Driving and coupled wheels for the Y14

 As an intermezzo in building the boiler, some machine work was nice to do. Turning the driving and coupled wheels is a straightforward turning job, but requires some planning in set-up and sequence to machine the several faces. 

The wheels were bought in England from Mark Wood,  in the days before the Brexit customs rules made this very difficult.
The wheel castings are of excellent quality and are fine cast. Mark did some special research on the prototype Y14 locomotive so that they are very close to scale.

Update:  Mark told me today that: 

Just after Brexit I had problems with long customs delays and even parcels being returned to me - that was with DPD.  Now I use UPS and pay the local duties in advance and parcels have been delivered to Europe in about 3 days from posting. 

So this gives a good prospect for future model locomotives. 😀 Take a look at his website, because he offers many wheel castings. 

First the backside is faced, so there is a reference plane to start with. 

With all the wheels faced, the outer flange had to be cleaned up. But the jaws of the chuck were too deep to give enough clearance. So some aluminum strip was bent, so it could be clamped over the inner jaws. 

This made it possible to give just enough clearance. 

Gripping the wheels on the machined outside rim, the front could now be faced.

The bosses are 3,5mm outside the rim and could also be faced. 

Then the backside could be finished and faced to the final thickness of the wheel. 

In the same setup, the wheel is bored for the driving axle. By doing this in one setup, the hole and backside are dead square to each other. This way the wheel will run without a sway. 

Because the spokes are close to scale (and therefore thin), the wheel was clamped between two aluminum disks. With three bolts the disks are screwed together. 

Now the rim could be turned to the final diameter of 133 mm and the flange could made.

It's a job that takes some steps for each wheel. Every step is done for the six wheels, before changing to the next set-up.  So a lot of set-up time: clamping in the three-jaw chuck and between the disks and changing the lathe tools, was involved.  A few evenings behind the lathe were needed. 

For the flange, the top-slide was set to 18 degrees. 

Finally, a small radius was made on the flange. 

To drill and ream the crankpins, a set-up was made in the milling machine. A short stub was mounted on the milling table from which the center of the wheel was positioned.
The stroke of the crankpin was done first with a center finder used on the stub, setting this to zero and then moving the Y-axis to 26,5 mm.

With a small piece of round brass, that was turned to the same diameter as the boss, the correct position of the crank could be determined by turning it over around the center, after which the wheel was locked down with the clamps. 

  

With two clamps the wheel was fixed to the bed. The hole was centered, pre-drilled with a standard drill, drilled with a three-lip drill and then reamed. 

The small brass plate under the wheel is used as protection for the milling table, in case a drill or reamer is going too deep. 

The backside of the crankpin hole is countersunk, so a screw can later fix the crankpin.

The axles are a job that could be done by using the collet. 

"On its wheels" (well, without the hornblocks yet)

Maintenance Milling machine part 2

Re-greasing the vertical spindle of my Deckel FP1.

With Ramon's help, we did maintenance on my milling machine earlier this year. But on his advice, it was decided to re-grease the main spindle cassette as well.

Although the machine was running ok and without any problems (this was since the replacement of all the bearings, see earlier post), a check of the main spindle cassette was done. With the expert help of Ramon, this was a job that was done in an afternoon.

The old grease (of this 45 year old machine) was not in good condition. So this job, in hindsight, was really necessary.

The bearings of this cassette can be replaced (As Ramon did for his machine), but we found that the bearings of this spindle were still in good condition. So the only cost was the special Kluber grease.

Removing the spindle cassette out of the machine was already learned the last time, when we replaced the bearings, and now could be done without removing the vertical head from the milling machine. 

Once the cassette is on the bench the dismantling can start. By loosening 4 small inbus bolts, the main nut can be removed. Then the inner spindle and housing can be taken apart. The inner spindle stays on the workbench, while you lift the outer house off. There are no press-fit bearings. In my case, some rings got a bit stuck with old gummed-up grease. Using break cleaner spray and scraping the old grease away, everything came loose without too many problems.

Cleaning with brush and thinner and then carefully regreasing with the special Klüber Isoflex LDS 18 Special A grease. This grease is advised by the manufacturer Deckel. It is relatively expensive, but it should do the job for years to come. 

Assembling was done the same way, but then in reverse order. With a 0.002 mm dial indicator, the pre-tension on the spindle was set to 0.003 mm. This is done by adjusting the nut on top of the spindle.

A test run was done, starting with a low rpm for a few minutes and thereafter, in several steps, increasing the spindle speed to 1000 rpm. At each different spindle speed, the machine was run for 5 to 8 minutes. No heating up or strange sounds were noticed.

The machine now runs wonderful.

 Parts for the crank axle of the Y14 

Girder plates

One of the last parts for the boiler that had to be made were two girder plates. They are positioned on top of the firebox and will be the connection between the firebox and the outer wrapper. 

They are made of 3 mm copper sheet and are relatively easy to make, but need to be made with accurate dimensions and shape as the will take care of the proper position of the inner firebox in relation to the outer wrapper.  An aluminum former is therefore made. This simple milling job was set up in the machine vice using a large mantle head mill.

Clamping down the two copper plates, for milling the water spaces.

After annealing, the first bend is made. 

Sanding down the lips, so there is a good flat surface and reference face for the next bending operation. 

Two pilot holes are drilled, which makes it possible to clamp the girder to the correct height on the aluminum former. 

In the vice, the plate is bent, by the use of the hammer. 

A second annealing operation is needed, so the sharp corner can be made. 

The test set-up shows that the upper lips, closely follow the radius of the outer wrapper. 

By placing the two girders to the correct width distance between lips, the height between top of the firebox and the outer wrapper is set. By this boiler it is 43 mm. Designing in Solidworks has the advantage that all these dimensions can be measured in the 3D drawing. The dimensions and shape for the aluminum former block were also be dirived this way.

The inner dome was a straightforward turning job. A hefty piece of bronze bar was needed. And a lot of material is transformed in to chips.

Much was machined and reduced to chips

A filler plug is also made of bronze (M16 x 1) with a hexagonal key width of 20 mm.

This at first wouldn't fit in the dome. The screwthread was too tight. Only after a few turns into the dome and got stuck. It puzzled me for a time why this happened, because the tap and die had cut beautifully, without any difficulty. After measuring I found that the predrilled hole for the thread was 14.9 mm instead of 15mm (as stated in the screwthread table).

After reaming the thread in the dome to 15mm, it fitted perfectly 😀

The large chamfer is needed so that it will fit later on under the outer dome cover.