Stuart ‘Victoria’ : a beginners tale..

[GarryCParticipant @garryc]

Hi Neil

Remembering back to school days and 'O' Level Maths – I'm assuming Pythagoras can / is used to calculate this. I have 'iMachinist' on my iPhone with a trig calculator and yes it comes out at 1.5 thou difference at 1 degree angle for a 10" bar. Interesting! I've been wondering if I do a similar calculation when it comes to the taper on the con rod – but I'm not at that stage yet to worry about that just now… Cheers.

Hi Norman.

Mental blockage at the moment in how to read out loud as it were 0.00039in! Cheers.

Hi Geoff.

I use a small granite 'block' which I bought from Axminster Tools. I do find it a bit small and wish I had bought slightly larger. I keep it wiped over now and then with a cloth and some meths – it seems very good though. Cheers.

Direct link is **LINK**

Allan.

[GarryCParticipant @garryc]

Day 45.

The Piston Crosshead. (Mild Steel)

This is the second attempt at this after failing the 1st time over Christmas when a drill bit snapped in the end of the bar drilling the 2BA tapping hole – with my 'cheap' drill bits.

This time around I was looking forward to trying the new Cobalt bits and was not disappointed – superb to use, completely effortless on the handwheel of the tailstock. To my mind they make it obvious the other bits were 'unfit for purpose'. How on earth has the country gone from leading the Industrial Revolution to selling rubbish like that….

The Crosshead has some chuck marks left on it, maybe I tightened too much, (next project I intend to concentrate much more on the surface finishes…)

The stages involved in this were almost identical to the Valve Crosshead but on a slightly larger scale.

The Piston assembly drawing (with the Crosshead at the top).

The short piece of 3/8" square section bar supplied for the Piston Crosshead.

Milling the square section to rectangular form for the piston crosshead. (Previous time spent milling all the vice faces square have made many little jobs like this much quicker and easier, time very well spent).

Have lately switched to using an automatic centre punch in place of the ordinary type and hammer and find it much better – I only ever punch once and very lightly now since using the wiggler or tailstock centre to setup – with much better results..

Setting up the bar for the Piston Crosshead in the 4 Jaw Chuck.

Drilling the hole for the Wristpin in the Piston Crosshead.

Test fitting the Wristpin in the Piston Crosshead.

Centre Punch marking in the end of the Piston Crosshead.

Drilling the end of the Piston Crosshead before turning the diameter. This was where the cheap drill bit had snapped on the 1st attempt.

After tapping 2BA, the finished Piston Crosshead.

Test fitting the Wristpin to the Piston Crosshead.

Test fitting the Piston Crosshead with Wristpin on the Engine.

Regards

Allan.

 

 

Edited By Allan. on 08/01/2014 19:15:16

Edited By Allan. on 08/01/2014 19:15:54

[GarryCParticipant @garryc]

I was hoping someone may take a quick look at this, I can't quite get my head around if I'm on a hiding to nothing..

The Replacement bar supplied for the Con Rod is bent quite a bit and I'm not sure if its a non starter (for me anyway). The bar is 7 inches long and I intend to turn between centres, the ends have to be milled flat.. The bar measures on the micrometer 12.69 x 15.82mm and is 'banana' shaped. The gap at the top of the 'try square' photo is about 1/16" and the other sides are bowed – should I just ask for another bar do you think? Thanks very much if anyone can advise. Virtually all of the length of the bar has to be used..

Apologies for the quality of the photos.

The Con Rod Drawing.

The end the bar is standing on has been faced in the Lathe.

Hopefully the bowed shape can be seen here.. The bar is on my granite block surface plate.

Thanks again.

Regards.

Allan.

Edited By Allan. on 09/01/2014 11:49:06

[Anonymous]

It's difficult to tell what the material is from the photos, but I assume it's steel? If it is hot rolled (black mill scale finish and rounded corners) I'd just belt it with a hammer until it was straighter than it is now, and then machine as normal. Hot rolled is unlikely to distort much during machining. If it is cold drawn (dull grey finish and sharpish corners) I'd belt it with a hammer and then anneal it. If you don't anneal cold drawn it'll look like an EU reject banana after machining.

Regards,

Andrew

[GarryCParticipant @garryc]

Thanks Andrew, from your comments then I would say it is cold drawn mild steel. I must get around to ordering some spare bar stock myself and asap I think..

Cheers.

Allan.

[JasonBModerator @jasonb]

Yes I'm with andrew, hit it with a hammer.

J

[GarryCParticipant @garryc]

Hi Andrew and Jason

Yes cheers, after quite a bit of 'gentle and not so gentle' thumping and a bit of tightening in the vice it is a fair bit better, don't have a heat source to Anneal it so have to see how it goes from there.. It seems surprisingly springy for a chunky bit of steel..

I've asked Stuart models to replace, I don't know if they will yet – its a fair bet I''ll need another restart with this..

Ta very much, I'll try not to bother anyone for a while now ..

Cheers

Allan.

[Anonymous]

Posted by Allan. on 09/01/2014 13:40:05:

Ta very much, I'll try not to bother anyone for a while now .

I wouldn't worry about that; yours is one of the threads I always read.

Andrew

Edited By Andrew Johnston on 09/01/2014 15:25:23

[Alan .204Participant @alan-204]

Me to I look every night to see what you've been up to, keep up the good work, I may have a go at one of these models my self one day when I get every thing else finished.

Regards Alan.

[Sub MandrelParticipant @submandrel]

Keep posting Allan!

There should be enough meat in that bar to compensate for the bow – bear in mid that you take very little off teh ends, but quite a lot in the middle which is where the bow is.. Rough turn the centre section of the bar leaving an allowance for any further movement, let it stand for a day or so, then finish turn it. Remember the critical dimension is the distance between the holes.

If you have a gas cooker, it should be able to get the bar more or less red hot. you don't need it to be glowing bright red to normalise it (i.e. stress relieve it).

Neil

[Steve WithnellParticipant @stevewithnell34426]

Definitely keep posting Allan – you are passed 22,000 views already!

Your circulation is going to be bigger than ME if you keep going!

Best regards

Steve

[GarryCParticipant @garryc]

Cheers Alan.

Hi Neil, thanks, I wouldn't have thought of using the cooker, ours is LPG, also we have a coal fire, I wonder if I could use that.. I'm going to have a read up on some of the various heat treatments, it would be good to at least start getting some info of the basics, my 3 x Great Grandfather is probably turning in his grave – he was a blacksmith! Shame knowledge like that stopped being handed down a long time ago…..

Hi Steve, I'm going to have to put some cans in the post to a few people when its up and running, not least yourself..!

I have made a start on the Con Rod now although not much progress yet. In the workshop today it was all about holes, you will have to excuse the photos, I guess they will all look the same, a bit sad maybe, but I have to say it felt like a bit of a 'Top Gun' moment and was well chuffed when turning the bar over to see where the 'little end' hole had come out – brilliant, I don't get many little victories like that! I'm sure I would not have managed that when first starting out… and what a difference it makes to have drill bits that just get on and do the job – even though not exactly perfect, I have been having so much trouble previously drilling in steel the result was better than I thought I would manage 1st time around..

I was well chuffed with my little drill today! I found out early on, drilling holes in exactly the right place is not as easy as it looks, especially in steel..

Setting up to drill the Con Rod using one of the wigglers to line up the hole. Despite doing this I found it better (essential for me anyways) to start with a small centre drill (I used a 1mm) and stopped and checked the position almost immediately – then if slightly out put in a larger centre drill and adjusted the position, then likewise again if needed… The 'little end' in particular left no room for error as the 3/8 hole was almost the same width as the the bar..

Test fitting the Wristpin through the Con Rod 'Big End'.

Con Rod Wristpin Hole side 1. (The chamfer on the bar is slightly more on the one side, making it look worse than it really is here)..

Con Rod Wristpin Hole side 2.

Drilling the Con Rod 'little end'. I only bought a few of the small sizes Cobalt Drill bits (to first see what they were like) and so had to use my existing bits going up in 0.5mm at a time once the hole was started all the way through. But they were ok for this. There is no way I could have started the initial hole with them though. I need to get some more sizes Cobalt Bits now as they are excellent. Not even a hint of them finding it hard going..

The Con Rod 'little end' side 1.

The Con Rod 'little end' side 2.

The Con Rod so far. The bar is faced off at about 12mm over length at the moment to allow room to put in and then get rid of the Centre Drill holes in the ends for later turning between centres – not done them yet. One will get 'lost' in the fork on the one end..

Regards

Allan.

Edited By Allan. on 10/01/2014 15:34:46

[Sub MandrelParticipant @submandrel]

Coal fires are great – poke a bar into the base of the fire when it's burning low and you're off to bed. pick the horrid-looking but nice and soft and stress-free metal out of the ashes in the morning.

Fine for bars etc. to be machined all over, or chunky castings. Don't do this to stress relieve a chilled flywheel though – I did and got something resembling a pretzel back

Neatly placed holes too!

Neil

Edited By Stub Mandrel on 10/01/2014 17:48:06

[Steve WithnellParticipant @stevewithnell34426]

I only ever use my mill for drilling "important" holes – so I mark the centre of the first hole, then drill the other holes on a co-ordinate basis. Partly because my marking out could be better, partly because my Warco mill is much more robust than my bench drill and partly because I find the workholding to be easier on the mill bed.

The Victoria is a great engine to build, do you plan to add the governor kit?

Steve

[GarryCParticipant @garryc]

Hi Steve

I need to try that myself with the Mill and see how it compares to the bench Drill.

and yes completely agree about the Victoria, it's very enjoyable to build, it is sold as suitable for beginners with a small lathe and feels like a great introduction to Model Engineering – guess I'll only know if thats true looking back, I've certainly started to learn and discover some of the basics as a result of building – I hope.

May look at the governor kit when it's all together as well but I've still a way to go yet.. and I'll probably look at doing another Stuart Steam Engine again next project, but something on as large a scale as possible that my current kit will cope with….

Hi Neil

Thanks thats well worth knowing it works and something to try in the future.

Cheers both

Allan.

Edited By Allan. on 10/01/2014 20:36:05

Edited By Allan. on 10/01/2014 20:49:25

[JasonBModerator @jasonb]

The other advantages of using your mill to do those two holes are

1, as the work will not have been moved both holes will be parallel to each other, by remounting for each hole there is a risk of teh work being held in a slightly different paosition, rotating in the vice is the most likely to happen especially a drill vice.

2. the mill generally can be run slower than teh drill so you could use that to ream the holes which would give a better hole than drilling, not sure if the Stuart drawings say to ream but they would have been best reamed to final size not drilled.

I now do virtually all my drilling on the mill and use edge finders and the DRO rather than layout.

J

[GarryCParticipant @garryc]

Cheers Jason, that makes a lot of sense and certainly as Andrew says for the 'important' holes.. I'm converted and will do it this way in future, and of course on the next Con Rod attempt – I'm sure I'm going to need one..

If you (or anyone) could give me some idea of the procedure for turning the taper (between centres) on the Con Rod I would be very grateful?

Thanks

Allan.

[JasonBModerator @jasonb]

First rough out to just over the largest diameter for the whole length.

Then change to a tool with a rounded end HSS will be fine though the button ended indexable tools can be used if you prefer and take the whole thing down to the widest part of the belly eg 5/16"

Now to get the belly you roughly divide the length by 3, the middle stays parallel and the two ends taper from 5/16 to 1/4, a bit of trig gives an angle of 1.1deg but you will have to use some trial and error.

Turn the 1/3rd nearest the chuck to the taper until it is 1/4 at teh end and fades out about 1.6" along the length.

You can now either sawp the part end for end and do the other taper which will be the easiest if working between ctrs, if you are holding one end and just supporting the other then the topslide will need adjusting again.

Now you have the three facets its just a case of using a file while the work rotates to blend the areas where they need followed by some emery cloth, make sure you cover the lateh bed, I use a board or cardboard, avoid a cloth as it could get caught in teh spinning work.

Don't think I have any pictures of rods being done but this shows a pully rim being crowned which is the same process but I divided the width into 5 as you should be able to see on the surface towards the top

This is the type of thing you should be aiming for

Edited By JasonB on 11/01/2014 12:43:20

[GarryCParticipant @garryc]

Brilliant, Thanks Jason, best thing I could have done was coming on here…

Cheers

Allan.

[JasonBModerator @jasonb]

One thing I should have added is to mill the flat faces of the ends before turning and mark out the shape of the ends so you know where to stop with the rounded tool, particularly on the forked end as its hard to judge where the round meets the "U" if left full thickness.

J

[Steve WithnellParticipant @stevewithnell34426]

Here is my setup – be interested in Jason's view of it!

As per jason, I turned three facets two long ones at either end and a short flat in the middle. On my C6, the top slide only just had enough travel to complete the long facets. The next bit is a bit more like woodworking, I used 80 Grade emery tape to rough out the shape, then used 400 grade to get the scratches out, then finally using Brasso with well worn 400 tape. DO NOT wrap the tape around your fingers to get a good grip!

As an aside The same sort of approach has my cylinder end caps looking almost like a chrome plated finish, it's amazing how well cast iron will polish up and it does retain that finish very well.

Steve

[Steve WithnellParticipant @stevewithnell34426]

My best effort at a sketch – The blue lines are the facets in the previous notes, the red line is the shape of the rod that best fits the plan, the end dimensions and the mid dimensions are taken from the plan.

Steve

[GarryCParticipant @garryc]

Hi Steve

Thats a good point, Ill have to check the length of travel on the top slide, bound to be less than your C6 I expect, may mean the tapers will just have to be a shorter length.

Just ordered a 10mm, round profiling tool holder as I don't have any rounded tools at all at the moment (the Glanze replaceable tip 'round button' type)..

I can carry on and mill the ends now..

Cheers

Allan.

[JasonBModerator @jasonb]

Steve as long as it gives a shape that is pleasing to the eye it probably has little effect on how you do it. The only thing I can see between the two methods is that my turned 1/4" and 5/16" extremities don't get filed so they can be set to the exact sizes, your blue lines don't correspond with these sizes so there is a bit of calculated gues work.

I've done a few sketches too.

The first shows the three facets to the curve in red. The two vertical green lines are at approx 1/3rd distance. I have exagerated the angle slightly so it shows up better.

The next shows a 70" radius curve between the two facets which are now in blue and the curve purple, this is what I would do with the file.

This elevation shows the two areas that are filed underlined with the highlighter

You can now start with the abrasives to blend it all into one.

And this last one shows how far I would go with the milling before you start turning although I have left the middle shown as turned

J

[GarryCParticipant @garryc]

Jason

This is simply superb, such a massive help for someone like me trying to make one of these first time around.

If you / the magazine were to organise an online training course / range of courses I would be the first to sign up! I'm sure it would allow and encourage more people to get started as well…

Wonder if there are many reading this and like me who would do likewise, or many who don't take the magazine itself as the content is almost exclusively 'too advanced' when first starting out, but would with a bit more knowledge / experience etc?

and of course you would likely make a fortune!

Many thanks.

Allan.

ps for what it's worth, I for one would love to see regular very (and I mean very) basic tutorial type content in the magazine and lots of it – the advanced stuff is interesting too of course…

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