Beam Engine Crankshaft

Having finished the crank, the obvious next step is the crankshaft. This will link the flywheel to one end of the beam and introduce the first interesting motion to the project. It is also the start of the wee small bits, at least according to my experience. Learning experiences were anticipated.

First I tackled the end that goes on a pin sticking out of the crank. I again used the method of milling the piece out of a larger bit of stock with the extra used to hold on to. In a flash of enlightenment, I realized I could up the game a bit by using my small toolmaker’s vise to hold the stock. I could then rotate the part 90 degrees without unclamping the stock.

The major work was done with the vise clamped to the rotary table. The fun bit was getting the appropriate spot centered on the table. I did this by center punching the spot, deploying my fancy new coaxial indicator which came with a tip for just such a purpose and gently tapping the vise around until it was centered. I then clamped it down and rechecked to make sure I didn’t shift it. Surprisingly, I also managed to get the thing square in the x-y plane to within 30 arc minutes. (I needed to know where to start and stop the rotation of the table to be planar with the straight sides of the piece.)

After I got the main body of the piece shaped and drilled, I needed to drill a hole in the flat end for the shaft. This was easily done by clamping the vise on its side in the mill vise. I found the edges by using a drill blank because there wasn’t room to get my center finder in there next to the vise jaws. I know that things are at right angles because the toolmakers vise has precision ground sides for just this sort of thing. I may have committed a sin by clamping on the jaws of the vise, though.

The last operation was just reclamping the piece wide side up and skimming off the back side. This was easy in this case because there are two parallel sides unlike the crank.

Next, I made up the crank shaft itself which was a simple matter of threading one end of a 3/32″ brass rod and cutting it to length. For the exercise, I used the lathe to square and shorted to final length the cut end. Here is the piece to date. I still need to do the other end which has a fork to go around the beam. I added my machinist scale to the photo for a size comparison.

DROp Dead Gorgeous

A fine old machine and her new cybernetic enhancement! After much (years) consideration, I decided to invest in a digital readout (DRO) for my Myford ML7 lathe. The DRO experience I have gained on my milling machine convinced me that increase in accuracy and precision would be worth it. (A DRO measures actual positions unaffected by backlash in the screws)

Next came a version of the build vs buy dilemma. Go with the UK vendor that sells machine specific kits for the ML7 or cobble together my own from components sourced on the internet. This sort of design challenge in an area where I am decidedly inexpert can cause me to decent into analysis paralysis for a long time. Maybe forever. Thus, I eventually decided to substitute money for stomach lining and invest in the machine specific kit from Machine DRO.

Upfront, I will say that I estimate that the kit cost roughly twice as much as buying individual components off the net would have. Given my historical propensity for underestimating things, the actual savings would be less than that when the job was finally complete. If, I should say. With the proven design and excellently written and illustrated instructions from M-DRO, I have a working installation 4 calendar days after the package arrived.

The kit is mostly bolt together using the included hardware including 1/4″ BSF hex studs that bolt into the existing taper attachment mounting holes on the back of the lathe bed. I challenge anyone to find those on this side of the Atlantic! The one notable exception and one that is optional but preferred, is installing the magnetic tape on the cross slide. This requires drilling and tapping two holes for mounting an extension block on the back of the slide and milling a 1.8mm slot in the bottom of the slide. My very first experience in working with cast iron!

I discovered that my milling machine had about of 1/4″ of room left when I set up to drill those holes.

The cross slide is way too big to hold in my milling vise so I had to clamp it directly to the milling table. This is another first and the also the first time I really used the clamping set that everybody buys when they get a mill.

The green painters tape is intended to keep debris off of the important sliding surfaces of the slide. Cast iron doesn’t produce chips but rather grey dust that is very abrasive. I ended up following along the milling passes holding my shop vac nozzle right up by the cutter. Who knew you needed dust collection for metal working?

All when according to plan and I have got the display mounted, at least temporarily on the backsplash. I am not entirely please with this but it will do for now. The backsplash is not as solid as it should be for this sort of purpose and I plan to eventually mount the display on the supplied mounting arm but I need to execute my under lathe cabinet plan first.

Final cleanup remaining is cable management and grounding the display. The read heads come with what I presume are standard length armoured cables that clearly would work for going all the way from one corner of a full sized mill or enormous industrial engine lathe. The kit came with copious hardware for this purpose which is much appreciated.

I am looking forward to learning how to use this thing and see what it can do to improve my results.

Metrology Monday: Height Gauge

The first measuring tool I want to cover is the one depicted in my teaser photo, the height gauge. I expect that things will get a bit more consistently structured as I progress in this series but I aim to cover what the tool is for, features and what the options are and any alternatives.

What Is A Height Gauge For?

This may surprise everyone but the basic use of a height gauge is used to measure height. More specifically, the height of a point above the surface the gauge is sitting on, ideally a flat surface. (Next week, surface plates!) The gauge has some sort of linear scale and a probe. You move the probe to the point to be measured and take a reading. This is also probably the least useful use of a height gauge.

The pointy probe is called a scriber and, again those machinists with their tricky obscure names, can be used for scribing a line at a specific height. This seems to me to the most useful function. My gauge’s scriber has a sharp silicon carbide tip so I imagine it can put a scratch in any material I am planning to work with. I have visions of getting all the handrails at the same height or marking cut lines for kit bashing.

The third use of a height gauge is as a stand for a dial test indicator to use for checking the parallelism of a surface with the surface the gauge is sitting on or the flatness of that surface. This is more of a machinist thing where you are attempting to judge how reliably parallel machined surfaces are as reference points. I suppose you could check wheelsets for concentricity.

Lastly, the dial test indicator/gauge combination can be used to check multiple parts for conformance to a specific height. You set it up to a standard and then pass multiple instances of a part under the indicator probe to see how far out they are from the standard.

Options

My height gauge is a Mitutoyo 18″ Vernier Height Gauge. It is graduated in both imperial and metric and reads down to .001″ and .01mm respectively. It is a good quality model but way taller than I am likely to need but was available used for an excellent price. If I was buying one new, I would get a 12″ or even a 6″ one. I don’t inticipate the need to mark a lot of truncation lines on O scale rolling stock.

Like almost any took, height gauges are available in a range of qualities from plastic maybe junk up to ludicrously accurate and breathtakingly expensive models. In fact, machinists usually talk about toolroom versus inspection grades in terms of metrology tools. Inspection grade is for when they start talking millionths of an inch and not what I need.

In addition to Vernier models, you can buy gauges in dial and digital models with escalating price levels for each type. Digital models are handy in that you can zero the display at any point. My model can be zeroed only at base surface level or thereabouts.

Alternatives

The common economical alternative to a height gauge is a surface gauge. It is more or less the scriber on a stand without the measuring capability. Presumably you can also hang an indicator off of it as well. You can buy surface gauges but shop made ones are a common beginner project.

Next week I plan to cover the surface you set you gauge on.

Woodwork Complete

Yesterday, I finished assembling the frames for the backdrop and light bar for Comstock Road. Other than whatever accessory mounting work might come along, that concludes all the actual cutting of wood with only the gluing of hardboard panels and installing mounting hardware left to make things actually useful.IMG_20200523_135222617

I came up with a better temporary assembly jig by putting the framing square on the outside. This allows me to just bang both pieces into the corner and clamp; much more efficient than having to separately align the ends with the square on the inside.

Hopefully, I can get the panels glued on over the next day or so and start getting things mounted. If all goes according to plan, Comstock Road should look dramatically more complete in just a short time. Of course, some actual scenery wouldn’t go amiss, either…

Modelling in the Time of Covid-19

Like much of the world, Ontario, Canada has gone all-in on social distancing as a mitigation to the spread of the Covid-19 virus. My household has been avoiding non-essential interactions as one should. Humourous declarations aside, socializing with other model railroaders is non-essential which is not the same as un-missed. Humans are a social species and, despite some opinions, that includes modellers.

As an experiment in a face-to-face get together at the pub, I invited a few model railroad friends to join me last night for a video based meeting “at the bench”. Five us got together using the Zoom conferencing app to spend part of our evening chatting about the usual things, current projects, tools and tips, our choice of beverage, and the like. Bernard Hellen even worked in a video tour of his Quebec Gatineau layout.

I consider the night a great success especially when my goals were on the order of let’s give it a go. The Zoom app worked well for us but there are numerous other video and/or audio meeting options out there. What we lacked in pub atmosphere we gained in lack of travel time and proximity to our actual hobby sites.

I encourage others to consider setting up their own virtual meets. Even in the eventual absence of a pandemic lock-down, it looks to be a nice way to increase one’s social participation in the hobby or whatever shared interests you care to hang the even on.

Book Nook Mockup

It appears that I have some time on my hands in the next few weeks so I intend have a go at my proposed railway themed shelf insert. I cut the pieces for a 8.5x11x6″ wide box from 1/4″ plywood on my new table saw(more on that later). In my enthusiasm, I glued one side to the back before I realized that one would generally find it easier to build up the scene before enclosing it inside a box…

So, last night I took some salvaged foamcore and mocked up an alley. The black colour makes the jog in to the right hard to pick out but, like a bare plywood baseboard, I can see the intended result in my head. The major point was to check lines of sight which were satisfactory.

Next step is permanently glueing the foamcore together (currently held with straight pins) and attaching each section to the appropriate wall. I haven’t committed to scale and gauge yet but, as the bit of N scale flex indicates, On18 is a possibility. This would put me in the neighbourhood of the Guinness brewery railway’s 22″.

IMG_20200316_212316908

Turnout Control Progress

I have mentioned previously that getting hand laid points connected up and suitably under control has been a stumbling block in past efforts. The achievable scope of Comstock Road (4 or 5 turnouts total) makes the mental size of the task easier to contemplate. I have begun the new year as I mean to go on, by tackling the mentally hard things and have made further progress.

First up is the connecting rod from switch stand location to throw bar. Increasingly prototypical possibilities have occupied my imagination but when I found myself contemplating scratchbuilding scale clevis’, I realized that I was making things harder than they should be, certainly for a first attempt. I resolved to make something out of the piano wire on hand.

I needed an eye or loop in the wire to connect to the vertical shaft comping up from beneath the layout. (I am going for a rotational motion like a switch stand rather than the model railroady back and forth in a big hole. I fashioned a simple jig consisting of a piece of scrap plywood with a nail driven in and cut off, and adjacent to a piano wire sized hole. A right angle bend near the end of the wire goes into the hole and the wire is wrapped around the nail to form the eye. I got the idea for this jig from the Animated Scale Models Handbook.

Here is the jig.bentwirejig

And here is the result trimmed up.eyeinwire

I have got the vertical brass tube and wire combo installed and connected to the throwbar. (We pause while I dash downstairs to take a photo of the installation which I apparently forgot to do. Lack of photos is usually a good sign since it indicates that I have got a head of steam up.) Here is a shot of the connecting rod installation. Bending the crank in the end of the vertical wire was a challenge and I will consider better alternatives such as soldering on a separate piece of brass bar. It does work and will be concealed by the switch stand. The other reason for a separate bar would be to allow the vertical wire to continue up through the stand so the target can rotate.connectingrod.jpg

Finally, we get to installing the servo, Tam Valley Octopus servo driver and associated electrical bits. I have got as far as fashioning a bracket for the servo using a section of 1/2″ aluminum channel from the big box store. I picked this idea up somewhere in the model railway reaches of the internet and it works a treat. The servo is just a friction fit in the channel after a slight pinch with a pair of pliers.bracketmk1

Micromark Spiking Pliers

After a very stressful couple of weeks, it was good to get home and do a bit of work on the layout. I finished correcting the various gauge tightness issues on the high track turnout (rail braces can only push in, not pull out so you had better start wide) and have got the guard rails and rail braces installed. I will still need to fit the gauge plates and throw rods but the test car runs through each leg if I spike the points over. I am pleased that I have got things all working without messing up the flowing lines in the original Templot template.hightrackturnout

In doing this bit of trackwork, I have been trying out another one of my purchases from the GTA Train Show: a pair of Micromark spike insertion pliers. I had been meaning to get a pair whenever but a vendor at the show had a large array of Micromark items available including the pliers so I jumped at the chance to get them right now.

The plier are similar in feel to rail nippers but have flat jaws with a T-shaped groove in the ends to hold a spike. My dodgy photo show the T but the Micromark site has a much better version.

spikingpliers

These pliers are kind of pricey and I was not certain they would work with the Proto87 Stores etched spikes but it turns out they do! The fit isn’t tight but it works well enough and considerably better than the ol’ needle nose.

I estimate that using these pliers doubles the speed at which I can get a spike in while also reducing the number of bent spike failures. Bent spikes are an expense in modeler composure if nothing else. 10 seconds vs about 20 doesn’t sound like a big deal and in the single case it isn’t. If I calculate the total savings in time then the purchase is a no brainer.

roughly 36 feet of track x 22 ties per foot x 4 spikes per tie x 10 seconds = 3160 seconds ~ 9 hours

~$30 / 9 hours is 3.33 / hour.  Anyone’s time is definitely worth more than that. The reduced aggravation from more precise spike placement and fewer (almost none) bent spikes also significantly increases my enjoyment of track laying. Another on my list of should have done it a long time ago things.

First Turnout Done-ish

I have been remiss in posting but I am pleased to report that some of that time away was spent actually working on Comstock Road which is the primary point of this exercise. I have got all the rails and most of the details installed or at least fitted and awaiting installation on the first turnout. I also got about a foot and a half of the diverging route laid beyond the frog. Therapeutic pushing of the test car back and forth now includes the sweet sound of metal wheels running through the frog.

I still need to install the gauge plates and throw bar but I did get as far as getting them cut to the correct length. These cast brass Right O Way parts need to be cut to length, at least for Proto:48 gauge. I made a start on a jig for sizing these so I can repeat without having to measure each installation. It is the minimalist approach of some lines on a block of wood. I do the actual cutting with my bench pin and saw frame. I am pleased to have gotten enough practice with these tools that they now feel like the easy solution not merely the necessary one.

Here is an overall shot of the turnout. I think I will need multiple closeups for a useful tour of the detail parts I used.oneanddoneish.jpg

Gaposis

My first attempt at cutting a rail gap on Comstock Road with a motor tool cutting disk did not produce satisfactory results. Maybe I am just picky but this looks terrible.

mindthegap

Not the effect I am going for with the baseboard joints. To remedy this, I unsoldered the left side, filed the ends square and resoldered the rail closer. This looks like it will do.

bettergap

I will have to figure out what to do in general. I can’t use my jeweller’s saw since I can’t get the blade down horizontally that close to a surface and the underside at the joints is encumbered with support structure so no drilling a hole and slipping the blade through.

Best option I have so far is to butt separate pieces up at the joints. It makes alignment a bit of an issue but it is more or less how I do it for regular joints anyway. Joint bars are applied afterwards merely for cosmetic effect.

The sharp eyed viewer may notice that the plastic tie plate on the left has melted during the resoldering operation. Not entirely unexpected but I was relying on those spikes to maintain alignment. It will be scraped out and replaced. It also serves as a caution about in which order soldering and tie plate installation need to happen.