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[Jerry C]

I'll deal with you later Ben.
Jerry.

[wrongtimeben]

Lol 

[Jerry C]

The 3" feed pump kit arrived yesterday together with the 4 1/2" boiler tube and the tube for the funnel, so I'm only waiting on the burner tube and the cast phosphor bronze for the bushes. The boiler tube as supplied was rough cut with a saw and approximately 1/2" over size. Those with a nervous disposition, look away now. What follows is almost certainly inadvisable but I did recognize the fact and wore my crash helmet and worked at arms length. I shipped the 4 jaw chuck and mounted the tube over the jaws then used the dial gauge to centre the chuck end of the pipe. I used my little folding rule as a feeler gauge between the tube and the lathe bed to get the tube roughly straight then dial gauged the tail end of the tube. Then I nipped up the chuck and did a final check. Max run out 2mm with 1/16" clearance from the bed and 3 1/2" overhang. I switched the motor to slow speed and set the drive belt to slowest speed. I ran the lathe and all seemed ok with just a gentle wobble on the table, (it's not very rigid at the best of times). Then, with my sharpest tool in the tool holder, I started taking 2 thou cuts working from inside to out. No problem at all, kept my patience and didn't try to rush it and after 1 1/2 hours the end was squared  and finally smoothed off and de-burred with a file. I reversed the tube on the chuck and dialled it in again. Turning the chuck by hand and using the pointy bit of the tool I scribed a line to mark the 5" length. I then ran the lathe and cut a shallow groove to guide the hacksaw when I finally cut the tube to length. I transferred the tube to the vice with the jaws at max opening and clamped the tube with a clamp using the jaws as a sort of V block. Then began cutting in the groove with a hacksaw, long, slow strokes, with minimal pressure, using the tip of my thumb as a fence to protect the tube should the blade jump the groove. I rotated the tube in the vice often and after about 30 mins the end came off quite neatly. Back in the lathe again to dress up the cut end. Please don't shout at me, I know I took the lathe to its limits but it did the job and I'm safe and sound. There was a little puckering but thankfully not on the work piece.
    Now to the feed pump kit. It comes with 6 castings in, I guess, bronze, with comprehensive drawings, O-rings and valve springs. I'm going to need a couple of number drills and a few reamers. I've probably got enough s/s round to get it done. The drawings are third angle projection, which if memory serves me well I was taught as "American Projection". At the time (Grammar School), it fitted in my head easier than first angle. A bit of Googleing to brush up I think.
    The picture shows the castings and, reading from left to right, no 1 is obviously the cylinder, no 2 the valve chest, no 3 the water cylinder, no 4, I think is the water cylinder top cover and no 5, I think, is the cylinder bottom cover, and finally no 6 is for odds and sods.
     I'm not sure in my head how to mount rough castings in lathe or mill and the order of making good faces etc, I would appreciate some tips which would add to the thread for others watching.
Jerry.   

[Circlip]

Wrapping (not the talky thing) an overlong straight edged strip of paper around the tube will give a straight edge to cut to.
 
  Regards  Ian.

[Jerry C]

Nice one Ian. Thanks,
Jerry.

[Jerry C]

I ordered some number drills, reamers, a slot drill, a cutter and a D bit which should come tomorrow. Today I made a start on the cylinder casting. I checked that the milling attachment was mounted square in the slide then, using the fly cutter, I cleaned off the valve chest side. Putting this side down on the fixed jaw face of the milling vice and, using a square to set the cylinder axis at a right angle to the milling table, I cleaned off the top of the cylinder. I transferred the piece to the vice and removed the excess length with a hacksaw, intending to use this piece to make the top cover out of. I replaced the piece in the milling vice valve side down and the top face against the table, then milled the bottom face until clean, then took it down to length of 0.900". When I measured the width of the casting, to get an idea how much I would need to remove each side to get it to size I found that the casting was less than the finished width in the rough! I cleaned both sides off and the width ended up 45 thou under size. All faces were however perfectly square and the width is not a problem as there is still enough metal outside the stud holes and the nuts won't hang over the edge. Phew! The 5 holes in the cylinder for the valve chest studs are copied from the valve plate, so the plate has to be right. I put the piece I cut off the end of the cylinder in the milling vice backed up by parallels and attempted to mill it flat. Failure as not much to get hold of and it distorted and was ruined. I have some thin aluminium plate so I cut a piece on my scroll saw over sized a bit. At the same time I cut a piece for the valve plate. I marked out for all the holes, (13). As shown in the picture below, using double sided sticky tape, I attached it to a block of oak which is parallel, and put it in the milling vice. Looking at the marking out I decided it wasn't going to be good enough. I put the Jacobs chuck on the spindle with a 1/16" centre drill loaded and used this, together with the graduated wheels on the mill and the slide,to find the centre of the plate I zeroed the wheel markers and then used the graduations to navigate the drill around the plate and marked out the 5 securing stud holes with the centre drill. Finally I replaced the centre drill with a No. 50 drill and drilled the final holes. I will use this method to do as many holes as possible as transferring holes from one piece to another doesn't look the "right" way to me when I can put a hole exactly in the right place like this.
      I noticed when looking at the plans that the 4 holes in item 6 ( the top cylinder cover) are not drawn the same way as they are in item 1, (the cylinder). If the datum mark in item 6 is the centre of the cylinder, what is the significance of the 45 deg angle and 0.325" radius if the holes form a square of side 0.5"???
      Also missing on the drawings for item 2, (the valve chest), is the depth of the recess for the valve rod O-ring.
Any way all stopped now awaiting kit.
Jerry.
 

[derekwarner]

Jerry...it happens especially with pre CAD drawings..........having said this, it can be perplexing  ....but it does happen & is usually the result of the Drawing not being checked by a second person

You may find in the title block the notation NTS [not to scale]

Having said all of this it can go from the sublime to the ridiculous....that same Mudgun hydraulic cylinder Drawing I mentioned in the 'political correctness' thread shows port connections in the endcap with nominated radians in........ degrees, minutes & seconds 

Some very diligent junior drafts person in Luxemburg had picked a scanned copy of a hand drawn drawing & in CAD nominated such ridiculous positioning's.........unfortunately this was checked & signed off by a senior engineer from Paul Wurth  .....

Another issue is metrication of imperial Drawings.......eg., we see the original dimension as 7/8" or a whole number & by convention only toleranced to the general tolerancing table on the Drawing.......however when this whole number is metricated it becomes 22.225 mm

Some genius may take this further & nominate the new dimension as 22.20 +0.02/-0.00........ ....

If you have a dilemma with an o-ring cavity....just yell out.......or refer to your BS Standards .........Derek


 

[Jerry C]

Thanks Derek, I think all the O-rings are the same thickness, just different sizes so one recess depth fits all?
        The rest of my order arrived first thing so continued with the cylinder. I marked the centre of the bore then loaded the casting in the 4 jaw chuck, found the centre by eye and magnifying glass then used progressively larger drills until I was 2 drills below 1/2". I thought that as the drills got bigger I'd need to slow the piece down but actually the opposite seemed to be the case. Too slow and the drill juddered and crabbed stalling the motor. Still, on the big drill, things were getting a bit violent hence stopping 2 short. I put the piece in the vice and reamed to size. This was not without it's problems. After each pass I moved the blades up a turn on the threads. At first this was OK but as I progressed the reamer started to judder causing ripples in the bore. I reduced the adjustments to 1/4 turn added a dash of cutting fluid and gently removed the marks. The bore is 10 thou oversize as a result. Hey ho. I put a slit in a piece wooden dowel, put a short length of emery tape in the slot and lapped the bore. It is the last bit of a roll of tape I bought 30 years ago in my motor bike building life. I need some more.
        Loaded the piece in the milling attachment valve side to the chuck, found the centre of the face and using my northing and easting method, drilled all the stud holes and tapped them 10BA, then drilled the No55 ports before repositioning the piece and drilling and tapping the exhaust gallery and union  ports 5/32"x 40 tpi.  Then repositioned finally and drilled the inlet and exhaust galleries top and bottom before replacing the drill with a 1/16" slot cutter and opening the ports into the bore. I gave all faces a good lapping on a lapping plate made from a pane of greenhouse glass with strips of waterproof self adhesive abrasive from 800 to 2500 lines. All that remains now on the valve plate is to cut the channels for delivering steam to the shuttle ends on the reverse face.
         That was a hard days work with plenty of opportunities for foolish mistakes and impatience. I think my plan to base all measurements on the centre axis of the bore is a good one. where the drawings indicate positions by radius or PCD (Pitch Circle Diameter) (I looked it up), it's a simple r x sine 45deg to get N & E. I believe that using the graduations on the wheels will always be better than I can do it. Digital readouts are starting to look desirous. Will continue with valve chest and covers tomorrow. Thanks for watching,
Jerry.

[southsteyne2]

Jerry you can still re chuck the cylinder and finish with a round nose finely honed boring bar to prevent possible tapering of the bore
Cheers
John

[wrongtimeben]

With drilling, I was always taught "reduce the speed, increase the feed" with the diameter of drill increasing. At 1/2" I would imagine you've reached beyond the capabilities of the taig, so bring on the boring bar. 


That said, the 1/4" boring bars are good for the lightest of cuts only as they flex and chatter like mad. I expect you will need to make a tool post with a 3/8" hole and clamping slit to give you more rigidity. But that's a project for another day. It was something that appealed to me about the taig, that because of t slot fitting and small size,you could have a shelf full of toolposts all set to the correct height, ready to go. Abit like router bits.


Anyway, lovin your work, I shuttup now.


Ben.

[southsteyne2]

Hi Jerry you don't need numerous toolposts the one in the attached picture does me fine and as mentioned previous sharp tools are essential at least on the taig lathe to help eliminate chatter and with your skills would take very little time and be the best mod for any lathe as it is easy height adjustable and can hold larger size bits ,keep up the good work as I am still battling with the regulator easier to buy one lol also waiting for your boiler build update
Cheers
John

[southsteyne2]

Also have plans and video of the toolpost if you are interested
John

[Jerry C]

Thanks John, I only have two tool posts one front and one back. I like the look of yours especially the height adjustment. Would love the plans and video. If your willing, put them on here, if not PM me.
Jerry.

[southsteyne2]

Thanks Jerry I made mine on the taig and you can also mill the tool slot in situ  video here https://www.youtube.com/watch?v=oJHDSY7tZ8c
Cheers
John

[wrongtimeben]

That certainly is a nice piece of kit.


I think the main cause of chatter for me was thinking the taig was a Colchester. I got there in the end but always preferred the 3/8" boring bar.


John, do you have a quick method of centring the tools once mounted on the post? Obviously the centre in the tail stock and I know about the steel rule on the workpiece. 'Twas always a bain to me, changing the tool.


Jem, getting new shed this week, so whilst sorting, have come across some odds and sods for your pile. 


Looking forward to next update.


Ben

[ooyah/2]

The 3" feed pump kit arrived yesterday together with the 4 1/2" boiler tube and the tube for the funnel, so I'm only waiting on the burner tube and the cast phosphor bronze for the bushes. The boiler tube as supplied was rough cut with a saw and approximately 1/2" over size. Those with a nervous disposition, look away now. What follows is almost certainly inadvisable but I did recognize the fact and wore my crash helmet and worked at arms length. I shipped the 4 jaw chuck and mounted the tube over the jaws then used the dial gauge to centre the chuck end of the pipe. I used my little folding rule as a feeler gauge between the tube and the lathe bed to get the tube roughly straight then dial gauged the tail end of the tube. Then I nipped up the chuck and did a final check. Max run out 2mm with 1/16" clearance from the bed and 3 1/2" overhang. I switched the motor to slow speed and set the drive belt to slowest speed. I ran the lathe and all seemed ok with just a gentle wobble on the table, (it's not very rigid at the best of times). Then, with my sharpest tool in the tool holder, I started taking 2 thou cuts working from inside to out. No problem at all, kept my patience and didn't try to rush it and after 1 1/2 hours the end was squared  and finally smoothed off and de-burred with a file. I reversed the tube on the chuck and dialled it in again. Turning the chuck by hand and using the pointy bit of the tool I scribed a line to mark the 5" length. I then ran the lathe and cut a shallow groove to guide the hacksaw when I finally cut the tube to length. I transferred the tube to the vice with the jaws at max opening and clamped the tube with a clamp using the jaws as a sort of V block. Then began cutting in the groove with a hacksaw, long, slow strokes, with minimal pressure, using the tip of my thumb as a fence to protect the tube should the blade jump the groove. I rotated the tube in the vice often and after about 30 mins the end came off quite neatly. Back in the lathe again to dress up the cut end. Please don't shout at me, I know I took the lathe to its limits but it did the job and I'm safe and sound. There was a little puckering but thankfully not on the work piece.
    Now to the feed pump kit. It comes with 6 castings in, I guess, bronze, with comprehensive drawings, O-rings and valve springs. I'm going to need a couple of number drills and a few reamers. I've probably got enough s/s round to get it done. The drawings are third angle projection, which if memory serves me well I was taught as "American Projection". At the time (Grammar School), it fitted in my head easier than first angle. A bit of Googleing to brush up I think.
    The picture shows the castings and, reading from left to right, no 1 is obviously the cylinder, no 2 the valve chest, no 3 the water cylinder, no 4, I think is the water cylinder top cover and no 5, I think, is the cylinder bottom cover, and finally no 6 is for odds and sods.
     I'm not sure in my head how to mount rough castings in lathe or mill and the order of making good faces etc, I would appreciate some tips which would add to the thread for others watching.
Jerry.   

Jerry,
Just been reading your post on cutting your boiler tube,.

You must have some IRISH blood in your genes as you are one LUCKY LUCKY Dude.
Machining copper is one of the most fraught procedures on the lathe, one little dig of the tool and you could have had a major incident, the tube being unsupported at the end could have jumped out of the chuck, distorted the tube and possibly wrenched the lathe head on such a small lathe.

If you have no steady you could have plugged the tube end with a piece of timber, trued the tube up with a D.T.I. and then brought the tail stock revolving center into the timber to support the end of the tube before machining.

In fact there was no need for you to machine the tube as once cut around the mark you could have cleaned the end up with a file as there is no need in the boiler design for the end to be machined as there is going to be a smoke box at one end and a fire box at the other which go over the tube and pinned on.

I know that its academic now as you have managed to get away with no problem but I write this in the hope that somebody else reading your build who  may try your method and not be so lucky.

As it happens I am at present building a boiler from the same drawing and have used the method suggested by Ian ( Circlip ) that is wrapping a straight edge piece of paper around the boiler marking with a pencil and cutting with a fine toothed hack saw blade and then cleaning up the edge with a file.

I would post some pics of this build but unfortunately since the forum change I can't post pics, I will however mail them to you and perhaps you could post them on the forum.

Please don't take this as criticism, rather as a suggestion that somebody may try the old paper wrapper method and cut with a hacksaw.

George.   

[Jerry C]

Hi George, if you remember, you taught me the paper trick when I made my de-oiler for Wear's plant. I didn't have a piece of paper big enough to go around this one. I didn't want to mention it in case Circlip thought I was being a smartarse. I fully acknowledge that it was a risky procedure, but alls well that ends well.
     I'll be putting some more on the pump cylinder machining maybe tomorrow so will gladly post your pics at the same time. Have you got a thread for your boiler build or shall I just include it on mine?
        No offence taken on criticism if it's to keep me and others safe, I appreciate it.  It's a canny wee lathe all the same.
     John, thanks for the drawing, I'll certainly have a go at the tool holder.
Jerry.

[southsteyne2]

Hi Ben I usually do a small face cut and line the tool with the knob in center of the work or the center in the tailstock chuck
Cheers
John

[ooyah/2]

Hi George, if you remember, you taught me the paper trick when I made my de-oiler for Wear's plant. I didn't have a piece of paper big enough to go around this one. I didn't want to mention it in case Circlip thought I was being a smartarse. I fully acknowledge that it was a risky procedure, but alls well that ends well.
     I'll be putting some more on the pump cylinder machining maybe tomorrow so will gladly post your pics at the same time. Have you got a thread for your boiler build or shall I just include it on mine?
        No offence taken on criticism if it's to keep me and others safe, I appreciate it.  It's a canny wee lathe all the same.
     John, thanks for the drawing, I'll certainly have a go at the tool holder.
Jerry.

Jerry,

As it's only a one off to point out the dangers of machining copper just post the pics on your thread,.
Your doing a good job, keep it up.

George.

[wrongtimeben]

Thanks john. Sorry Jem thread hijack over.


Ben

[Jerry C]

Ben, and anybody else watching, if it's pertinent to the thread and contains info helpful to me and any body else put it on here and don't worry about hijacking thread. There are all kinds of skills on here from total amateurs to professional engineers. Also people that think they can never do this type of thing. My purpose is to show how I work it out and how I learn. One of my biggest beefs about school was that they taught us a whole load of stuff but never actually taught us how to learn.
Jerry.

[Jerry C]

George (ooyah2) asked me to put pics of his project, similar to mine) because he can't.
Jerry.

[Jerry C]

more.

[Jerry C]

more more

[Jerry C]

and finally

proper job!