Escapement Arbor
  • Hi Guy's
    the Escapement Arbor on my Sextus keeps sliding outwards, producing FRICTION between the face of the ring stop and the frame. The Arbor is level checked with IPhone I am thinking of stripping down to bare frames and putting bearings on that Arbor.
    Has any body else had this issue? The whole drive system runs beautifully until I attach the Pinion to the shaft and then it grinds to a stop
    Thanks
    Andy
  • One of the ringstops on the arbor will pretty much always be contacting the frame, you can only prevent this happening if the arbor was rigidly held in the axial plane.
    However the pressure of the ringstop against the frame is negligible and can not really be the cause of your sextus not running.
    Do not use bearings, this will only make things worse, the escapement arbor weighs only a few grams and gets only a minimum of drive force, so ball bearings would just increase the friction.
    Your problem is certainly to be found somewhere else.
  • Thanks Dave
    the elusive tick is been worked on
    Andy
  • Another Escapement Arbor issue-

    I have a perplexing issue with the rotation of the escapement wheel #16 on my Sextus. When the wheel is rotated, it wobbles out of round from 11.1mm to 22.2mm!
    Please consider the following:

    *The arbor spins true and freely in the frame with no components attached.

    *The wheel component (#16) is dead flat when it is placed on a flat surface, so it is believed not to be warped or out of round.

    *The coupling is confirmed to be inserted completely flush against the #16 wheel.

    *The coupling is sitting flat against the frame.

    Unlike a bicycle wheel where spokes are provided to achieve rounding the wheel travel, I'm at a loss as to how to correct this condition. Worse yet is where is the wobble coming from and how do I eliminate it?
    Thanks for your suggestions and comments!
    Mark C.
  • Just as a check that the coupling really is sitting correctly in the wheel, I'd put the arbor into the coupling far enough to grip it but not right through the wheel, so that the arbor only protrudes from the coupling side. Then sit the wheel on a flat surface with the arbor pointing upwards and rotate the wheel. If the coupling is square with the wheel the top of the arbour will remain in the same place. If things are slightly askew the the top of the arbor will move in a slight circle. I've found that to be a useful check when gears have run out more than I expected.

    Good luck in finding the cause!
  • I think I understand. I'll give it a try. Thank you also petec for the "run out" terminology!

    Now I'm thinking if the run out is still unacceptable, I presume the only fix (other than a replacement cog) is to attempt to re seat the coupling less than "to the hilt" and off kilter enough so the run out is diminished?
    That will be a fun exercise.

    Do you know if small file videos can be attached in these forums?

    Will update!
  • petec, your hunch was correct!
    Just tapping the coupler in to what I thought was flush, was the issue. I ended up removing the gear wheel from the coupler, reinstalling the coupler on the arbor, then the gear wheel just 2/3rds of the way. I started rotating the gear and gradually tapping the out of range side of the gear back onto the coupler till the gear was close to the coupler's shoulder, and without any run out!
    So it's not quite up aginst all around the coupler, but the rotation travel is true!
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  • Glad you've got it running true. From your photo it looks as if you could tap the coupler further into the wheel without causing problems.
  • Agreed and have done so!
    Close to completing all construction and possibly start running in next week!
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  • Looking great mark! Post a video link on YouTube when her heart starts!
  • Thanks Chris-not quite finished yet, but close. I plan to dismantle it all and give a final paint coat on the frame and I want to get the hands to be a little easier to distinguish from all those cool workings.
    I will attempt to post on You Tube; for the humor value at the least!
    (well I hope not!) ; )

    I do believe all the easy friction is in the wind, my hair and on the floor though! Blowing on the escapement does set the gears in motion but you would think I was blowing out a 50 candle B'day cake in the process!
  • Hello, I have finally finished the Sextus and have now fitted a 2.1kg weight with the pedulums weighted to speed the clock up, everything has been working as it should (now and then) with a good strong backwards and forwards escape wheel movement, the clock has been stripped numerous times to remove any friction, the clock has run but stopped a few days later after working faultlessly. I have weighted the clock at the front with a 2.3kg weight and removed all tight gear problems associated with the frame deforming under load. I have run the gearing without the pendulums connected on a very small load with the gears running very slow but smoothly without stopping so no problem with the gear train. I noticed a small squeak coming from the arbour of the escape wheel. This was removed and repolished with a small amount of graphite applied as a lubricant, everything worked fine, the squeak came back and now not running at all well with it stopping frequently. I have noticed a small but significant amount of play at the hole closest to the escape wheel, is this the problem, could the squeak be coming from the glue joint between the two timber frame members, very very frustrating, please help (Was thinking of installing a bearing as someone previously commented upon) but this was rejected as it would have caused more friction, how about a bass tube at the front with the arbor running through it, I think as the pendulums are acting on the escape wheel the wheel is moving around the larger hole.
  • It sounds as if you have managed to eliminate any major causes of friction, so in such a case I would tend towards taking a closer look at the grasshopper, is it engaging and disengaging as it should, a give away is when it always stops on the same pallet.
    Also take a look here:- PENDULA SWING TIMES
    And here :- LAZY
  • Dave my current situation is I'll get a run time to the floor, but after the rewound, I will restart three or four times.
    I had purposely kept the windings to the back 1/2 of the spindle concerned about sag. (I don't think it's a concern on this setup.) Upon experiencing the same results the past weeks, I decided to move the windings forward. Now I may have to restart only once or twice.

    I did add a tiny bit of weight to my lazy pallet so that probably and concern has been eliminated.

    Marking all the points after a stop is nearly a "I'm going nuts" process and was given up on when I needed a fourth color!

    I need to verify my thread settings as I don't seem to be getting updated notices!
  • Another thing, (asking all who may have tried and especially Dave of course!)
    I am using a statue as my counter weight. Yes it does exceed your recommended weight and the clock when running is fast.

    Can you say with any confidence if it would be possible to make other adjustments on the pendulula to compensate for this unforunate variable?

    I could cut the base to reduce the weight to your reccomendation, but how much to remove would be a total "Crap shoot ". I'd rather play with any of the other possibilities first than doing the most obvious by messing with the brass statue. (I'm up for the challenge too if it has ANY promise.)
  • This may sound like a huge task, but there may be another way to calculate how much mass would need to be removed from the statue. ...
    Fill a container with water large enough to hold the entire statue right to the rim. Do this outside so that no water spills anywhere important. Weight the container of water when it's full. Place the statue in the container and have it displace the water. Remove the statue and reweigh the container. This will tell you it's volume. Divide it's displacement by its full volume weight. This will then tell you a numeric value of weight in water to its total weight. Weigh the statue. Divide the weight of the statue by the displaced water weight. Thus will give you a value in volume of water. Then calculate the amount of weight needed to be removed to make the weight correct. Refill the container. Place the statue in water until it diplaces the correct volume needed to remove. That will then tell you if removing the base is enough or even feasible.


    Sounds like a lot, but really simple.
  • What is statue made of ? could it be drilled out and fine tweaked with lead shot ? Chrisj sounds spot on with method. If you weigh a tub of water full to brim, place statue in fully and remove and note differnt weight of water. Weigh statue and this will give grams per liter mass of statue. ie if statue weighs 2000gms and displaces 1000gms of water thats 2000g per liter mass of statue. to remove say 300gms then 1000gms water( 1000cc) divided by 2000gms mass x300gms to remove = 150 cc to remove from statue which would be a pretty large hole or a few smaller ones. Think thats right but prefer backup before you tried it.
  • Thanks for backing me up George ;). Never once in my life did I ever think that displacement taught in 8th grade would ever be useful, but heck.....I've been wrong before :)
  • Thanks for the suggestion on how to better the odds on the "caps shoot" weight reduction but I'd prefer not to modify the brass statue. Hence why I'm asking about alternative solutions.
  • One of the potential issues I foresee is in lengthening the pendulums. Since thier swing makes them nearly touch at the bottom of thier arc, lengthening them would be pretty limited due to mechanics. Additionally, lengthening them may cause ( just spit balling here) issues with pallet engagement as then the action of each pendulums rotation on its center axis becomes shorther. This will force you to have them engage and disengage quicker on a smaller radius. Oddly for clock building, I might suggest ( and never thought I would ever say this ) adding friction to the drive train. This however would be challenging to calculate how much. I may have another suggestion. .....add pulleys. This would effectively cut the drive force in half. That may be too much of a reduction, but at least the balance of the weight needed to drive the clock is easily calculable. Take the drive force needed to run the clock times 2 and subtract the statues weight. The difference would bring you very close if not in fact dead on the the balance of the weight needed ( at least theoretically ).

    Hope this helps
  • Adding a pulley would be productive if I had opted for one of the >15# statues. This one is a bit over 7.5#, so I believe adding a pulley would be two steps forward, then 1.75 steps back! (yes, too much of a reduction)
    There isn't much hollow area to add lead in any form.
    I expected a challenge but still, Arghhh! : )
  • Revisiting the pulley idea again......couldn't tyou add the pulley then add slightly more weight back into it by adding something to it additionally outside the cavity of the statue?
  • I use a counter wound draw sting on Primus, remove weight and pull to wind in seconds, its only a small wooden pull similar to light switch but if you did same with heavier pull it may counter act excess weight. Not something i would try though as only stressing frame more.
  • Excellent idea George! That way the counterweight is calculable and easy to fix