Stuart Twin Victoria (Princess Royal) Mill Engine

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Stuart Twin Victoria (Princess Royal) Mill Engine

Home Forums Work In Progress and completed items Stuart Twin Victoria (Princess Royal) Mill Engine

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  • #532371
    Dr_GMJN
    Participant
      @dr_gmjn

      To be fair it was only a question of chucking in the fire for the evening and hoping for the best. It's supposed to make it cut like butter.

      After the test on Friday worked, I put the whole lot in the fire last night, and got a nice even spread of fuel:

      This is how they came out this morning:

      One of the cylinder caps had stuck itself to a spoke, but it pinged off after I hit it with the poker. All seems a bit medieval, but it's good fun – the kids love it.

      There's a hell of a long way to go with this one – especially at this rate…

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      #532554
      Dr_GMJN
      Participant
        @dr_gmjn

        I got a length of 1" diameter steel bar stock to make the between centres boring bar. I obviously need to face and centre drill each end, but I don't have a fixed steady (I do have a Myford travelling steady). Is there an alternative method? I assume with a fixed steady, I could set the bar in the chuck, run the fixed steady up to it and adjust, then slide it along to the end of the bar and face and drill as normal?

        Any other methods, or is it £100 on a fixed steady?

        Thanks.

        #532559
        Ramon Wilson
        Participant
          @ramonwilson3

          Well a fixed steady is a good accessory to have – when you need it – which from my perspective isn't that often.

          You can jury rig it with a decent thick piece of ply wood bored to a good fit on the bar. Clamp or bolt the plywood to an angle plate and then to the cross slide and set as you describe. Not ideal but it would just about get you by for drilling two centre holes – and save you a hundred quid

          Perhaps others may have other suggestions but If I only had to do two holes that's how I'd tackle it

          Good luck yes

          #532564
          JasonB
          Moderator
            @jasonb

            Clamp to cross slide with packing or to the Vertical slide of you have one. Flycut the end. Put DTI in lathe chuck and adjust bar's position until dti shows it's true and ctr drill with drill in spindle. I have used the wooden block method Ramon mentions in the past when I did not have a fixed steady for the Emco

            Strictly speaking the holes do not need to be spot on but it's handy for measuring tool projection though that can be got around by turning down a section around the toolbit hole to a known diameter

            Is a 1" bar going to be of use on your cylinders as it won't fit!. 3/4" would allow it to pass through the core (I think) and allow room for a few cuts & swarf

            Edited By JasonB on 08/03/2021 13:31:20

            #532609
            Metalhacker
            Participant
              @metalhacker

              I am just doing the cylinders on my Twin Victoria, my first steam engine project, and I wonder how deep the 7BA tapping holes should be. I don’t want to drill through into some thing vital! Especially in the cylinder face of the steam chest.

              Any advice gratefully received!

              Andries

              #532610
              JasonB
              Moderator
                @jasonb

                I drilled them about 6mm deep which should be plenty of thread engagement without having to bother with a plug tap, I was using a spiral flute one. End flanges nearer 4.5-5mm if you don't want to see them break through the back of the flange but not an issue if clading. The hole that comes closest to doing some damage is the 3/16" exhaust one.

                #532611
                Dr_GMJN
                Participant
                  @dr_gmjn
                  Posted by JasonB on 08/03/2021 16:45:47:

                  I drilled them about 6mm deep which should be plenty of thread engagement without having to bother with a plug tap, I was using a spiral flute one. End flanges nearer 4.5-5mm if you don't want to see them break through the back of the flange but not an issue if clading. The hole that comes closest to doing some damage is the 3/16" exhaust one.

                  It says in the Princess Royal write-up that breaking through from the feet fixing drillings into the cylinder, is likely, but not much of an issue if you do. I suppose if the holes are small and there are no burrs, it's all sealed anyway.

                  Having said that, I wonder if the feet holes are orientated such that they would miss the piston packing rings though? If the packing goes over a hole it might damage it.

                  #532612
                  Dr_GMJN
                  Participant
                    @dr_gmjn
                    Posted by JasonB on 08/03/2021 13:29:38:

                    Clamp to cross slide with packing or to the Vertical slide of you have one. Flycut the end. Put DTI in lathe chuck and adjust bar's position until dti shows it's true and ctr drill with drill in spindle. I have used the wooden block method Ramon mentions in the past when I did not have a fixed steady for the Emco

                    Strictly speaking the holes do not need to be spot on but it's handy for measuring tool projection though that can be got around by turning down a section around the toolbit hole to a known diameter

                    Is a 1" bar going to be of use on your cylinders as it won't fit!. 3/4" would allow it to pass through the core (I think) and allow room for a few cuts & swarf

                    Edited By JasonB on 08/03/2021 13:31:20

                    Sorry, I meant 3/4":

                    I was going to reduce it in diameter a bit: a) to get some practice in machining between centres – I've not really done it before, and b) to give a bit more clearance for swarf:

                    It would also be a good check of my tailstock alignment I suppose.

                    #532613
                    JasonB
                    Moderator
                      @jasonb

                      Think I would tend to keep it as solid as possible.

                      #532643
                      Metalhacker
                      Participant
                        @metalhacker

                        Thanks guys. My first cylinder end was about 4.5, so I will continue with that throughout. Is there some formula which gives a ratio of depth to thread diameter, ie twice or three times depth?

                        #532704
                        Dr_GMJN
                        Participant
                          @dr_gmjn

                          Just looking at the beds again, and the cylinders. This might seem trivial, but:

                          The drain cocks and operating mechanism don't seem to be defined too well in the article. Which drain cocks are good for this application? The ones I used on the 10V are pretty stiff, and the handle shape wouldn't lend itself to being drilled for linkages.

                          Reason I ask at this stage is I'd like to do all the drilling of the beds while they're square, rather than drilling on the draw angle later. If an operating spindle or rod needs a hole, and a boss, I'd like to plan for it now.

                          Ramon – I notice you've got a nicely engineered system – but I can't see which drain cocks you used. Could you elaborate please?

                          #532713
                          JasonB
                          Moderator
                            @jasonb

                            The straight ones that most of the other ME suppliers sell come with a flat lever that is drilled with a few holes so easily linked together and they also have a pipe union on the other end. The alternative would be to plumb the two drain holes into one 1/4 turn valve either centrally mounted under cylinder or hidden in the base

                            #532721
                            Ron Laden
                            Participant
                              @ronladen17547

                              I know nothing about this engine but looking at the cylinder couldn't that be set up in a 4 jaw with spacers to clear the end flanges if needed and then bored with a standard boring bar.

                              I am probably missing something

                              #532722
                              Dr_GMJN
                              Participant
                                @dr_gmjn
                                Posted by Ron Laden on 09/03/2021 09:15:21:

                                I know nothing about this engine but looking at the cylinder couldn't that be set up in a 4 jaw with spacers to clear the end flanges if needed and then bored with a standard boring bar.

                                I am probably missing something

                                I think you can, but the boring bar would have to be quite long, and the one I've got would be getting a bit flexible at that extension.

                                Plus its another technique for me to have a go at.

                                #532780
                                Steve Withnell
                                Participant
                                  @stevewithnell34426

                                  I've a ton of pictures I took whilst building my Victoria. I took it quite away beyond the 'kit' Stuart supplied in the end.

                                   

                                  Most are here in the blog I ran at the time:

                                  Victoria BLog  First Page

                                  Some the posts on this site too – ME Forum Post

                                  I did mean to serialise all of this for Model Engineer, but never got round to it.

                                   

                                   

                                  Steve

                                  I met a guy way back, he had built the Stuart Twin Victoria as a clockwinder for a client…

                                  Edited By Steve Withnell on 09/03/2021 14:43:22

                                  Edited By Steve Withnell on 09/03/2021 14:44:09

                                  Edited By Steve Withnell on 09/03/2021 14:48:38

                                  Edited By Steve Withnell on 09/03/2021 14:58:15

                                  #532840
                                  Dr_GMJN
                                  Participant
                                    @dr_gmjn
                                    Posted by Steve Withnell on 09/03/2021 14:41:58:

                                    I've a ton of pictures I took whilst building my Victoria. I took it quite away beyond the 'kit' Stuart supplied in the end.

                                    Most are here in the blog I ran at the time:

                                    Victoria BLog First Page

                                    Some the posts on this site too – ME Forum Post

                                    I did mean to serialise all of this for Model Engineer, but never got round to it.

                                    Steve

                                    I met a guy way back, he had built the Stuart Twin Victoria as a clockwinder for a client…

                                    Edited By Steve Withnell on 09/03/2021 14:43:22

                                    Edited By Steve Withnell on 09/03/2021 14:44:09

                                    Edited By Steve Withnell on 09/03/2021 14:48:38

                                    Edited By Steve Withnell on 09/03/2021 14:58:15

                                    Thanks – really nice and runs beautifully.

                                    #533405
                                    Dr_GMJN
                                    Participant
                                      @dr_gmjn

                                      I need to get some additional reamers – 1/4", 7/16" and 3/8". I can get them from ARC (as hand reamers) no problem, just wondering if there are any benefits or disadvantages to getting imperial/metric equivalents in terms of availability of the bar that ultimately goes through the holes? I thought I read somewhere that some were unavailable.#

                                      The 3/8" hole isn't a running fit, I think its for the crank webs, that require spigots machining to fit on the crankshaft. I might be better boring these holes – assuming my boring bar will fit?

                                      Thanks.

                                      #533410
                                      JasonB
                                      Moderator
                                        @jasonb

                                        I'd bore the bearings and crank that way you can fine tune the fit, For example you want the flywheel bore a slightly tighter fit than the bearings so unless you are going to invest in 0.001" increment reamers you won't get it with a single nominal size one. 1/4" is easier done with a reamer.

                                        As for metric/imperial it really depends on what you are thinking of making in the future, imperial designs are often best done with imperial stock.

                                        #533433
                                        Dr_GMJN
                                        Participant
                                          @dr_gmjn
                                          Posted by JasonB on 12/03/2021 13:03:43:

                                          I'd bore the bearings and crank that way you can fine tune the fit, For example you want the flywheel bore a slightly tighter fit than the bearings so unless you are going to invest in 0.001" increment reamers you won't get it with a single nominal size one. 1/4" is easier done with a reamer.

                                          As for metric/imperial it really depends on what you are thinking of making in the future, imperial designs are often best done with imperial stock.

                                          I think it said that the bearings were best reamed, to get a perfectly matched centre height from the mounting face (or something like that). I don't think the flywheel is specified as reamed, so that's ok.

                                          On the subject of the flywheels, the use of a double key, one of them stepped, and the riveted together rims seems pretty elaborate. Couldn't just one key be used, and the rims screwed together with CSK screws, and the slots filled? It's all machined flush in the end anyway. Presumably the key configuration is to replicate the real thing, but I cant figure out why you'd use rivets rather than screws, especially since the rims are Araldited together anyway, so it's not like they're going to move relative to each other.

                                          #533442
                                          JasonB
                                          Moderator
                                            @jasonb

                                            With a chance that the drill could wander and the reamer just follow the drilled hole I would say there is more risk of different heights when reaming, Boring will true up any wayward drilled holes and provided you have the bottom of the casting against a fixed stop like the vice's fixed jaw then heights should come out the same.

                                            Double tapered keys will be less likely to "tilt" the flywheel to one side which can happen with a single key if the flywheel is a bit loose on the shaft, stepped key is only if things don't line up.

                                            From your photos it looks like you have the "lightweight" flywheels so will have to go about the joining slightly differently and if you want the barring ring than that will have to be added as a separate piece. The reason rivits are suggested is that they also expand in thickness when peined over so will ensure there is no movement unlike a screw with a bit too much clearance that can fret.

                                            I would forget the Araldite on any part of the model, we now have JB Weld which will do a better job and if you put some into the holes during assembly then screws can be used, I would probably do with M3 cap heads into counterbored holes which can then be filled. Also measure OD of the screws and use a close fitting drill for the clearance holes eg 2.8mm or 2.9mm as they are often undersize.

                                            #533463
                                            Dr_GMJN
                                            Participant
                                              @dr_gmjn

                                              Hmm I didn’t realise there were different types of flywheel.

                                              Id really like to incorporate the barring notches – how do you suggest do it?

                                              Thanks.

                                              #533483
                                              JasonB
                                              Moderator
                                                @jasonb

                                                They don't do the heavy one now which just has a rectangular section rim, yours is a "T" shape with the six bosses.

                                                The lugs want removing from both the outer faces anyway, so on one side you would just need to turn a crisper recess and then make a separate barring ring that could be JBWelded into place. If you do it right that will cover the screw heads and as it will be painted could be made from anything easy to cut or what about a 3D print?

                                                barring ring.jpg

                                                I did something similar on this engine where the barring holes were central so made it up from 3 water jet cut parts. Worth looking through it all as it covers a fabricated beam engine.

                                                #533490
                                                Dr_GMJN
                                                Participant
                                                  @dr_gmjn

                                                  That fabricated flywheel looks great.

                                                  I was wanting to try cutting the notches myself, possibly using a gear wheel because I don’t have a rotary table.

                                                  I could get an aluminium or mild steel ring laser-cut, JB weld it into the machined recess, and paint the whole lot. Then machine the notches out of the aluminium? I wanted to leave the notches bright.

                                                  #533491
                                                  JasonB
                                                  Moderator
                                                    @jasonb

                                                    In that case do it in steel

                                                    #533509
                                                    Dr_GMJN
                                                    Participant
                                                      @dr_gmjn

                                                      I suppose aluminium would look a bit bright.

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