Thread: Hercus Model 0

Hello Bob, (and the many other Hercus owners around)

Almost all the brass is turned, I have 2 small pillars for the back cock and one long one for the maintaining power. The yet to be turned collets number approx 10 and all have slightly different sizes for each of the wheels. After that it is all steel in doing pivots, arbors etc. The escapement is what takes the time as it needs to be accurate. When they are finished I will post the photos. CNC does save a lot of work and for many of these wheels it was how the spokes were made by one of the group. It is practical and for me, time efficient. I have cut my fair share of material by hand and using 21st century techniques I am going to actually finish a project in the same year it was started as opposed to the same decade.

The gear tooth is a cycloidial form and quite different to an involute. They were cut on a wheel engine, a specialised type of clockmaking machine with direct indexing. You can cut them on a mill with no drama but the cutter runs at high revs, sometimes up to 6,000rpm. The chips fly - safety glasses essential. The multi tooth cutters are all imported and cost about $160 each. You can make fly cutters if you have the skills and they do the same job if made correctly.

The clock is to a design by John Wilding, an English horologist. It is a Regulator style and will have a 10" dial. It is a very plain looking clock but it is a high accuracy time keeper. The plans cost about $80 and the book is a collection of the articles first serialized in Model Engineer or similar with plans and appendicies. I am part of a group and we are all making the same clock and keeping each other encouraged. Things like the pillar screws which are stainless are being contracted out to save time. Other screws are bought as standards.

The Type "O" is very close now, the 24V is almost complete and the last thing is a registered sparky to put the 240V connections and 3 phase connections in place on the VSD and do a safety certificate. I am hoping it will run on Friday. First job will be a few tee nuts. I will let you know how it runs after the weekend.

Fingers crossed,

Michael

Hello Michael,

Undertaking a complex project such as your clock requires perseverance and I imagine being a member of a group with the same aims provides the encouragement to keep going. It's hard sometimes when there are a number of components that require completely different machining processes. I remember looking at a book twenty years ago on clockmaking written by George Daniels and thinking" where the hell would you start!" Impressive, complicated stuff.

I finished the knurled adjuster and centre this afternoon which concludes the making of the major components of the tailstock. When I cut the slot in the side of the centre for the locating screw, I first used a 1/8" slot drill in the vertical head. The drill skated erratically on the curved surface. Fortunately, there was little damage. I had the mill running at the highest speed but I may have come unstuck because it was a long series slot drill. Any ideas? The centre is made from 4140 bar. I successfully cut the slot with a slitting saw mounted on the horizontal arbor.

I've attached a couple of shots of the nearly completed project. The final component to make is the drive plate for between centre work.

Please post some more photos of your clockmaking efforts and also the No.O at work.

Regards Bob.

Hello Michael,

I just read an article about John Wilding online at the Craftsmanship Museum. Certainly a prolific writer and clockmaker. I need to pursue this further. I had never really thought about clockmaking as a use for the gear in the shed. Could be a direction!

Regards Bob.

Hello Michael,

George's book was on the subject of watchmaking not clockmaking. Considerably more daunting!

Regards Bob.

Hello Bob,

I had a thought about the slot drill, I suspect the work surface may have had a bit of localized hardening - I have had to use a dremel and grind a small area prior to drilling before on 4140 especially the ground rod. Sometimes the material is supplied normalized as opposed to annealed so it can get up around 300hbn, much harder to machine. Annealed can be 180-220hbn and with a 1/8" cutter it does not have a lot of meat before crunch, long series cutters much worse. It is often a challenge to get the tool nose pressure high enough to punch through the skin and start to cut before the web cracks and there are bits everywhere. You don't notice it on a lathe as much as a mill.

Clock making has to be easier on the eyes than watchmaking and you eventually get to play with wood for the case. Wood, yes wood, felt I needed to make a link back to the Woodworkers forum at some point.

The tailstock looks well made, have you used the headstock on anything yet ?

regards

Michael

Hello Michael,

It was 4140 PG bar that I used. I don't know what the problem was because I had successfully taken a light, maybe 2 thou cut along the bar before the dancing started with the second 10 thou cut. The tapered nose of the tailstock spindle is offset by 1/8" which meant a lot of interupted cuts on the lathe. HSS worked well in that application. The taper may have added to the problem with the slot drill.

I would not say the dividing head has had a hard life. It was pressed into service when I needed to mill the four flats on the end of a replacement 4140 screw for an incomplete 3 inch Hercus mill vise that I purchased. The vise came minus the screw, bronze nut and the cast iron boss that supports the screw at the rear of the sliding jaw. The rotary table gets a hiding compared to the dividing head.

Originally Posted by Anorak Bob

Hello Michael,

Undertaking a complex project such as your clock requires perseverance and I imagine being a member of a group with the same aims provides the encouragement to keep going. It's hard sometimes when there are a number of components that require completely different machining processes. I remember looking at a book twenty years ago on clockmaking written by George Daniels and thinking" where the hell would you start!" Impressive, complicated stuff.

I finished the knurled adjuster and centre this afternoon which concludes the making of the major components of the tailstock. When I cut the slot in the side of the centre for the locating screw, I first used a 1/8" slot drill in the vertical head. The drill skated erratically on the curved surface. Fortunately, there was little damage. I had the mill running at the highest speed but I may have come unstuck because it was a long series slot drill. Any ideas? The centre is made from 4140 bar. I successfully cut the slot with a slitting saw mounted on the horizontal arbor.

I've attached a couple of shots of the nearly completed project. The final component to make is the drive plate for between centre work.

Please post some more photos of your clockmaking efforts and also the No.O at work.

Regards Bob.

Hi Bob,do you have the drawings for the tailstock as I would not mind making one as it may be better than the Chinese one I have which is the fourth one on warrantyas the grubscrew and lock nut that stops the centre from turning they keep ripping the thread out plus I would like a bigger tailstock than what I have as you have very little adjustment to line it up with the dividing head

all the best derek

Hello Derek,

The drawings that I have consist of a number of very rough sketches. To redraw these in a clear, understandable fashion would take some time. Is it your intention to build a replica of the 3 ½ inch centre height Hercus tailstock or are you after a design of tailstock that provides angular and vertical adjustment?

Regards Bob.

Thought that it was about time I stopped lurking in this forum and put fingers to keyboard.
I purchased the mill (though this forum actually!) just before Christmas and have spent the last 8 or so months stripping it down and doing it up. I am quite pleased with how it turned out – I even braved cutting metal on it the other day.

So, another mill to add to the list.

Now, all I need is a dividing head, the tail stock, ....

The before and after shots are below

Regards,
Rodd

Very nice. Great to see the old Model O restored. Had mine nine months and all I have is a pile of bits. I'll get around to it sometime, hopefully before I forget where aall the bits belong.

Nev

So who is going to buy the one on ebay??

Nev and Michael,

Where are you?

A while back I received a box of mill parts from Hercus. Amongst the treasures within was a casting that turned out to be the predecessor of the offset casting, housing the drive gear for the vertical head. Having never seen a real Hercus slotting head and having next to no chance of finding one, I decided to have a go at making my own utilizing this casting.

If you are around and interested, I can show you the progress.

Regards Bob.

I used one of these mills brand spanking new in high school in 1985, it was shipped with a small grease gun filled with white grease so I faithfully pumped the vertical head full of grease and ran it for a while; it got so hot it could not be touched. It turns out the grease nipple was really an oil nipple and the supplied grease pump should have contained oil. No real damage done (I hope)......these days the machine shop is for pottery or basket weaving or something. There was also a model 260 and a Hercus shaper too.

Originally Posted by Anorak Bob

Nev and Michael,

Where are you?

A while back I received a box of mill parts from Hercus. Amongst the treasures within was a casting that turned out to be the predecessor of the offset casting, housing the drive gear for the vertical head. Having never seen a real Hercus slotting head and having next to no chance of finding one, I decided to have a go at making my own utilizing this casting.

If you are around and interested, I can show you the progress.

Regards Bob.

I'm here. Must have missed this post. Yeah, show us what you are up to.

Nev