I mentioned in my Parting tool upgrade post that I planned to upgrade the locking clamp for the tailstock too. Like many locking clamps on the Unimat III the locking clamp for the tail stock is an M6 cap screw. It being tucked down the side of the tail stock body it isn’t always convenient to get to. Watching the videos from the GOG virtual shows done by the late David Smith (DLOS) on workshop practice I noted that he had done a similar upgrade and it prompted me to think about it. I finally go to it. As luck would have it I have a small stock of 50mm stainless M6 cap screws. These are only threaded for part of their length so I started by threading one of them along it’s entire length. Not an easy task in stainless but I got there. Next I cut of the head and cut it approximately to length. Then I drilled and tapped a short length of 16mm aluminium bar M6 and turned a 20% taper on the closed end. Having tried to fit it all together so that I could work out the handle length I realised that I had it too tall and it wouldn’t screw past the body of the tail stock. I parted off 5mm and that cured the problem. I screwed it on hand tight an marked where the handle was gong to be and had to change plans again. My initial idea was to use another M6 screw for the handle and make a knob similar to the pinch boss to fit on the end. My test run proved that there just wasn’t enough room for any kind of knob so I was pondering what I might do when I remembered that I had a short length of steel bar in my tool box that I had had for years and it usually found use as a drift so was a little battered on the ends. I faced one end off and turned it down to 5.85mm to thread M6 again it being stainless, made this a bit of fun but once I got it started it wasn’t as hard as threading the screw. Then I decided to taper the rest of it to make a handle shape so I centre drilled the threaded end and used a live centre to support it while I turned the taper. After initially completely forgetting that I needed to turn the topside feed not the carriage feed I ended up with the handle below which I was quite pleased with.
Having cross drilled the pinch boss I assembled it all and it looks like this
This is the unlocked position and a quarter turn locks it
Carried away by this success I have ordered some more 8mm stainless rod to make another to replace the cap screw on the quill lock.
After my efforts to create the lovely safety valve bonnet yesterday I was dismayed when I learned that I had orientated the ellipse at the top in the wrong direction. It should run in line with the boiler….
Today’s first task was sorting that out. All was not lost as I learned a bit more while correcting it and I have an even better end result for my efforts.
Next up I drew up a replacement chimney to the correct dimensions for the Class J and initially I added rivets around the base but Tom alerted me to the fact that the NER used countersunk bolts so nothing was visible on the chimney base after painting. A few steps back on the Fusion timeline removed them. It’s certainly much easier to remove them than to add them…
Although the Class J didn’t have a brass cap to the chimney the drawing that I worked from showed it so I couldn’t resist depicting it on the photos at least.
Finally I drew up a replacement dome so that should draw a line under this particular little project if you will pardon the pun.
After posting my earlier effort at the safety valve bonnet, fellow NERA member Tom Burnham pointed out that I had made an error and the the cover should be oval at the top not round. He kindly provided me with the info to put it right.
3D drawing has been a bit of a distraction from the other things that life has thrown my way recently but I also made a small upgrade to my parting tool holder for the Unimat.
Due it small size I had to buy a mini parting blade and this is what it looks like below
The bit that’s supposed to hold the blade and keep it from moving is this bit, which is for all the world like a bent washer.
After parting a few items off I noted that on some of them the back of the part was actually convex because the cutting force had bent the “washer” and allowed the parting tool to move to one side as it was cutting. Having bought my long length of steel from Wickes I decided that I would look at making something a little sturdier.
This is what I came up with.
The slot is wider than the blade (1.45mm) because my smallest milling cutter at present is 3mm but I do have some brass bar that will fit in the remaining slot should I need to take out any slack.
Here it is fitted.
There is a small shim in between the fixture and the tool holder which helps apply an even pressure. The fixture is thick enough not to bend under pressure and long enough to hold the blade inline with the tool holder without being able to twist while cutting.
Next I plan to make a locking handle for my tail stock. It currently locks via a cap head M6 screw which isn’t always very convenient.
Moving swiftly along from the brake standard modifications. You may recall that some time ago I made a stove for the brake van using my Silhouette cutter. Although I proved it was possible, it was extremely fiddly to assemble and I certainly wouldn’t want to be doing a lot of them.
It’s also a perfect candidate for 3D printing so yesterday morning (after amending the brake standard files) I started to draw up the stove.
It has proved to be my most ambitious and ultimately satisfying design project to date.
My apologies for the image overload but I am delighted at how well it has turned out.
Looking to start adding as much as I could details wise, before
assembling the main components. I dry fitted the tank filler and the vent pipe castings
on the tank top plate. Although the latter are generally not bad castings, when
I opened out the etched holes, they both sat lopsided. I attempted to tidy them
up using a square needle file but wasn’t able to correct the lean.
I decided to have a go at turning them, but gripping them to
turn them in the lathe was going to prove interesting. So, I took a leaf out of
the late David Smith (DLOS)’s book, and made a split collet from a length of aluminium
I had recently watched a YouTube video of someone doing just
that and the guy who made the video had left a collar on his split collet to
make it easier to get it in and out of the lathe collet.
This shot shows how the casting sits in the split collet.
You can see in the shot below how lopsided the base was. The
rim of the base plate was so thin that I dare not turn too much off or I would
have ended up having to turn a collar to replace it. Which was plan B if I hadn’t
been able to get the existing base plate to sit flat
Thankfully I got away with it and didn’t need to resort to plan B.
The recent hot weather has somewhat killed my enthusiasm for actual model making so instead I have been drawing up a few more bits and pieces. Some of them are still work in progress but I finished an LNER Brake standard last night.
I have long wished for a correct LNER brake standard casting so now assuming that it prints okay my wish should be fulfilled.
Modelling time has been in short spells just recently, hence
my lack of posts. I have been beavering away at detailing the front and rear of
the tender but I haven’t taken any photos yet. However, a discussion on the
Guild forum about details of the coal pusher fitted tenders had me looking
closely at the drawings of the modifications done to the 9 Ton tender to
increase coal capacity to 10 Tons. There are drawings of the upperworks in LMS
Profiles no 4.
The tank vent castings cleaned up quite nicely by spinning
them in the mini drill with a bit of scotchbrite and although the water filler
was a reasonable casting, when comparing it to the drawing it’s a bit on the
undernourished side. So, using the same bar as I used for the eccentrics which
was just the right diameter, I decided to make a replacement. I had a look at
as many photos as I could find and it seems that David Andrews has the type of
hinge mechanism pretty much correct albeit that all the ones that I saw had
plain straps without visible fasteners.
After turning, I transferred it to the mill and used a
recently acquired edgefinder (less than £7 posted from Allendale) to help to
accurately position the holes. I then used a 1mm collet to hold a .06mm drill and
away we went. Fitting such small drill bits into a collet on the mill is a bit
of a fiddle and you could really do with another hand but it’s worth it.
Although I dressed the backhead a couple of weeks or so ago, I hadn’t managed to get it to fit into the cab before now because the stub of the whistle protruding through the cab roof stopped it from sliding in. One of those little few minute jobs that seem to take forever to get around to…. I finally got to it and the backhead now fits in place as if it was made for it.
Following the visit last week of the Volker Rail Beaver 1900 Tamper surveying the line last week (photos above) we have had several visits this week from a Volker Rail 2004 and today we had the chance to really get up close and personal as it levelled the line at the back of our house. What a fascinating machine to see in action.
We had something a little different down the branch this afternoon or rather it went up the branch last week but I only caught sight of the rear cab window as it disappeared out of view. We thought it odd that it didn’t return (usually most ‘trains’ go up the branch and return the same day). We have had quite a bit of works train traffic on Monday’s of late but much of it has been seen before so I haven’t posted any photos.
They look to have been working their way back from Redmire surveying the branch because it had already passed our house on the way to Bedale when I became aware of it and popped up to take a look. By good fortune it had stopped a couple of hundred yards away and after marking up the ground, (when the machine made a series of loud beeps) it then reversed to about 20 yards beyond the house on the Redmire/Leyburn side. More beeps more marking up and it reversed direction again heading back off towards Bedale. I reckon it must be sat in the passing loop at Bedale station now, because just before 5pm we had the Class 20 featured previously, come past light engine heading to Leyburn/Redmire.
For those it might interest, there are more details shots on my Flickr site
After spending a week teaching myself 3D drawing, I was back
at the workbench today. I had originally planned to just turn a couple of
appropriately sized top hat bushes, file some flats on them where they come together
and job done. My recently acquired mill offered more possibilities to make
something that at least looks like the original even if it doesn’t attach in
the same way. This will be soldered to the cylinder front in between the slide
bars, instead of being suspended from a substantial bracket between the frames.
This is my first real item produced with the mill and I am
happy with how it turned out.
This is where it will sit in between the slide bars on the cylinder front. I have added some fastenings to make it look as if it should be there, when it’s ultimately lost in the gloom between the frames.
At the risk of boring people with my new found skill I have drawn up a couple more items yesterday. First was a much simpler task than the chimneys that I have drawn so far, this time a dome for the D2.
Then at a friend’s suggestion I had a go at the GNR version of the Ramsbottom safety valves.
I had got this far when Chris looked over my shoulder and said “it looks good but it doesn’t look right” she was of course correct the springs should be on the lever that I hadn’t drawn yet not the valve stems… To be continued…
The D2 chimney must have been beginners luck. The next one took me two days of fighting to get it finished. Despite the frustrations I have learned much from the experience (I am a great believer that mistakes and things going wrong are far better teachers than when things go swimmingly).
This chimney is for non condensing C12’s and J52’s. According to the drawing, the condensing versions were fitted with shorter but otherwise similar profile chimneys. I feel that I have done a better job of this one and it’s a bit finer in shape/detail.