Has anybody built Beng's Danni Steam engine.

A tool with a V end with an angle of less than 45 degrees both sides being cut with the compound slide. A tool where one side is at 45 degrees and the other less - one side being cut with the compound slide. Or a V tool with 45 degrees on both sides aka a form tool where it would be plug cut in one go or to reduce the load on the lathe via compound slide set at 45 degrees.

John

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Brian, could you rig a vertical slide using an angle plate and your top slide?

I suggested that earlier John. Brian seems to be a bit worried about making something up to do the job.

I suspect he will have to as one mounted where the compound slide fits probably wont travel far enough past the centre of the lathe to make full use of it so will need mounting on a plate to offset it. On the slides itself it may be difficult to find metric ones as well.

John

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I was initially reluctant to make something if a vertical slide could be bought off the shelf but due to the lack of availability it looks like I may have to go the ''home-made'' route. I am thinking about it while I make up all the other parts.

John : the Toolmaster L276 is metric and it will fit my lathe exactly but there are none to be found anywhere.

In the meantime : the steam chest is 16mm square X 30mm long. The supplied brass is about 32mm long so the ends will have to be faced off. I do not have a four jaw chuck so I intend to make a jig using some 30mm diameter X 24mm round brass I had in my scrap box. I will drill/bore the hole (about 22.6mm diameter) in the cylinder take the square brass and then drill and tap the cylinder for three M3 grub screws to hold it in place. I should then be able to face off the ends.

Is there another/better way to do it ?

Edited By Brian John on 12/09/2016 10:00:44

Flycutting with the cylinder vertical on the cross slide looks an even better option now, this would also square off your 16mm block

Here you go brian, flycutting as I suggested earlier.

Infact I used the boring bar on the right as it will be easier for you to make one but a small flycutter like the one on the left will also do the job with the right cutter in it..

Take off the topslide then use a tee nut, stud and nut to hold the cylinder in position, pack it upto ctr height. Set the cutter tip to be 15mm from the central axis, you could do this by touching it against the top or bottom flange. Then simply take a cut, advance the carrage a little, take another cut and so on.

As you can see this gives a good flat surface to solder to and the corners are nice and square.

I would suggest a trial cut first on some scrap and also when rotating it is hard to see the cutter so you may want to refit the chuck guard for this.

Okay, I can now see how that would work. I will have to order a fly cutter and make up the cylinder.

Today I made up two of the joint parts (20). This connects the control valve to the eccentric outer race. The plans call for the M2 thread to be cut on the spigot (?) with a die but I have found it much easier to leave off the spigot then drill and tap for an M2 threaded rod. The threaded rod is held in place with Loctite. This gives a neater finish with the parts sitting flush when screwed together.

Edited By Brian John on 13/09/2016 10:25:32

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Well done, Brian

That's proper 'Production Engineering'

MichaelG.

I have made the jig for the steam chest and it has worked well : the square brass has been faced off and shortened to 30mm ready for drilling and tapping. I probably overdid it with three M3 socket caps....two probably would have been enough.

Can I use this jig somehow to drill the 6H7 hole for the control valve like drilling a hole for an eccentric ? The centre of the hole is 6mm from the side so that makes it 2mm off centre. I think I need a 4 jaw chuck for that. The diagrams are on page one of this thread. I may have to drill it in the drill press, lining up one side with the drill bit to ensure the hole is parallel with that side.

Edited By Brian John on 14/09/2016 08:07:23

Edited By Brian John on 14/09/2016 08:09:40

Edited By Brian John on 14/09/2016 08:10:54

Edited By Brian John on 14/09/2016 08:12:39

Would this 19mm fly cutter be suitable to do the cylinder ?

**LINK**

Yes, probably go for the smaller of the two heads as the tool bit is not so thick and will need less grinding.

This steam engine will be mounted on a base together with a boiler to form a steam plant. I finished silver soldering the boiler today : the main boiler section is made from 65mm diameter X 70mm long copper pipe. All this was salvaged from the scrap yard. I experimented with some silver solder purchased from the plumbers supply shop but although it is cheaper, I will not be using it again. The silver solder I buy from the Miniature Steam is far superior : it melts and flows very well.

I still have to apply the insulation and the wooden lagging made from mahogany strips. I use a standard Mamod safety valve as the filler plug.

Edited By Brian John on 16/09/2016 11:39:08

More smaller parts completed : the connecting rod bearing(13), the bearing cover(12) and the eccentric outer race (19).

I just realised that I have spent so much time thinking about the flat side of the cylinder that I have not given much thought to the cylinder itself. If I bore the 15mm hole first then that might make it difficult to turn the inner diameter of 24mm because I cannot support it between centres. But if I turn the inner and outer diameters(24mm and 26mm) first while supporting between centres than that will make it difficult to hold the piece securely in the chuck when I bore it later. How should this be done ?

Edited By Brian John on 17/09/2016 11:50:00

Brian you can make a simple plug to fit nicely in teh bored hole with a shoulder to stop it sliding all the way in and ctr drille dfor your tailstock support

Nice going Brian - I vaguely remember some one suggesting you should take up knitting.

John

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In principle Brian you could do it between centre but driving it around will prove difficult. It's possible to use tube centres. All that really means is that the cone on the centre is larger than the bore.

When I have had this problem in the past I have more or less done what Jason suggest except drilling and tapping a hole in the centre of the arbour with a 2nd tap so that the thread is only fully cut say one tap dia in and then 2 slits with a hacksaw at roughly 90 degrees apart. The part that fits in the cylinder needs to be a bit short of the finished length so that the part can be reversed to face the other end. This is just a simple expanding mandrel as the arbour will expand when a screw is run into the hole. These can be bought but Arc don't seem to have found a well priced decent set so sell one at a time.

Not needed for a long time and suspect I used mild steel but as the fit before expansion needs to be pretty good aluminium should be ok. It needs to be a nice tightish sliding fit in the bore.

John

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I completed two plunger joints (part 14) today using a jig I made from 8mm hex brass. I was able to hold the work piece in the tool post while I used the slitting saw to cut a slot and the jig was also used when drilling and tapping the cross hole. I did try to make the M3 thread using a die but the die is stuffed : I had forgotten to order a new one. So I just cut the end off the piece then drilled and tapped for M3. I did not have any M3 threaded brass (it is on a slow boat from China) so I cut the thread off a stainless steel M3 socket cap and then fixed it in position with high strength Loctite 263. It seems to have worked out okay. I made the minor shaft all 5mm in diameter rather than 4mm and 5mm as per the plans as this was easier to hold in the hex jig. The jig has two M3 grub screws on either side to grip the work piece. I think 10mm brass hex would have been better to give more thread for the grub screws.

Edited By Brian John on 20/09/2016 08:36:57

I have made two cylinders and started the cylinder covers. I was going to turn the other 15mm ends of the cylinder covers to fit the cylinders when I remembered that after I mill the flat on the cylinder then I have to bore two 2.5mm holes into the cylinder walls so this will ruin the smooth finish I have put on the bore. Is there some way to clean up the two holes on the inside of the cylinder without damaging the bore ? Or will I have to take a cleaning pass (0.1mm) with the boring bar and then repolish the cylinder bore ?

NOTE : I am thinking of buying a 4 jaw chuck to mill the cylinder. Machinery House have one left in stock but I am not sure if it will take the 34mm cylinder end on ; it might be at its limit doing that so I will ask first. The first photo below shows the wooden mandrel I made for polishing the cylinder bores with 800 and 1500 grit.

Edited By Brian John on 25/09/2016 05:26:09

The piston won't actually be sliding past those holes when running so just clean up any burrs with a half round needle file or small scraper. If need be just run your lap in again by hand.

You could well be limited with the 4-jaw as to what you can hold, probably OK if it were a 34mm long rectangular block as all jaws could be reversed but you won't be able unlikely to be able to grip the curved sides if you have teh ends held in the reversed jaws.

Okay, I will leave that piece for now. But I may need a 4 jaw chuck to make some of the other pieces. I started making the eccentric today using the flat edge of my parting tool. I kept shaving a small amount off my moving the tool from right to left until I got a good fit with the outer race as per photo #2. Now the instructions say to bore the 6H7 hole using a jig which I proceeded to make but how am I to bore the 18mm hole in the jig ? I have cut the 30mm X 3.9mm disc as per the instructions. Should this now be mounted horizontally in a vice and the 18mm hole drilled with the drill press ? I do have a set of large drill bits (12-24mm) of doubtful quality.

If I had a four jaw chuck I could mount the eccentric work piece from photo #2 off-centre with a 3mm ''chock'' then bore the 6H7 hole that way. Is that how it is done ? I think the 6H7 hole could also be bored in the steam chest using the same method.

Edited By Brian John on 26/09/2016 08:25:10

Edited By Brian John on 26/09/2016 08:26:24

Edited By Brian John on 26/09/2016 08:30:22