Hack Chat Transcript, Part 1

A event log for Mechanical Timekeeping Hack Chat with Clickspring

"Tick, tock, everything's a clock."

Dan MaloneyDan Maloney 02/03/2021 at 21:070 Comments

Chris11:59 AM
Hi Folks!

Nicolas Tremblay11:59 AM
Should be fun and a bit different from the usual chats.

Chris11:59 AM
How is the day treating you so far?

mmca joined the room.11:59 AM

Mark Jeronimus12:00 PM
rainy. bri'ish weather

mmca12:00 PM
G'day Chris

OK everyone, let's get started. Despite my earlier mistake, today we're very excited to welcome Clickspring to the Hack Chat. I'm Dan, I'll be moderating today, BTW.

Hi Chris, welcome aboard. Care to give us a little rundown of how you get into the horological arts and sciences?


Tian van Rooyen joined the room.12:02 PM

Steve Pomeroy joined the room.12:02 PM

Chris12:02 PM
I kind of wandered into it sort of by accident - I had just started to build up a small home shop and wanted a project that wasa bit more meaningful than just something that would sit on a shelf, abd I thought, hmmm a clock would be good!

Steve Pomeroy12:03 PM
Any suggestions for some good starter projects for someone just getting into brasswork? Clearly a clock is quite ambitious :-)

Chris12:03 PM
A bit of digging into it, and I soon found that it was this amazing intersection of art, science, math - and I was hooked!

Wooden clocks seem like a popular entry-level project. Did you start there or jump straight to metal?

selective.luddite joined the room.12:04 PM

Fjodor12:04 PM
what made you decide to build the clock you ended up building?

Chris12:04 PM
For me the best way to get into it was exactly that - getting started on building a clock

Dan Twedt12:04 PM
can I 3d print a binary 24 hourglass?

andypugh12:04 PM
The difference is that you built the clock. I was at the same point, then decided that the lathe would be more useful CNC... And ten years later the clock is still just a few gears and a mainspring barrel.

John Dugan joined the room.12:04 PM

Ken Berkun12:04 PM
FWIW I've just started assembling this kit, very easy and straightforward. I can't wait to hear it ticking!

Ken Berkun12:05 PM
(replying to question about wooden clock kits)

Chris12:05 PM
There are a lot of tools to be made as part of the process too that are excellent practice for getting acquainted with the machines - the brass scriber project I did for Make: is pretty much the perfect first lathe project

Mark J Hughes12:05 PM
@andypugh I never got past "gee, that looks like a fun project" so you're still one step ahead of me.

Nicolas Tremblay12:05 PM
@Ken Berkun WOW nice kit

Chris12:06 PM
It's all a bit daunting at first, but its like anything elso you dothat's complex, just break it down into components and then start making

Rob Ward12:06 PM
Do you have any formal qualifications Chris?

Nathan Brown12:06 PM
I second the Brass Scriber! I made one on a unimat from the 1970's

Dan Twedt12:06 PM
hams have to ID every so often... maybe pitch a mechanical clock to them 73 de KK6VDR

Chris12:06 PM
No quals in this fiedl at all

Chris12:07 PM
I've learned entirely from books and videos, highly recommend the DLC course material from the British Horological Institute:

andypugh12:07 PM
@Mark J Hughes I got this far...

Chris12:07 PM
oooh lovely work Andy!

Juan Sandubete12:07 PM
wow, nice site Chris. Lovely at least

@Dan Twedt - A mechanical clock that mechanically sends your callsign in Morse every 10 minutes? Now that would be cool!

Steve Pomeroy12:07 PM
Also, I just wanted to say thank you Chris for inspiring me to get into working with brass (by hand). I'm a computer guy by day and so this is a refreshing way to get away from screens.

andypugh12:07 PM
@Chris I imagine you have read the Daniels Watch Book. Does that tempt you at all?

Rob Ward12:08 PM
But any degrees, certificates in anything? I am interested where your capacity for research and precision working comes from.

Michael Möller12:08 PM
@Chris "I had just started to build up a small home shop" - lathe pressdrill, scrollsaw, all for metal work - doesnt seem a "small"


Ken Berkun12:08 PM
@Nicolas Tremblay my wife gave it to me for Christmas. Um, a year ago. Finally getting to it.

Mark Jeronimus12:08 PM
I researched A LOT about horological movements and parts on the free parts of the net, mostly about complications (extra features expensive watches have). Now a clock seems like childsplay. If only I had a workshop.

Chris12:08 PM
Yes, barely a day would go by where I don't pull out either that book or this one from Malcolm Wild:

selective.luddite12:09 PM
@Michael Möller His workshop is *really* smalll :) Have you got a link to your blog on it @Chris ?


Blog Archives

My shop is definitely what you would call 'compact'. At 1.7m x 3.8m, its not much more than a walk in wardrobe! I would say it is best described as like a galley kitchen... without any food. I walk in, and basically from a standing position, I can reach pretty much everything I need at any time.

Read this on Clickspring

andypugh12:10 PM
Yes, big home workshops are people like Steve Summers or Always Sunny in the Shop.

Chris12:10 PM
@Rob Ward I have a Mech Eng degree

Fjodor12:11 PM
any plans for designing your own clock and making that? maybe add a strike train or other complications?

Steve Pomeroy12:11 PM
For folks like me who don't have a mech eng degree, are there any good resources that you know of to learn those ropes?

Chris12:11 PM
@Fjodor Yes, I am protoyping all of this years projects at the moment, one is a clock movement

John Dugan12:12 PM
I'm trying to recall the specifics, but in school for a CAD and then machining course the entire thing centered around this clock that I believe was intended to be an apprentices first project.

andypugh12:12 PM
Not wanting to put words into Clickspring's mouth, but I don't think that there is as much intersection between a MechEng degree and clockmaking as you might imagine.

Chris12:13 PM
@Steve Pomeroy Yes certainly - you can get started with the two excellent books mentioned above (Daniels, Wild), and without doubt, the Distance Learning Course from the BHI is a very good starting point too.

Nathan Brown12:13 PM
[insert 20 minutes of thanks and praise here ]


Have you learned any surprising lessons from ancient hand cut gears that make your hand filled gear better today?

bundeena47 joined the room.12:14 PM

Juan Sandubete12:14 PM
@andypugh hhmm well, the system for energy harvesting and storage in those spring accumulators may be some related to MechEng

Chris12:14 PM
@andypugh Yes, correct. I mention the degree only because it was asked, but its essentially irrelevant tothe craft, although it probably has contributed to things like comfort with CAD etc

Gilliam joined the room.12:14 PM

Mark Jeronimus12:14 PM
@Chris how long did it take you to master 'making square holes with a vile

Mark Jeronimus12:15 PM
I often have to make square holes in plastic project boxes, and I always overshoot my target dimensions (especially in the corners)

Chris12:15 PM
@Nathan Brown Probably the biggest thing I've learned is that tooth profile in mathematical gearing has almost no bearing on friction. I was quite surprised by that.

Nathan Brown12:16 PM

Mark Jeronimus12:16 PM
Tooth profile has a lot to do with the linearity of the motion transfer

Marcus12:16 PM
What CAD package do you use?

andypugh12:16 PM
@Chris Indeed, that was what I was trying to say. Not having a mech eng qualification is absolutely no reason to not try making a clock. (did I get the right parity on those negatives?)

Chris12:16 PM
@Mark Jeronimus They are a pain in the neck every time! The main things I find I need are good workholding, and light. Be sure to check out that filing tips video I did a while back, its all in there.

Steve Pomeroy12:17 PM
Chris, your videography is absolutely amazing and has been from the start. Did you have any background in it before your first clock?

John Dugan12:17 PM

Chris12:17 PM
@Mark Jeronimus Yes, agreed. The triangular profile has a really wierd velocity profile, several full stops, ramps etc. So awful for power transfer. But for simple calculation non of that matters.

Danail Ivanov12:18 PM
@Chris what measures you take when dealing with tolerances?

John Dugan12:18 PM
*Sorry didn't realize that was going to send right away. That was the result of the aforementioned CAD exercise. Didn't mean to derail.

Chris12:19 PM
@Steve Pomeroy Thanks very much Steve! No background in video making, I just dove into it. I think my chosen field of making helps enourmously, the subject matter is natuarally photogenic.

andypugh12:19 PM
@Chris Here is a question that I find myself asking every time I watch one of your videos: You are really skilled with the fretsaw and with files. So why do you cut so far from the line? Is it to get even more filing practice?

Rob Ward12:19 PM
@chris People I show your videos to are very surprised that the ancients had metal working lathes. Would you consider making a proto-lathe like you did for the drilling machine to explore what it might have required?

Chris12:20 PM
@Danail Ivanov It depends a bit on the part - for something like the perimeter of frames, large cosmetic parts etc, it might be as large as +- 1 or 2 mm. If its somethinglike the center pinion of a very small timepiece its going to be +- 0.01

Steve Pomeroy12:20 PM
Chris, yeah it's true that they're totally photogenic, but adding the details like filming the switch turning on/off, and the start/stop of a long process is extremely satisfying.

Chris12:21 PM
@Steve Pomeroy So pleased you're enjoying them mate :)

Mark Jeronimus12:21 PM
@Rob Ward check this fella

Chris12:22 PM
@andypugh Great question, I get that one a lot! I really don't like to rework a part, and so that's my way of managing that risk. It's just too easy to drop a cut inside where you ultimately want ti to be. I'm better with a file at close range!

Juan Sandubete12:23 PM
any thoughts on harmonic gearing for clocks?

I imagine a lot of the time spent dialing in the precision with hand files ends up on the cutting room floor, so to speak.

Nathan Brown12:25 PM
Do you have any mental techniques for keeping focus on your projects? Especially when you find you need to make yourself another tool, or to do the side research like you did on the AKM.

Steve Pomeroy12:25 PM
Perhaps this is a bit of a metalshop n00b question, but what's the best way for dealing with metal dust collection?

Chris12:25 PM
@Rob Ward Yes, its in the works now. Documented proof of lathe tech from the era is almost non-existant. What we do have tho is the result of the tech, so its well implied (along with mentions by Vitruvius etc that carry little actual detail) The Antikythera Mechanism is itself awesome proof of virtually all of the fine metal arts tools required and used all oftheway up to the 18thC

andypugh12:26 PM
@Rob Ward A lathe can be very simple. See this one for example (it's rather remarkable for the unconventional choice od limbs to operate it with)

Chris12:26 PM
@Juan Sandubete Tell me more

Mark J Hughes12:26 PM
@Steve Pomeroy I like to breathe it :) But it drops to the ground and you can sweep it right up. Doesn't stay in the air long at all like wood.

Steve Pomeroy12:27 PM
@Mark Jeronimus ha!

OMG, those tools must be scalpel-sharp

Fjodor12:28 PM
@andypugh that's basically the same setup as the very first lathes, bow driven.

bundeena4712:29 PM
@andypugh I prefer a pole lathe - at least you have both hands free for turning the job.

@Chris - Gday mate Jeff here

Mark J Hughes12:29 PM
Probably why Guy suggested that Jason construct a rudimentary lathe to defeat the rock monster.

Chris12:29 PM
@andypugh Exactly. Between center turns essentially takes care of all of the turning requirements. A watchmaker today will still be totally comfortable with this tech - Roger Smith has some terrific videos on the subject. Much more robust tool, made for the scale ofthe work, but the principle is identical.

Juan Sandubete12:29 PM
@Chris no much to say!. I know they are widely used in robotics and idk if they have some applications for clocks. The thing on these harmonic gear is that they can reduce a lot the ratio in no much space and I guess it may be good for some random reason

Chris12:30 PM
@bundeena47 Hello mate :)

Fjodor12:30 PM
for a lot of fine turning (like watchparts) I actually prefer a bow powered lathe (or 'turns' to use horological terms). makes it more precise and you can stop right away if you notice something going wrong, rather than having the machine slowly come to a halt

Chris12:32 PM
@Steve Pomeroy For shop cleanup, I have a mid sized home central vac, plumbed around the walls. You might be able to see the piping in the videos.

bundeena4712:32 PM
@Fjodor several of the members of the Clickspring discord are watch makers with manually powered lathes but foot powered keeping their hands free.

Chris12:32 PM
I don't usually have to deal with dust so much, but definitel;y having a clean shop means I lose fewer parts!

selective.luddite12:33 PM
Another advantage with the 'Turns" is that you can repeatedly remove the work (for checking etc) and return it and it will still be perfectly centred.

Mark Jeronimus12:33 PM
harmonic gears sound like a power hog. And clocks must be as power efficient as possible

andypugh12:33 PM
(Anyone who likes seeing Clickspring at work should probably watch the Roger Smith videos too. I especially admired the Straight Line Engine one)

Steve Pomeroy12:33 PM
Woah, central vac! You don't see those much in the States

Fjodor12:33 PM
@bundeena47 I guess that's just preferences, I've tried a foot powered lathe once, once! :')

Danail Ivanov12:33 PM
@Chris Do you find yourself demotivated, feeling down? Where do you get inspirations from? What makes you continue with your work?

Looks like you do most of your really messy stuff outside.

Chris12:33 PM
For all here, @selective.luddite is a genuine expert on this field, and has made several working machines

Juan Sandubete12:34 PM
@Mark Jeronimus any number to show on harmonic gear efficiency? just curious

kags joined the room.12:34 PM

kags12:34 PM
HI Chris from Discord Patreon Chat

bundeena4712:34 PM
It was @selective.luddite I was referring to.

Chris12:34 PM
@Steve Pomeroy I splashed out! I was sick of the weak vacs you get from the hardware store...

Chris12:35 PM
hey @kags :)

Chris12:36 PM
@Dan Maloney Yes mostly - I'm lucky to have a bit of space next to the shop, so all of the really messy stuff can go outside.

selective.luddite12:36 PM's me (Duncanbootmaker on the Discord chat). Are you confusing me with someone else?

selective.luddite12:37 PM
I don't think of myself as an expert; just interested in stuff.

Chris12:37 PM
@selective.luddite No, just promoting your talents :)

bundeena4712:38 PM
@selective.luddite I'm Jeff A on discord. Agreeing with @Chris

Juan Sandubete12:38 PM
@Chris btw, do you run simulations with the designed system before building it up or you get there directly with your maths?

Juan Sandubete12:38 PM
how much accuaracy do you get with them? estimate only jaja

Chris12:39 PM
@Juan Sandubete I model everything in CAD, if only to getit straight in my head. Lotsa problems solved right there.

andypugh12:39 PM
@Juan Sandubete I just designed a harmonic clock in my head. I was going to show off and CAD it up but realised that F360 doesn't do gears easily. Here is the idea. A 59 tooth gear inside a fixed 60 tooth gear. The second hand is driven by <handwaving> and has an eccentric round it, which oscillates the 59 tooth gear just enough to engage the fixed ring gear. The minute hand is engraved on the oscillating gear. I haven't got as far as the hour hand yet.

kags12:39 PM
Which tool do you wish you had bought earlier ?

andypugh12:39 PM
(internally-toothed 60 tooth)

"I just designed a harmonic clock in my head" -- wow

Chris12:40 PM
I tips me hat to you @andypugh !

selective.luddite12:40 PM
....ok.... Thanks guys ( pressure.......) Good to see a few from Discord :)

Ben12:40 PM
@Chris might have been already asked, but do you have any tips on how to keep motivated to finish projects?

Mark Jeronimus12:41 PM
@Juan Sandubete They have a lot of strain stresses. If you instead meant Cycloidal drive then I can imagine that sitting in a clock.

Fjodor12:41 PM
I do the same. I get ideas for clocks that I want to build some day (when I finally have the time from the stuff I get paid for to do) and just keep rolling those ideas through my brain every now and then to see if it will work. my daydreams are different than most I guess... :')

Chris12:41 PM
@kags I looove the little 1" belt sander from Delta Rockwell. Gets so much use, its crazy, considering what it is. They are no longer made, but if you ever see one buy it immediately.

juul van den bosch joined the room.12:42 PM

selective.luddite12:42 PM
I like the 'mental' clock design @andypugh :)

juul van den bosch12:42 PM

andypugh12:42 PM
A harmonic drive doesn't have to use a flexspline. The commercial ones do, but I see them as just one implementation of gearing that uses the Vernier princiole.

Mark Jeronimus12:43 PM
wiki the Cycloidal drive

kags12:44 PM
@chris My 1"sander is a non name brand but the moment that I clicked you could use the belt sander to sand brass was a eureka moment....cut down on the hand filing curves

andypugh12:44 PM
The problem with a flexspline is that eventually this happens:

(that's my own photo, an unlucky eBay purchase)

Chris12:44 PM
@Ben Best advice I can give is make projects you 100% are in love with. As in "I must have that thing, I want it soo bad I'm going to spend 12 months designing and then making it" kind of love... It gets real easy to get knocked off course by the never ending stream of problem solving. The love of the project itself is the key for me personally. Also, make it beautiful.

Chris12:45 PM
@juul van den bosch G'day mate :)

Mark Jeronimus12:45 PM
Evident from the hiatus on the AKM

juul van den bosch12:45 PM
Dragonlolz from the Discord chat :)

oneohm joined the room.12:45 PM

kags12:45 PM
The final assembly of something made from individual parts into this bigger thing that works just makes me smile

juul van den bosch12:45 PM
indeed that was quite the Hiatus, but damn right it was one worth it for the sake of science

@Chris - So does that mean the open-frame clock enjoys a place of pride in your home?

Chris12:46 PM
@Mark Jeronimus The AM research was soooo time consuming...

Mark Jeronimus12:46 PM
@Chris I would love to see the AKM finished sooner than later, but I even more want it to be as accurate as possible. I've been in love with the AKM since I first saw it in 2006 or so

Chris12:46 PM
@kags Me too :)

andypugh12:47 PM
@Chris Any feedback from the archaeological world about your proposal?

TekMakes joined the room.12:47 PM

Chris12:47 PM
@Dan Maloney It does indeed! Mrs Clickspring was the nominal beneficiary...

MaBe42 joined the room.12:47 PM

feezell joined the room.12:48 PM

Juan Sandubete12:48 PM
@Mark Jeronimus in terms of efficiency and so on, these gears seems to be the best. And, with good materials, idk what could be the problem with high stress

BTW, here you have a document about all the maths of harmonic drives (in spanish though):

Chris12:48 PM
@andypugh Nothing formal. The wheels of academia turn at a glacial rate.

andypugh12:49 PM
@Mark Jeronimus As you spotted, my idea has a lot in common with a cycloidal drive, but without the output roller stage.

Mark Jeronimus12:49 PM
@Juan Sandubete flexing generates heat, which must come from somewhere

juul van den bosch12:49 PM
are there any regrets from the Skeleton Clock in hindsight