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Member postings for Bruce Voelkerding

Here is a list of all the postings Bruce Voelkerding has made in our forums. Click on a thread name to jump to the thread.

Thread: Bearings
28/12/2017 12:53:34

I was an engineer at Warner & Swasey, Cleveland, Ohio, in the 1980's as the change was made from oil-lubricated taper roller bearing Headstocks with selectable gear trains to grease lubricated Ball Bearings. This change came about due to the vastly improved Spindle drive motors coming onto the market. Many of the Lathes (8" to 12" Chuck) were sold with no Gearbox. Larger Lathes (16" to 24" Chuck) were sometimes fitted with a separate 2-speed Gearbox.

The Ball Bearings were typically sourced from FAG. We had a "clean room" in which the bearings would be packed with a German grease, Kluber if I remember correctly. The grease was weighed out for each bearing. It was stuffed in a large plastic syringe which had been previously weighed so the grease could be ejected till the final net weight was obtained. This remaining amount would be injected around the bearing. Typically we had 3 Ball Bearings and the head end and 2 at the tail end - all angular contact (15 to 20 degree).

One of the most important steps of the process was the running in of the Spindle. I seem to remember this run-in lasted 4 hours. Since these were all CNC machines, it was a matter of loading the run-in program, attaching a couple of thermocouples and hitting a button. The thermocouples were used "just in case" as the machine was run-in without supervision. The Spindle would run at 50 rpm for 15 minutes to start, then bump up to 100 rpm for a minute, back to 50 for 10 minutes, then up to 200 for a minute, back to 50, and so on. At the end the Spindle could run all day at its max design speed. We had a range of Spindle designs from 1,800 rpm to 4,500 rpm.

I remember one machine where the run-in was missed. As the machine was being prepared to do a customer's demonstration part, the Spindle locked-up and kicked out the Drive Motor. It was determined the run-in had been missed. The grease had not been "channeled around the Bearings". The ensuing churning of the grease generated enough heat to cause the Spindle to expand and lock the bearings. The Spindle was allowed a day to cool naturally, the run-in procedure was done, and no measurable problems could be detected in the bearings. That was a relief as those bearings cost in the neighborhood of $1,000 back then.

The long and short of it is - pack the bearing around half full, allow the grease to "channel" by running the lathe at a low speed for say 15 minutes.

Thread: Boring bar/head
08/04/2017 15:00:44

I was given a Boring Head with a set of Boring Tools from a local Machine Shop. It was given to me because " I don't know what's wrong, it chatters". I traced the chatter down to the R8 Shank was undersize. I replaced the R8 Shank and it works very well.

The set of Boring Bars I received look like the picture in the Arc-Euro ad - the shanks are plain diameters with no flats. At first I thought to put flats on the Boring Bar shanks so the set screws would not cause dings in the shanks which would make it horrible to remove the m from the Head. Then I realized there was no way to put the Boring Bar in the Head and assure the cutting surface was parallel with the Head motion (as mentioned by John Haine above). I did put flats on the shanks, but the solution was to measure the shank diameter of the Boring Bars. I then put each Boring Bar in the Mill Vice horizontal and rotated the Boring Bar axially until the cutting face of the Carbide was exactly 1/2 the diameter of the shank diameter below the top of the shank (easy to do with a Dial Indicator). I then milled a flat along the shank to a width equal to the set screw size. I can now place a Boring Bar in the Boring Head and slightly jiggle it as I tighten the set screws and it is always aligned correctly. Plus the dings do not prevent the Boring Bar from sliding out freely.

Of course the Boring Head in a Mill is only as good as the clearance in the Quill (unless you lock the Quill and feed using the Knee).

Another one of those "I did it quicker than the time it took to write this project".

Bruce, Cleveland, Ohio

Thread: Engineering videos
07/11/2015 13:55:37

some very good YouTube videos on model locomotive building by MrCrispin96. Search

Home Workshop Engineering - Assembling the Chassis Part 1

Thread: My little engine (continued)
07/11/2015 13:46:33


a process step I would have done first would have been to turn & face the end of the stock which is held in the chuck jaws. This gives one a better surface to grip on (no worries about stock taper or ovality). Plus the finished back surface is there in case you need it for a measurement or setting/clamping in a mill vice before the part is parted off. But, great progress ! It's great to see your posts.


30/08/2015 16:06:17

Garry - 3 comments:

1. if I were machining the side of the Steam Chest as your picture shows, I would do it the same with parallels locating the inside surface BUT I would use shorter parallels to allow a better grip in the vice. Check your high-speed tool blanks, they are quite parallel but often one side is different thickness than the other. Mark with felt tip pen.

2. if I were holding the Steam Chest in the 4-Jaw Chuck to machine the Valve Rod Gland as your picture shows, I would do it the same BUT I would use say 1/4" x 3/4" pieces of steel across the Steam Chest on the two Jaws which are "gripping air". To keep them from dropping out when adjusting the 4-Jaw, I would have used double sided Scotch tape between the Valve Chest and the steel pieces. I had a very similar set-up as yours shift on me once.

3. when machining an INSIDE rectangle like the start of your Valve Chest machining, I first get a clean sheet of paper and make a very simple sketch of the part as it sits in the Mill. I place it on my workbench next to the Mill. Note I do not have digital readouts on my Mill, I use the hand wheel graduations. I enter the Endmill into the Steam Chest and make a cut all around the interior profile. A light cut - just enough to see how the casting is aligned. The IMPORTANT part - as I do this cut I write down the Hand Wheel numbers. As an example, with a RH Endmill you will cut the side closest to you going from right to left. On my sketch I first would write CW at the bottom of my sketch with the value of the in-out handwheel. The I turn the right-left Handwheel CCW to cut to towards the left side of the Steam Chest. When I stop the cut, on the LH side of the sketch I write CCW .086 (or whatever the number on the Hand Wheel is). I do this all around the part for all the faces.

Now I can measure how much needs to come off and determine how many passes are required. I write these numbers under the numbers on my sketch and go at it. Notice I do NOT use any stops. I write the CW and CCW down as I once used a machine with a "backwards" thread and I have been ruined for life. By having the CW & CCCW I do not get confused. I just run around the inside of the part keeping an eye on my sketch. Once you understand the system it becomes second nature and takes less time than fiddling with the Stops. You can stop at any time and measure th part and make fine adjustments by tweaking the numbers on the sketch.


Thread: Soldering/brazing a boiler.
08/03/2015 13:47:37

I have a question, when silver soldering the end caps. does one apply flux to the surfaces and then push them together, or does one just apply flux at the joint after assembling the parts ? What about the washer by the chimney ? Would one apply flux on top of the cap and under the washer, or not ?

I have silver soldered various pipe fittings, but never a boiler.

Thread: Little Tich
30/12/2014 22:27:55


I hope you realize the Axle Boxes are not in the "nominal design" running position on your drawing. Bottom of Frames to Axle center should be 5/8" (I do not see the 1/8" clearance under the Axle Box). I would imagine there are a lot of Tichs running out there with Axle Boxes hard down in the Horns - but this will make a lot of measurements seen odd later as you progress drawing the Connecting Rod and Valve Gear.


Thread: Indexable tool holders
14/09/2013 13:36:32

Perhaps Cabeng could discuss more re tip geometry. It seems many users are not quite aware of the various top rake angles available with carbide inserts. I designed lathes for 12 years and I know the top rake angle was carefull selected for each customer runoff (to the likes of Caterpillar, John Deere, Ford, New Departure,etc). Most steel and iron jobs were run with negative rake insetrs due to it being a more robust insert. Another concern was the BUE. Another big concern was life of the insert.

I do not have first hand experience as I still use hand-ground HSS tools in my hobbyshop.


Thread: Is this the trend in small locos?
31/08/2013 13:41:58

Ady1, there are quite a few popane fired locomotives here in the States (very clean, low fire risk). I live in Ohio where fires are relatively unheard of, but there a number of propane locomotives. I have never seen an oil fired one around here. But out West I imagine one needs to really think about fuel type due to forest fires.

My son (age 27) is just completing an electric locomotive. Yes, it is to a steam locomotive profile, but it his first effort. I think in that respect it is a great first step into this hobby.


Thread: What did you do today? (2013)
25/08/2013 14:05:26

a solution to the lost funnel - use the top off a 2-liter cola bottle. One can shape the "bell" to suit the application. I came across this idea once while changing oil in a sailboat - the engine was tucked under the cockpit. And the oil does not wet the surface - every last drop runs out of it.

Thread: what is the Driver doing ?
25/08/2013 00:30:38

there is a good YouTube video "6024 King Edward I attains 2000 (Draw bar horse power) on Wilmc".The video is by "psovmainline". It is a split screen with video in the cab and from outside. The question I have is: at 1:38 the Driver has just shut the Regulator and is opening it for maximum drawbar pull. BUT at the same time he does not let up swinging a lever underneath the Reverser Screw. The question is : What is that lever ??

Could it be the sanding lever and it requires stroking to maintain the flow of sand ?

thanks in advance,


Thread: S50 cylinder machining setup
08/05/2013 01:45:29

Gary, I would do the same setup EXCEPT I would not use the bar. Your setup assumes the tops of the vice jaws are parallel to the milling table. Are they ? I would guess the vice's fixed jaw is just as perpendicular to the milling table. I would set the casting at the midpoint of the jaws to minimise any twisting effect of the clamping force out of line with the vice screw. Set the casting as low as you can place it with allowance for the cut. I would put a piece of paper between the moveable jaw and the casting face. I never learned the use of paper in the "real" world, rather I learned it in ME. It does work. Also, watch carefully as you cut. You should notice a better finish cutting one direction versus the other. I would take all the finish cuts in one direction only.

Thread: Clarkson Stirling Single 3.5"
21/04/2013 15:03:30

All, I have just had contact with Blackgates and they have acquired the drawings and patterns for the Clarkson's designs. They now have the Stirling 8' Single 4-2-2 drawings available with castings to come. I am ordering my drawings tomorrow !

Thread: LBSC's Netta in 3-1/2" gauge
26/12/2012 14:43:25

No one has an answer regarding the question " should the radius of a locomotive type Expansion Link equal the length of the Eccentric Rods" from my email above ? I would appreciate any comments.


25/12/2012 16:28:25

I am building my Netta with LBSC drawings and castings from Reeves. However, I am making slight detail changes here and there, hopefully to mke it a bit better. I did not care for the cylinder angle shown on LBSC's drawings, I am leaning towards making it 3 degrees.

I discovered the issue with the Wheel counterweighta as I began to face them and I heard a second click in the interrupted cut as I began to face the hub. My solution was the same as John's, I milled the weights to size. I took the opportunity to reduce the counterweight and hub on the leading axle by 1/32" per side.

As a side note, I machined the wheels on the usual "turned in place" stub mandrel with threaded end. Since all the wheel bores were within .0005" (all made at the same time with the same process), I decided to do one operation per wheel per mounting, i.e. I rough turned all the ODs one after the other, I then finish faced the wheels one after the other, etc. It did mean mounting and dis-mounting the wheels many times, but as I have no quick-change tool holder. The oerations were executed very fast as I was not constantly re-adjusting the tool or measuring size. My old SouthBend lathe is very repeatable. All eight wheels were finish turned in ~10 hours tops.

I do not understand the Frame Stretcher problem dimension. It does foul the Eccentric Rods and I assume that is the reason for the large opening in it. On sheet 2, middle of the drawing, it shows a dimension of 1" from the axle centerline to the face of the Stay. It seems like you erected the Stay backwards, although with the Reeves Hornblocks, that would not fit without maching more off the back face.

I am coming to a point where I have two questions:

1. is there an error with the Eccentric Rods ? Their centers are shown as 5 1/8", but they are attached to a loco style Expansion Link which has a 5 1/4" radius. Although I have a couple of books on Valve Gears, none state explicitly that the radii should be identical. I note they are the same for LBSC's Maisie.

2. Crosshead clearance: the locomotive centerline to cylinder centerline is 1 7/16" + 1/8" + 1 1/16" = 2 5/8". Minus half the Crosshead thickness gives 2 5/8 - 7/32 = 2.406". Compare this to the leading Coupled Wheel 1.641 + .500 +.188 + .062 = 2.391" or .015" clearance per side. Since the wheel face to bearing face clearance is 1/64" per side, this would indicate the clearance could drop to zero when rounding curves which would allow the CrankPin or leadoing Coupling Rod clicking the CrossHead. I am addind clearance to my model. Any comments ?


Thread: whats a suitable steel for turning and welding
10/11/2012 00:04:10


be sure to stay away from steels with either sulphur or lead. Both of these elements will lead to cracking.


Thread: Milling internal rectangles?
30/09/2012 15:29:37


in such a situation, I would mill the opening as you mention, Then I would clamp a steel bar to each side of the steam chest in the bench vice (horizontal). The bars would be aligned to the machined opening. They will act as guides to limit the file's cutting depth. I have done this just recently. I guess if you are really unsure of your filing, you could also clamp a set of bars vertically in the corner you are filing. These bars would be clamped with a toolmakers clamp.

If you are really worried, you could machine two plates with an internal corner (or two corners to do one side of the steam chest at a time) and use as described above.


Thread: Driving Trucks
03/09/2012 15:51:27

A late member at our local track had a beautiful original Royal Scot in 3-1/2" gauge, an absolute delight to drive. His driving truck had a very simple brake. There was a lever on the side atached to a cross-shaft mounted on the frame. I do not remember the detail construction, but it just swung a "brake" pad (approximately 5" square) down onto the rails. I seem to remember it was suspended at its trailing end by a swing link of same radius as the leading operating arm, so the pad remained horizontal as it swung down paralllel to the track (but forwards so it would not grab and de-rail the driving car). A spring was used to hold the brake off.

Since our track was close to dead level, one could apply a light pull to the brake and load up the locomotive. Due to its size and chamfered leading edge, it never caused a derailment. Since it wasn't a bunch of tiny parts rubbing on wheel profiles, one never felt guilty using it lap after lap.


North East Ohio Live Steamers, USA

Thread: Jason's Firefly .46 Build
15/07/2012 19:17:18


I tap holes in my shop like you show - with the tap wrench in the MIDDLE of the tap. However, I find it a nuisance adjusting the drill chuck, so over the years I have turned up "bushings". The OD is just a clean-up cut for concentricity then I drill to fit the tap shank diameter (actually I relieve the tap hole till the guiding surface is one diameter long - don't know if this is required). At first I thougth I would be making one for each tap, but some do work for multiple taps.


Thread: Electric Motor RPM?
14/05/2012 01:51:39

I heard once that at power stations (here in the US) they had a synchronous clock in the turbine control room driven from their generator. In the early morning (around 4:00 eastern time) all the Power stations would compare their time to a nationally broadcast time clock. The time diference would indicate how many extra or fewer their particular turbine/generator sets turned. The speed was then altered to zero the count difference.

It seems hard to believe that that actually works, considering the Power stations are all connected via the Grid. Perhaps this was before the Grids.

Does anyone know if this was actual the case or an urban legend ?

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