Strutt Epicyclic Train Clock (maybe?)

[kvom]

Making a start on the 4 pillars that connect the front and rear plates, I immediately machined 2 of them slightly short.  So they'll go back into the brass rod depository.  But I did succeed with one of the top pillars, which starts with 3/4" diameter rod.  Since all 4 need to be the same length between the plates (2.375"), I put together some gauge blocks and locked a caliper as a visual reference.  My goal was to do all of the machining with a 1/8" parting blade.  Keeping it locked in position in its mount meant that I could use the Y-axis DRO to set all of the varying diameters.  I'd only remove the tool at the end to machine the needed chamfers.

I'll do the second top pillar next time, but will need to use 1" diameter rod for the lowers instead of the the 1.125".

[kvom]

I've completed the second top pillar and one bottom pillar.  With snow coming this weekend, I have no reason not to go into the shop.

[crueby]

Great  shapes!   

[Kim]

The pillars are looking good!   

Have you made the frame yet?  Or will that be coming next?

Kim

[kvom]

The pillars are looking good!   

Have you made the frame yet?  Or will that be coming next?

Kim

I can make a temporary frame set from acrylic with the laser that I can use as a temporary structure.  But for metal I need to wait until I get my CNC mill working properly.  Since brass will be quite expensive, I'll hold off until I'm confident I can complete the clock.  I might try a test version with aluminum too.  There are a lot of parts I can make beforehand.

[Kim]

Makes sense!  And yes! Brass is very expensive!  You don't want to do a lot of experimenting with the frames in brass 

How close are you on your CNC mill? That's quite a project in itself.

Kim

[steam guy willy]

Making a start on the 4 pillars that connect the front and rear plates, I immediately machined 2 of them slightly short.  So they'll go back into the brass rod depository.  But I did succeed with one of the top pillars, which starts with 3/4" diameter rod.  Since all 4 need to be the same length between the plates (2.375"), I put together some gauge blocks and locked a caliper as a visual reference.  My goal was to do all of the machining with a 1/8" parting blade.  Keeping it locked in position in its mount meant that I could use the Y-axis DRO to set all of the varying diameters.  I'd only remove the tool at the end to machine the needed chamfers.

I'll do the second top pillar next time, but will need to use 1" diameter rod for the lowers instead of the the 1.125".
 What do the numbers on the bottom part of the 2" gauge block refer to ??  Good work happening here
Cheers  Willy

[kvom]

Makes sense!  And yes! Brass is very expensive!  You don't want to do a lot of experimenting with the frames in brass 

How close are you on your CNC mill? That's quite a project in itself.

Kim

I've had it "working" for a while, but the accuracy is not where it needs to be.  I wanted to change the X-axis motor mount for one that's integrated to the end bearing.  I ordered one on eBay, but when it came it was the wrong size. I've had one on order from China, but it may be another week for it to show up.  In the meantime, I "ordered" a second CNC mill from a Kickstarter project.  This promises to be more rigid and accurate although smaller, and it offers a 4th-axis.  That may make cutting the wheels better using gear cutters.  I likely won't get it until April or May.  Finally, I've supported another Kickstarter project: a laser cutter engraver.  It looks to be very accurate, and can engrave brass quite deeply.  It's possible this machine could cut the wheels from brass sheet, but it would be too small for the frames.

The frames themselves don't need precision as long as they're symmetrical.  So the current mill can cut these in metal even if the dimensions are off a thou or two.

[kvom]

Finished the 2nd bottom pillar, and decided to make a start on parts of the depthing tool following Smith's drawing.  The "nuts" went well, turned from brass, drilled and tapped 5/16-24.  I dug out knurling tool I got with my lathe 19 years ago and never used.  I did knurling in machining class before that, so I had some idea of how to use it.  Not the greatest knurl in the world, but it will solve its purpose.  I did clean them up a bit after I took that photo.

When I had turned its mate and used a die to thread the shaft, the nuts refused to screw on.  I possibly started it crooked (doesn't look like it), or the cheap die isn't any good.  I might just cut the thread on the lathe, but that will have to wait for the next session.  Or I can dig up a screw and cut off the threads.

[crueby]

Is the die a split one? If the set screw is too far in it would make the threads too shallow and not go in the nut.

[Roger B]

Those pillars are looking good   

[kvom]

Is the die a split one? If the set screw is too far in it would make the threads too shallow and not go in the nut.

Not split.  I may have turned the shaft too large.  I'll redo it with a smaller diameter, as a tight fit isn't needed.

[kvom]

It seems I didn't reduce the shaft to the required major diameter.  I did so today, and the nut screws on easily.

I made the 'slip washer' today.  The larger 5/16" diameter hole slips over the 1/4" center arbor allowing the partial 1/4" center hole to snap into a groove in the arbor.  The small hole allows a 0-80 screw to connect the great wheel to the washer.

[kvom]

Finishing up the carriers for the depthing tool.  Rather than turn entirely them from 1" brass rod, I made them in two pieces The head was from the larger rod, while the threaded portion was made from 5/16" rod.  The two were then joined by 620 Loctite.  Once the joint cured overnight, I drilled and tapped the cross hole 6-32.  This allows the screw to lock in the 1/8" runners.

[kvom]

After a more detailed reading of Smith's book, my idea of temporary acrylic plates is not a good one.  The alternative will be to make the initial pair in aluminum, and if I have success there I can machine the outlines in brass and use the aluminum ones as drill guides.

The second CNC mill I've ordered via Kickstarter will be delayed at least a month, so I don't anticipating getting mine until June at the earliest.  Assuming the motor mount for the DMS2 arrives next week, I'll see if its accuracy will be up to the task of the parts needing less precision.  I may end up surprised.  But for the dial and the plates, I feel confident that it will serve.

I also signed up for a Kickstarter mopa fiber laser engraver that can engrave brass quite deeply.  It claims very high precision, and may well be able to produce all of the wheels except the great wheel.  The latter is likely to thick.  I may get this machine in March or April.  It can also engrave uneven surfaces.

I've drawn up the clock dial.  The drawing of everything but the chapter ring I modeled in SolidWorks, and moved the resulting DXF file to my CAM software, CamBam.  CB has a much friendlier facility for manipulating text.  I've attached an image of the result.

Another thought I've had is to construct arbors from multiple pieces of rod held together with Loctite. Three arbors have multiple sections of different diameters, and it seems to me that if I can drill and tram the ends accurately, I'll save myself the need to turn precise diameters on long pieces of thin stock.