My little engine (continued)

[Ian S CParticipant @iansc]

If the tap won't start in the hole, put a little chamfer on the hole.

Ian S C

[JasonBModerator @jasonb]

Nearly all my taps have been ground down to flat ends so you are in good company Alan

There is probably enough bearing surface at either side of the crosshead pivot that you could have drilled right the way through from to to bottom or at least broken into the cross hole which would have made tapping easier anf not lost strength.

[GarryCParticipant @garryc]

Some great little insights to pick up on there again, thanks Andrew, Ian and Jason. So often I find my mistakes get much offset by understanding why they likely happened on here.. No small thing that and a massive help in not repeating them when you're beginning in the hobby..

I really should get into the beer distribution business, seriously…

Cheers

Garry

[Ian S CParticipant @iansc]

In times gone by taps had a normal centre drilled in the ends, it was found the with HSS tools these caused an area prone to cracking during heat treatment, so the manufacturers changed to a male centre, so grind it off, and watch out for the other end, it can scratch you too, a wee touch on the grinder there won't hurt.

Ian S C         PS, not a beer drinker, but is the distribution thing what happens after you drink it?

Edited By Ian S C on 03/07/2015 10:27:01

[GarryCParticipant @garryc]

Hi Ian

I've just looked and yes there are small centres in the end of taps I was using – can't believe I didn't even notice they were there… I should be using them..!

"PS, not a beer drinker, but is the distribution thing what happens after you drink it?"

no thats usually more of a sprinkling job Ian..

No real progress today other than to get me back where I was starting from yesterday but with my own larger size MS bar – making it straightforward to get the Piston Rod thread in properly.

Just need to mill the face down to size now – and someday soon I'll stop putting my nuts on upside down..

edit: I forgot to mention that the 2 and a half threads on the end of the Piston Rod have made it a really solid fit, it didn't look like there would be enough but its so tight and solid it feels like one piece – I had been wondering how it would be as it didn't look quite right..Nice surprise.

Cheers

Garry

 

Edited By Garry_C on 03/07/2015 12:09:55

Edited By Garry_C on 03/07/2015 12:26:41

[Ian S CParticipant @iansc]

Garry, if you are tapping in the lathe you can use the centre at the square end with a centre in the hole to guide the tap while you turn it with a tap wrench. The original use was in the machine when they were being made, and you get them for free to do what you like with.

Ian S C

[GarryCParticipant @garryc]

Hi Ian

Thanks, and yes I'll definitely be trying as you say – but also I see I have a little 'centre' type attachment in one of my Tap and Die sets that I've not noticed and can use on the Mill with this method. I'm often a bit limited tapping on my small Mill because of lack of length between the Table and Tool – the Centre attachment is quite a bit shorter than the little 'Pin Vice' type tool that I usually use [not tightened] with a collet. So could be really useful – heck no looking again and with it pushed right up into a collet its going to be much shorter – what a useful little find, thanks again Ian..

I normally use the small 'pin vice' type tool in front of the little centre in the photo for tapping on the Mill.. The Collet should come right down to the knurl on the little centre, thats a big difference..

Makes me wonder what other things I have that I may not have realised or don't know how to use..!

Cheers

Garry

Edited By Garry_C on 04/07/2015 17:37:26

[GarryCParticipant @garryc]

I've been a bit sidetracked lately so just an update to say I'm able to continue again now – although looking this morning I can see that I've measured the Piston Rod wrongly (too short) so I've had to order some more 5/16" stainless – hopefully here in a day or two…

This is where I'm at now.. Sorry photo's are not too good.

The crosshead needs milling down to size / shape, its way too big yet..

I've made a slight error as well with the end width and thought I would need to redo this as well but the fit between the guides feels really nice so maybe I'll be ok with it. I'll decide for sure when I've finished it. Had trouble visualising this part from the start but it seems straightforward now if I do need to redo – followed Jason's advice with the plunge milling and its worked perfectly..

Sliding up and down between the guides it feels like a nice fit – there is a bit of play but hardly anything..

 

I'll get going again when the stainless bar turns up…

Cheers

Garry

Edited By Garry_C on 15/07/2015 10:37:54

[Gas_mantle.Participant @gas_mantle]

Hi,

Good to see you are back to working on the engine, I look forward to following it's progress.

Peter.

[JasonBModerator @jasonb]

Looks like you missed off the 5/8" piece that should locate behind the plates, no big problem it can be made from a bit of 1/8" thick material and secured with a couple of CSK screws tapped into the main block.

looking at your last photo the 1/2" width will locate the crosshead front to back but without the strip behind the plates the crosshead will want to move from right to left and there is nothing to restrain it.

 

J

Edited By JasonB on 15/07/2015 13:18:08

[GarryCParticipant @garryc]

Hi Jason

Thanks I wouldn't have known the importance without trying it, you've saved me a lot of time. I've just looked and yes I can take 1/8" off the block end and replace with the larger piece – I've just the right the screws for it too.. I can get that done now while waiting for the stainless bar to arrive.

I seem to be much more vulnerable to making mistakes when I have less regular workshop time..

and thanks for the comments Peter..

Cheers

Garry

[JasonBModerator @jasonb]

Posted by Garry_C on 15/07/2015 14:06:40:

I can take 1/8" off the block end and replace with the larger piece

Careful if you do that as you will then loose the 1/2" width where the plate edges come as they will then be running where the semi-circular grooves are.

You may have to turn the crosshead upside down and retap for the piston rod so that the 13/16" dimension includes the 1/8" plate

Also you still have metal to come off the top of the cross head which will require an even longer piston rod to maintain the 3 3/4" hole to shoulder distance.

 

Edited By JasonB on 15/07/2015 16:30:12

[JasonBModerator @jasonb]

Should look like this with teh 1/8" plate running in the 5/8 x 1/8 slot you milled in teh standard, 1/16 before teh semicircles starts runs to the edge of the plates

[GarryCParticipant @garryc]

Jason that's brilliant thanks. I'm going to remake after your explanation and that diagram will be a big help. Its so much easier to see it like that.

Cheers

Garry

[GarryCParticipant @garryc]

Thought it may be interesting to show this – all going well I think in remaking the Crosshead. I remember seeing on 'Steve's Workshop' Site before I started that the Stuart no.1 castings had a slight issue with alignment on the sole plate, it went over my head at the time and as I couldn't see me managing to allow for it I carried on – its resurfaced though. The pics below hopefully show – The Crosshead alignment on mine is just under 1mm out but the Piston Rod slightly out as well (that I'm sure is my own error) – so I've offset the piston Rod Hole in the Crosshead to allow and will take off the <1mm to fit the Con Rod fork and hope all will be well. After splitting the Con Rod bearing it was nice to see it fit with no play on the crankshaft, it will need to loosen up just a bit but should bed in nicely between the Crank Webs I think. The new Crosshead so far slides very nicely between the Standard Groove. I've lots to do yet with it of course..

Anyways someone else making one of these might find it interesting – its all very slight and no big problem I hope..

This is the very useful explanation from Steve's site [ the site says the plans are free so I hope its no problem showing this here.] It shows the standard base of the casting slightly offset.. I've ended up just a bit less than 1mm out on mine.

I have to be realistic as this is only my second engine, I was never going to be spot on.. But its all easily allowed for in remaking the Crosshead – I say hopefully.. The other side of the Crosshead in this photo is flush with the side of the Fork gap.

This is with the new Crosshead (so far in the making) but with the old piston Rod that's too short – my replacement stainless bar not arrived yet… (not ordered from Stuarts and only ordered day before yesterday I think).

It needs a general clean up really now – I've been at it on and off over a year now apart from a little break a few months back.. I'm going to try [spray] painting more of this one, bearings etc than I did with Victoria – long way off yet though..

Not everything is tightened up fully..

Cheers

Garry

Edited By Garry_C on 17/07/2015 09:56:56

[JasonBModerator @jasonb]

It's comming together nicely Garry. I have just written up about how I preped and painted the Gade here which may be of use.

[GarryCParticipant @garryc]

Hi Jason

Thanks very much, i've just been reading through the Gade 'prep and paint' link, its a terrific step by step and is going to be so useful when the time comes – and for future engines as well, another one to print off… I'm determined to make a better job of it this time.

Cheers

Garry

[GarryCParticipant @garryc]

Just a few quickie photos of progress today.. Still with soon to be discarded short Piston Rod..

Starting to Mill the Crosshead.[ Using the 'stop' for quick removal and replacement while trying on the engine..]

I was using the bar from my first attempt – from the other end and upside down, but ended up with the hole showing through, I should have measured beforehand with more care – so to clean up I had to mill to size from the bottom, it won't leave enough metal to do the rather elegant 'upsweep' but I think it will be fine..

Showing the fit around the Guide Plates and the 'under hole' removed – I've not redone the curved half rounds yet but will do next session.. Quite surprising how solid it is in the Standard now, I can't budge it side to slide but slides up and down perfectly..

I've spent a little while on it this morning and it looks like i've done nothing – taken a bit too much off the fork end of the crosshead but as I say there is no movement at all – I needn't have taken so much – I came across Andrew Smiths comments too late, they were along the line of – when assembling the crosshead don't have anything more than finger tight at first, good lesson learned even if a bit late..

and my replacement Stainless bar has just arrived..

Cheers

Garry

Edited By Garry_C on 18/07/2015 13:18:44

[GarryCParticipant @garryc]

Again these photos will likely look the same as yesterday – but I have the grooves in the Crosshead done now and also the Piston Rod made to the right size.. I managed to leave off the 5/8" thread length somehow when I measured to make the first one..

Hopefully I can start going forward again now and may even get to see how its turning over so far in the next day or so..!

Cheers

Garry

Edited By Garry_C on 19/07/2015 13:12:15

[GarryCParticipant @garryc]

A couple of photos of todays progress.

I have the crosshead fitted now but although its a solid fit and doesn't have any play the best I can manage does have a too big a gap in between the Con Rod fork – it feels like I've learnt an enormous amount from doing and fitting it so I'll leave as it is while I'm ahead I think.

I found it a bit of a crunch time as the Crosshead seems to 'link' many of the vital parts, I found I had managed several errors so far that had to be sorted out before fitting –

1. I had not made the Con Rod Fork deep enough – so a bit more plunge milling needed – that went perfectly.

2. I did not have the Con Rod 'shoulder' in the right place, just a tiny bit out but it was catching on the lowest Guide Plate bolts – bit more plunge milling required but it looks fine I think..

3. Needed just a tiny bit of easing to the Standard Groove.

Had great fun spinning it over once it was done – and it feels very smooth…!

Drilling the oil hole – I put in a small CSK as well…

The finished Crosshead and Piston Rod.

Progress so far..

Another one of my poor attempts at video.. The 'tapping' noise is just the Bottom Cylinder Cover Gland moving – there is no packing in the Gland yet to tighten it against..

Cheers.

Garry

[JasonBModerator @jasonb]

Looks nice and smooth. You should also be able to try it by pushing the piston rod up and down to keep it revolving once you have started the flywheel to turn by hand, a bit like this. That should bring a smile to your face

[GarryCParticipant @garryc]

Happy days

I could stand there all day doing that..!

[GarryCParticipant @garryc]

Looking to do the Piston next – my lack of experience and knowledge shining brightly through again though. Often for me some of these parts need working through for a first time before things click – I can see that I should have been considering this earlier and I think it didn't register with me because the supplied Piston Rod was the exact same size that was needed. So I didn't have to / couldn't skim and as such my now finished made Piston Rod doesn't have any centres, I can see two ways to proceed and intend to go with no 2 below unless anyone advises differently..

I could I think either –

1. Set up the Piston Rod in the 4 Jaw and put in the centres – but it's only 5/16" diameter and has threads both ends, only two threads on the one end. I'm thinking the centres would have to be tiny without weakening the rod too much and the piston is quite a heavy 2" lump of cast iron to attach and work between centres, so would they be able to be big enough and hold ok? As I can't skim the piston after putting in the centres I'm not sure how accurate that would be either..

2. This is what I'll do unless advised otherwise – Drill and tap the Piston in the 3 jaw, set the piston rod to run true in the 4 jaw and screw on the piston (I wonder if I need to use a bit of loctite or maybe run the lathe in reverse to stop the piston coming undone) and do the outside diameter, face the top end, do the Piston Ring grooves, then remove the Piston from the Rod, reverse in the chuck and face off the other end (bottom) parallel to the top..

The slot can be milled at the end either way.

But as almost every time i have tried to outline like this I have been wrong in the past its probably best I give it a day or two for me to see if i'm off the mark again.. These things often appear very straightforward when reading the drawing and sat in a comfy chair with a cuppa – but the practicalities are often much more challenging – and interesting I think, for me anyway!

The other thing I was wondering if anyone could advise on a decent tool for fitting the rings, I assume i'll need one.. The Piston is 2" diameter. My pack doesn't seem to have any rings, they should be there unless I mislaid – so I'll need to order..

The Piston Drawing.

Thanks if anyone is able to comment..

Cheers

Garry

[Ian S CParticipant @iansc]

What is the cylinder made of? If cast iron, cast iron rings could be used, reasonably easy to make your own. If the cylinder is bronze, soft packing, graphited hemp, Teflon, or "O" rings.

No tool needed to fit the rings.

Ian S C

Edited By Ian S C on 23/07/2015 12:11:57

[JasonBModerator @jasonb]

Hold piston blank in the 3 jaw, face and turn to 0.010" over diameter.

If there is not much to hold it by put a ctr drill hole in the end and bring up the tailstock for support.Cut the two piston ring grooves 0.130" deep

Drill and tap using the tailstock to keep the tap square as you rotate by hand.

Reverse in chuck, face to finished thickness then mill the screwdriver slot.

Place piston rod in 4-jaw and set to run true with just a little of teh full dia protruding. Screw the piston on tight by hand  Take very light cuts with a sharp tool to bring the piston down to finished dia, debur and job is done.

My preferance would be to do away with the screwdriver slot and cut a counterbore so you can use a thin locknut to stop the piston comming loose. I would also have tapped the piston first so the die can be used to make the thread on the rod a good firm fit.

Edited By JasonB on 23/07/2015 13:05:37

[Author]

Posts