Adams "O2" - Calbourne

[mbrown]

Lovely work as always.

I think the prototype would have had two fitted bolts exactly as you have made them. But there would also be a tapered cotter between the brass and the end of the conn rod.

Malcolm

[springcrocus]

Thank you for that information, Malcolm.

Eccentric sheaves and straps

The sheaves were made by turning complete from 1.1/2" dia mild steel bar and parting off a little overlength. After turning the o/d to 1.15/32" and facing the front, the groove was formed with a 2mm carbide grooving tool by touching the front of the workpiece, then winding the compound slide along a measured amount and making the first plunge. Two further plunge-cuts were made followed by sliding the tool back along the bottom of the groove. The same tool was used to start a parting groove, leaving the work ten thou overlong.



In reality, a hacksaw was used to cut off each billet using the groove as a guide although I polished the bottom of the grooves with a thin strip of emery cloth first. The sheaves were reloaded to soft jaws and the backs faced off to leave the sheaves 0.250" thick.



Guess what the straps were made from? Pumphouse bronze, of course. A 2" wide slab was able to provide eight billets, each cut off at 7/8" long. Unfortunately, there was quite a lot of swarf as I had to thin them down to 1/4" but was unable to get two pieces from a single billet.



The billets were machined all round to give me eight pieces 1.15/16" x 13/16" x 0.240" thick. This is ten thou less than the sheaves to ensure they dont rub together. This was followed by machining the bolting lugs to each end of the billets.



The step-down is 5/32" so the opposite end was done by resting on a 5/32" drill. Slightly out-of-square won't matter in this instance.



The next thing I did was to drill the bolt holes and fix them together with 8BA screws, in pairs, marking each set with a letter to keep them matched. Then they were returned to the mill vice and centre-drilled for setting up on the lathe.



A long centering-rod was held in the tailstock and the first set clocked true in the independent 4-jaw chuck. Flatness was handled by loading each assembly proud of the jaws, then pressing back with a flat plate until level with the jaw faces.



However, I found this wasn't going to work very well when the first one moved whilst drilling the pilot hole through. I should have put a large-diameter, hollow backstop behind the work for support. Time for "Plan B", which was to return to the mill and remove the centre by using different sized slot drills to move up in stages, finishing off with a 20mm boring bar that made a 1" diameter bore. Plenty of support and a much better set-up.



The exersize was then repeated using a boring head, adjusting upwards about fifty thou per pass, until I could finish all four sets with a 1.312" diameter bore. Then it was back to the lathe and the clearance for the rims of the sheaves machined in. A packing ring was set behind the work and a 45 thou deep reccess machined on each side, out to 1.1/2" diameter.



The first set was disassembled and fitted around a sheave but was found to be a bit too tight so it was reassembled, using the mill vice to ensure flatness, and rechucked on the lathe. Run-out is unimportant here, just flatness, and an extra two thou per side removed by winding the compound slide along the required amount. With the width correct to fit the grooves, a tiny amount of easement was needed to get the sheaves turning nicely in the straps. This was done with fine sanding drums in the dremel, slow and steady being the order of the day. These are the assembled sets showing each sheave lettered to match it's respective strap.



The next stage is to drill and ream the axle hole in each sheave, followed by broaching a keyway in them. As them late Don Ashton and many others have said in the past, there is only one correct position for the eccentrics and mine will be fixed to the axle with keys. The straps will be finished later, also.

Regards, Steve

[springcrocus]

I'm jumping about a bit with this build because I'm getting on with things that I have material for. However, I shall start to bring some of the sub-assemblies together in the next few weeks.

Reverser Frame

The reverser frame is a mild-steel fabrication with some interesting shapes to machine. The mounting block had a 1/8" wide channel milled into it to locate the plate and I also milled a pair of 2mm channels at the front to locate the webs. The webs were made from 2mm (0.080") material, rather than 1/16" as drawn, and the plate had a pair of 2mm channels milled for the webs. I also drilled and reamed the 3/16" dia hole for the pivot pin and the cutaway which is on the prototype but not on the drawing.



The parts were silver-soldered together, resting on packing pieces so that heat could be applied from below.



The two latch plates were cut from 1/8" material and clamped to the back of the reversing frame. The assembly was then loaded to the milling vice and the two clamp-screw holes drilled for 8BA bolts.



The rotary table was used next to enable forming the shape at the top. The webs have been machined parallel with the base for the time being to facilitate clamping and a locating pin was made to fit the pivot point. Twenty-five thou depth-of-cut passes were made until I hit the 2.250" radius.



With the top finished, I set the frame square to the table by clocking along a side face, then roughed out the two cutaways at the top. Multiple plunge cuts with the boring bar took me to 1/2" radius.



Then a boring head was set up to 9/16" radius for the last few cuts.



The penultimate job for the rotary table was to cut the inside radius of the latch plates. A 4mm end mill was touched on the outside edge, moved inwards by 410 thou to set the inside radius and the winding process repeated until the waste dropped away.



With the frame set square to the table once more, a 1/4" dia endmill was used to reduce the width of the lower section which also formed the radii at the lower corners. The final shaping was done freehand using the linisher, files and sanding drums. The only machining operation remaining was to taper the webs towards the top and the frame was mounted on the angle table for this. Trial and error set the angle to about three and a half degrees.



The reverser pole was made by mounting on one of my milling fixtures and adjusting one end or other to get the taper.



The other small bits and pieces were quite straightforward comprising of spacers, handle, latch lever, lever handle and pivot pins. This is the frame unit temporarily assembled.



I will make the notches once the reach rod is made and distances are worked out.

Regards, Steve

[springcrocus]

Weighshaft and lifting links

The weighshaft is just a length of 5/16" diameter bar with three arms silver-soldered on. Two connect to the lifting links and one to the reach rod. I had a nicely-ground bar that came from a defunct scanner and used this for the shaft. The two inner arms were made on one of my simple milling fixtures but the outer arm has a pair of bends in it which were done first. Then the holes were drilled and reamed followed by profiling the sides. As with all these type of parts, one end was fixed and the other clamped after moving over a calculated amount.



The inner arms were soldered on first and, to keep them aligned, a piece of 4mm bar was passed through the eyes and nutted each end. After fluxing up, solder rings were placed on each end and the position of the arms carefully adjusted. Heat was applied to the middle section of the rod and the inside faces of the arms only and the solder drawn through.



The outer arm needed to be placed radially with respect to the inner arms as well as maintaining the 5/16" dimension from the end of the weighshaft. I drilled and tapped an M2 hole in the outer arm and used an M2 grubscrew to hold the arm in place. Once soldered, the protruding screw was linished away. The two trunions seen on the drawing were made from bronze offcuts, they are just simple top-hats.



The lifting links were made from lengths of 5/16" dia rod, drilled 11/64" with a 1/4" dia spigot turned on the end and parted off at the respective lengths. 3/8" x 1/8" flat bar was drilled 1/4" dia at each end and the rods silver-soldered into place.



They were then held in the vice propped up on some 1/16" packing, thinned to 3/32", profiled with a 4mm endmill and, finally, reamed 3/16". Reaming after soldering ensures that the two holes are parallel to each other.



These are the two lifting links after a bit of cleaning up. Because DY's valvegear dimensions were not optimum, both the links and lifting arms are made to new dimensions.



And this is the weghshaft mounted between the frames. The shaping on the trunions can be seen and is to clear the bend in the reach rod arm.

I've just realised that, nowadays, I seem to silver-solder everything in sight. Before we made the Britannia boiler, I used to avoid silver-soldering if I could and look for a bolted or pinned solution instead. Now, I instinctively go to the blowlamp when two parts need joining. It just shows how important practice and self-confidence are when it comes to making things.

Regards, Steve

[Roger]

Great setups and solid techniques that everyone can learn from. Excellent work as always.

[jon38r80]

I am impressed with the way parts are built up rather than machined from solid, and then still have the appearance of being made from the solid. Neithe my silver soldering or machining achieve the that level of detail. Practice and experience I suppose, Im afraid Im a mud and concrete engineer.

[springcrocus]

Running boards

I was in the mood for a bit of tin-bashing so decided to make a start on the platework. This is mostly specified as 16 swg brass sheet but I shall be using 1.2mm steel sheet throughout which comes from the skip of a local fabricator (with their permission, of course) and is galvanised. I do all my marking out, cutting drilling etc first, then get rid of the zinc by pickling in citric acid before final clean-up and assembly. Paint does not adhere well, if at all, to galvanising even though it appears to be one step backwards with regards to rust prevention.

I'm making a few changes here because the rivet detail on the drawing is wrong and the base of the side tanks are the actual running board, which I don't like at all. First job was to calculate the actual rivet spacings - 515 thou instead 0f 500 thou - and I also added some extra rivet detail not shown on the drawing. This is a top view of the latest "00" gauge version of the "O2" from Bachmann and this malachite green livery is only available from the Isle of Wight Steam Railway. I've checked the rivet detail at Havenstreet and it is very accurate.



There are six pieces in all, two from the front buffer beam to just short of the tanks, two to the centre of the cab doorways, one piece for the rear footplate and bunker combined and, finally, the small front central panel providing access to the oil reservoir. These are the first two sections cut and drilled.



I've made the separate running plates for the sides and the cab footplate as well, once again spacing the rivets to match the prototype. There won't be many pictures of this work, it's just simple cutting out and drilling of holes. The tanks will be stand-alone items that fit to the soleplate. This overview shows the first five panels bolted together and sitting on the frames.



The final panel is the front cover and I've made this as a single panel as per drawing. In real life, there is a hinged section that gives access to the ends of the cylinders (Dan will correct me if I've got this wrong) but this isn't large enough to get to the oil tank which hides below so a deep scribed line will mimic the join. It has a couple of tight bends in it to match the shape of the frames and these were formed by bending around some 5/8" dia bar for the first one...



... then around 9/16" diameter bar for the second one. I don't have a bender so this has to do. The previous picture actually shows where I've returned to the first vice to straighten it out a little.



When it comes to simple drilling, I don't always bother to clock out the component accurately. I just load against parallels and wedges set in the table slots, then set up the DRO by eyeballing a scribing needle held in the drill chuck. Within five thou is plenty good enough for decorative rivets.



This is the front panel nearly complete. I can't set the finished depth until the smokebox is made and will put the lifting knob in once the final size is known. All the rivets will be fitted when I'm happy there is no further work to be done to any of the panels but, for this front panel, two of the rivets will be soldered in with tails underneath to act as locating pins into the top of the buffer beam. All the others will be cut and hammered flat underneath



Tanks next.

Regards, Steve

[springcrocus]

Side tanks

Although most people seem to make their water tanks from brass for obvious reasons, I'm staying with the steel sheet. The Britannia tender was drawn as a sealed-for-life tank under the coal shute so that had to be rust-proof but there is full access to the inside of these side tanks because of the removable tops. Therefore, I'm going to try and line the inside of the tank with latex or similar when the panels are fixed together.

Most of the panels are straightforward rectangles but the outside panels curve upwards towards the roof for a short distance. I used the boring head set at the correct radius to form these curves as I think it's easier this way but they could have been cut freehand because there is beading to be added later which would hide imperfections.



I'm using 8BA countersunk screws to fix the tanks together and now everyone can see where all that brass angle I made was used. I have made a separate inset panel for the bases so that the tanks can be removed intact from the loco if ever needed. The first tank is built up and the parts for the other are in a heap on the bench.



To fix the tanks to the soleplate, I have silver-soldered three 2BA screws, with most of the heads removed, to the baseplate so that the tanks can be nutted from below. Matching holes were drilled in the soleplates.



The tank tops needed the filler pipes fitted and these were made from mild steel bar, turned with a locating spigot and silver-soldered to the lids.



And, finally, a couple of pictures of the tanks sitting on the soleplates, the last one with the filler caps rested in position. There is a lot more work to do on the tanks but this is a good start.





Regards, Steve

[mbrown]

You are making cracking progress - and enviable workmanship too.

Malcolm

[springcrocus]

Front splashers

The front splashers include the leading sandboxes and I'm planning on making these functional. I've made a couple of changes to the sand valves but that's for later. The main part of the fabrication consists of four pieces, the curvy bit which runs from the back to the underside of the top panel, the top and end panel with the bend and the side and inside panels which are both the same. I'm really annoyed with myself because I accidentally deleted four photos of the individual parts and the set-ups for soldering so the first couple are the panels silver-soldered together.



The two side panels were clamped around two spacers to hold them square and the curvy part, made over-long at both ends, was soldered first. Then it was dressed flush with the top and the bent section, also overlong at both ends, soldered on and dressed back when cool. The inside panel is recessed so that they fit up against the frames although there is a cutout needed at the front. The large hole is for the filler pipe to be fitted to and the smaller one the top of the valve assembly. There is also a hole shown on the drawing for the feed water pipe but I won't put this in until the boiler is done.



There is a floor piece to separate the sand hopper from the wheel splasher which is shown brazed into place. I'm going to keep mine unsoldered but a good fit because, once soldered, there is no further access to the sand valve. The floor piece is screwed to the soleplate to locate the main assembly over but, now that I've tested it, I'm going to solder a lug on at the front to hold the sandbox down onto the soleplate. Two screws already hold the back end in place.



After that, I made all of the small parts assocciated with the sandboxes and fixed the filler pipe to the top with silver-bearing soft solder; I didn't fancy bringing the assembly back to silver-solder temperatures again. The last picture shows the filler caps and the top of the sand valves but I haven't fitted the spindles yet.



Regards, Steve

[Nigel Bennett]

May 6, 2022 7:13:04 GMT springcrocus said:

Front splashers



There is also a hole shown on the drawing for the feed water pipe but I won't put this in until the boiler is done.



Regards, Steve

Make this hole a slot. Otherwise the pipework will be permanently attached to the splasher!

[springcrocus]

Bunker

I've continued with the platework, making some of the bunker and cabin parts, and the first part to be made was the rear spectacle plate. Most of these items are simple marking-out followed by cutting and filing to shape and this one has to follow the underside of the roof. I used my Abrafile to cut the shape, then cleaned it up with sanding drums and files. The windows were cut out with a hole saw, then finished with the boring head. I get a couple of free penny washers as a bonus.



The sides were next, the rectangle just sawn to size and two of the curves formed once more with the boring head. There is a cutout where the panel that spans the doorway fits and this was milled out with a small cutter to ensure a nice square corner.



The bunker rear panel was a little more difficult because of the two bends and me not having a bender / folder to use. A variety of clamps, vices, metal bars and large hammers were all used to beat the thing into submission. Suprisingly little swearing for this one, I must be getting the hang of this lark. Here, it sits between the two side panels.



The various holes for the lamp irons and number plate were drilled, along with all the fixing holes for the jointing angles. More of my home-made brass angle was cut to suit and the three components fixed with 8BA countersunk screws. These allow me to assemble and disassemble at will, but will be filled with putty before any painting starts. The grey finish is where I have dissolved away the zinc in citric acid, followed by soaking in phosphoric acid for the protective layer.



The two pieces that bridge the doorways were made next and have been joined to the rear spectacle with brass angle. I'm planning on making this whole section removable so there will be some changes to how DY has drawn this area. For the moment, it just rests in place with a couple of clips to get a visual.



And, finally, a view from the rear quarter showing how the basic shape is coming together. I never used to like tin-bashing much but it's quite satisfying when so much comes together in a relatively short space of time.



I will make the bunker front bulkhead next; this is a little busier because of the two side lockers, with seats, and the coal hole.

Regards, Steve

[springcrocus]

It seems that Pete (doubletop) and I are the only ones doing any model engineering around here at the moment, everybody else is too busy pissing about with electric cars.

Footsteps

There are four sets of steps on the loco and they are all the same so four pieces were cut from the material and also a piece of MDF to act as a support. I've sawn out the shape on the MDF because I've found that the milling cutter speeds I use for the steel are too high for the MDF and it scorches, overheating the cutter. The dust is pretty awful also and I usually wear my respirator mask when using this material but it is nice and flat and takes good clamping pressure so I'm happy to use it.



I thought it easier to do all four as a stack and put the single bend in later on. After working out where the centre of the radii were, I used a 12mm end mill to rough out the waist / waste (both being appropriate here) followed by the boring head which had been preset to cut 1.250" diameter.



A third clamp was added near the middle before removing the right-hand one to allow acces for drilling the rivet holes. The two steps will be fixed with 1/16" diameter iron rivets after the zinc is removed.



Eight treads were made next, four of each, bending the backs first followed by drilling the rivet holes and, finally, curling the ends upwards. The top of the steps were bent but the fixing holes will be drilled once I decide how to fix them to the underside of the running boards.



The parts were pickled in citric acid before riveting together. These are the four steps ready for fitting.



Regards, Steve

[steamer5]

Nice work Steve!

Can I ask how you set the boring head for the radi you need? I have a bunch to do & rather just taking a stab in the dark on setting up & stuffing up a heap of already done work

Cheers Kerrin

[stevep]

When machining MDF (and cast iron), I use the shop vacuum cleaner, with the nozzle clamped near to the cutter, to suck away all the dust. Much nicer than a respirato

[GWR 101]

Steve, Quote "It seems that Pete (doubletop) and I are the only ones doing any model engineering around here at the moment, "

I am still working on the Jubilee, its just that I am drilling and tapping lots of 6 BA. holes in the cylinders. 

Your build looks great a real lesson in how to go about this lark. Regards Paul

[springcrocus]

May 14, 2022 15:38:15 GMT GWR 101 said:

Steve, Quote "It seems that Pete (doubletop) and I are the only ones doing any model engineering around here at the moment, "

I am still working on the Jubilee, its just that I am drilling and tapping lots of 6 BA. holes in the cylinders. 

Your build looks great a real lesson in how to go about this lark. Regards Paul

Hello Paul,
Yes, following along with you, I was just having a grumble about the EV thread. In the last three days, there have been more posts in that one thread than ALL of the posts over the whole of the rest of the forum in the last seven days. Where have all the loco men gone?

May 14, 2022 8:27:11 GMT steamer5 said:

Nice work Steve!

Can I ask how you set the boring head for the radi you need? I have a bunch to do & rather just taking a stab in the dark on setting up & stuffing up a heap of already done work

Cheers Kerrin

Hello Kerrin, and thanks.
Sorry, no clever tricks or fancy method, I'm afraid. When I remove the boring head from the mill, I always jot down the size that I was cutting and store it with the head. If it needs adjusting, I usually just calculate the new size needed and adjust using a plunger clock. Importantly, I always set up a piece of scrap material and test-bore a hole before I set the job up if I'm planning on using the boring head.



Regards, Steve

[jon38r80]

As usual, neat work and good set ups make it easy to follow what you are doing.

My apologies for stiring up the EV thread. It wasnt my intention.

[flyingfox]

Greetings, concerning model engineering activity, just for the record, I am about to tackle the final painting of my A4, have completed the frames, axleboxes etc for the Stanier 2-6-4 tank, and have the boiler stripped on the 0-6-0 tank to repair a leaking wet header, and yes I am interested in the EV "battle"
I still run my A3 most Sundays.
Regards
Brian B

[jcsteam]

Nice work.

If I may regard myself as one of those loco men. I've been scratching my head for the last few months on what to actually build. Also working on a 3.1/2" gauge design, which was originally a scaled down pannier, however its slowly evolving and its lost its tanks and now has a large dome and tender.....Still to figure out the valve gear on that one, which is a minefield when you try to do it right. I have been playing with electric locos though, (big kid grin) hehe.

Jon