adrian
Flying Squad
It's not that clean, the sheet of paper in the background hides a multitude of sins behind it.
They are from the S7 stores.
adrian
Flying Squad
Workroom floor is laminate which has it's pros and cons. On the plus side when I dropped one of the scale hardware bolts I knew where it had gone because I could hear it hit the floor. On the downside it tends to bounce on laminate so it may not end up where it started!
Now I've got the main part of the rear of the chassis sorted, just detailing bits to do. This is a great bit in the instructions, plenty of photo's and instructions to get you to this stage then it finishes rather abruptly with "add the remaining castings".
The next stage is to get cracking with the motion, however the kit as supplied covers the loco's with fluted coupling rods and LNER style return crank. As I believe I mentioned previously the loco I've chosen has plain rods and the LMS style 4 bolt return crank, which was why I was very interested in your efforts in this area. So that's probably the next task once I've sorted the expansion link out.
adrian
Flying Squad
Sorry that one had slipped past my radar. To be honest there is no desperate need in S7 for the bogie to be compensated. It's just with the drivers being sprung then it seemed a shame to stop halfway and I looked on it as a challenge. I'm sure that as built rigid it would have been fine, as there is adequate movement in all axes to cope. However if built as rigid then it will end up on 3 points at some time, even with the short wheelbase. Making sure all 4 wheels stay on the deck is just for my engineering self-satisfaction.
28ten
Guv'nor
Ah yes, i do like it when they say that
still at least you get photos which helps a bit.
adrian
Flying Squad
Right the next stage was moving onto the motion, I'd been putting this off because it needed a replacement return crank but thanks to Richard's work I've got something I can plagiarize.
In the instructions it starts with the expansion link and radius arm so these are the bits.
All brass castings, two halves for the expansion link and cast radius arm. The top one showing my effort to get the valve gear the right colour, i.e. steel. The brass castings are far too yellow for me so I'm experimenting with tinning all the castings to give me that steel colour. I'll just have to be very careful soldering the joints!!
Anyway as good as the kit is it's always useful to check the photo's. In this case there was a problem with the expansion link - something was missing (or not depending on your point of view). There's a couple of holes missing in the expansion link.
So a couple of holes were drilled in the appropriate place and then pinned together with scale hardware bolts. The instructions say to use nickel-silver wire, but the bolts are too prominent so it had to be the scale hardware. As per the kit design the radius arm can slide freely up and down the expansion link.
The expansion link journals are more brass castings for soldering to the motion bracket.
So stage 1 is complete.
Next stage is the return crank so I'm off to drill plenty of holes in little bits of metal, hopefully after 5 or 6 attempts I'll get something looking reasonably square and presentable.
In the instructions it starts with the expansion link and radius arm so these are the bits.
All brass castings, two halves for the expansion link and cast radius arm. The top one showing my effort to get the valve gear the right colour, i.e. steel. The brass castings are far too yellow for me so I'm experimenting with tinning all the castings to give me that steel colour. I'll just have to be very careful soldering the joints!!
Anyway as good as the kit is it's always useful to check the photo's. In this case there was a problem with the expansion link - something was missing (or not depending on your point of view). There's a couple of holes missing in the expansion link.
So a couple of holes were drilled in the appropriate place and then pinned together with scale hardware bolts. The instructions say to use nickel-silver wire, but the bolts are too prominent so it had to be the scale hardware. As per the kit design the radius arm can slide freely up and down the expansion link.
The expansion link journals are more brass castings for soldering to the motion bracket.
So stage 1 is complete.
Next stage is the return crank so I'm off to drill plenty of holes in little bits of metal, hopefully after 5 or 6 attempts I'll get something looking reasonably square and presentable.
adrian
Flying Squad
I was quoting from memory - the instructions actually say "Assemble the outstanding fittings to the body and tanks. The assembly for the most part is self explanatory, those of note are explained below. Consult the prototype photographs of the prototype for guidance in relation to pipe runs and positions etc."Ah yes, i do like it when they say that
Although the castings are of exceptional quality I think this is referring to having some left at the end rather than their standard. The only slight wrinkle being that there are some castings included for slightly different versions. So I just know at the end I'm going to have a small pile of casting trying to decide whether these are the outstanding castings I've missed putting on somewhere.
adrian
Flying Squad
Well I seem to be working 3 or 4 weeks behind Richard in build this valve-gear, which allows me to plagiarize all the good ideas!
Just been having a go at the return crank. The MOK 4MT kit supplies a casting for the LNER style clamp return crank.
As mentioned many times before the "Standards" were anything but standard. The loco I'd chosen to model has the LMS style 4-bolt fixing return crank so picking up the lead from Richard this is my effort. Tweaked slightly because as always I seem to do things in my own inimitable way.
This shows the building blocks for my return crank.
The first thing to note is the blackened steel bar at the bottom of the photo, this is my drilling jig. I don't know how Richard built his but there was no way I could drill 4 sets of holes in 4 components and get them looking anything like the same. Also I'm lazy and the thought of marking out 4 sets of holes wasn't my idea of fun. So I got a small strip of steel bar, marked out and drilled the 4 bolt holes, the centre hole and the hole for the eccentric rod joint. This was actually the third attempt at getting something like symmetric. The blackening is not "chemically induced"* but as a result of hardening and tempering the steel - hopefully I'll be able to use it again.
The return crank is then a bit of 38thou nickel silver to which I clamped the drilling jig and drilled the holes. On the 4MT the 4 bolt holes are very close together and quite hefty so I've used the 1mm bolts from scalehardware, #SNH-10. Also with the bolts being close together it was going to be a challenge to fit the bush in the centre so I opted for making the bush the other way, this is flat on the return crank but provides the bushing for the con-rod, which I reamed out at 1/8". On a 12BA thread the return crank seemed a little thin to be robust so by turning it around I can get a good length on the 12BA thread. The centre hole on the return crank is then drilled and tapped 12BA so that I could hold the two together with a steel bolt whilst soldering the two together.
I then soldered in the scale hardware bolts.
Followed by a 10thou overlay to give that slightly sunken look to the bolts. Unfortunately a couple of the holes ended up with a bit of solder flooding in so they are not quite as crisp as Richards version. I'll have to work out a better way of soldering on the overlay.
Now got one more to make, with a bit of luck it may end up looking similar to this one!
*with a nod to Steve Earle!
Just been having a go at the return crank. The MOK 4MT kit supplies a casting for the LNER style clamp return crank.
As mentioned many times before the "Standards" were anything but standard. The loco I'd chosen to model has the LMS style 4-bolt fixing return crank so picking up the lead from Richard this is my effort. Tweaked slightly because as always I seem to do things in my own inimitable way.
This shows the building blocks for my return crank.
The first thing to note is the blackened steel bar at the bottom of the photo, this is my drilling jig. I don't know how Richard built his but there was no way I could drill 4 sets of holes in 4 components and get them looking anything like the same. Also I'm lazy and the thought of marking out 4 sets of holes wasn't my idea of fun. So I got a small strip of steel bar, marked out and drilled the 4 bolt holes, the centre hole and the hole for the eccentric rod joint. This was actually the third attempt at getting something like symmetric. The blackening is not "chemically induced"* but as a result of hardening and tempering the steel - hopefully I'll be able to use it again.
The return crank is then a bit of 38thou nickel silver to which I clamped the drilling jig and drilled the holes. On the 4MT the 4 bolt holes are very close together and quite hefty so I've used the 1mm bolts from scalehardware, #SNH-10. Also with the bolts being close together it was going to be a challenge to fit the bush in the centre so I opted for making the bush the other way, this is flat on the return crank but provides the bushing for the con-rod, which I reamed out at 1/8". On a 12BA thread the return crank seemed a little thin to be robust so by turning it around I can get a good length on the 12BA thread. The centre hole on the return crank is then drilled and tapped 12BA so that I could hold the two together with a steel bolt whilst soldering the two together.
I then soldered in the scale hardware bolts.
Followed by a 10thou overlay to give that slightly sunken look to the bolts. Unfortunately a couple of the holes ended up with a bit of solder flooding in so they are not quite as crisp as Richards version. I'll have to work out a better way of soldering on the overlay.
Now got one more to make, with a bit of luck it may end up looking similar to this one!
*with a nod to Steve Earle!
Dikitriki
Flying Squad
I like that. The reversed bearing strikes me as easier than my solution, and the drilling jig is a good idea. I was sort of making it up as I went along, not even sure whether I could do what I wanted, whereas you have thought it through further.
Soldering the overlay on: I principally soldered (145 deg) at the eccentric rod end, and just smeared a little round the outside of the rest in the hope I wouldn't flood it.
Regards
Richard
Soldering the overlay on: I principally soldered (145 deg) at the eccentric rod end, and just smeared a little round the outside of the rest in the hope I wouldn't flood it.
Regards
Richard
adrian
Flying Squad
Cheers for that - I'm happier with the second attempt. I drilled slightly larger holes (N0. 53) in the thin overlay which seems to give a better look and less prone to flooding with solder.
So now I had a couple of return cranks more or less the same the next stage in the instructions covered the eccentric rod. In the kit there is a cast pin which is intended to fit through the eccentric rod and solder to the return crank. Naturally I had to tweak it! Instead I turned a small top hat bush and tapped it 12BA. The rear of the return crank was lightly countersunk.
The top hat bush then providing the bearing for the eccentric rod. So the current state of play is this, the rods need finishing off and straightening up!
Unfortunately it's School half term this week so I'm unlikely to be able to make any more progress this week.
So now I had a couple of return cranks more or less the same the next stage in the instructions covered the eccentric rod. In the kit there is a cast pin which is intended to fit through the eccentric rod and solder to the return crank. Naturally I had to tweak it! Instead I turned a small top hat bush and tapped it 12BA. The rear of the return crank was lightly countersunk.
The top hat bush then providing the bearing for the eccentric rod. So the current state of play is this, the rods need finishing off and straightening up!
Unfortunately it's School half term this week so I'm unlikely to be able to make any more progress this week.
adrian
Flying Squad
Well this is a bit of an experiment to be honest. The brass castings are simply tinned with solder to give the steel appearance. If I was scratch building then I'd use steel to get the right colour.
mickoo
Western Thunderer
adrian
Flying Squad
Well I'm plodding slowly along. With building the return crank I was really struggling to focus on the fine detail, so my achievement for 2012 is finally acknowledging that I need glasses. So after a small delay for the eye test and a few pounds lighter in the wallet I can finally see what I'm building!
So continuing with the motion, next up was connecting the rotating arm with the expansion link. Now the instructions say to use nickel silver rod as pins and solder in place. However I like to be able to dismantle the motion and on the prototype all of the "pinned" joints have a steel collar around the pin. So I got a small piece of nickel silver bar, turned the diameter down a little and drilled No.66 for tapping 14BA. The pivot in the end of the rotating arm was slightly too big for 14BA so it was drilled out slightly and bushed. The weigh shaft arm was given a similar treatment, this has a small cast bearing block to fit to the radius rod. 14BA cheesehead steel bolts providing the fixings.
Next I moved onto the slidebars and crossheads, again another nice set of brass castings. The slidebars are pinned to the rear cylinder cover.
The end of the crossheads are drilled out and a short length of steel bar is soldered in.
Fixing of the conn rods to the crosshead is a nice design. The ends of the conn rods are bushed and slot into the crosshead. A 12BA bolt is used to fix the two together, although the nut needs a little filing and the bolt trimming in this photo. However the rear of the cross head is drilled larger than the screw head so the bolt fixes the bush in place and is virtually flush with the back of the crosshead. The only down side being that the supplied bush was about 5 thou under 1/8", rather than mess about I reamed the conn rod 1/8" and turned up some new bushes to be a good fit.
Finally for tonight's installment I soldered the drop link to the crosshead and fitted the union link. Once again the union link has a small collar soldered on and tapped 14BA so the two are bolted together with a 14BA steel cheesehead bolt.
So continuing with the motion, next up was connecting the rotating arm with the expansion link. Now the instructions say to use nickel silver rod as pins and solder in place. However I like to be able to dismantle the motion and on the prototype all of the "pinned" joints have a steel collar around the pin. So I got a small piece of nickel silver bar, turned the diameter down a little and drilled No.66 for tapping 14BA. The pivot in the end of the rotating arm was slightly too big for 14BA so it was drilled out slightly and bushed. The weigh shaft arm was given a similar treatment, this has a small cast bearing block to fit to the radius rod. 14BA cheesehead steel bolts providing the fixings.
Next I moved onto the slidebars and crossheads, again another nice set of brass castings. The slidebars are pinned to the rear cylinder cover.
The end of the crossheads are drilled out and a short length of steel bar is soldered in.
Fixing of the conn rods to the crosshead is a nice design. The ends of the conn rods are bushed and slot into the crosshead. A 12BA bolt is used to fix the two together, although the nut needs a little filing and the bolt trimming in this photo. However the rear of the cross head is drilled larger than the screw head so the bolt fixes the bush in place and is virtually flush with the back of the crosshead. The only down side being that the supplied bush was about 5 thou under 1/8", rather than mess about I reamed the conn rod 1/8" and turned up some new bushes to be a good fit.
Finally for tonight's installment I soldered the drop link to the crosshead and fitted the union link. Once again the union link has a small collar soldered on and tapped 14BA so the two are bolted together with a 14BA steel cheesehead bolt.
adrian
Flying Squad
I've been lucky to grab a few more hours today at the workbench to I made a concerted effort to get the motion finished.
First up was the return crank / radius rod bearing. Once the brass bearing cover was fitted then it was going to be difficult to tighten the 12BA screw into the top hat bush. So I had to make a small modification, I decided to drill a small hole in the rear of the radius rod near the bearing and put a small notch in the top hat bearing. So once the brass bearing cover is fitted then I can push in a small bit of wire to hold the top hat bush whilst I tighten up the 12BA screw.
I then continued fitting the rest of the motion, the valve spindle was pinned and the the slide bars pinned and soldered to the motion bracket, so the final result is.
So next job is to see what I can make of the coupling rods. The etchings supplied are for fluted rods but my chosen loco has solid rods so I need to see if I can swap them around to build the solid version.
First up was the return crank / radius rod bearing. Once the brass bearing cover was fitted then it was going to be difficult to tighten the 12BA screw into the top hat bush. So I had to make a small modification, I decided to drill a small hole in the rear of the radius rod near the bearing and put a small notch in the top hat bearing. So once the brass bearing cover is fitted then I can push in a small bit of wire to hold the top hat bush whilst I tighten up the 12BA screw.
I then continued fitting the rest of the motion, the valve spindle was pinned and the the slide bars pinned and soldered to the motion bracket, so the final result is.
So next job is to see what I can make of the coupling rods. The etchings supplied are for fluted rods but my chosen loco has solid rods so I need to see if I can swap them around to build the solid version.
adrian
Flying Squad
Blimey 3 posts in less than a week! It can't last as I'm back to work on Wednesday and the inclement weather has helped.
So the next task was the coupling rods. As supplied they are built up from 3 layers of lamination. Two laminations stay attached for folding and then the third is overlaid. One of the laminations has the fluting half etched into it, so by folding the wrong way I was able to hide the fluting inside the laminations and produce the solid rods required.
However when placed against the conn rods the crankpin bosses looked a little bit weedy in comparison. Fortunately thanks to the excellent service from a well known bookshop I had a copy of Geoff Holt's loco building guide and one of his tips for etched rods was to solder on another layer of lamination. There was plenty of spare nickel on the sheet from the coupling rods, so a few blanks were roughly hacked out with a piercing saw. Not too fussed about getting the shape perfect as once they were soldered on I could simply file them back to the shape of the etched rods.
A little bit of filing later and the results were an improvement.
So even more cutting and more filing I finally have a set of coupling rods.
Next job is to sort out the crank pins, the leading driver will need some form of recessed captive nut. I've a couple of ideas to try but for the moment it's probably just going to be a countersunk screw as a temporary measure.
So the next task was the coupling rods. As supplied they are built up from 3 layers of lamination. Two laminations stay attached for folding and then the third is overlaid. One of the laminations has the fluting half etched into it, so by folding the wrong way I was able to hide the fluting inside the laminations and produce the solid rods required.
However when placed against the conn rods the crankpin bosses looked a little bit weedy in comparison. Fortunately thanks to the excellent service from a well known bookshop I had a copy of Geoff Holt's loco building guide and one of his tips for etched rods was to solder on another layer of lamination. There was plenty of spare nickel on the sheet from the coupling rods, so a few blanks were roughly hacked out with a piercing saw. Not too fussed about getting the shape perfect as once they were soldered on I could simply file them back to the shape of the etched rods.
A little bit of filing later and the results were an improvement.
So even more cutting and more filing I finally have a set of coupling rods.
Next job is to sort out the crank pins, the leading driver will need some form of recessed captive nut. I've a couple of ideas to try but for the moment it's probably just going to be a countersunk screw as a temporary measure.
Dog Star
Western Thunderer
Adrian, much as I try, I do not understand what was the problem... and what was the solution. If possible, can you please add some detail to those points.
regards, Graham
adrian
Flying Squad
Thanks for that idea - I'll probably use that as stage 1, but having just finished reading Geoff Holt's book it's given me an idea for a cunning plan which might be stage 2. Some parts are on order so I'll post an update if I get anywhere with it.
Whilst you're in the loop it's reminded me to ask about the working reversing gear. I'm thinking that I've gone to all this trouble to build the motion and it all moves from full forward to full reverse, it seems a shame to have to fix it in a fixed position. As you've been down this path do you have any suggestions on mounting servo's in the frames, how did you link the servo to the reversing gear? I'm a DCC novice so do I need to build any adjustment into the linkage or can that be programmed into the chip?
The problem was that the top hat bearing was totally enclosed once the brass cover was soldered in position. It'll probably be easier to explain with a drawing and a couple of photo's so I'll post another update later today once I've produced the necessary diagrams.
Regards
Adrian