Member postings for Alan Crawley

I bought my round stuff from Macs Models, they have it for £13.46 a metre length.

My clock has been running for close to three years with a glued and pinned CF rod now in an area where the temperature changes a lot throughout the year. I never adjust it between the necessary change for daylight saving(!) and it is always within 30 seconds of correct time at that point

How can you save daylight? We tried capturing some in a lightproof box.

I just got some BA taps from Tracy Tools. 9,10, and 11 BA carbon steel, £2-£3 each and marked Dormer and Presto,

and I expect they will perform well. As somebody pointed out the advantage of HSS is in the name, it can be used at high speed. Unless anyone is daft enough to machine tap at high speed with a CS hand tap, any good make will perform well. I may be just me, but I think HSS breaks easier than CS I the small sizes.

Sorry I've not got back for a while. Second vaccination laid me low!

I have made a gear which drives the carriage satisfactorily. I cast my mind back to the days when I was a design draughtsman and searched out some information which said that theoretically the perfect pinion for running on a rack could have round pins. I made a cutter as close as I could to the unworn part,and cut the little gear. This part is actually a compound, with the other bigger gear running on the clutch gear.I turned down the worn gear to 8mm and pressed on the new gear. I then drilled half-and-half holes and tapped M3 and put in grub screws. It winds by hand and with the power feed smoothly. The pitch circle is a little small when checked on the hand wheel, but this is of no consequence as it has DRO fitted. Incidentally this machine is a Feeler Mk.2 and when it was at British Aerospace we found that parts from a Hardinge HLV-H were all interchangeable I seem to recall though that the Feeler used metric screws. One slight difference I came upon is that it has useful jacking screws to get the apron off easily.

There's a clue in " it runs on a rack on my Hardinge clone" Sorry. I couldn't resist it!

I have a damaged gear that I need to reproduce. It is .750" or 19 mm diameter and has 14 teeth. This does not fit any Mod or DP formulae as far as I can see.

The closest is 1.25Mod but that gives 20 mm diameter, it runs on a rack on my Hardinge clone, and I seem to recall from way back they tended to use weird gears. I seem to think I have two options, make a single point fly cutter and cut 14 teeth or make the blank 19mm diameter and cut 14 teeth 1.25 Mod.on it. The pattern is cut onto the shaft and has an unworn section so the diameter is as I stated.

I'm sure there are people on here who will be able to point me in the right direction.Thanks in anticipation.

The only slight thing that is wrong with your last post Lee is the word "disputed". The bolts are nipped up and left alone, indisputable.

And the other poster's idea of bending the bolts to effect adjustment is horrifying. One part slides across the face of the other.

As you say, the ultimate tightening of the three conical screws holds it all in place.

Lee has summed it up neatly.

I have watched a couple of videos about these chucks and have to wonder if the users have read the maker's instructions. It only claims to repeat accurately at the diameter set, and also that the chuck key should be used in the same hole every time. You have to forget the habit of checking all three. And the same number should be used to unloosen it.

I have used one professionally for a good number of years without problems. The retaining screws are never touched. And I believe I may have stated earlier, if ham-fisted users strain them so they are bell-mouthed the jaws can be corrected carefully on a surface grinder. No need to grind the bore and make the jaw face concave.

My UK made Hardinge has one and the screws under the backplate so there is no way of adjusting on the run so to speak. If the instructions are followed and all taper screws are tight, as long as the mounting screws are tight enough to prevent endplay everything should be ok. No eccentric movement possible.

Edited By Alan Crawley on 19/10/2020 14:15:21

All of the above explains how my friend who completed a trip back home from Oz on Concorde from Bahrain arrived here before he left there.

Someone mentioned Fisshguard and I frequently stay with friends there and the shift in daylight is very noticeable.

A further aside-I think the carbon fibre rod looks nice with the brass bob and weights etc.

I fitted the carbon fibre rod as advised and all is well!

I recently used the term "amazingly accurate" when running on a length of 6mm EN3B. This was meant to be a relative term as it is amazing to me, my first ever clock in my ninth decade. It cost well over £300 for materials, and is not as accurate as a £4 clock from Aldi!

Another question, I learned that the term "Regulator" was used as it was the accurate clock in the clockmaker/repairers workshop to adjust other projects. What did they set the Regulator to? Or did it set standard time for the area it was in? I recall reading that railways had problems where different companies ran to different time. Much like today, it seems!

Many thanks for the help and guidance.

Edit:- comma after "to be honest"

I’m beginning to realise my IQ is too low for this conversation!!

Let’s try to simplify my original question- do I need any compensation for the Carbon Fibre rod?

My main interest is going into my little workshop and making nice bits. To be honest to me this engineer- designed regulator is running with amazing accuracy with common BMS rod.

This is not to say I am not grateful for the interest shown.

i have now made up a carbon fibre pendulum rod with glued and pinned threaded ends.

The original design with Invar rod has a brass tube inside the bob as a compensating device. I guess that this is no longer needed with carbon fibre, has anyone any information or thoughts on this, please?

The clock is still running with an ordinary mild steel rod and it is obvious with the current temperatures how much it affects the time. It is almost spot-on at 6-30 am but probably about 10-15 seconds behind in the early evening, and then is accurate next morning.

This has produced some interesting replies and I particularly liked Duncan's link about gearing. That's life-we all enjoy the situation of "tell us what we want to hear" I wish I had read it earlier and I would not have worried so much about many hours of work being in vain.

Lockdown has at least given me the time to spend on this project and after over sixty years in engineering/toolmaking, and nearly fifty with my own small specialist business, I can still get immense enjoyment from something new and different.

You won't be able to imagine my excitement after a few little setbacks, how excited I was when this clock settled down and ran on its initial test.

I have one other small query about the CF rod, will it be ok where it is subjected to the friction of the crutch? This consists of two 3mm silver steel pins in a brass disc that can be rotated to adjust clearance to the pendulum rod. I would like to thank everyone who has taken the trouble to help me with my project.

Regarding the distance the weights descend and the height of the case, i have managed to calculate that it does not need sixteen turns on the barrels but about fourteen for a month going, and that there is probably just enough room if the weights are wound up to their limit.

I am completely out of my depth now with the information about pendulums that I don't understand regarding the comment I quoted about bob weight being unimportant. I read this in a couple of publications from respected clock makers, and during my process of crude lash-ups to see if my creation would run (an 'expert' told me it had no chance of running because I used involute tooth form) I used various objects on the pendulum rod ranging between around 2 kilo to the correct 4kilo as designed weight for no difference in timekeeping over periods of 36-48 hours. With the correct weight it has run several days spot on.

It's solid wood, so weight don't fall below case.

Edit- case is 51-1/2" inside

As a newcomer to clock making I read lots of information about it, and one thing i learned is that the weight of the pendulum is not important. With my current testing stage, I removed the bob and the clock started and ran without it, albeit quite fast! That surprised me!

The Model Engineer articles describe a glazed case for this clock, and I am somewhat confused about this aspect, too. It's all in Imperial dimensions, so I will use them. It is a thirty-day clock. The winding barrels have an effective diameter of 1-1/4" and sixteen turns, so 1.25 x pi x 16 =approx 63" The cable is doubled with pulley, so effective length is approx 31-1/2". When fully wound up the top of the clock to bottom of the weight is approx. 25", which gives an overall dimension of some 56-1/2" when weight is fully down, but the case is only 50-1/2" inside.Have I missed something?