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How To Make A Clock In The Home Machine Shop – Part 20 – The Crutch Assembly And Eccentric Bushing

How To Make A Clock In The Home Machine Shop – Part 20 – The Crutch Assembly And Eccentric Bushing

G’day Chris here, and welcome back to Clickspring. As I approach the end of the skeleton clock
project, its time to start work on a crucial part of
the mechanism, the escapement. Generally speaking the escapement is considered
to be the pallets and the escapewheel, but there are usually a few extra components
required to make the whole thing work, and its those related components that i’m
making in this video. There’s an eccentric bushing that permits
a small adjustment of the pallet depthing with the escape wheel, enabling fine tuning of the escapement. And then there’s the crutch assembly, which receives the energy released by the
escapement, and transmits it to the pendulum to keep it
moving. For materials, I’ll use a small piece of this
thin brass sheet to make the crutch fork, and a selection of rod stock to make most
of the other parts, The exception is the pallet arbor that I completed,
back in episode 12. So lets get started. The crutch assembly clamps onto the pallet
arbor, and is itself a small sub assembly consisting
of 3 parts: the fork that embraces the pendulum block,
the arm and the upper fitting. Now this upper fitting has some complex features
crammed into quite a tight space, and given that its such a small part, its a great candidate to be formed on this
small lathe. Once centred in the 4 jaw chuck, I gave the stock a quick facing cut and then formed the central hole that’ll accept
the crutch arm. Next I removed the headstock, and set up the lathe for its rather unusual
method of forming a taper, in this case an included angle of 20 degrees. With the taper formed, I transferred the work
to the mill, to put in the other features. The embryo part can now be cut from the parent stock, to form the small clamping slot. But before i make the slot, here’s a closer
look at the fastener hole. One half has been drilled for clearance, and the other half is at the correct diameter
to be tapped for the fastener thread. The slitting saw takes out the transition
point between the two inside diameters, leaving the smaller diameter isolated on one
side, and ready for tapping. Back on the lathe, a facing cut reduces the
part to size, and leaves a clean cut on that upper surface. A final light touch with an oilstone takes
care of the sharp corners, to complete the part. Ok, so that’s the top fitting taken care of,
now for the fork. Wildings plans have the arm connected directly
to the fork, with a spot of silver solder. But I’ve modified the design to have this
little extension to receive the arm. Its not that much of a change, but it should
make the join to the fork a bit stronger, and perhaps a bit neater too. I’ve turned a small spigot on the end of this
extension, to securely register the parts together as
they’re joined. That spigot will also serve another useful
purpose, which you’ll see in a moment. The base of the fork is a simple sheet metal
profile, and I’m using the template method to mark
out the stock. The scroll saw makes short work of this thin
brass sheet, and the belt sander brings it quickly to the
line. Now soft solder would probably be quite adequate
for this join, but given the nature of the intersection I don’t want there to be any doubts around
its strength, so I’m going to use some of this combination
flux and silver solder paste to do the job. Its a very convenient way to accurately position
flux and hard solder around a small join like this one. I’ve got the work set up on this pumice stone
to protect the bench, and the heat is being applied using a small
butane torch. Up close, you can see the flux run, leaving behind a tiny matrix of silver solder
adjacent to the join. A little more heat, and then that solder melts
and wicks into the small gap between the parts, while the excess solder forms a nice fillet. The part can be cleaned up with some acid
pickle, but in this case I’d like to take a light
pass with a cutter to bring up a fresh metal surface. So I’ve I’m using super glue arbor to hold
the workpiece, and that small spigot I mentioned previously to locate the part on the central axis of
the lathe. Some whisper thin cuts with a universal cutting
tool remove the flux, and reveal some fresh metal. And I’m happy enough with a tool finish for
this part, so I’ll leave that as the final surface. The spigot has done its job, so that can be
taken off with some abrasive paper, leaving a grained surface finish on that underside
surface. The final step for this part is to use needle
files and abrasive paper to bring the perimeter to final shape and
dimension. As for the upper fitting, a light touch with
an oilstone breaks the sharp edges, leaving a presentable edge, and that completes
the fork. Next up is the arm of the sub assembly, which
is a nice straightforward part, made from thin rod stock. The plans specify brass rod, but I’m using
drill rod of the same dimension, for the material contrast. Once cut to length, I tidied up the ends on
the belt sander to make them a good fit into each of the crutch
fittings. The bend locations are positioned roughly
one third in from each end, and it really is just as simple as getting
a good hold of it in the vise, and giving a careful push until its about
right. The 3 parts of the crutch assembly are now
complete, so a small spot of Loctite on each end is
all that’s required to bond them together. OK, now on to the eccentric bushing. And this component can be thought of as an
optional extra. Its not strictly required, the pallet arbor
could simply be planted at the correct distance and left as is. But its a very helpful addition to the clock
mechanism, to permit fine adjustments to the pallet depthing, particularly as the pallets begin to wear
after a few years. You’ll get a closer look at its function in
the next video, when I use it during the initial setup to
minimise the drop onto the entry pallet. I started work on the part by forming the
basic profile, and then it was transferrred to the mill,
to form the pivot hole. The central axis was located with a wiggler, and then a tiny offset was introduced to the
spindle, so that the hole would be formed off center
– as the name of the part suggests. I drilled undersize at this stage so that
I could broach out the hole to fit the pivot later, and I used this roller cutter to form an oilsink. In this case I made it quite deep to account
for the fact that I’ll be facing the part once the screwdriver
slot is formed. I formed the screwdriver slot just clear of
the oil sink, and then took the part back to the lathe to
be faced to length. And at this point whilst the overall profile
of the part is ok, the entry and exit points need a bit of a
tidy up. So after a quick cleanup in some denatured
alcohol, I used a hand held countersink and an oilstone
to break all of the edges. The last of the parts to be made are the fasteners. In this case I need 2 to hold the bushing
in place, and one to clamp the crutch assembly onto
the pallet arbor. All three were made in the same way that you’ve
seen in previous videos, using the small lathe. They were then hardened, tempered, and then
polished and blued. Ok, so with the fasteners complete, I can start to put a few of the bits and pieces
together. Now In a previous video, I opened up the pallet
arbor pivot hole in the front frame as I positioned the regulator and suspension
post. At the same time I spot marked the rear pivot
position. So this time, I re-identified that position,
using a wiggler, and then with the required offset dialled
in, I drilled and reamed the hole to accept the
eccentric bushing. The two fastener holes were also formed and
tapped. And for the last powered cut on the frames, I formed the oil sink for the previously drilled
front frame pivot hole. A quick deburr of the hole perimeter, and the eccentric bushing can be installed,
along with the adjacent fasteners. As I did for the other pivot holes of the
clock, I used clockmakers broaches to open up the
holes to fit the pallet arbor pivots. And like before, I’m aiming for a decent amount
of angular freedom. Particularly since the eccentric bushing can
introduce an additional offset angle depending on where it sits in its rotation. Once it looked about right, I put the frames
back together to give it all a test fit. There is a bit of end shake for the pallet
arbor, and the crutch assembly coasts to a gentle
stop, indicating minimum friction. I’ve left the barest clearance between the
crutch fork and the pendulum block, to minimise energy loss, and the eccentric bushing is ready to be adjusted
as required in the next episode. Which leaves just a few key components to
be made, before I can set the clock running. Thanks for watching, I’ll see you later. And if you’ve just made your way into this
clockmaking series, thanks for checking it out. This is just one episode of a longer series, where I show all of the steps to make a mechanical
clock from raw metal stock, so be sure to check out those other videos. If you enjoyed this video and would like to
help me bring you more project videos like this one, then consider becoming a Clickspring Patron. As a patron of the channel you get access
to exclusive Patron only video content, free plans for the patron projects, and the chance to win the actual project at
the end of each build. Like for example this useful little hand vise. Find out more by visiting And finally, if you’re looking for some new
projects for your lathe or mill, then take a moment to visit where you’ll find a range of plans available
for download, including plans for some of the tools I’ve
made to help me construct this clock. Thanks again for watching, I’ll catch you
on the next video

Reader Comments

  1. I was trying to look up info about the roller cutter you used but all I seem to be getting online is drill bits for oil drilling, is there another name for it?

  2. Your videos are absolutely perfect. I'm a woodworker with almost no knowledge of metalworking and I love watching this series. Much love from California!

  3. I work as a drafter, and it would be interesting to see a video on how you model your parts digitally and what programs you use.

  4. My comment my come off as extremely strange, but, here it goes. Please accept this as a compliment and not anything negative! Over the past few months or so, I have been watching your videos, many of them several times, as they are so well put together, and I have commented on several of them, again, really fine work! Last night, I was watching this one again, and the girlfriend was on the couch reading one of her books, as she typically does, I was watching this video, ((hang in there, this will make sense in a moment))… Both her & I have a really hard time falling asleep, let alone staying asleep, we were just born that way, anyhow, I'm a few minutes into watching this video, and the next thing I noticed, she is completely knocked out asleep. I didn't put much thought into that, until the video came to an end, and then when your voice had stopped, she woke up, and under her breath asked me to continue to play the video, lol… still a bit lost, as to what or why she had asked me to keep playing your videos… ((please note, this has not been the only time she has comfortably fell asleep, while listening to your voice, lol.)) Talking with her today, I asked her if she would like to start at the beginning of your video set on clock making. Her reply was that she couldn't give two cares what it was you were making or doing as this kind of stuff is of no interest to her, ((((BUT)))) she mentioned how soothing your voice is, how calming it is, and she even stated that your voice is very sexy, lol. Of course, I wasn't catching on quickly enough, as I thought maybe, with my single tracked mind, me and her would both sit together on the couch and watch your videos from the beginning, due fact, of how amazing your videos are. I don't really know how to state my point to you, other then, my girlfriend absolutely just loves the sound of your voice and how smooth your narrations of your videos are, so much so, that the calming effects of your voice allows her to fall asleep, and stay asleep for the duration of your video(s)… lol… She was funny, when trying to explain how it felt listening to your voice, she said, (( I don't have a freakin clue as to what the heck he is rambling on about, and I don't even care, all I know, is that his voice is so relaxing and nonthreatening, that it actually calms me.)). lol. Myself, from the first video I seen of your productions, I always noticed how well they have been put together, extremely systematically orchestrated with perfections in every detail. Like I have mentioned in previous comments, Thanking you for your attention to detail, the lighting, camera angles and to not take for granted that some of the elementary methods & techniques that not every person will know them, and you'll include them, for benefit of the doubt, I thank you for that. Now, after discussing this deal with the lady today, I think I have to agree with what she has to say, your narration is very calming and nonthreatening to listen to. Please accept all of what I have stated, as a compliment! If you feel that this is inappropriate, I will understand 100% if you desire to remove this comment, I will not be offended at all, but, I did think you would find it either funny, or odd, or at the very least, entertaining? You can now add one more beautiful woman to your list of followers, even though, she doesn't care what you are talking about… lol. Again, great job on this video as well! OH, I am supposed to ask, what your accent is or your nationality is, as she wants to try to find online stories or documentary's that have your accent, as that is something she does as a sleeping aid, listening to online books with those little ear bud things, unless, it is to block me out from my snoring? I suppose the last question is a bit rude, you are not obligated to answer, I'm sure she be hunting for various book narrators, until she finds one that would do the trick… Thank you, please pardon the oddness of this, Drew

  5. your camera is too good for your own good Chris… the ware is stating to appear at 16:00, no complains though some polish will solve that …. awesome video as always, can't wait to see it running

  6. Next project can you whip up one of the moving map cities from the Game of Thrones opening? Maybe Bravos or Mereen? ;P

  7. Thank you for sharing your world. You are quite skilled at what you do and it shows. Your attention to detail and patience with explaining how every step works is truly remarkable.

  8. The craftsmanship in this series is amazing. I just built a 1911 hand gun and thought all the sanding and fitting was difficult. I can't imagine doing all the work needed for something like this.

  9. Great work! If your still open for suggestions for next project then something I would want to see was a moving mechanical Planetarium, with your skill and explanation I think that would be amazing. 🙂

  10. +Clickspring. You have spoiled machining videos for me now. Everything else pales compared to your little journeys into machining.

  11. Chris, it's a joy to see your work mate and it is inspiring. Now if by chance you produce a full build video of the project as was mentioned in the comments, I would be more than happy to upload it for you since my net connection is over a gigabit. I would need you to mail me a copy once it's completed on any media you choose – even vhs! lol Think about it and if you decide to do it then email me and I will send you my address. Thank you for sharing your skills with the world. Cheers!

  12. Wow, what a wonderful series! Was told about your channel the other day and I've just finished watching all of your videos.
    You've done a bloody brilliant job with the production quality of these videos.
    Cheers for the knowledge and entertainment, keep it up Chris!

  13. I just have to say, the production quality of the videos themselves and the knowledge presented in the actual content of the videos is astounding!

    I just can't understand how you both know how to make, use and build both the tools and the parts and at the same time know exactly what camera angles, editing cuts and special effects (the 3d-overlay when doing certain parts) that creates a pristine video. Also, the soft and really nice voice is not taking away from the quality either. The videos are just long enough to make me want to watch a bunch more, while keeping the pace going. The explanations given are short and concise enough to allow me to understand what's going on, while not overexplaining stuff I could easily google if I wanted more knowledge about.

    These videos are as near perfect as I could possibly imagine a video series to be. Amazing work! (Are you a team doing these videos or just one guy? From the vast amount of knowledge required to get this kind of quality I'd argue there must be a team, but I've been baffled by single person projects before)

  14. My dear man you have some skills that a man like me would kill for if this is what you do for a hobbies WHAT do you do for a day job ??

  15. Hey Chris! I was wondering, where are you in the world? You sound Australian, if so, where in Australia? 🙂 Once again, great video!!

  16. I`'ve been almost entranced as I've watched every video. I was only going to say "Thank you". But I must also say, whoever calls you an amateur must be a God. I look forward to more.

  17. just awesome! im following this project since the 3rd episode or so.. when she was ticking the first time on its own.. goosebumps 🙂

  18. anyone have any information of how to make a simple moving pendulum school project for young children? I'm trying to to a dancing Santa for kids at my school.

  19. Can you give a little more detail on how you blued the brass screws? Was that copper wire you wrapped around them and heated up? Was any chemical applied to the brass screws before heating? How long do you heat it?

  20. Your videos are sharp and very neat to watch. This was no exception. I can't help but wonder though: What part(s) had to be done multiple times (or planned out by using multiple test pieces) until you were happy with the process from start to finish? Some of your processes are so intricate that it seems like at least sometime you must have to redo something as you rethink the process and see something you want to do differently. So, what part or parts gave you the most trouble or at least required the most trial and testing before you settled on the final design?

  21. This series is with out a doubt the best most interesting, well made ,well filmed, subject on YouTube
    and I can't stop watching it

  22. You are the friggin' Frank Howard of the metal-working world. He's a wood-worker.
    Beautiful work man, simply splendid.

  23. You could make youself a small pipe/rod forming press. All you need is 3 rollers of which one moves. I'm a metal fabricator and I love forming rods and pipes.

  24. How do you get the super glue cleaned off the parts? By the way, I truly enjoy your content and I have had it on my goals to get a metal machine lathe this year.

  25. I remember a friend telling me that if you had a lathe you could build every other tool in the shop. Never thought that was true, but after watching these I'm starting to believe it.

  26. You do know you can start your tap in a drill press for a square tap. Put the tap in the drill chuck and start it and then shut it off and let it screw into the work and come to a stop. Now loosen the chuck and finish taping it. Square taps made easy.

  27. Your machining and finishing skills are second to none mate! Such patients and precision. Makes me want to buy a tabletop lathe and give it a shot making something. I look forward to future projects for sure!

  28. hi! Where do you get your oilstone? My father asks for his sharpening tree grafting knifes and tools. I appreciate your response. Keep up with the good work. Thanks!

  29. Something I've been wondering since I first watched this series:
    If the solder is silver, why does the fork appear to be all solid brass after you machine it after soldering?

  30. 01:50 – I seeeeeee! Those runners are to hold it true when you have it at zero! That keeps it sturdy when you need sturdy, but flexy when you need flex! You've no idea how much I'm soaking up from watching your channel! Thanks again for a great video, Chris!

  31. What is that rolling cutter? What does it do that a ball endmill wouldn't? And why does it have to roll? I have so many questions, but unfortunately it's so niche that Google doesn't even know what that is.

  32. The quality of your videos is just stunning. Everything about it. I have no real idea what is going on on the machining part, I'll probably never get close to a lathe, but boy am I impressed with what you do and how you present it. There is not one single shot out of frame, nothing out of focus, everything aims for perfection. WOW!

  33. er… What silver solder did you use? It was not in your list for some reason? How do you clean the super glue off from the back plate?

  34. I often forget to hit the like button, being in such a rush to see the next episode. Thanks Cris for the amazing art work, incredible!

  35. FFS, I am really hungry, have good food in front of me, but I don't want to look away to eat it… Your videos are too good.

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