Lisa
Statesman
Posts: 806 
|
Post by Lisa on Dec 11, 2018 8:09:50 GMT
By the time I'd thought of (or heard of!) clupet rings I'd already bought the regular type, but they're certainly something I'd consider in the future. Meanwhile, I've drilled and tapped four of the five bolting holes for the left cylinder, but this one isn't going to happen as the buffer beam is now hard against the mill base... I'll see if I can wangle it in under the bench drill somehow, otherwise it'll have to be done with the pistol drill. It might be possible to spot through with the pistol drill then drill properly on the bench drill with the cylinder out of the way... we shall see. I'll do the other side first.  |
|
|
|
Post by Roger on Dec 11, 2018 9:15:12 GMT
Could you hold the drill in a collet which might be shorter and give enough room to hang the drill out more?
|
|
Lisa
Statesman
Posts: 806
|
Post by Lisa on Dec 11, 2018 9:32:34 GMT
The length is fine Roger, I just can't move the table over to align the drill with the hole as the bufferbeam's up against the base of the mill.
|
|
|
|
Post by Roger on Dec 11, 2018 11:23:37 GMT
The length is fine Roger, I just can't move the table over to align the drill with the hole as the bufferbeam's up against the base of the mill. Ah, I assumed that lifting the buffer beam up onto the mill base meant that you ran out of height with the chuck you've got and that you might still be able to do it if that was shorter. |
|
Lisa
Statesman
Posts: 806
|
Post by Lisa on Dec 11, 2018 11:46:56 GMT
Ah, I assumed that lifting the buffer beam up onto the mill base meant that you ran out of height with the chuck you've got and that you might still be able to do it if that was shorter. I hadn't thought of lifting the frames up as there's not a lot of height to spare as it is; but while lifting the buffer beam up on top of the mill table won't work (even with a completely flush collet, there's not enough room there to have the cylinder in place to spot the hole through), it might be possible to lift the frames maybe 20-30mm which, given the shape of the mill base, might gain the few extra millimetres of table travel needed. Or maybe even spot the hole with a punch, then drill it with the frames lifted and no cylinder restricting the height. I'll do the other side while I ponder that, ta. |
|
stevep
Elder Statesman
Posts: 1,073
|
Post by stevep on Dec 11, 2018 16:05:08 GMT
Lisa,
Having managed to drill through most of the holes, I am sure that, if you fit the cylinder with bolts through the holes you've already drilled, then spot the remaining holes with the pistol drill, after removing the cylinders, it will be very easy to then drill the remaining holes on the pillar drill.
It wouldn't be too disastrous if you even had to finish the drilling with the pistol drill. The spotting (if deep enough) would ensure the hole is in the right place.
|
|
|
|
Post by David on Dec 11, 2018 21:57:08 GMT
And if one or two holes are not quite right you can open them out sufficiently in the frame and no-one will ever know.
|
|
Lisa
Statesman
Posts: 806
|
Post by Lisa on Dec 12, 2018 10:35:11 GMT
Lifting the frames up did the job on the tricky hole, though I also had to use the collet chuck to get few extra millimetres of height.  The base of the mill is slightly tapered, so lifting the frames up meant I could move them over just a little further, which was just enough to get the hole under the drill. The other side wasn't a problem, as the handedness put the hole at the back rather than the front, and I could just turn the frames to an angle across the x/z axis that gave the few extra millimetres without needing the packing. |
|
|
|
Post by delaplume on Dec 12, 2018 13:11:49 GMT
Nicely done there Lisa.....a proper bit of Human ingenuity !!!
|
|
Lisa
Statesman
Posts: 806
|
Post by Lisa on Dec 13, 2018 12:11:53 GMT
Next on the 'oh bugger' list, it seems I need to shorten the piston rods:  |
|
|
|
Post by Roger on Dec 13, 2018 13:59:36 GMT
I presume you've measured the clearance at the other end? I'd hate you to shorten the rod, only too have it hit the other cover!
|
|
Lisa
Statesman
Posts: 806
|
Post by Lisa on Dec 13, 2018 15:12:17 GMT
I have, yes; there should be about 2mm clearance at each end once it's in the right spot. I'm going to need that M8F die now though, as I don't fancy trying to extend a thread with screwcutting on the lathe!
|
|
|
|
Post by Roger on Dec 13, 2018 17:53:19 GMT
I have, yes; there should be about 2mm clearance at each end once it's in the right spot. I'm going to need that M8F die now though, as I don't fancy trying to extend a thread with screwcutting on the lathe! If it's only 2mm, could you recess the end of the Piston or undercut the end of the thread? Maybe you don't need the thread to be that long? |
|
|
|
Post by Jim on Dec 13, 2018 20:42:47 GMT
Next on the 'oh bugger' list, it seems I need to shorten the piston rods: I pleased to see I'm not the only one with an 'oh bugger' Lisa. Actually I have quite a collection including one headed 'injector delivery clacks'  Your loco is looking great and piston rods aside you should be pretty thrilled with progress to date.
I hope you and your dad have a great Christmas and wish you both lots of cooler weather for the festive season.
Jim
|
|
|
|
Post by Cro on Dec 13, 2018 20:45:05 GMT
I have, yes; there should be about 2mm clearance at each end once it's in the right spot. I'm going to need that M8F die now though, as I don't fancy trying to extend a thread with screwcutting on the lathe! If it's only 2mm, could you recess the end of the Piston or undercut the end of the thread? Maybe you don't need the thread to be that long? Could you bore the crosshead 2mm or so for the Dia of the piston rod itself? that way you aren't weakening the piston rod removing the thread and can screw up hard on a shoulder with support around it? Looking forward to seeing this turn a wheel Lisa! Adam |
|
|
|
Post by David on Dec 13, 2018 21:25:38 GMT
At least it should be easy to measure how much you need to shorten the rod by. Unless you were trying to get it spot on by measuring beforehand I think a long piston rod is pretty normal.
What did you do about the crosshead bracket being out of place?
Looking good!
|
|
Lisa
Statesman
Posts: 806
|
Post by Lisa on Dec 14, 2018 2:52:51 GMT
If it's only 2mm, could you recess the end of the Piston or undercut the end of the thread? Maybe you don't need the thread to be that long? It needs to be shortened by 6mm, then there'll be 2mm of clearance at each end. The piston is already only threaded for half its length, the other half being a tight sliding fit on the piston rod, so there's not enough thread there to do this at the piston end. Could you bore the crosshead 2mm or so for the Dia of the piston rod itself? that way you aren't weakening the piston rod removing the thread and can screw up hard on a shoulder with support around it? I could, but I'd wanted to make a thin nut to go on the piston rod; which would both act as a lock nut, and would simplify pulling things apart without having to clamp onto the rod itself. Also, as mention above, it needs to move by 6mm (which would still leave a good 14mm or more of thread in the crosshead), 2mm is just the clearance at each end of stroke once it's in the right place. If I skip the nut I could certainly do this though. Looking forward to seeing this turn a wheel Lisa! As am I! Though I was rather pleased that turning them by hand as far as they go, it all had a rather nice 'tight but smooth' feel to it. At least it should be easy to measure how much you need to shorten the rod by. Unless you were trying to get it spot on by measuring beforehand I think a long piston rod is pretty normal. It's about 6mm, give or take a half. Certainly better long than short I'd say! What did you do about the crosshead bracket being out of place? At the moment, nothing. I'll probably just make a new motion bracket that's a little shorter, and put up with things not being the same each side; I suspect this is a remnant of the impatient teenage me that put the frames together. One cylinder is just a little higher, and more angled, than the other. It's not like it'll have any knock-on effects to the valve gear, slip eccentrics are rather forgiving. If I wanted to get it right, I'd likely end up replacing the frames (and wow would I do those differently to the plans if I went down that path!). Thanks. |
|
|
|
Post by delaplume on Dec 14, 2018 5:03:38 GMT
Hi Lisa,
Quote}---". One cylinder is just a little higher, and more angled, than the other. "...
Looks OK from where I'm standing ( Shropshire, UK ) ---- LoL !!
Crack-on and don't worry about it............Compared to Diesel and gas turbine these steam powered, piston engines are very forgiving and will continue to function in the most adverse of conditions....
Alan ...
|
|
|
|
Post by Cro on Dec 14, 2018 6:28:20 GMT
Lisa,
Understand about the nut. As an alternative I have done the 9f like so:
- 2 holes in end of piston and a tool that fits in and I can use a socket set on it.
- Grub screw on side of crosshead screwing down onto flat on thread which you can work out once you have all the positions set out.
Just thinking of alternatives to help avoid possibly awkward machining.
Good luck,
Adam
|
|
Lisa
Statesman
Posts: 806
|
Post by Lisa on Dec 14, 2018 7:13:15 GMT
One would hope those holes in the piston are blind!
That's quite a neat sounding arrangement Adam, I'll have a look into it, ta.
|
|
