I applaud your selection of red bricks ($$$!); the contrast between the supporting structure and moving parts helps the viewer visualize details. The measured slow down of the drive train during the test run makes it appear as if the manual energy was stored in a weighted flywheel, yet it's all Lego!
honestly, making the videos is a drag. tedious and laborious. i promised some family members a timepiece of their own, so i was commited to the task. i still have to shoot the tutorial for adjusting and tuning the clock. draaaaaaaggggg..... KEvron
***** Your step-by-step frames would have driven me bonkers to film and cut so cheers for sticking with it! I tried making guides by using LEGO Digital Designer but it doesn't have some of the old bits you use here. Also for complex builds I found LDD generates crazy instructions. Yet to find the right tool for sharing Technic designs.
Really epic!!!!!!!!!!!!!! The content on your channel so far will totally shows that you have potential in the TH-cam community!!!!!! I subscribed because you really deserve the push towards getting more subscribers! Keep it up and props!!!!!
thanks for your excellent questions, Richard. i'd reply to you directly but, for some reason, your linked comment lacks the "reply" button. i've been designing these things for about 14 years now. each design is built upon previous successses. earlier pieces reveal to me my design flaws, as well as the limitations (and possibilities) inherent to my chosen medium (wonderful lego!), so i try to overcome those flaws and limitations with each subsequent attempt. i originally intended the galileo clock i presented in may of last year to be a skeleton clock like this one, but i quickly talked myself out of such a design as i didn't think i could succeed at a viable piece. after devising a new knife edge suspension for the pendulum, i immediately realized its potential wrt a skeleton design. that piece gelled rather quickly for me (maybe a few days). still, never one to rest on my laurels, i continued to develop the piece. in fact, the clock seen in this video is the fourth of now five incarnations! much of my development time is spent in deliberation rather than actual construction, so putting a time frame on any given design gets complicated. best said, it's an evolution. drive train ratios are predicated upon my desired drop rate of the drive weight and the limitations of the lego. you can throw only so much drive weight on a piece before it ultimately yields! scape wheel size - specifically, the tooth count - has a lot of influence over the final drive train design; a 40t scape wheel design requires about 1/5 of the drive weight that an 8t wheel design with the same drop rate would require. then there's the pendulum's period rate. a one-second pendulum runs out twice as fast as a "seconds" (two-second) pendulum, and the seconds pendulum has a better q factor than the former, but it can be unstable, being more susceptible to disturbances to its swing. i find the unconventional 1.5-sec pendulum i've used in my last few designs to be a good compromise; more stable than the seconds pendulum, runs longer than a one-sec pendulum, its proportions are more aesthetically suitable than the much longer seconds pendulum and its rate allows the 40t scape wheel arbor to double as a second hand arbor. i hope i've adequately answered your questions. happy tinkering! KEvron
@kevronista Thank-you for this design, I've always wanted to build a Lego clock and this was just the insperarion I needed. This is not like any other build I have done before, in fact the build is just a few minutes work, but getting to run.... aghhh! Afyer a week of fiddling mine will now run for 40min at best. I have rebuilt it twice with different selections of part (non of them are new). The pendulum just stops swinging. Still working on it... Thank-you.
i'm glad you're enjoying it. yes, the build is pretty simple; it's getting it to run reliably that takes all the effort. stick with it, you'll get it. i''ve been sitting on an improved version of this clock. i'll get around to posting video of it soon, so stay tuned. happy tinkering! KEvron
This tutorial, along with the tuning/adjustment video, is fantastic. My 7-year-old is fascinated with clocks, so we bought the parts and are building your clock together as a Christmas present (for both of us!). I don't think I can say thanks enough. It is all assembled and the parts seem to function as they should,, but we do have one fairly major problem. The pendulum doesn't seem to be able to maintain its momentum for more than 2 minutes. We get between 80-100 ticks out of the clock but after that the amplitude has diminished enough that the pawl and the pallet can't do their job. I know that the weight (I am using an 8-oz swing bottle) should be enough to keep the pendulum moving, but for some reason, I guess there is not enough energy being transferred, or maybe there is some other adjustment I need to make that I am not thinking through. I have tried a 16-oz weight, and that seemed to increase the run time to 160 ticks (4 minutes), but clearly that still isn't enough. Maybe there is too much friction somewhere in the gearing and the force from the weight is too diminished by the time it is distributed to the gear interfacing with the pallet? I was wondering if you might have any advice. I can certainly post video if you think that would be helpful. Thanks!
+Jason Walther you shouldn't expect your results to match what you see in the video. even the slightest deviation between my adjustments to the action and yours can result in significantly different results for each of us. this is especially true of a galileo-type escapement. it may be the case that the action between the pendulum pallet and the scape wheel could be improved. another possibility is that the action is fine, but the pendulum's amplitude is greater than that seen in my video, so will require more drive weight to maintain the swing. a rub in the drive train could be the culprit, but such issues tend to be cyclical; the rub causes the stoppage to occur in regular intervals. remember that it's not just how much power you apply to the scape wheel, but how long the tooth on the wheel maintains contact with the pendulum's pallet. you want to adjust the action so as to maximize that contact time. the greater the percentage of the swing in which the scape wheel is in contact with the pallet, the more push you get from the wheel. often the culprit here is unlocking the scape wheel a little too early. "too early" can mean the tiniest of adjustments! hope this helps. if you want to publish video of your piece, i'd be happy to try to analyze your problem. be sure to include a straight-on view of the escapement in action, and douse it light! KEvron
+Jason Walther i think the problem is as i suspected, that the scape wheel is unlocking just a bit too soon. try another adjustment to the unlocking contact. you might also try closing the headroom gap between the scape wheel and the pallet. when the pallet swings in toward the scape wheel, you want only enough clearance to miss the gear tooth. it's hard to see in the video, but it looks like you have just a bit more clearance than you need. one way to do this is to adjust the pallet, which is actually two adjustments, and can be quite tedious, or you could try elevating the position of the locking pall. as the pall position goes up, the gap between the scape wheel and the pallet closes. of course, too much of an adjustment here will close the gap complete, and the pallet will collide with the scape wheel. lastly, do check all of your arbors for rubs, especially where the position of the arbor is held by bushes. also, you don't want to much play in the arbors, either. just enough to ensure smooth performance. i don't think this is the problem; minor rubs tend to be problematic only at the scape-wheel-end of the drive, where the drive runs fastest but has the least torque. hope this helps. keep me posted. i'd hate to think i've given anyone a bum steer. KEvron
+Jason Walther ....something else: i couldn't get a good look at the action of the locking pawl, but it suspect it's catching more of a bite on the scape wheel tooth than it needs. it should be adjusted so that only enough of the pawl interacts with the wheel to stop it. you want just the edge of the pawl to catch just the edge of the tooth. now, if you catch too little, the scape wheel can skip off the pawl, causing run-away, so you'll have to watch for this. the depth of the pawl's bite is set with that arm above it, the one with the two pole reversers; one is to keep the lever from falling away from the escapement, and the other to prevent the pawl from penetrating the wheel too deeply. also, you want only enough mass on the counter-weight to assure proper performance. any addition mass is just extra resistance on the pendulum. adjust the mass by sliding the weight along the axle. the closer its position to its arbor, the less is its effective mass; the further from the arbor, the greater the mass. everything in the design is about "only just enough." but that's a galileo escapement, and that's why only hobbyists bother to use it. it's probably the lousiest pendulum escapement design, but it's the easiest to realize in lego. happy tinkering! KEvron
+KEvronista Thanks for all the pointers. I've been walking through some of the adjustments, and I just thought I'd add something else that I've noticed after some of this tinkering: it seems like no matter which tooth of the scape wheel the pendulum starts on, it always stops at the same three or four teeth. I may be deceiving myself, but it also seems like those three or four teeth are just a little shorter and don't give the same "push" to the pallet that the rest of the teeth do. Have you ever seen problems with the scape wheel itself? Could it be that the LEGO gear I am using is not symmetrical enough? I might try switching it out later, but if this is a red herring, I'd rather not go through the trouble. It seems like if the pendulum has enough momentum, it should be able to withstand a few slightly shorter teeth...
Jason Walther *"it seems like no matter which tooth of the scape wheel the pendulum starts on, it always stops at the same three or four teeth"* that would indicate a cyclical issue. something in the drive train, and probably near the scape wheel. again, check your arbors for sufficient play, and check that the clock frame has no loose connections, especially where the uprights attach. you may also try changing out the last two or three arbor assemblies (the scape wheel arbor and the next one or two arbors). be careful not to mix in any of the replaced parts with your substitutes. but try the pall depth first. displacement of the pawl is the only work that the pendulum must do, but the task can require a lot of energy, relatively speaking. if improperly adjusted, it'll require more energy for the pendulum to displace it than the pendulum receives from the scape wheel. KEvron
Yet another fantastic (lego) clock design! It is just magnificent (as are its predecessors). However, I was wondering how long it takes for you to design your clocks, and how you decide upon the gear ratios. Cheers, Richard
One more thing: at 6:00 in this video, when the second differential gear casing goes in with the other two small gear assemblies on that side, there's something amiss. Either there is a missing step, or the differential is backwards. The six gears on that side -- those at either end of the differential, the two joining those one bracket down, and the two attacked by axles to those last -- only connect to one another. They don't engage anything in the drive train. Could the differential case be backwards? Or am I missing something? Thanks!
no, the steps are correct. the 16t crown on the second diff meshes with the 16t gear on the hands arbor (5:10 assy). the 24t gear on the smaller of the other two assemblies will mesh the 24t crown to the drive train; it spans the gap between the diff and the drive, and it corrects rotation. KEvron
***** I believe the solution to this issue is demonstrated in another of your videos. Lacking the Technix reverse-arbor pieces (I think that's the right term), I used a 1x2 with hole plus a 1x2 no hole, stacked, in each place to keep the differential properly spaced from the other assemblies. This turns out to be too far. I am going to try replacing the 1x2 no-hole with 2 1x2 plates, which should allow the 24t gear and 16t gear to engage properly.
i've never priced the parts. the chains, alone, will run you $30+. the clock and the pendulum, maybe another $40. i have another piece for which i'm preparing to shoot a video. it's another skeleton clock like this one, but it uses string instead of chain. the string will shave $30+ off the cost. KEvron
I just purchased the "string" version on BrickLink. It is my first time so perhaps I am not doing it cleverly, but I managed to purchase via 3 shops. Grand total = 65€, of which 25€ shipping & handling.
Thanks again for the great instructions. The clock is sitting in the living room, ticking away. One question for you -- is there a reason that you didn't bring the second hand up to the clock face? Some of your earlier models use a small 1X1 plate with a tooth as a second hand offset on the clock face. I'm thinking about trying to do something similar with this, but I wanted to check and see if there were some major pitfalls I should try to avoid.
the second hand is driven by the scape wheel axle, which puts it at the very end of the drive train, where additional mass has its strongest resistance. keeping the mass of the second hand assembly to a minimum should be considered. also, technic axles tend to have a little bend to them. the longer the axle, the more noticeable the bend. to put the second hand at the face would have required a 10L or 12L axle, and that bend can adversely affect the performance of the scape wheel. for my most recent version, i've put the second hand right on the scape wheel axle, using a white, 1x2 thin liftarm and a 7L axle, counterweighted with another 1x2 thin liftarm, neutral color. this simplifies the design and reduces a good deal of superfluous end-of-line mass. it puts the second hand in a less than optimal position for viewing, and it turns counter-clockwise, but, really, it's inclusion is just to aid in setting the rate of the pendulum. afterall, it doesn't tick seconds, it ticks 1.5 seconds! KEvron
Hi, I know this video is a little older but here goes nothing. :D I absolutely love your model, I've been waiting for a good recreateable lego clock for a long time. Thank you so much for putting all the part numbers, that was super helpful. For the past three days I've been looking for all the parts. I found most, had to hunt down a few. I have all the parts queued up for purchase. And I saw your video with the striking chain. And I was just wondering if you made this version of the skeleton clock into a striking. Or if you have instructions for the Striking Movement. Is there anyway to add a striking movement to this version of the Skeleton Clock? Or is my clock destined for silence? :) At any rate, thank you so much for this tutorial. Its awesome. And if you could help me, i'd appreciate it.
A few pieces -- notably the clock hands and the bars attaching the balance-edge blocks to the pendulum head -- are no longer available. Have you considered other ways of building a knife-edge setup? Also: I am finding that the pendulum head has a tendency to twist slightly each time the release on the pawl is struck. Any thoughts about resolving this?
i have published videos of alternative solutions for both the co-axial hands and the knife edge suspension. these videos provide solutions which utilize elements currently found in the lego catalog. hands: th-cam.com/video/fETLWEjKJgA/w-d-xo.html knife edge: th-cam.com/video/m2HjLjbvgC4/w-d-xo.html also, youtuber and fellow horolegoist ben van de waal has published a video for a knife edge solution. i have not yet determined its construction, so i cannot say if he has utilized discontinued elements to realize it. as to the twist: i've never observed this phenomenon in my own construction. then again, i've never looked for it. my first thought would regard the amplitude, and its relation to the drive weight. the greater the drive weight, the greater the friction between the scape heel and the pawl. sufficient friction would likely provide enough resistance to cause the twisting. two solutions would be to either reduce the amplitude/drive weight, or to somehow relocate the unlocking pin to the centerline of the pendulum head, as opposed to the lateral position i presented in the video. happy tinkering! KEvron
Christopher Lehrich something else occurred to me: are you using the 2 oz weight elements for your pendulum bob? i use four in my design, giving me a 1/2 lb bob. without a substantive impetus to give it leverage, the pendulum's swing would surely be subject to perturbation upon contact with the pawl (when the contact pin is located laterally). if you don't have the weight elements, try using a loaded battery box, or several large rubber wheels. KEvron
***** I think my pendulum bob is weighted as you proposed. I have, however, changed the knife-edge system for one balanced on a thin axle (not a full cross-axle) run through two Technix holes, replacing the knife-edge assemblies. This is annoying, because to lift out the pendulum head one has to un-stick the Lego units, but at this point the pendulum seems to be swinging evenly and producing the desired escapement alternation. If my tinkering works, I will post my solution -- with suitably grand kudos to you, of course! And many thanks for your advice and suggestions.
3647 was the previous 8t gear design; lego replaced it a few years ago with 10928. i used the 3647 gear in the ratchet because, given its inferior design, it's dispensable. you could use 10928 instead. i was just overthinking it. KEvron
which other? i've designed a few. if you mean the galileo i designed last year, the accuracy is comparable and the drop rate is the same, but the weight demand is greater for this one (maybe 50% more). if you mean my other recent skeleton(s), i'd say this one is more accurate. the pulleys i employed in my previous skeleton had a fatal flaw: even a minute variation in the diameters of the two pulleys (and a variation did exist) distorts the intended 1:1 ratio. those clocks have the potential for an accuracy comparable to this one, but that deviation rendered the second hand useless. without an accurate second hand, it's difficult to fine-tune the rate of the pendulum. for accuracy, the arnfield beats them all. a gravity escapement is far superior to any inertia-dependent design, and the galileo is one of the least accurate of those (although it's one of the easiest to realize in lego!). plus, the arnie uses a two-second pendulum, while these galileos use a 1.5 second pendulum, which, of course, exhibits an inherently poorer q factor than the former. all that said, this one is accurate enough to let you know when your shows are starting. you might have to adjust the hands every few weeks or so, but i'd say that's tolerable for a homemade, novelty timepiece. KEvron
Sorry, yes you have made quite a few clocks. I was referring to the Arnfield escapement clock that you posted a tutorial for earlier. I think you answered to its accuracy, but how does the weight drop compare?
dapperhippo well, they're considerably different systems. the arnfield requires two drive weights, both dropping 2"/hr. were i to design it for just the one weight, that weight would have to drop 4"/hr. with the pulley system, the galileo's single weight drops .8"/hr. KEvron
vinesthemonkey as a matter of fact, i have only my k-12 public education upon which to draw. horolegology is just a hobby for me. it's taken years of reading up on the subject and asking questions of other designers to reach this meager level of accomplishment; there's still more to learn, and plenty that still eludes me. thanks for the compliment, bub. KEvron
vinesthemonkey *"mislabeled as 3257"* d'oh! fixed. *"put a note about the additional parts required for using string"* there's a list for the pulley assy; i've added a note about string length to it. i'm afraid the rest is up to the builder to resolve. KEvron
Thank you for uploading this video! Using this design as a guide, I made my own version of the clock. I wasn't able to replicate your design precisely because I do not have many of the Lego components that you use. Specifically, I have no plates, bushings, or gears with the sideways facing teeth that the 16 tooth clutch gear uses. (and I don't have a 16 tooth clutch gear). I haven't been able to achieve accurate time with my design, but I'm within a few minutes per hour. Frankly, that is simply due to my laziness and the fact that I don't want to do the math to find the proper pendulum period. I am planning on uploading some instructions and maybe a video. And I will definitely reference you. By the way, you frequently mention problems with weight - that Lego pieces can only take so much - but you use either a 4x4 round brick or a 16 tooth gear as your drum. is there a reason for this? I use a larger drum (the largest Lego rim I own) and can achieve the same torque with much less weight.
+Russell Richard i'm glad you found it useful. any parts you lack can be purchased from private sellers at bricklink.com. the math only works for a theoretical pendulum. a practical pendulum is a compound pendulum; finding its center of oscillation is compounded by the mass of the rod. my own solution is to use a pendulum with an adjustable bob, hunt-and-peck to find a length that's close to accurate, then adjust the bob to dial in accuracy. looking forward to your video. a larger drum results in a greater drop rate for the drive weights. using 4x4 round bricks instead of 2x2's would double the drop rate. i'm comfortable with the range of drive weight i currently supply to my pieces. thanks for your comments. KEvron
+Oliver Vogel that's the 2 oz. boat weight. it's listed in BrickLink's catalog under the "boat" category. they're becoming scarce, so best to act soon. in this video, i've provided an alternative solution: watch?v=31MFPzNDVqk @ 11:24 KEvron
I have entered the parts list into rebrickable, to save people having to enter the parts list themselves : rebrickable.com/mocs/MOC-13373. @Kevron : contact me if you want to take ownership of the page
Yes unfortunately they did not accept the model since I am not the creator and they are afraid of lawsuits. I have resubmitted and included this thread, hoping that they will allow it this time.
heh! to be honest, i find the making of these videos to be laborious, and i don't get much satisfaction in the process, so i keep it as simple as possible. KEvron
little tolerance for off-topic banter here, in deference to the sensibilities of the expected viewership. if there is a matter with which you would like to approach me, you may do so in the appropriate forum. KEvron
I applaud your selection of red bricks ($$$!); the contrast between the supporting structure and moving parts helps the viewer visualize details.
The measured slow down of the drive train during the test run makes it appear as if the manual energy was stored in a weighted flywheel, yet it's all Lego!
yeah, running the drive train is another one of those inexplicably satisfying sensations. it's the little things....
KEvron
Great design! Thanks for putting the time in for such clear instructions, I know a lot of folks who will want to give this one a go!
honestly, making the videos is a drag. tedious and laborious. i promised some family members a timepiece of their own, so i was commited to the task. i still have to shoot the tutorial for adjusting and tuning the clock. draaaaaaaggggg.....
KEvron
***** Your step-by-step frames would have driven me bonkers to film and cut so cheers for sticking with it! I tried making guides by using LEGO Digital Designer but it doesn't have some of the old bits you use here. Also for complex builds I found LDD generates crazy instructions. Yet to find the right tool for sharing Technic designs.
I have built and ran 3 of Kevrons clocks now. Each one more satisfying than the last. I think Ill keep this one running for a while. Thanks Kevron!
glad you've enjoyed them, bub. thanks so much for the kind words.
KEvron
Really epic!!!!!!!!!!!!!! The content on your channel so far will totally shows that you have potential in the TH-cam community!!!!!! I subscribed because you really deserve the push towards getting more subscribers! Keep it up and props!!!!!
thanks for your excellent questions, Richard. i'd reply to you directly but, for some reason, your linked comment lacks the "reply" button.
i've been designing these things for about 14 years now. each design is built upon previous successses. earlier pieces reveal to me my design flaws, as well as the limitations (and possibilities) inherent to my chosen medium (wonderful lego!), so i try to overcome those flaws and limitations with each subsequent attempt. i originally intended the galileo clock i presented in may of last year to be a skeleton clock like this one, but i quickly talked myself out of such a design as i didn't think i could succeed at a viable piece. after devising a new knife edge suspension for the pendulum, i immediately realized its potential wrt a skeleton design. that piece gelled rather quickly for me (maybe a few days). still, never one to rest on my laurels, i continued to develop the piece. in fact, the clock seen in this video is the fourth of now five incarnations! much of my development time is spent in deliberation rather than actual construction, so putting a time frame on any given design gets complicated. best said, it's an evolution.
drive train ratios are predicated upon my desired drop rate of the drive weight and the limitations of the lego. you can throw only so much drive weight on a piece before it ultimately yields! scape wheel size - specifically, the tooth count - has a lot of influence over the final drive train design; a 40t scape wheel design requires about 1/5 of the drive weight that an 8t wheel design with the same drop rate would require. then there's the pendulum's period rate. a one-second pendulum runs out twice as fast as a "seconds" (two-second) pendulum, and the seconds pendulum has a better q factor than the former, but it can be unstable, being more susceptible to disturbances to its swing. i find the unconventional 1.5-sec pendulum i've used in my last few designs to be a good compromise; more stable than the seconds pendulum, runs longer than a one-sec pendulum, its proportions are more aesthetically suitable than the much longer seconds pendulum and its rate allows the 40t scape wheel arbor to double as a second hand arbor.
i hope i've adequately answered your questions. happy tinkering!
KEvron
Nice video man I enjoy it I’ll definitely need to go back and upgrade my designs in the future :D
@kevronista Thank-you for this design, I've always wanted to build a Lego clock and this was just the insperarion I needed. This is not like any other build I have done before, in fact the build is just a few minutes work, but getting to run.... aghhh! Afyer a week of fiddling mine will now run for 40min at best. I have rebuilt it twice with different selections of part (non of them are new). The pendulum just stops swinging. Still working on it... Thank-you.
i'm glad you're enjoying it. yes, the build is pretty simple; it's getting it to run reliably that takes all the effort. stick with it, you'll get it.
i''ve been sitting on an improved version of this clock. i'll get around to posting video of it soon, so stay tuned.
happy tinkering!
KEvron
This tutorial, along with the tuning/adjustment video, is fantastic. My 7-year-old is fascinated with clocks, so we bought the parts and are building your clock together as a Christmas present (for both of us!). I don't think I can say thanks enough.
It is all assembled and the parts seem to function as they should,, but we do have one fairly major problem. The pendulum doesn't seem to be able to maintain its momentum for more than 2 minutes. We get between 80-100 ticks out of the clock but after that the amplitude has diminished enough that the pawl and the pallet can't do their job.
I know that the weight (I am using an 8-oz swing bottle) should be enough to keep the pendulum moving, but for some reason, I guess there is not enough energy being transferred, or maybe there is some other adjustment I need to make that I am not thinking through. I have tried a 16-oz weight, and that seemed to increase the run time to 160 ticks (4 minutes), but clearly that still isn't enough. Maybe there is too much friction somewhere in the gearing and the force from the weight is too diminished by the time it is distributed to the gear interfacing with the pallet?
I was wondering if you might have any advice. I can certainly post video if you think that would be helpful.
Thanks!
+Jason Walther
you shouldn't expect your results to match what you see in the video. even the slightest deviation between my adjustments to the action and yours can result in significantly different results for each of us. this is especially true of a galileo-type escapement. it may be the case that the action between the pendulum pallet and the scape wheel could be improved. another possibility is that the action is fine, but the pendulum's amplitude is greater than that seen in my video, so will require more drive weight to maintain the swing. a rub in the drive train could be the culprit, but such issues tend to be cyclical; the rub causes the stoppage to occur in regular intervals.
remember that it's not just how much power you apply to the scape wheel, but how long the tooth on the wheel maintains contact with the pendulum's pallet. you want to adjust the action so as to maximize that contact time. the greater the percentage of the swing in which the scape wheel is in contact with the pallet, the more push you get from the wheel. often the culprit here is unlocking the scape wheel a little too early. "too early" can mean the tiniest of adjustments!
hope this helps. if you want to publish video of your piece, i'd be happy to try to analyze your problem. be sure to include a straight-on view of the escapement in action, and douse it light!
KEvron
+Jason Walther
i think the problem is as i suspected, that the scape wheel is unlocking just a bit too soon. try another adjustment to the unlocking contact.
you might also try closing the headroom gap between the scape wheel and the pallet. when the pallet swings in toward the scape wheel, you want only enough clearance to miss the gear tooth. it's hard to see in the video, but it looks like you have just a bit more clearance than you need. one way to do this is to adjust the pallet, which is actually two adjustments, and can be quite tedious, or you could try elevating the position of the locking pall. as the pall position goes up, the gap between the scape wheel and the pallet closes. of course, too much of an adjustment here will close the gap complete, and the pallet will collide with the scape wheel.
lastly, do check all of your arbors for rubs, especially where the position of the arbor is held by bushes. also, you don't want to much play in the arbors, either. just enough to ensure smooth performance. i don't think this is the problem; minor rubs tend to be problematic only at the scape-wheel-end of the drive, where the drive runs fastest but has the least torque.
hope this helps. keep me posted. i'd hate to think i've given anyone a bum steer.
KEvron
+Jason Walther
....something else:
i couldn't get a good look at the action of the locking pawl, but it suspect it's catching more of a bite on the scape wheel tooth than it needs. it should be adjusted so that only enough of the pawl interacts with the wheel to stop it. you want just the edge of the pawl to catch just the edge of the tooth. now, if you catch too little, the scape wheel can skip off the pawl, causing run-away, so you'll have to watch for this. the depth of the pawl's bite is set with that arm above it, the one with the two pole reversers; one is to keep the lever from falling away from the escapement, and the other to prevent the pawl from penetrating the wheel too deeply.
also, you want only enough mass on the counter-weight to assure proper performance. any addition mass is just extra resistance on the pendulum. adjust the mass by sliding the weight along the axle. the closer its position to its arbor, the less is its effective mass; the further from the arbor, the greater the mass.
everything in the design is about "only just enough." but that's a galileo escapement, and that's why only hobbyists bother to use it. it's probably the lousiest pendulum escapement design, but it's the easiest to realize in lego.
happy tinkering!
KEvron
+KEvronista
Thanks for all the pointers. I've been walking through some of the adjustments, and I just thought I'd add something else that I've noticed after some of this tinkering: it seems like no matter which tooth of the scape wheel the pendulum starts on, it always stops at the same three or four teeth. I may be deceiving myself, but it also seems like those three or four teeth are just a little shorter and don't give the same "push" to the pallet that the rest of the teeth do.
Have you ever seen problems with the scape wheel itself? Could it be that the LEGO gear I am using is not symmetrical enough? I might try switching it out later, but if this is a red herring, I'd rather not go through the trouble. It seems like if the pendulum has enough momentum, it should be able to withstand a few slightly shorter teeth...
Jason Walther
*"it seems like no matter which tooth of the scape wheel the pendulum starts on, it always stops at the same three or four teeth"*
that would indicate a cyclical issue. something in the drive train, and probably near the scape wheel. again, check your arbors for sufficient play, and check that the clock frame has no loose connections, especially where the uprights attach. you may also try changing out the last two or three arbor assemblies (the scape wheel arbor and the next one or two arbors). be careful not to mix in any of the replaced parts with your substitutes.
but try the pall depth first. displacement of the pawl is the only work that the pendulum must do, but the task can require a lot of energy, relatively speaking. if improperly adjusted, it'll require more energy for the pendulum to displace it than the pendulum receives from the scape wheel.
KEvron
Yet another fantastic (lego) clock design! It is just magnificent (as are its predecessors). However, I was wondering how long it takes for you to design your clocks, and how you decide upon the gear ratios.
Cheers, Richard
One more thing: at 6:00 in this video, when the second differential gear casing goes in with the other two small gear assemblies on that side, there's something amiss. Either there is a missing step, or the differential is backwards. The six gears on that side -- those at either end of the differential, the two joining those one bracket down, and the two attacked by axles to those last -- only connect to one another. They don't engage anything in the drive train. Could the differential case be backwards? Or am I missing something? Thanks!
no, the steps are correct. the 16t crown on the second diff meshes with the 16t gear on the hands arbor (5:10 assy). the 24t gear on the smaller of the other two assemblies will mesh the 24t crown to the drive train; it spans the gap between the diff and the drive, and it corrects rotation.
KEvron
***** I believe the solution to this issue is demonstrated in another of your videos. Lacking the Technix reverse-arbor pieces (I think that's the right term), I used a 1x2 with hole plus a 1x2 no hole, stacked, in each place to keep the differential properly spaced from the other assemblies. This turns out to be too far. I am going to try replacing the 1x2 no-hole with 2 1x2 plates, which should allow the 24t gear and 16t gear to engage properly.
Christopher Lehrich
*"I am going to try replacing the 1x2 no-hole with 2 1x2 plates"*
yes, this approach will give you the correct spacing.
KEvron
If i bought all the parts new for say bricklink, how much would the whole thing cost do you recon?
i've never priced the parts. the chains, alone, will run you $30+. the clock and the pendulum, maybe another $40.
i have another piece for which i'm preparing to shoot a video. it's another skeleton clock like this one, but it uses string instead of chain. the string will shave $30+ off the cost.
KEvron
I just purchased the "string" version on BrickLink. It is my first time so perhaps I am not doing it cleverly, but I managed to purchase via 3 shops. Grand total = 65€, of which 25€ shipping & handling.
Thanks again for the great instructions. The clock is sitting in the living room, ticking away. One question for you -- is there a reason that you didn't bring the second hand up to the clock face? Some of your earlier models use a small 1X1 plate with a tooth as a second hand offset on the clock face. I'm thinking about trying to do something similar with this, but I wanted to check and see if there were some major pitfalls I should try to avoid.
the second hand is driven by the scape wheel axle, which puts it at the very end of the drive train, where additional mass has its strongest resistance. keeping the mass of the second hand assembly to a minimum should be considered.
also, technic axles tend to have a little bend to them. the longer the axle, the more noticeable the bend. to put the second hand at the face would have required a 10L or 12L axle, and that bend can adversely affect the performance of the scape wheel.
for my most recent version, i've put the second hand right on the scape wheel axle, using a white, 1x2 thin liftarm and a 7L axle, counterweighted with another 1x2 thin liftarm, neutral color. this simplifies the design and reduces a good deal of superfluous end-of-line mass. it puts the second hand in a less than optimal position for viewing, and it turns counter-clockwise, but, really, it's inclusion is just to aid in setting the rate of the pendulum. afterall, it doesn't tick seconds, it ticks 1.5 seconds!
KEvron
Hi, I know this video is a little older but here goes nothing. :D I absolutely love your model, I've been waiting for a good recreateable lego clock for a long time. Thank you so much for putting all the part numbers, that was super helpful. For the past three days I've been looking for all the parts. I found most, had to hunt down a few. I have all the parts queued up for purchase. And I saw your video with the striking chain. And I was just wondering if you made this version of the skeleton clock into a striking. Or if you have instructions for the Striking Movement. Is there anyway to add a striking movement to this version of the Skeleton Clock? Or is my clock destined for silence? :) At any rate, thank you so much for this tutorial. Its awesome. And if you could help me, i'd appreciate it.
i hope you'll enjoy the build. if you have any questions, i'll do my best to provide clear answers.
keep me posted!
KEvron
A few pieces -- notably the clock hands and the bars attaching the balance-edge blocks to the pendulum head -- are no longer available. Have you considered other ways of building a knife-edge setup?
Also: I am finding that the pendulum head has a tendency to twist slightly each time the release on the pawl is struck. Any thoughts about resolving this?
i have published videos of alternative solutions for both the co-axial hands and the knife edge suspension. these videos provide solutions which utilize elements currently found in the lego catalog.
hands: th-cam.com/video/fETLWEjKJgA/w-d-xo.html
knife edge: th-cam.com/video/m2HjLjbvgC4/w-d-xo.html
also, youtuber and fellow horolegoist ben van de waal has published a video for a knife edge solution. i have not yet determined its construction, so i cannot say if he has utilized discontinued elements to realize it.
as to the twist: i've never observed this phenomenon in my own construction. then again, i've never looked for it. my first thought would regard the amplitude, and its relation to the drive weight. the greater the drive weight, the greater the friction between the scape heel and the pawl. sufficient friction would likely provide enough resistance to cause the twisting. two solutions would be to either reduce the amplitude/drive weight, or to somehow relocate the unlocking pin to the centerline of the pendulum head, as opposed to the lateral position i presented in the video.
happy tinkering!
KEvron
***** Wow -- thanks! I will work through all this with pleasure.
Christopher Lehrich
something else occurred to me:
are you using the 2 oz weight elements for your pendulum bob? i use four in my design, giving me a 1/2 lb bob. without a substantive impetus to give it leverage, the pendulum's swing would surely be subject to perturbation upon contact with the pawl (when the contact pin is located laterally). if you don't have the weight elements, try using a loaded battery box, or several large rubber wheels.
KEvron
***** I think my pendulum bob is weighted as you proposed. I have, however, changed the knife-edge system for one balanced on a thin axle (not a full cross-axle) run through two Technix holes, replacing the knife-edge assemblies. This is annoying, because to lift out the pendulum head one has to un-stick the Lego units, but at this point the pendulum seems to be swinging evenly and producing the desired escapement alternation.
If my tinkering works, I will post my solution -- with suitably grand kudos to you, of course!
And many thanks for your advice and suggestions.
Christopher Lehrich
hope it all works out for you. i look forward to the video.
KEvron
What's the difference between the two 8 tooth gears?
3647 was the previous 8t gear design; lego replaced it a few years ago with 10928. i used the 3647 gear in the ratchet because, given its inferior design, it's dispensable. you could use 10928 instead. i was just overthinking it.
KEvron
How does this clock compare with your other in accuracy? Also, how does the weight drop differ from your other clock (slower or faster?)?
which other? i've designed a few.
if you mean the galileo i designed last year, the accuracy is comparable and the drop rate is the same, but the weight demand is greater for this one (maybe 50% more).
if you mean my other recent skeleton(s), i'd say this one is more accurate. the pulleys i employed in my previous skeleton had a fatal flaw: even a minute variation in the diameters of the two pulleys (and a variation did exist) distorts the intended 1:1 ratio. those clocks have the potential for an accuracy comparable to this one, but that deviation rendered the second hand useless. without an accurate second hand, it's difficult to fine-tune the rate of the pendulum.
for accuracy, the arnfield beats them all. a gravity escapement is far superior to any inertia-dependent design, and the galileo is one of the least accurate of those (although it's one of the easiest to realize in lego!). plus, the arnie uses a two-second pendulum, while these galileos use a 1.5 second pendulum, which, of course, exhibits an inherently poorer q factor than the former.
all that said, this one is accurate enough to let you know when your shows are starting. you might have to adjust the hands every few weeks or so, but i'd say that's tolerable for a homemade, novelty timepiece.
KEvron
Sorry, yes you have made quite a few clocks. I was referring to the Arnfield escapement clock that you posted a tutorial for earlier. I think you answered to its accuracy, but how does the weight drop compare?
dapperhippo
well, they're considerably different systems. the arnfield requires two drive weights, both dropping 2"/hr. were i to design it for just the one weight, that weight would have to drop 4"/hr. with the pulley system, the galileo's single weight drops .8"/hr.
KEvron
I'm curious, are you an engineer of some sort? Or did you just pick this up as a hobby? I think these designs are genius
vinesthemonkey
as a matter of fact, i have only my k-12 public education upon which to draw. horolegology is just a hobby for me. it's taken years of reading up on the subject and asking questions of other designers to reach this meager level of accomplishment; there's still more to learn, and plenty that still eludes me.
thanks for the compliment, bub.
KEvron
Hello,
Part 2357 is mislabeled as 3257
Also, you should put a note about the additional parts required for using string
vinesthemonkey
*"mislabeled as 3257"*
d'oh! fixed.
*"put a note about the additional parts required for using string"*
there's a list for the pulley assy; i've added a note about string length to it. i'm afraid the rest is up to the builder to resolve.
KEvron
Thank you for uploading this video! Using this design as a guide, I made my own version of the clock. I wasn't able to replicate your design precisely because I do not have many of the Lego components that you use. Specifically, I have no plates, bushings, or gears with the sideways facing teeth that the 16 tooth clutch gear uses. (and I don't have a 16 tooth clutch gear).
I haven't been able to achieve accurate time with my design, but I'm within a few minutes per hour. Frankly, that is simply due to my laziness and the fact that I don't want to do the math to find the proper pendulum period.
I am planning on uploading some instructions and maybe a video. And I will definitely reference you.
By the way, you frequently mention problems with weight - that Lego pieces can only take so much - but you use either a 4x4 round brick or a 16 tooth gear as your drum. is there a reason for this? I use a larger drum (the largest Lego rim I own) and can achieve the same torque with much less weight.
+Russell Richard
i'm glad you found it useful. any parts you lack can be purchased from private sellers at bricklink.com.
the math only works for a theoretical pendulum. a practical pendulum is a compound pendulum; finding its center of oscillation is compounded by the mass of the rod. my own solution is to use a pendulum with an adjustable bob, hunt-and-peck to find a length that's close to accurate, then adjust the bob to dial in accuracy.
looking forward to your video.
a larger drum results in a greater drop rate for the drive weights. using 4x4 round bricks instead of 2x2's would double the drop rate. i'm comfortable with the range of drive weight i currently supply to my pieces.
thanks for your comments.
KEvron
what is the part 73090b?i cant find it?
+Oliver Vogel
that's the 2 oz. boat weight. it's listed in BrickLink's catalog under the "boat" category. they're becoming scarce, so best to act soon.
in this video, i've provided an alternative solution:
watch?v=31MFPzNDVqk @ 11:24
KEvron
Thanks
I have entered the parts list into rebrickable, to save people having to enter the parts list themselves : rebrickable.com/mocs/MOC-13373.
@Kevron : contact me if you want to take ownership of the page
thanks! i'm not on rebrickable, so you'll have to maintain ownership, if you don't mind.
KEvron
"404 page not found"
KEvron
Yes unfortunately they did not accept the model since I am not the creator and they are afraid of lawsuits. I have resubmitted and included this thread, hoping that they will allow it this time.
that's a shame. well, should they visit this page, let it be known that you have my permission to publish the list.
KEvron
where is the final clicking and running
there is a link in the description.
KEvron
i can't find 44249
sorry about that. it should read 44294. it's the 7L technic axle.
KEvron
Thanks!
Your videos would be better than they are if you add music to them
heh! to be honest, i find the making of these videos to be laborious, and i don't get much satisfaction in the process, so i keep it as simple as possible.
KEvron
*THIS PIECE IS SUPERCEDED.* try this one, instead:
th-cam.com/video/VXrdAYdRv4c/w-d-xo.html
KEvron
No _lolls_ here, *****? :)
little tolerance for off-topic banter here, in deference to the sensibilities of the expected viewership. if there is a matter with which you would like to approach me, you may do so in the appropriate forum.
KEvron