Member postings for Peter Cook 6

I will continue to use MoI.

When I started to make things a few years ago I tried out the trial versions of various CAD packages. Never having been trained in 2D drafting or anything similar I found it very difficult to get to grips with the paradigm(s?) on which most of the tools are based.

Having tried the trial of MoI ( which is a cheaper version of Rhino I believe), I found its paradigm far easier for me to get to grips with. So much so that I took the plunge and bought a license for it.

Since getting a 3D printer it has proven invaluable. I find I can design almost anything I need to create fairly quickly and output it via a slicer to the printer. For things I want to make on the lathe or mill I can output 2D views, with dimensions, sufficient for my needs.

I have some cheap (Chinese?) digital ones. They have M2.5 threaded tips.

If I understand it, the two pairs of "contra rotating" pinions are not actually in mesh. The two meshing with the shaft A gears drive the cage round. The two meshing with the shaft B gear are driven by the cage and drive shaft B.

Presumably you could add more pairs at right angles if you wanted to transmit more torque.

If I understand him correctly ( at about 4:40-4:50 in) he drills the first side undersize with the carbide drill, and then uses the spade drill - which is made from the same pivot wire as will be used for the trundles - as a reamer for the front holes to get them to exact size. Then he uses those holes to support and control the shaft of the spade drill while he makes the rear holes.

His carbide drill doesn't look long enough to drill all the way to the back in any case.

It just looked like a neat and fairly simple way of getting the holes to exactly the size of the pivot wire.

There is an interesting You Tube video that I tripped over a few days ago that shows the making of a lantern pinion. He makes a spade drill from the pivot wire to drill the trunions.

DIY Cycloidal Gear Cutter: Part 4 Making the Lantern Pinion - YouTube

Might be an idea - the spade drill is probably a lot stiffer than a twist drill at that size

This over 55 (actually over 70) has some six machines - all in operation and meeting different use cases. Three tablets (all Win 10) two "desktops" and a fairly old laptop - hauled out on the occasions when I need to do a presentation somewhere. The oldest ( laptop) is probably 12 years old but has been upgraded with an SSD, the youngest is four years old. All run Windows 10 without problems.

None of the machines ( two of them Microsoft Surface tablets) meet the specification for Windows 11 so when Win 10 reaches end of life I will have to think.

My issue is that the reasons they will not run Windows 11 is not down to a technical issue, but because of policy decisions taken by Microsoft. Older processors work fine, but the installer checks and refuses to proceed, Neither do they have TPM 2.0 modules again a policy call by Microsoft. Is it to "ensure my online safety" or is it simply a mechanism to force me to buy new machines and simplify Microsoft's support issues.

Obsoleting perfectly useable machines seems to me to be going against the "greening trend. Wouldn't surprise me to see a volte-face by Microsoft (possibly when Windows 11 fails to gain the penetration) and either extend Win 10's end of life or more likely remove the arbitrary constraints on Windows 11.

Thanks Both - I feel more brain ache coming on!

Thanks John for the thought. It had crossed my mind. The pendulum hangs down behind the frame, so an arm at the top extending upwards past the suspension would be a possibility. But I am struggling to find a source of the math for such a pendulum. My applied math is so far out of date I don't think I could work it out from first principles.

Receipt of a copy of Ivan Law's book on gears (about which I knew very little), hard thinking and some spread sheeting over the last couple of days has produced a possible arrangement. Slightly longer pendulum with finer gears than scale on the great and second wheels and a few more pins in the escape wheel produce a set of figures that beat almost twice as fast, but still revolve the output shaft once per hour while the gear diameters remain fairly close to scale.

Now whether I could actually make a set of M. 0.4 ten pin lantern pinions, whether the required 0.6mm diameter (I think) piano wire/pivot wire would be strong enough for the pins and whether the resulting lantern would have room for an arbor are entirely other questions!!

Thanks again for the encouragement - although it does feel a little like I have stepped through Alice's looking glass and am being sucked further and further into another reality!!

Thanks Martin. More useful thoughts. At twice speed the great wheel turns once every 1.5 hours. Scale drum is 36mm diameter and 90mm long so 113mm of cable per rev and 16 revs per 24 hours = 1.8metres per day.

With 96mm of drum length, 8 days allows 12mm/day of width so max cable thickness is 12/16 or 0.75mm.

Thin steel cable @0.6mm has 20Kg breaking strain.

100lb breaking strain fishing line is 0.5mm diameter.

Hopefully that sort of pull will do it. However I will as you suggest start with the escapement and experiment.

The real pendulum is 1.5m long, so lengthening at scale it is a possibility.

I think I am beginning to understand why people build to existing sets of drawings - scaling reality is complicated!

Thanks Martin, more issues to muse upon. I had not really considered the weight issue. The real clock has 185Kg on the chime train, 110 on the strike and a mere 27Kg on the time train a grand total of 322 Kg hauled up 10 metres twice a week. The Chime and strike are three pulley systems, the time is only two.

I think I was hoping to get away with rather less than the 80Kg that comes from dividing by four, but I think some serious math on run times and weights is going to be required. I have a couple of longcase clocks with barrels about 2" in diameter that run for eight days, so if I am careful with pivot quality on the time train I might be OK.

A quick calculate suggests that with scale barrels I will need about  2metre of cable for a 24 hour run if I allow it to run at double speed. But getting 80 pins on the pinwheel might be a challenge! Lots to think about. It looks like this will take all the time until my backlog is cleared just thinking about the issues.

Thanks again - its the things you didn't know you didn't know that are the most helpful in these forums.

PS Michael - While browsing the Burton blogs up popped a link to my clock. Most surprised!!

Edited By Peter Cook 6 on 31/10/2021 17:25:17

Thank you Michael for the information sources. Plenty to peruse and muse upon in the darkening winter nights.

JA - No I haven't ( as yet) approached Smiths. However one of their service engineers is due any month soon to do the annual service on the clock - so I will pick their brains while keeping them company in the tower (H&S you understand!).

Having to stop the clock for an hour this morning due to the end of BST, and because the weather was unfit for the walk I usually do to while the time away, I took some basic measurements of the clock to see what I faced. The largest wheels ( the driving gears for the chime & strike trains) are 16" in diameter, so at 1/4 scale they will be 4" - and within the capacity of my Taig - so the project looks possible. However these wheels (2 off) look to have 150+ teeth, and the big wheels (again 2 off) for the fly's plus the time train great wheel are 120+ teeth, so its possible CNC may rear itself up the project list!!

Thanks again for the pointers and help. I must get some workshop time to reduce the backlog of projects and clocks needing repair so that I can possibly start on this one.

Thanks Michael, I suspect that as a clock it is actually less complex than the Wilding design in many ways. The trains are simpler, and as far as I can see the clock was a "mass production" design, so the bearing carriers are identical front to back. The great wheels on all three trains are the same, as are all the lantern pinions and the wheels for the chime and strike - so once I have sussed out how to make one - I will be into production, and the second one of anything I make is usually better than the first.

And it has the overriding advantage that I can simply have a look at the real thing whenever I get stuck.

I have access to (OK I have wound it twice a week for 20+ years) a flat bed tower clock in the local church. It occurred to me recently that creating a model of it it might make a good build project (once I get the current list out of the way in a year or so!).

It is a three train flat bed clock made in 1889 by Smiths of Derby, and still maintained by them.

The movement is fairly simple, pinwheel escapement, count wheel chime and strike. Each train has a limited number of wheels. All the pinions are lantern, and the bearings are brass bushes, some in iron castings individually mounted on the top and bottom of the bed so depthing should be fairly easy. The bed is one piece cast iron - but I would probably fabricate it from steel.

The real thing is about six feet wide. It beats 3150/hour, and trips the chime train four times for each revolution of the output shaft (closest to the camera on the image above) . Thinking it through I t seems to me that if I made a 1/4 scale version it would beat twice as fast, and if I tripped the chime train twice per rev I would get a clock that looked OK, and kept to time. The motion work behind the dial ( about 20ft above the clock) is driven by a pair of bevel gears.

By halving the ratio of these gears I should be able to get the hands to turn at the right speed.

I can't see anything too difficult (apart from having to learn how to cut wheels!!) except possibly the pair of bevel gears that send the output up to the dial and those on the motion work, and the latter could probably use a standard commercial set as they will be non scale and hidden behind the dial.

The chime barrel will be fairly fiddly to get right, but in principle should be doable.

Before I set to measuring the real thing, counting teeth and planning a bit harder, I thought I would ask on here to see if anyone has done something similar - or if anyone can think of any major gotcha's I might run into.

Edited By Peter Cook 6 on 30/10/2021 16:23:31

Don't know if it will help, but there is a (slightly bizarre) video on YouTube at Manual - Albion Gearbox - YouTube which shows what looks like a similar box being reassembled.

The cog on that one is splined on, and seems to have a threaded retaining nut. Could the damage pointed out by Dave be the result of someone using something like gland nut pliers to get the nut on/off?

PS all the images I can see of Albion gearboxes seem to have the same or similar output shafts with splines for the cog and a retaining nut. So my money would be on that ring being threaded on.

Edited By Peter Cook 6 on 29/10/2021 19:07:01

Presumably it depends on the type of leaves on the line!!

Depending on what you are planning to use it for, you might want to look at a Taig/Peatol. 2.25 x 8.75 (or 3.25 x 8.75 with riser blocks) vs the Hobbymat's 2.5 x12. There are a couple going fairly cheap on Ebay at the moment.

They are good little precision lathes, which are very modifiable, but don't have leadscrews or screw cutting capability as standard.

If you have a couple of DTI's try using them to track down the source of the wandering by elimination while doing some test holes.

One on the drill shank, and one on the side of the chuck if possible - that will tell you if the drill is wandering in the chuck, or they are both wandering together - eliminates the chuck. Move the one on the drill to the quill. Is the chuck wandering relative to the quill, or are they wandering together. Move the one on the chuck to the side of the tailstock. Is it the quill wandering in the tailstock, then tailstock relative to the bed.

You might want to do the tests both horizontally and vertically.

Once you know which two parts are wandering relative to each other you might have a chance of fixing it.

PS - also check it's not the stock moving in the chuck!

Edited By Peter Cook 6 on 26/10/2021 10:49:27

It's not just runoff in some places. I live in the Lambourn valley in the Berkshire downs, which are all chalk. In winter and spring the water table within the chalk rises to the surface in the valley. Any cracks or leaks in the sewer pipes then allow groundwater to flow into the sewer system frequently overwhelming it.

It has been a long standing problem, and causes sewers to overflow. Thames water have spent a lot of money lining the main sewers with continuous plastic pipe to minimise the inflows ( the main sewers are quite deep in places and well under the water table levels. But they haven't (can't) lined all the side drains from individual properties which still fill with groundwater when the water table rises.

Sherline & Taig do both M22 x 1.5 and 3/4 x 16 tpi chucks, although the UK distributors don't stock the Metric version. Both sizes would leave a reasonable amount of space for a threaded adapter.

Could you start with a suitable high tensile bolt (M22 or 3/4 16) and bore and tap the centre to M14 * 1.5.

John, Noel - the motor is clearly marked 60Hz 240V, and if you look at the closeup of the speed controller, inside the red box it looks like the one I linked to.

But I must confess I haven't tried my controller ( used for an old electric drill) on an induction motor. I wouldn't expect it to work.