Buffalo WorkBench

by buffalo

original page on Old RMweb

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This is the third page of the Buffalo build copied from the old RMweb. I have removed the sections on my 14XX/48XX and these will appear in a separate entry.

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??? posted on Wed Jul 08, 2009 7:32 pm

Thanks for the comments I, too, had wondered about the lifting rings, Nick. Since you raised the question I went back to the photos and drawings in Russell, and it turns out that one of Stephen's suggestions is correct. There is a third lifting ring at the rear centre. It's obscured by the safety valve lever in a couple of the photos, but the drawing by J. N. Maskelyne (fig 233) shows it clearly. Once you know where to look it may be just visible, with the eye of faith, in a couple of the photos.

Nick, did you make your own rings for the 1854s? It looks like I'll have to make at least one for the Buffalo, but I'm not entirely convinced about replacing the front ones as they are one of the better parts of the tank moulding on the Gibson kit.

Nick

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Comment posted by Bertiedog on Wed Jul 08, 2009 8:02 pm

I don't think they had lifting rings on my next project, B&E no 71 Saddletank on Broad Gauge!!!..darn good steps though....

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(Picture in Public Domain due to age)

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Comment posted by yachtie on Wed Jul 08, 2009 8:04 pm

Yes, Nick! I made the rings by winding brass rod around a small soldering iron bit (cold!), snipping off a series of rings then soldering the join. SEFinecast/Wills provided split pins in their kits to use as handrail knobs and I had masses of those in the 'spares' box, so I used them to hold the rings. I cut a small square of brass for the base, drilled a hole and Robert's your Uncle!!.

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Now I've seen the photo, it might just be a bit overscale but looks OK on the model!! I rushed them (8 hours with other bits and pieces too!) for two locos and measured by 'eye'! Won't be doing that again!!

Nick

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??? posted on Wed Jul 08, 2009 8:17 pm

The photos in Russell don't help either! At least two are claimed to be as built at Wolverhampton and these have the two different types of ring alignment.

Nick

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??? posted on Wed Jul 08, 2009 8:21 pm

You've got a Taff Vale S class to finish first, Stephen, but I'll certainly be looking forward to seeing the B&E build

Nick

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Comment posted by Bertiedog on Fri Jul 10, 2009 6:08 pm

The BE project is an old one, the body is nearly finished, part finished chassis, but no wheels at the moment, as at the time, Mike Sharman did some.

My old broad gauge layout was lost in a move years ago, I only saved some track and buildings and the locos. The track, and wheels are to P4 principles, as per prototype. I will have to find out if there any 4mm broadgauge rail section suppliers these days, I had to have the rail especially drawn for the old layout, far to costly to be considered now. I may use flatbottom rail with the tie bars, as most broadgauge was deeply ballasted around the rail anyway.

I have not been well for a while, but back to the Taff vale soon.

Stephen.

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??? posted on Fri Jul 10, 2009 10:13 pm

Good to see you back in action tonight, Stephen, hopefully recovered from the flu?

Broad gauge has long been one of those things I'd like to tackle. Maybe one of the convertible Buffalos, though I do like the various 4-4-0Ts that ran on the B&E and SDR.

Nick

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??? posted on Fri Jul 10, 2009 10:46 pm

Not a great deal of progress on the Buffalo since Monday as I've been concentrating on odd details when I've found time for modelling. Buffer bodies have been soldered to the beams. I quite like the Gibson sprung buffers as the end cap inserted into the rear of the body gives a positive location in the buffer beam hole. The holes needed opening out much larger than they had been etched, a straightforward job with a suitable sized broach.

The short handrails and tank filler have been added, as have the handrails on the bunker sides. At this point, the discussion of lifting rings cropped up. So, encouraged by Nick's example, I made one up by filing a piece of 1/16" H section brass into a T section, drilling a hole through the web and filing to represent the curved shape of the bracket. A small ring of 0.4mm brass was inserted and the base was soldered on to the top rear of the tank. I now hope I can live with the moulded ones at the front...

Whilst studying Russell's picture of 1601, I noticed a few other details that will need adding. There are more short handrails high up at the rear of the tanks, but no matching steps on the sides. There is a safety valve lever passing at an angle into the cab (What do these look like inside the cab?). There is also a small pipe running up the cab front, apparently from the top of the tank, situated to the right of centre. I wonder if this is some form of tank vent? The Maskelyne drawing of 1564 and the photo of 1176 show something of similar size just behind the chimney. Then there is the sight glass valve lever on the outside of the cab, a common feature of GWR engines of the period.

So, a couple of photos of progress so far. As before, many of the parts are just resing in place. The dome and safety valve will need further polishing. As with the w-m castings, these look like the moulds are getting old as it took quite a bit of work to remove the lines caused by the mismatch between mould halves. The dome and water filler have a few tiny air holes in the castings, but nothing that a bit more polishing or a touch of filler won't fix. The chimney is borrowed from my Finney Dean Goods.

As you can see, I've also made a start on the chassis with a couple of High Level hornblocks fitted. Unfortunately, I only have four, so will have to wait for more to arrive before I can finish this part.

The second photo shows that there is some air under the boiler, although it won't be so obvious once the frames are in place. Nevertheless, I am beginning to wonder whether some representation of the inside motion might be required.

Nick

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Comment posted by Brinkly on Sun Jul 12, 2009 8:25 pm

Rather nice kit Nick, I do like the older GWR locos the Buffalo being one of them. They don't make them like they used to!

Keep us posted.

Nick

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??? posted on Sun Jul 12, 2009 11:13 pm

Little modelling over the weekend as I've mostly been using the good weather to catch up on some external domestic work, guttering, soil stack, etc. A break from the Buffalo was probably a good thing, though, as Saturday began with the first cock-ups of this build. I began by adding the extra handrails just below the safety valves at the back of the tanks. My first mistake was drilling a hole for a handrail knob in the wrong place However, this was easily fixed and the hole was plugged with solder when I put the knob in the correct place. Hopefully, the error won't be visible, but you know what photos can be like...

With the handrails attached and the smokebox/tank front soldered in place, I turned my attention to the chassis. I'm still waiting for some extra High Level hornblocks to arrive, but I thought I'd be able to get the middle pair aligned. The rear ones had already been fixed last week. So, the first task was to drill out the crank pin holes in the rods. Each pair of rods were drilled together using pairs of drill bits sunk into a block of wood to ensure that the distances between holes on each side matched. The holes in the front pair of rods went fine but, with the rear pair, a slight snagging of the drill bit tore the thin part representing the articulation joint away from the rest of the rod

Careful inspection of the surviving and damaged part showed that the break occurred at an obvious weak spot. The rods are the typical two style components seen in a number of kits, especially for GWR engines. One side gives plain rods, the other fluted. The plane faces are half-etched to make the bosses stand out as a little thicker than the rest of the rod. The break was at the end of this half-etched section and there is a very short (c. 0.6mm) area where the thin material is not supported by the laminated backing. I know it was my fault but, at least, I can explain what happened -- that's my excuse, anyway

Whilst thinking about repair options (it's not just a matter of adding a thin backing/strengthening piece), i went back to studying the photos in Russell. I had assumed that the plain type would be appropriate for most saddle tanks and the fluted might make an appearance on the pannier conversions. However, it turns out that the plain type with raised bosses only appears on some of the panniers, and usually at a late date. On all other Buffalos, both saddle and pannier, there is an earlier type of rod without raised bosses and with what Russell calls a 'marine type bearing' on the centre crankpin. This centre boss has a characteristically much more rectangular shape and one half of the bearing is held in place by a wedge or cotter pin. A real late-Victorian feature, and now that I've spotted it, I can't really build 1601 without it. So, there's the answer to my broken rod problem, I'll just have to make my own...

Have I bitten off more than I can chew? Watch this space,

Nick

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??? posted on Mon Jul 13, 2009 11:11 pm

Brief update:

Tonight I made a start on my replacement 'old-style' rods. Starting with a sheet of 10 thou (0.25mm) nickel silver and an offcut of the 18 thou (0.46mm) used in the kit etches, I made up a sandwich of two outer layers of 10 thou on the outside and one of 18 thou on the inside. The idea is that the outer layers will overlap the inner at the articulation joint. I've drawn up a sketch with all the main dimensions, based on a side-on shot of 1282 with pannier tanks but the older rods (fig 247 in Russell). Next comes the drilling and rough shape milling, but I'll need daylight to do that as the garage lighting and my eyesight are not up to it after dark

Today's good news:

Colin has sent me a new chimney It is, in fact, the one listed as 4M730 and is intended to represent a 633 or 517 chimney. Apparently, there never was a correct Buffalo chimney and the tapered one was always supplied with this kit.. The new one is quite a good match for the taller parallel chimney shown in the picture of 1601 (fig 230) and the drawing in fig 229. The only minor issue is that the casting is intended to fit on the smaller radius smokebox of the 633 and 517, so it will need a little adjustment to fit the larger radius of the saddle tank. Hopefully, this shouldn't be too difficult. Colin also included the missing part from the kit -- a 2mm pin-point axle, intended to be used to form the rivets. A bit late for that, but I'm sure I'll find a use for it one day, though maybe not as a rivetting tool So, many thanks to Colin for his continuing support

Nick

edit: fixed metric/imperial conversion

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Comment posted by wagonman on Sat Jul 18, 2009 7:37 pm

It's available from the Broad Gauge Society, but only if you're a member... Probably worth the cost of subscription as there are lots of other goodies too.

Richard

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Comment posted by Knottyjohn on Sat Jul 18, 2009 9:29 pm

Hello Nick,

Just catching up on this, sorry about the mishap with the coupling rods, I can see how that looks to be a little bit of a weak spot. I've nearly done that myself! Can I pass on a tip that might be of use next time? I don't use a drill for opening out the holes in the coupling rods. I have a single taper reamer, with a piece of masking tape attached part way up, reinforced with a dab of epoxy to stop it sliding around. This way I know that if I open up the hole in the coupling rods gently to just this point, it will then be a nice close fit on the spigot on the hornblock alignment jigs, and in turn (hopefully!) just about the right amount of clearance on the crank pin bush.

I accept in theory if you do it this way, you could end up with one set of rods very slightly longer than the other. But I don't think this should be a problem, and if in doubt you could mark one set of rods with a blob of paint to indicate left/right. Hope that's of some interest. John

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??? posted on Sat Jul 18, 2009 10:15 pm

Thanks for the tip, John. I don't know why I didn't use a reamer for this in the first place as I would normally do so for other similar jobs

Well, not much has happened in the last week other than several attempts to make the new rods. Two unsuccessful attempts were made before a third finally arrived at something like what I wanted to achieve. Here, I drilled all the holes in the laminated sheet before attempting any shaping. Once I was happy with the final shape, I used a reamer to open up the holes to fit the jig and the crankpin bushes.

Earlier, I mentioned my intention to use a triple laminate. This turned out to be a bit too thick and did not allow the central boss to stand out prominently from the rest of the rods as it does in some photos. The final version used a double laminate with the 0.46mm sheet at the front and the 0.25mm behind. The centre boss was then added as a third layer of the thinner sheet. This allowed what will, I hope, be a fairly strong articulation joint where one 0.46mm piece is sandwiched between to 0.25mm pieces, and hinged on a piece of 1mm nickel silver rod.

The result is shown below, complete with an attempt to represent the cotter pins and oil cups on the centre bush:

Now the chassis construction can start at last. Today, I have prepared the High Level hornblocks and tack soldered them to the frames using my homemade jig:

Finally, for today, another dry assembly showing the new chimney. I still need to adjust the radius at the base to get it to sit on the tanks but, to me, it looks the part. You may also just be able to make out the step treads added to the buffer casings. These still need cleaning up but I think they make a significant improvement to the plain buffers as supplied. The treads are small pieces, about 1.5mm square, of cross-hatched etched brass originally intended for cab fall plates.

Nick

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??? posted on Sun Jul 26, 2009 10:29 pm

Starting these posts with 'not much progress this week' seems to be becoming a habit Apart from some filling around the smokebox front to tank join very little visible progress has been made on the Buffalo. I think I mentioned earlier that I intended to make this my first attempt at a CSB chassis and, to that end, I've been estimating the final weight of the model (about 210 grams, I think), studying the relevant CLAG web pages (http://www.clag.org.uk/) and using their spreadsheet to decide on the layout of the spring supports. One side effect of this is that i will need to change my earlier intention to use a high Level Load Hauler Plus gearbox. Although it might be made to fit, I would prefer a little more room between my EM frames to experiment with the CSB, so I also need to decide which other High Level box to use.

Nick

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Comment posted by Bertiedog on Mon Jul 27, 2009 1:38 pm

Just read up on the CSB., (continuous springy beam) method of springing, and I would humbly like to ask, why re-invent the wheel?........ as the method is almost the same as Varney and Lindsay in the US adopted on the 6 and 8 coupled chassis they marketed on the Super Pacific in the late 1950's

The method is the same for layout, determination of the fulcrums, but the UK CSM CLAG group somehow seems to have missed a very vital point, that this style of springing is fully adjustable, requiring no pre-setting of the locos weight.

Any style of fulcrums can be used and any method of keeping the wire across the top of the axle boxes works fine. I use 11thou nickel plated steel guitar wire, which runs from fixed points behind the buffer beams, across each bearing, with "buttons".... small screws with an un-threaded area under the head....... as the fulcrums.

Most of the time I endeavour to have the fulcrum half way, unless the weight of the loco is very oddly distributed.

But now comes the vital part, and seemingly disregarded by CLAG, and that is what to do with the other end of the wire.

It is crimped or soldered to a small coil spring, which is attached to a nut on a bolt running through the drag bar or any handy place at the back of the chassis. It becomes an adjustable shackle.

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The loco is placed on the track and the bolts tightened till the loco rises up to the correct running level. Some un-balanced designs may require extra wires to bear on the outer bearings if the loco ends up not level, but this is rare, most designs will be level straight away. I add a lock nut to the shackle bolt, which is usually 10 BA.

You might need to experiment a touch with finding the right coil spring, one can be wound from the same or slightly thicker wire, or a small one about 15 turns about 1/2 inch long and 4mm dia usually does. It just needs two the same, but the adjustment will cover this as well.

Really heavy locos, say a fully cast kit, may need a larger diameter wire, say 15/20 thou, and a stronger coil and 8 BA shackle bolts.

I have a Varney Super pacific, with all the Kemtron extras, the Lindsay ball raced motor, and it is the smoothest loco possible, and runs on any junk 16.5 track!! It can handle the lot! bad joints, warped track, etc, and I have used the system on many chassis over the years.

It would fit the Buffalo, and be invisible, but would need a rear attachment beam for the shackles.

Stephen

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Comment posted by intelegence on Mon Jul 27, 2009 2:47 pm

I don't normally reply to postings on (electric powered) steam models, and I must confess that I missed the "Varney" era due to my extreme youth (But I do have an old used interurban model that was supplied to me in an adopted Varney box) .

Firstly, I don't believe the the CLAG team has laid any claim to being the original inventors of CSB's. Many of their comments on various lists have humbly referred to merely building on the work on others.

Secondly, I thought the CLAG preference was to leave BOTH ends and all fulcrum points of the wire loose. Then the wire stiffness, (acting as a springy beam), as well as it's free sliding through each fulcrum, would tend to equalize theamount of bending over each axle, and hence automatically optimally balance the vehicle. But I'll defer to any reply that comes from CLAG's experts on that matter.

But having replied to the assumptions posted, I would like to say that, as a past manufacturing industry professional, the thought of an "adjust on test" requirement on a design intended to be reproduced by others as simply as possible , seem to me to be a major retrograde step.

Andy Reichert

California

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Comment posted by Bertiedog on Mon Jul 27, 2009 3:15 pm

The spring wire is still loose over the axle boxes and is not attached in any way to them, or to the fulcrums, and the springing action is exactly the same as the un-sprung wire, and the extra adjustment is all that's added ironing out any need to pre-work out anything.

All the dimensions suggested by CLAG work, it is only the addition of the coil spring that helps set-up and fine tuning. Some US chassis builders used two springs, one on each end of the sprung wire, but it was found that one worked just as well. These nothing complex here, just a wire and spring.

Stephen.

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Comment posted by Bertiedog on Mon Jul 27, 2009 4:02 pm

I have not got a suitable chassis under way at the moment to show the modified CSB method, the Taff Vale is an 040 and has end restrained single spring wires, one per wheel, bearing on the fulcrum point on top of the bearings, unfortunately more difficult to set up.

The chassis is too short to fit the adjustable end springs. It could have a single wire as per CLAG, but as the wheel base and weigh is low a very thin wire would be needed, or a flat thin spring, along with being un-adjustable.

Stephen.

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Comment posted by intelegence on Mon Jul 27, 2009 4:06 pm

I beg to differ slightly on that functionality. As I understand it, the CLAG version does not fix the ends, and therefore the wire slips and bends between each pair of fulcrums until just the loose wire curvature tensions match the axle weights and equilibrium occurs.

An example of the increased effect of adding your two (fixed and sprung) ends is a slipping powered capstan. A power capstan works by an operator lightly pulling the loose end of the cable, hence slightly increasing the linear tension in the cable curved around the slipping drum, which in turn causes an increased inwards pressure towards the drum, and hence an increase in friction forces, which then allows the powered drum to yank the business end of the cable much harder.

In your case, the spring acts as the capstan operator's pull, and the force of the extended spring is added to the overall downward force on the hornblocks. Not likely to be a big effect I expect, but then the loco weight divided by the number of hornblocks isn't much either. And the dynamic curvature tension changes in the wire when the loco is traversing bumps is pretty minute also. Without videoing your end spring possible movement, while the loco is travelling over bumps, it's a difficult assessment to make. But the spring tension could be a significant part of the dynamic forces acting acting on the hornblocks at intermediate wheel heights and could possible completely change the suspension operating characteristics vs. the fully loose CSB's.

Andy

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Comment posted by Bertiedog on Mon Jul 27, 2009 4:20 pm

I did not say that CLAG originated it..........

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So.... all spring designs should work without adjustment, and each loco would need individual diameters to suit the weight? The only adjustment possible* on the beam is the diameter...unless other springs are added. Adding the coil spring eases matters all round.

*without adjusting the fulcrum points, and consequent spring length

I think that you may be over estimating the effect of the spring, it is the wire beam that takes the weight, not the coil spring, which is there to exert extra assistance to the springing. May I add I too have long experience in engineering and instrument design, and also have built large quantities of chassis with this springing, all worked. When I suggest a method, I know from practical experience that it works, and make the suggestion a simple as possible to aid newcomers.

Nice 14xx ........back to the Buffalo yet?

Stephen.

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