The Bolton -Bertinat -Bailey Triple expansion engine

[vtsteam]

Lots of good tips and methods in this build. 

[steam guy willy]

Thanks for all the comments and this is the advantage of being a septuagenarian ...that one has a lifetime of experience to fall back on ??!!! after making lots of mistakes ..etc etc  the jig has now been used to drill and tap all the eccentric straps and when I tap holes I like todo it horizontally rather than downwards on top as  ones hands work better in that configuration ???!!.  The next job is to make the steel eccentric rods using the steel jig 

Willy

[Roger B]

Good progress on the eccentrics 

I also often find it easier to hand tap horizontally 

[steam guy willy]

I have started on the rods and the bolting part is drilled and filed to fit ...the steel bar is bigger then the finished dimensions and it needs filing to shape ...after bolting it in place I file it inset and I use guide pins in the vice ....these are broken 1/8th centre drills that are hardened steel . holes are drilled at right angles the cast iron vice jaws and the parts are held in the vice in the correct position and the file is used to just bear on the part being filed . when turning the shaft on the Unit lathe I use a small jubilee clip as a stop for the cross slide. and when turning parts I use the Smallwood gauge to get the finished dimension ...

Willy

[steam guy willy]

More work on the eccentrics ..these ar quite complicated parts and all have yo be very accurately made   so are jigs on the way
Willy

[crueby]

Great  progress  Willy!   

[steam guy willy]

Thanks Chris ,,,and more on the rods and I have turned them to size and tapped them 5 BA to attach to the upper forks I have the drawings and also the Model engineer writeup that have different dimensions on them so again I will have to make the parts from both ends to marry them up ?? however some state   "check from job "  ??!!

Willy

[steam guy willy]

 The eccentric rods are ready to be silver soldered and also tapered ...so a small jig to make for that
Willy..............

[steam guy willy]

hi all , I posted a reply about 3PM  but when I look back the page seems to be just a white empty blank  image ????!!  It washout the taper turning ??

Willy

[crueby]

Your thread is showing again.   

[steam guy willy]

thanks  Chris ...more photos & I have offset the tailstock centre by turning up a new one and fileing  down the side and putting it in the Jacobs chuck with one jaw facing forwards .??!! I did this with trial and error  !! but there may be a trigonometrical formulae for this  . The rod is 1.5" long and the dimness are .156  down to .125....5/32nd to 1/8th... So any ideas ????!!!
Cheers
"W"

[crueby]

Do you have a four-jaw chuck? With a 4-jaw you could offset a center for the headstock and have another center 'centered' in the tailstock. Another way is to angle the headstock to the side and use two normal centers. The Unimat you have allows the headstock to be rotated to the side, doesn't it?

As for how far to offset one end, you want to move it one half of the difference in the diameters from one end to the other. So, move it by:
     (5/32 - 1/8) / 2
which works out to 0.0156"    No fancy trig needed!

[steam guy willy]

Thanks Chris and yes no fancy trig needed just old fashioned turning ,sawing and filing  ..what we all did before digital electronics took over  !!!!??? 

cheers

willy

[steam guy willy]

More work on the forks   6 of them ..they are made from 3/4" X 3/4"   X 3/16th " mild steel .. I purchased some stock of this dimension from EKP and it arrived the next day ?!!  seed off 3/4" ing length and use the bought size to drill the holes  10BA. No 54 drill  and the 5BA ,,these were tapped first so I did not have to machine the next dimensions in case t snapped off the taps  I turned the part in the Milford useing the small Emco chuck and turned this dimension using the lead screw and the large end handle that has the 1 thou dimensions stamped on it  !!

[steam guy willy]

and more pics ....
Willy