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Member postings for Iain Downs

Here is a list of all the postings Iain Downs has made in our forums. Click on a thread name to jump to the thread.

Thread: Air regulation for my Engine
25/09/2021 12:31:48

Thanks, Jason.

I've had struggled my way through amazon to work out the ancillary bits needed to hook up the regulator and so on. And purchase them.

I got to the end to find that the Amazon version of the regulator will take a month, so I went back to bearing boys. Should have stayed there in the first place.

Many thanks.


24/09/2021 18:24:42

Soon (in a relative way) I will have got my engine in a place where I can push some air into it and hope that it turns round.

What I'm looking for is a regulator which I can control at the bottom end of the pressure scale (I hear posters boasting of their engines turning over at 2psi or less).

So I want something to do two jobs. Firstly to regulate up to a couple of bar with some granularity and secondly to have a tap on so I can turn it off quickly.

Or do you professionals just turn the regulator tap to start and stop?

Any advice welcome!


Thread: Small bandsaw needed
22/09/2021 16:55:04

I have the smaller femi and i love it.


Thread: Steam Engine Number One
20/09/2021 21:05:37

Now what questions

So I have all the parts made, nearly 3 years on.

I need to scrape the big end bearing and I want to do a bit more on the main bearings.

I want to lap the face of the valve chest and D Valve.

I haven't put any balance on the crankshaft, though I can refer back to some articles on that in ME or MEW. I don't know important that is in practice, bit I expect I should do something.

I've only trial fitted things so far. There's a good bit of fixing a thread sealant for when I finally decide to put things together.

I don't know how to tune up the engine. I know that I need to balance the D Valve so that it exposes the same amount of valve port on the up and the down.

What I don't know is how to set the timing. the engine is roughly based on A Stuart 5A, certainly in terms of the valve timing (though converted roughly to metric).

Any help on that (or pointers) would be much appreciated).


20/09/2021 20:53:17

What TWO postings in one day!!!

This is a gasket cutting post.

I was much inspired by a couple of articles in MEW recently and also a hint from Joe Pie in his recent model steam engine build.

I had 3 sets to build. First gaskets for the steam inlet and outlet ports (brass in the previous picture).

I found I had a leather punch with a hole about right for the steam hole, so I started by punching a hole in some gasket material. next I mounted the port over the hole and carefully trimmed round the edge with a craft knife.

gasket steam inlet01.jpg

next I mounted the port upside down in the vice and put the gasket material over it. Then knocked out the bolt holes with an automatic centre punch.

gasket steam inlet02.jpg

That went reasonably well. I think I only ruined one or two.

Next for the steam chest. I needed two here one for the top and one for the bottom.

I started by slicing round the steam chest for both pieces in one go.

Then I clamped the chest walls and top with the gaskets between them and carefully drilled through with a 4mm end mill.

gasket valve chest01.jpg

I'd had a previous go at cutting out the centre on a surface with just the chest walls, but this just resulted in a mess.

I also found later that I could have just put the end mill in a spare chuck and done it by hand.

gasket valvechest02.jpg

The cylinder end caskets were more tricky. This is mainly because I kept getting the end wrong. Despite what you may think would be ideal, the two cylinder ends are NOT quote the same. One a fraction wider and they seem to have subtly different hole patterns. A couple of bits of gasket material went in the bin there, as well.

So I started by placing the cylinder on the gasket material. then careful cut round, except where the valve chest stuck out. Then rotated the cylinder 180 and lined up on the cut circle then cut the rest.

Turn the cylinder upside down and clamp the material to it in 3 places.

gasket cylinder01.jpg

Cut the inside out with a craft knife and then punched through the mounting holes with an automatic punch. I actually found this could leave a bit of a ragged edge so I tidied up with a 4mm reamer followed by a 5mm reamer (the bolt circles are 5mm).

gasket cylinder02.jpg

I'm quite pleased with how these ended up.


20/09/2021 20:37:45

To mount the items above I milled some flats on the sides of the support pillars

supportpillars milling flat for bolt.jpg

And the spotted and drilled through.

supportpillars spotting.jpg

Notice that the pillar sticks out a long way. I was worried that there would be too much movement, but the engineers jack seemed to work nicely.

Oddly, the closer I get to the end of this journey the more likely I am to sketch (on paper) and hack away rather than go back to my CAD model. At least some of that is because the CAD model is now rather complicated and messy and I suspect my dreams of a data driven parametric model have been lost in the noise of minor changes. Ah well.

And here, at last is the majority of the beadt.

engine most parts.jpg

At this point the only part I need to make is the valve chest cover, which I have since done...


The sceptical reader may recall that my name (Iain) starts with a capital I and may suffer from the misapprehension that the 1 (one) symbol is, in fact an error in manufacture. Not true of course.

It needs tidying up a bit (and I may recut it, now I realise an I (eye) is would have worked better!) wink


Thread: Backing up computers across a network
23/08/2021 16:26:10

Have you considered a 'cloud' backup option? the Data is stored on someone else's servers, which also gives you disaster recovery.

I use crashplan and have about 3.8TB stashed away for 10 quid a month or so.

You can also use an off the shelf (including free) backup from each machine to a central one (just stick more hard disks in one, they're cheap). and then back that up to the cloud.

It may take a while to catch up with your current storage, but with modern internet connections, it keeps pretty up to date.

As Stuart says, it's not entirely simple, as there are trade offs, but cloud is a useful option to consider.


Thread: Steam Engine Number One
02/07/2021 12:36:53

I suppose the starting point is to admit that Jason was right and I was wrong (hard to imagine how that could ever be!)

Having looked at the valve chest I couldn't see any way my idea would work, so I tapped an M12 in the end and made a gland to fit in it. Pride goeth...

valvechest 10.jpg

and here's a shot of the gland nut being made - putting a hex on the end of the nut.

valvechest 11.jpg

One 'interesting' thing about the gland nut is that I happened to have a bit of sliver steel the right length and diameter so tried to cut that. I went through most of my tooling before I settled on a (steel) carbide insert which did the job. I burnt the tip of an hss home ground tool, smashed the tip of an aluminium insert and had some success with a brazed carbide tool facing, but it really didn't like to turn the diameter down. Of the lot, the carbide insert that worked seemed the least sharp! Oddly the thread cut easily (with a die).

However, what has given me the most pain since the last post is the eccentric guide. It's taken me 3 goes sad.

The first attempt wasn't too bad, but I'd not taken into account that I'd shifted some dimensions to deal with a 1.5mm offset of the support struts from the main bearings, so the shafts weren't symmetrical around the bore. I'd forgotten (two lessons- one don't get it wrong early on and two - don't take several years to make something - you will have forgotten what you did wrong!).

The result was that I couldn't quite set the guide plate in place.

I'd done the first try clamped to the mill bed on a sacrificial plate, but that meant the quill was full extended and nasty singing noises happened.

I decided to buy some thin parallels so I could mount it in the vice. They arrived, but time passed and I'd forgotten about them before I came for my second try. I'd be less embarrassed if the time in question was months rather than weeks (or less blush )

I'm not sure what happened but the forensic evidence is that the clamps slipped - the piece was pulled off centre and too; my only 4mm 2 flute cutter with a long cutting area with it.

Finally, I ordered some 4mm carbide 2 flute cutters, remembered the thin parallels and made my third and final attempt.

support eccentric three goes.jpg

I have two more main bits to make (plus gaskets). The support strut for the cross head guide and the steam chest lid.

I've also got to work out how to control the stephenson reversing gear. I think I just need a longish arm that secures the gear and can be moved left to right by a lever. Longish to keep the left right movement of the gear to a minimum by minimising the angle of movement. I think.

The end is in sight!

One question I will be asking shortly (which in this build terms is probably about 3 months) is how to set the valve timing. Let me wait until then though.

Thanks for the advice Jason!!


Thread: Moving machines
21/06/2021 07:56:25

When I moved my mill in (240kG - a lightweight compared to some), I found a chap on ebay hiring his engine hoist for somewhat less than a hire should would have charged. Two particularly challenging parts:-

getting the machine over the ridge of the door in the shed. The door and frame were integrated so there was a 3 cm bar there. I build a platform of two long wood joists, lifted the mill onto the outside of the door with the engine hoist, pushed it along by hand, (somehow) navigated the hoist over the mill and continued at the far end.

The other issue was that there was ONLY just enough height in the shed to lift the mill in place. Probably not an issue with a lathe, but worth thinking about.

OH - I had the help of a strong young man. I could not have managed on my own.


Thread: Filing machine uses?
07/06/2021 19:28:30

Check out some of Clickspring's videos on Youtube. He uses a filer quite a lot and the results are impressive.


Thread: Steam Engine Number One
04/06/2021 20:07:17

I should learn patience.

Many thanks for your advice (as always, Jason). In this case, I'm afraid I jumped a little too soon as I liked the idea.

I've already drilled and bored the other end and will eventually make a gland to bolt on. What I DID get however, was JB Weld. Something I've not really had contact with. I will use that to secure the pin in the end I don't want.

But for all that, this has been a good week! With the valve chest done (and drilled), I was able to put the beast together for the first time smiley.

first assembly.jpg

And, yes, Jason, my workshop is ALWAYS that messy... wink.

The remaining items are some support brackets (for the eccentric rod and the cross head slide), the chest cover and the valve gear control handle.

Oh and seeing if 3 years of pain have paid off in something that at least kind of works!


30/05/2021 11:05:30

My final post of the day. Something which went well. Yes, I was surprised too.

Mounted the cylinder in the milling machine. The basic idea was to put the cylinder on the valve face and bolt some 2 4 8 blocks to it and then use the 2 4 8 blocks to mount in the vice. I'd tried this before for some operation, but there was a bit of wiggle.

By dint of some 2 4 8 blocks, some wooden chocks and surface plate I was able to establish that the bottom face was pretty much at right angles to the bore of the cylinder and the top one a bit off. This was not surprising (and to an extent expected) as I'd done the base and bore in one operation and the top after turning and remounting.

So I bolted the cylinder to the mill table and took a light facing cut.

Then assemble the fixture, mount in the vice and centre drill, drill and tap the chest holes.

cylinder drilling chest holes.jpg

And lo and behold, it fits together!

cylinder with chest.jpg

Any ideas on the steam gland would be gratefully received by the way. It turns out that the chest fits slightly better on the cylinder with the would be eccentric hole at the top, so I have another good (?) excuse to turn the chest round and mount a gland on what will now be the bottom.


30/05/2021 10:55:21

The next challenge was to create the valve chest. The pictures below are a mix of the first attempt and the second attempt. I can't quite recall what went wrong with the first attempt, though most likely it was getting a dimension wrong. My second attempt came so close. And for once the failure wasn't my fault (though I will face the judgement of public opinion if need be).

The item is a hollow rectangular block drilled through for bolts into the cylinder and with a stub at one end to contain the steam gland for the eccentric.

First step was to face to size and then drill the bolt holes.

valvechest 03.jpg

You can see the stub on the right which will hold the steam gland.

Next to chain drill the inside out before finishing with a milling cutter. This is something I saw on Joe Pie's channel and is supposed to reduce the strain on the cutter or something. Made some sense to me!

valvechest 04.jpg


valvechest 05.jpg


valvechest 06.jpg

Here's where things get sticky.

And I've remembered what happened to the first attempt. The failure came when milling out the end to leave the stub. I hadn't tightened my drawbar enough and the 10mm carbide cutter pulled out and took too much off.

This time I got further! However then I wanted to turn the stub into a cylinder. I tried any number of ways of mounting this on the lathe with no success. It's too long and there's not enough material to grab and thin enough that it slips into the chuck body. I tried a variety of things with parallels under and round the base, but I couldn't see how I could get something even firm enough to clock in (I'd but in a reamed 5mm hole where the eccentric rod would go through and was/would indicate off that.

I gave some thought to mounting it on a faceplate, but the only angle block I have of the right size is something other than 90 degrees and would have left things out of whack (I looked at 2 4 8 blocks and bolts and clamps, but it was just getting too much).

So I thought, why not bore the outside? I'd done this before and set up my boring head with a brazed carbide cutter, running in reverse (or the head unscrews - don't ask me how I knew).

This lasted about 15 seconds before the carbide cutter objected to the interrupted cut and cracked.

At this point I turned out the lights, went inside and found my PC had expired.

A pause for respect for a much loved an faithful motherboard.

Now we've got the bits and they're all back together (though it seems my purchase of Toshiba hard drives was a mistake as they appear to be expiring, requiring the purchase of another hard drive ).

Made myself a reverse boring bar and set to on the stub.

valvechest 07.jpg

valvechest 08.jpg

Quite pleased with the result (so far).

Now I have a 10x1mm tap and die set so the idea was to thread this to 10x1 to give some nice controllability to the gland. I have a set of 9.2mm drills (eBay, of course), chucked one up drilled out and inserted the tap.

The tap fell straight in. Didn't touch the sides. Yes. Words Were Spoken!

This is the only one I don't want to take the blame for. The b***y drill was bent! how can someone sell you a new drill which is bent!? For that matter how can you make a bent drill?

So rather than cutting on both flutes it was only cutting on one and .03 or so mm wider.

I had a bit of a think. I didn't think the part would work with a 12mm coarse drill and certainly didn't want to but a tap and die set just for this. What I plan to do (I think) is to make a separate gland housing and bolt it on.

I've cut the boss off

valvechest 09.jpg

It's left a countersink in the top and I'm struggling a bit to see how to fit that into a housing, so I will probably close that up and mount something at the other end.

Would 638 cope with the steam temperatures or do I need to silver solder? It's a big piece to heat up.


30/05/2021 10:28:41

I thought quite a bit more time had elapsed since my last post as it's been busy, but not with good things! I have three pieces of engineering progress to report and I will sandwich the unhappy one between two better outcomes - a management skill apparently!

As well as some frustrations in the shed, my home PC melted down a couple of weeks ago (CPU/Motherboard dead) and it's been something of a struggle to repair it. Apparently I keep PCs for too long as by the time the damned things break down all the parts are obsolete! I am now slightly the wiser on the advances of the last 10 years and am again working. Quite how long it will take to find all the programs I had on the older system (or indeed if I need them), is another story.

However, let's start with some positivity, shall we?

Jason advised on creating some flanges for the steam pipes and I thought that to be a good idea.

First take a piece of round brass stock face to size and put a 16mm spigot (is that the right word) on each end. The first one held in the 3 jaw, the second one by placing the 16mm end in an ER32 collet. Drill through and tap to 14 bsp. I did have a challenge on the drilling - foolishly cut a pilot hole and then the large drills pulled themselves in and jammed. I didn't want to stone off the edges for a single use, so managed to baby the hole with much wincing.

steamflange 01.jpg

It turns out that one of my two cheapo carbon steel tap and die sets has 1/4bsp tap and die. Whilst the other tools in the set have lasted about 10 minutes when faced with steel, I'm hoping these will last a bit longer if they only deal with brass.

Next drill some 4mm holes in just the right place (14mm from center.

steamflange 02.jpg

And return to the 3 jaw to be parted in two

steamflange 03.jpg

Brass is nice. Why does anyone use steel?

Then put each piece in the mill kept in registration by a pair of pins

steamflange 04.jpg

And trim off the top and bottom. Leading to this

steamflange 05.jpg

Which I'm quite pleased with.

Apart from my drilling challenge mentioned above, I also broke an Ally carbide tip. I thought to see how this would work, but when I was reducing the stub, it caught on the part and - well, let's just say the results weren't good. i had to replace the drive gear on the motor.

I ground myself an nice zero rake HSS cutter which finished the job in style!

And that was the successful job!


09/05/2021 17:16:06

So the latest item on the production line was the DValve.

This was a fairly straightforward piece of milling, marred in the first instance by my measure (wrong) once and cut... oh dear ... approach.

Second times the charm.

valve chest 01 dvalvetop.jpg

valve chest 02 dvalve bottom.jpg

My original drawing had a slot and bar approach to connecting the eccentric rod, but I decided to change it for a gap with nuts and washers (which is what my main source the Stuart 5A has). It may be that the ridge is now not high enough, but the DValve is also easy enough to remake, so I'm not too worried.

Also attempted in this period was the valve chest. Sadly, this failed part way through due to the cutters pulling out of the collet and digging too deep, spoiling the part. It looks like the root cause it not enough drawbar tension, so I hope it will work better this next time!


Thread: MIlling cutter pulling out of collet
09/05/2021 17:09:37

Thanks (as usual) for all the feedback.

I've checked the cutter I've been using. This shaft measures around 0.01 mm ( 2 tenths) undersized (9.99mm) though it's possible that the flutes are a tiny bit smaller - not easy to measure.

It is a tight sliding fit in the collet which measures (best I can with calipers) pretty spot on 10mm.

Good news I thought. I cleaned both with denatured alcohol and mounted them in the quill.

I've got a new torque wrench but had to make suitable socket to go over the 12mm drawbar. I would have happily bought one but couldn't find such a thing.

The socket was constructed from some mild steel bar drilled one end at 9.5mm and milled to 12mm the other and then squared up with 2mm carbide endmills. I had several approaches to this each of which lost me one end mill. In the end I was able to take 2mm deep cuts going round the square and it worked. For various reasons the socket is a bit of a mess, so no photos!

I applied what I believe to be around 28Nm of force and proceeded to mill the same piece.

10mm deep. I started at 1 mm depth of cut, but got brave and ended up with 2mm depth of cut. I cut 3 stripes at 2mm (6mm in total) conventional milling and then 3 more 2mm stripes climb milling.

As best I can tell there is was no movement between cuts.

cutter pulling.jpg

I'm not sure if you can tell from the photo, but there is almost no ridge to the finger touch on the top. Scraping a finger nail there is the slightest hesitation. In short this is about as good as it gets.

So it would seem that my earlier error was simply not to tighten the drawbar enough.

Having said that 28 Nm felt like a LOT at the end of the torque wrench and it was VERY hard to undo with the 6 inch spanner I normally use.

Is my general solution just to get a longer spanner? I'm not particularly keen on messing with a torque wrench to set tools.


04/05/2021 16:58:10

Thanks both.

Michael: I've not actually measured the bore of the new collet, but 10mm end mills (not reground) and edge finders fit in nice and snugly and don't drop out (unlike in it's predecessor) so I'm content that this is reasonably sized.

Martin: There's plenty of thread on the drawbar. There's more thread on the drawbar than it sticks up by when a collet is inserted and the drawbar fully unscrewed.

I will, however double check that.

I've ordered a torque wrench so I can apply some science to this, but will need to make an adapter between a 3/8ths socket and the 12mm square spanner nut thing on the top of the drawbar.


04/05/2021 12:59:47

Thanks for even more thoughts!

Jason - I'm not sure what you mean by 'out of thread'. The drawbar screws down about 40mm into the collet. Having said that some collets are still sticky at the end. I keep losening the setscrew in the spindle (which appears to be the issue - or more correctly R8 collets which have a keyway that's not to spec). Do you think this could be a contributor?


04/05/2021 08:03:03

Thanks again. In fact the collect is relatively new bought to replace one which was a tad oversized.

Jason - I'd actually planned to do that (cut the boss on the lathe) originally, but then thought that I would trim off the bulk of the material to minimise the interrupted cut. Now it's more a question of working out the right technique as a matter of principle.

Sadly, I am now in the day job, so will try and do some more tests tonight. I believe I no longer have a torque wrench, so I may need to leave that aspect until Mr Bezos can deliver something.


04/05/2021 01:24:24

It looks like I measured once and cut twice with the text of my original post.

The boss is 16 mm not 6mm and I was (as some of you have realised) suggesting use an ER32 collet chuck rather than the R8 collets I was using here.

I've had a similar problem with trying to tap with this machine is well = the shank of the tap doesn't seem to be gripped well by an R8 collet.

I will try ER32 once I've found some stock and taken it back to size!

I will double check the dimensions of the mill tomorrow.

Thanks all.


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