled the vice first one way then the other.



It was then just a mater of cleaning it up and sculpting to shape with a dremel and some Swiss files.





Then it was a mater of putting it back in the lathe to ream the bore 6mm and part off.



All that remained was drill the base and the four holes at the top:-

This what it looks like with my little helper Jack.   



Stew

[tom osselton]

Nice work!

[SwarfnStuff]

Must nearly be time for "Jack" to have a coffee break?   
Thanks again for this post

[tom osselton]

The motor is going to be bigger than your man I think your going to need a bigger boat!

[sbwhart]

Thanks Chaps

I've given Jack his dinner, roast beef with all the trimming followed by apple pie and custard:- don't know where he puts it.

 

On with the cylinder:- First a turned up a blank in the lathe then transferred the chuck over onto my spin indexer on the mill and proceded to mill the valve port face and to sculpt away the shape of the cylinder by indexing 1 deg steps until I got the finished shape.



Then it was a mater of drilling the valve ports and the drilling and tapping M1 for the steam chest.



Then everything was moved back onto the lathe whilst every thing was nice and secured I finished off the shape



Then drilled and reamed 6mm the bore 6mm



I just parted it off to length



Centred it under the mill



The drilled and tapped m1 for the covers and drilled and milled the air passage at both ends.



I've also made the top and bottom covers.

Heir's all the bits assembled to date.



I'll be having a rest from this for a couple of days has we have visitors stopping.

Stew

[awemawson]

Good work Sir!

I'd need new eyes to do small things like that. M1 threads - that's swarf !!!!!

[krv3000]

love it

[steampunkpete]

You can't fool me, that's all your own work. Jack doesn't really help you, he just watches - I can tell 'cos the spanner is too big, and it's worn out; it wouldn't undo a nut! 

[DMIOM]

Jack's holding it that way because he's just used the screwdriver blade on the bottom of the handle to tighten those slotted screws which hold the standard onto the base! (and, you never know, the 'blind' side of that spanner might in fact be some sort of pin-wrench?

[sbwhart]

Thanks Chaps

On with the next bit I seem to be settling into a routine of scrapping the first attempt for various reasons and getting it right with the second.

Fist op was to turn up a blank in the lathe and drill and ream the valve bore 3mm.



Then keeping the blank in the chuck transfer the whole lot over onto the spin indexer.



Then mill it up into the oblong shape.



Then to centre the mill up on the part in the x and y and using the indexer to manipulate it to proceed to drill and tap the part to the required sizes.



The transfer the whole lot back on to the lathe and part it off to length.



That it job done.



As the assembly is getting a bit bigger Jack has enlisted the help of his apprentice Liz.

Cheers

Stew

[sbwhart]

I've only just realised that I've missed off some features from two of the parts   

Putting that right will be my next job.

In the mean time I've completed some more parts the main bearings.

Again I started by turning and drilling a blank on the lathe.

Then manipulating it in the spin indexer mill it to shape.



The drill the holes.



Then back onto the lathe for parting off



I've used a catch wire to stop the part flicking off disappearing to be collected by the shop GREMLINS 

These are the finished parts



Cheers

Stew

[awemawson]

I really like the idea of a 'catch wire' when making small parts - I'm going to tuck that one away in what small amount of grey cells that I have left 
 
The idea of manipulating it in the spin indexer is also a very handy idea - ensures reasonable right angledness in a short set up time - I like it.

[sbwhart]

Thanks Andrew

On with the crankshaft:- this is made in one piece from a bit of 3/8" mild steel

1st turn up one of the main journals  2.5mm



Then make an eccentric bush by packing out one jaw to give the off set throw.



I drill the bush to take a grub screw to grip the work, it was then a mater of turning up the big end journal 2.5mm with a cranked tool so that I could get up close to the job.





Next I made a split bush to hold the shaft nice and secure to turn up the other main journal





Next using a pair of small vices and three parallels 2*1/8 and 1*1/16 thick mill the counterweight shape on the webs.





Job Done



And this is it after Liz had fitted it into to the main bearings.

 



Cheers

Stew

[vtsteam]

I have a hard enough time ruining a 4" long crankshaft blank. That tiny one looks fantastic!

What a cool little engine.

[sbwhart]

Decided to make the fly wheel next, so turned up a blank



Then keeping it on the chuck mounted it to the rotary table and centred it under the mill.



Then using the RT to move the angle and the DRO to walk round each segment drill the corner holes.



Then with a 3mm slot drill and again using the RT for the angle and the DRO to walk the segment, cleaned each segment up.



I just tidied everything up with some files and then tilted it in the vice to drill and tap M2 for a clamping grub screw.



Back into the lathe and part off, and then flip it round and got it running true and tidied up the back face.



This is it after Liz had fitted it to the engine   



Stew

[ImIndoors]

Great stuff Stew.  As always I'm picking up tips from your build log and full of admiration of this tiny project.
I take that Liz is on the Minnie Mum wage?   
Jim

[micktoon]

Cracking post Stew , small engines not really my thing but real good project so I have enjoyed and learnt from it  Thanks for posting 

  Cheers Mick

[sbwhart]

Thanks chaps

I take that Liz is on the Minnie Mum wage?   
Jim

    Nice one 

Now for the connecting rod:-

A chunk of 10mm brass bar was first roughed out in the spin-indexer.



Then using a 2mm slot drill mill little end fork and drill.

I also marked the position of the big end split line and the position of the bore with a spotting drill to aid alignment for later ops.



The onto the lathe for turning down the middle, and parting off.



Gripping it square in a small vice and lining up on the part off pip and the spot marks zero DRO.



Drill M1 tapping.



Cut off the bearing cap again using the spot marks to get position.



With the cap cut off tap M1

Then open up cap to M1 clearance 1.2mm



Screw the cap to the rod and set up on centre and drill 2.5mm.



Job Done





Stew

[steampunkpete]

Sir, I've just put my hat on so that I can take it off to you. You have made a lovely thing. 

[sbwhart]

Cheers  guys.

On with the eccentric:- as the engine will have reversing linkage the eccentric will have a double throw, it took me a while to get my head around George's method I also complicated things a little in changing his design half way through only to find that if I carried on I would not be able to assemble the arms so I had to start again, any way this is the sequence.

First make an off centre bush with a 1mm throw by packing out one of the chuck jaws.



The bush was drilled and tap to take a M3 grub screws.

Then on the 3/8 bar that the part will be made on mill a couple of flats 132 deg apart from each other using the spin indexer



Then in the lathe turn the little boss and drill 2.5mm



Then mount the bar in the off centred bush using a grub screw with a flat bottom so that the bar is pulled up level when it tightened up.

Turn up the first throw 6mm dia.



Then mount the bar locating on the second flat, and using a part off tool as the the first throw will get in the way, turn down the second throw to 6mm



Then over onto the mill and drill and tap M 1.6 for the eccentric clamp screw.



Back onto the lathe and part off

That's it Job Done.





Stew

[sbwhart]

We're really getting down to working with 2/10 of bugger all now 

Eccentric straps

I know it getting a little repetitive when I say in the spin-indexer but this is really the best way I can think of for holding these small parts.

So first up In the spin-indexer machine up a blank to make both straps back to back.



Then drill the holes in position and to the required size.



Then mill to shape



Mill the fork end with a 1mm slot drill:- yes I did say a 1mm slot drill I bought a couple of good quality Hertel drill they cut beautifully didn't break any at all.



Then slit them down the middle to form the two straps and cut them off the bar with a hacksaw



Mill them to final thickness



Mounted them on a mandrel to form the back.



Then filed the rad and tidied off the burrs



That's it job done





Cheers

Stew

[sbwhart]

Managed to get another bit made today in between baby sitting my 2 yr old grandson. :Director:

The quadrant link

Mounted a bit of thin mild steel plate to the rotary table that I had centred under the mill, then drill out the holes where required.



Then with the 1mm slot drill mill the radius slot and the outside profile.



Then it was just a matter of gently filing the rest of the profile.





Stew


IS THERE ANY ONE OUT THERE