Stuart ‘No.1’ : a beginners tale..

[GarryCParticipant @garryc]

I was wondering if anyone had any views on if there was any reason why I shouldn't fit the Box Bed Studs from the bottom of the bed so that they are threaded into the Sole Plate from below thus hiding the nuts i.e.. with the studs protruding into the hollow base? The 1/4 BSF nuts provided are a very close fit to the edge of the frame and 'Standard' seating mount when fitted as they should be from the top – they will fit with spot facing, just, but I think it may look better to hide them. Wondered if anyone else has maybe done this or similar? Would there be less 'fixing' strength to do so..?

(Jason, I can't see these nuts in the 'Gold' photo you sent me so I think something similar may have been done there as well.)

Thanks for any thoughts – some photo's to show better…

Plenty of room in the base and a standard length drill could be used – I have an 'extended' smaller one to use for a pilot.. Would just need to run a Die down the studs to extend the thread a bit..

The 1/4 BSF nuts would be a very close fit and maybe look a bit large when fitted 'normally'.

Regards and thanks.

Allan.

[JoParticipant @jo]

How thick is the sole plate where you are thinking of putting the "hidden studs"? Other Stuart No1s seem to not have their nuts over hanging. You could look to counterbore then add raised bosses for the nuts to sit on.

If you put the nuts one the inside make sure there is enough space for a box spanner to get round the nuts.

Jo

[JasonBModerator @jasonb]

Commercial nuts on models, thats one of my pet hates

It looks like they are now supplying mass produced nuts, 1/4BSF is approx 7/16AF and they also tend to be quite flat and have chamfers both sides. If you look at photos of old engines the nuts tended to have a smaller hex, be taller and also only chamfered on the top.

Take a look at these, left is a shop bought 1/4" BSF, middle is one I made for a model of an American engine and on the right one for an engine of English origin. The two homemade ones are from 3/8" hex bar and the US one has also been machined to look like what I think they call a washer nut where the bottom is machined to remove the hex.

So the first thing I would do is think about making some nuts.

Secondly you could move the hole positions out a bit further as there is enough metal to do so

The Golden engine does have the nuts on show and they have been spotfaced which is something I would do anyway, you don't need to go out and buy a spot facer, once the hole is drilled lightly plung cut with a 1/2" endmill until you have a smooth seating. Do the drilling and spot facing in the mill at the same position, don't try it on the drill press.

J

[GarryCParticipant @garryc]

Thanks for all the useful replies.

Jo, the soleplate is a solid cast all through and about an inch thick. The top of the Box Bed is about 1/4 inch all the way over. Don't want to be the only one with his nuts hanging about..

Jason, really interesting photo's, I'll be taking a much closer look at nuts now in future and its all your fault. I need to get in some hexagon bar as I'm beginning to see its uses – I remember thinking it would have come in handy when I was making the Air Compressor adaptor for Victoria's Cylinder..

John, you are right of course it will hide all my sins and think this may be my best option because of it, also have a feeling I may prefer the look – need think a bit more.

Cheers.

Allan.

[GarryCParticipant @garryc]

Think I'll have a go from the top after all and use an End Mill to spot face as Jason suggested..

Cheers.

Allan.

[NJHParticipant @njh]

Allan

" I need to get in some hexagon bar as I'm beginning to see its uses – "

Hmmmm well I had an old friend who said that hexagon bar was not accurate enough and milled his own for nuts and bolts from round stock ! ( However he was an engineer par excellence and, I believe, was the recipient of TWO SMEE gold medals. )

Cheers

Norman

[MM57Participant @mm57]

…maybe he had some of these, which would/should make the job pretty easy once the first cut is accurately made…

http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collet-Fixtures#ER32-Collet-Blocks

…or maybe he didn't

Edited By Martin Millener on 14/04/2014 15:28:18

[GarryCParticipant @garryc]

Hi Norman

I'm afraid I had 'look up' SMEE to see what is was!

Now I know though – very impressive! Oh for the chance to go back in time and be taught by a real engineer…

Cheers.

Allan.

[JoParticipant @jo]

Posted by NJH on 14/04/2014 14:42:01:

… I had an old friend who said that hexagon bar was not accurate enough and milled his own for nuts and bolts from round stock !

I agree, when I make my own nuts and bolts I always mill my hex out of round stock. Too often today you get metric size hex instead of BA. If you want the sizes then the Old BS standard will not only tell you the A/F, the acceptable thickness of the nuts and the angles of the tapers. And yes double tapers on nuts was one of the standard shapes, however much I don't like them .

If you are going to cheat I suggest you use a Cap head rather than slotted screw, Slots have a nasty habit of getting damaged.

 

Edit: If you are going to make your own hex use a dividing head/indexing head or index in the lathe. The last thing to use is those blocks.. it just takes one relocation to be wrong and you will have lopsided nuts  and you wouldn't want to be accused of that.

Jo

Edited By Jo on 14/04/2014 20:37:14

[Oompa LumpaParticipant @oompalumpa34302]

"Edit: If you are going to make your own hex use a dividing head/indexing head or index in the lathe. The last thing to use is those blocks.. it just takes one relocation to be wrong and you will have lopsided nuts crook and you wouldn't want to be accused of that."

Personally I have never had a problem, I think the trick is to securely mount (I use the rearmost slot on the Mill) a good angle plate on the table square on. Then as you turn the block before securing it, make sure it is fast against the Angle Plate. I have only had a problem whenever I have been over ambitious and I have too much sticking out (?)

graham.

[JasonBModerator @jasonb]

Though one misplaced pin on the indexer/div head can also result in wonky heads.

Having recently been lent one of the Stevenson 5C indexers I do find they are quicker than the blocks which is more of an advantage if you have a lot to do, repositioning the blocks does take longer in the vice and more so if clamped to the table.

I also find when doing larger items on the end of say a 12" bit of bar the weight hanging out the back wants to tip the other end up so you need to make sure they are well seated down.

If you only have the one mill with a small table the blocks are handy as you can stick them in the vice which is more often than not already on the table rather than have to remove the vice and mount the indexer. Plus they are easier to mount with the work vertically if needed.

J

[GarryCParticipant @garryc]

Another little update of progress – It seems there was 'almost plenty' of room for the Sole Plate fixing nuts after all..

It was another real eye opener and a 1st for me in using the Mill for drilling – found myself whistling instead of sweating, much much better for accurate working..

Using the Mill for drilling the Sole Plate fixing holes.

Using 1/2 inch End Mill to spot face the 1/4 BSF hole. Holes first drilled @ tapping size for spotting through to the Box Bed – using the Zeus guide @ 5.3mm instead of the Stuart 5.4mm recommended on the drawing chart. Likewise used the Zeus guide to later open out to clearance size after tapping the box bed @ 6.3mm and not the 6.4 recommended on the drawing – and it was fine with nice 1/4 x 26 tpi thread and very close fit with the studs through..

A close fit after spot facing – but fine…

Both nuts at the 'Standard' end in place after spot facing.

Showing all the nuts on the spot facings.

Spotting through the holes to the Box Bed from the Sole Plate.

Tapping the 1/4 BSF holes in the Box Bed

I usually run a plug tap through by hand ie. without tommy the bar after the 'second' tap – seems to work well for me.. must admit I haven't been using any taper taps to start..

1st one of the Box Bed Studs in Place.

Regards.

Allan.

(sorry about the poor photos again)

Edited By Allan. on 16/04/2014 15:07:15

[GarryCParticipant @garryc]

continued…

Another one of the Box Bed fixing holes being tapped.

Spotting through to the Box bed again after getting two studs in place..

All four studs in place on the Box Bed.

Test fitting the Sole Plate to the Box Bed 1.

Test fitting the Sole Plate to the Box Bed 2.

Regards.

Allan.

[JasonBModerator @jasonb]

They have fitted in quite well. I tend to do 95% of my drilling on the mill now, I also have a DRO which makes it even better but carful use of the handwheels will do you fine for now and its good to get used to them.

J

[GarryCParticipant @garryc]

Thanks Jason, the whole thing today felt like a big step forward… learning something new all the time – great!

Cheers.

Allan.

[GarryCParticipant @garryc]

Not really a progress update but in keeping with my last build I thought I would include all my little mishaps as well for people to make of what they will, hope some will find them at least amusing if not interesting.. This one not major I hope and concerning the 'least critical' (I hope) dimensions of the 'outside' of the 'Bottom Bearing' i.e.. the 1 inch outside length. I've ended up a full 1mm short but I do have both Bottom Bearings to within 1 thou of each other in this length.

I know the best way to have done these would have been to solder the two lower half's together and do in the lathe as one, but I don't have any soldering equipment at the moment (on order now) so I thought I would do the lower bearing half's on the Mill together at the same time. I've been reading at how Gunmetal 'grabs' at the tool and can now personally vouch for that – but made all the more likely by some very silly setting up on my part. Anyway to cut the story short I'm now facing the Lower Bearings to the outside size on the lathe, one at a time and trying to get them as close as possible to the same size – I seem to be able to get sizes to within 1 thou now regular and hope that will suffice with final lining up (boring) on the cross slide in situ on the Sole Plate later. I have ordered some 'Fryolux' Solder Paint to be able to solder the Upper Bearings to do on the lathe as one as this is a necessity I think – and then separate into the permanent Bearing pairs later, also a 'cheapie' gas tourch with 'Mapp' gas cylinder. I'll then be able to use this to solder and drill the final Bearing sets later before separating again.. Hope all that makes sense.. So I'm busy facing the bottom Bearings at the moment..

I think there will be a touch of 'permanent' soldering involved when I come to final assembly of the crankshaft later – I'm hoping to get some advice on here on what Solder I will need for that etc – but thats a long way off at the moment..

The Bearings Drawing.

The Lower Bearing Half Assembly Drawing to give a 3D idea of the final shape..

The Bearing Castings as supplied. Gunmetal.

How NOT to Mill the Gunmetal Bearings. What can I have been thinking of, holding them with so little 'Vice Grip' as that..! It seems obvious now of course but the blocks were 'grabbing' at the tool and rising, luck was on my side and I noticed pretty quickly – the original casting size was only a tiny fraction over 1' square if at all. Once I have both Half's faced to the same size on the lathe it will be back to the Mill to do the central channel – held together as one but clamped directly down to the Mill table I think.. As I said though its resulted in my having to go slightly under size to 'square' it back up again..

I've milled the important faces of the Vice itself all over and know that work placed in those vice slots Mill very accurately – caught out with the increase in scale is my excuse..

This is what I'm busy with at the moment. That's 12 faces to do – take quite a while on my little Lathe I expect..

Anyways hope some found it interesting..

Regards.

Allan.

Edited By Allan. on 20/04/2014 11:24:07

[GaryMParticipant @garym]

Hi Allan,

I'm no expert but the steps on the vice jaws are contributing to the problem. My vice just has parallel jaws with no steps or grooves meaning I can use parallels to position work so the milled surface is just above the top of the jaws. Gives a bigger contact area for clamping the work. Just an observastion, without a useful remedy.

Gary

[JasonBModerator @jasonb]

As Gary says using the rebates in the jaws is not the best way with thick parts. Your fairly basic vice will also have a tendancy for the moving jaw to lift as it is tightened more so than a milling vice. If the work is supported by parallels you can tap it down with a lead hammer as you tighten the jaws which will help keep things true. Something like this. You can make do with a couple of strips of steel flat for now if you don't have parallels.

One other thing to watch when first holding castings in teh vice is the surfaces are unlikely to be even or parallel. So its good to use a soft packer between the work and moving jaw so it can take up any irregularities, a scrap of aluminium will do.

When you come to cut the grooves I would use the vice, set the work down low and keep the same side against the vice fixed jaw which will be your ref face and all six grooves can then be cut at the same handwheel setting. Simon's thread shows it here

The solder paint will be fine, if you don't know how to tin the parts and then sweat together just ask. I'll look at the conrod drawings later but can't think of anything that needs permanent soldering.

J

Edited By JasonB on 20/04/2014 13:36:27

[GarryCParticipant @garryc]

Hi Gary

Yes, the vice is not great, I bought it really with the drill press in mind – I should look at getting a 'precision' milling vice designed for purpose. Top of this years Christmas Wish List now I think..

Hope you are recovering well..

Cheers.

Allan.

[GarryCParticipant @garryc]

Thanks Jason, some really good pointers there that I will use…

and I will definitely come back when the time comes to ask about using the Solder paint as it will be another 1st for me…

Back now to my facing off's…

Cheers.

Allan.

ps. Simon's thread / work – superb!

Edited By Allan. on 20/04/2014 13:55:43

[GarryCParticipant @garryc]

Little time unfortunately over the Bank Holiday to make progress, but I do have the bottom bearing 'blocks' faced to size and ready for the channels to be milled now. The reason for this post though is I've been trying to find some guidelines on sizes to aim for when making parts for fitting to another. e.g. How much undersize for a Push Fit, Close Fit, Sliding Fit, Interference Fit etc. I was hoping to find a 'basic' chart to use as a guideline but all I've found so far are charts with masses of numbers to include tolerances for the parts themselves. Does anyone have by chance a link to something simple. Feels like something it would be useful to have at least some idea on…!

The Bottom Bearings here I assume I would make as a close fit into the housing blocks, it would save time etc to have a target size to aim at.. Hope its not a dumb question.

Maybe there are no simple guidelines..?

Thanks anyway for anyone that does have a link or some info…

The bottom Bearing 'blocks' ready for Milling the channels..

Regards

Allan.

Edited By Allan. on 23/04/2014 13:55:04

Edited By Allan. on 23/04/2014 14:00:44

[Neil WyattModerator @neilwyatt]

There is a useful table in Tubal Cain's The Model Engineer's Workshop Handbook giving 12 classes of fit from shrink to large clearance.

Neil

[GarryCParticipant @garryc]

Great thanks Neil, that sounds to be exactly what I'm looking for..

Cheers.

Allan.

[GarryCParticipant @garryc]

Have one of the 'bottom bearing half's' fitted into the housing now..

Finding this an interesting little job and much more work than I first imagined, mainly due to my bad technique though I expect – there was nothing really like this with Victoria – fitting bearings to a housing. After marking out I used a 12mm end mill down the centre and across the 3 sides followed by a 14mm end mill – all with the mill table locked in the same position, then final fitting with some slight work with a file..

Both bearings done separately (I'm halfway through the second) – but with the same mill settings..

It's a first attempt at something like this and far from perfect, but the bearing is a nice tight fit and feels very solid with no movement…

Test fitting one of the bottom bearing half's 1.

Test fitting one of the bottom bearing 'half's' 2.

Test fitting one of the bottom bearing 'half's' 3.

Regards

Allan.

[GarryCParticipant @garryc]

For the sake of completeness – forgot to include the setup used on the mill for the channel…

Regards.

Allan.

Edited By Allan. on 26/04/2014 12:57:27

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