Santa came late this year, with a HMV 163

[nostalgia]

I have seen your video, Marco, but still can't figure out what the problem is with the autobrake on my machine. It does not stop the turntable when the record is finished playing, and I have tried several HMV records from around 1925-1930, and also, it makes the record play at uneven speed, something is disturbing the movement of the turntable, but I can't figure out what. Also even if I manually return the tonearm when the record is finished and I can hear the autobrake hits in, it does not stop the turntable from spinning.
Before removing it and substituting it with a autobrake found on a HMV 157 ( and diminishing the status of that machine) I want to ask if someone know if one can adjust the autobrake somehow by the screws holding the different parts of the brake? I have made a short video, that shows how the autobrake is working right now:

https://www.youtube.com/watch?v=HjhDy7zXab4

[Inigo]

Seems to work fine... But without the turntable, we don't know. Maybe it's the leather pad that should touch the inner part of the turntable rim to stop it. Chech if it is not protruding properly from its support, or if it is too dry and hard. Maybe you'll have to substitute it for a new leather piece. If you don't have leather, a piece of thick felt might work too.

[Phono48]

I've just compared the action of the brake on my 157, and yours acts in exactly the same fashion, so I would say that the problem lies in the leather pad that should hit the inner rim of the turntable. Test by putting a dab of grease on the end of the leather, replace the turntable, then actuate the brake in the usual way. If the pad is hitting the turntable correctly, you will see the greasy ring round the edge when you remove the turntable. Clean it off both turntable and leather with whatever you usual use to remove grease. If that proves to be the problem, and the leather need to be replaced, on no account should you try to open the two shoulders that are holding the leather, they will almost certainly snap, then you ARE in trouble! Instead, cut away the old leather, and cut a "v" notch out of both sides of the new piece, so that it will slide in from the open top of the shoulders, and when in position, twist it round with pliers, until the two notches are in a horizontal position.

I don't think your variation in speed in any way related to the autobrake, it more than likely to be due to the governors. The central rod that the governors slide along as they open up often gets very sticky and needs to be removed and cleaned, along with the inside of the governor main shaft (best done with a cotton bud soaked in thinners or white spirit. I have had the same fault with many HMV motors. Hope this helps!

Barry

[Inigo]

You should check all that first.
If the brake still doesn't work properly (you must try it with a record, or move yourself the needle to the usual position of the locked eccentric groove as if a record was being played, and simulate the light backwards movement to see if the brake is triggered) then you'll have to adjust the half moon position, but this is not likely unless someone has tinkered with it in the past... It is firmly attached and usually never needs readjustment.

[Marco Gilardetti]

I agree with all of the posters above: if it doesn't stop the turtable perhaps the leather pad is too short to correctly reach the rim, or deformed and touching the rim and/or the turntable not where it should. The mechanism seems to work perfectly, so in my opinion the causes of these malfunctions are to be searched elsehwere (turntable rim, relative position of the two elements, governor pad, etc.).

[HMVDevotee]

I have seen your video, Marco, but still can't figure out what the problem is with the autobrake on my machine. It does not stop the turntable when the record is finished playing, and I have tried several HMV records from around 1925-1930, and also, it makes the record play at uneven speed, something is disturbing the movement of the turntable, but I can't figure out what. Also even if I manually return the tonearm when the record is finished and I can hear the autobrake hits in, it does not stop the turntable from spinning.
Before removing it and substituting it with a autobrake found on a HMV 157 ( and diminishing the status of that machine) I want to ask if someone know if one can adjust the autobrake somehow by the screws holding the different parts of the brake? I have made a short video, that shows how the autobrake is working right now:

https://www.youtube.com/watch?v=HjhDy7zXab4

Nostalgia,

Just a point of clarification. You mentioned trying different records. Is that because no records, or only some records actually trip the brake mechanism?
Robert

[Inigo]

Yea, only the ones with eccentric locked groove at the end, for the mechanism only triggers with a backwards movement of the tonearm near the label. Otherwise you need to trip the tonearm completely to the right passed the spindle, manually. This seems a drawback, butt indeed it allows you to play records with very small labels without trigging the brake. No need to say that a bad "swinger" record would trigger the mechanism although the record hasn't yet finished!
Personally i prefer the auto brakes on which you set the position of the trigger mechanism first, with direct forward action of the tonearm. The mechanism is free until the point of setting, so no drag of any additional mechanism along the record. This is especially noticed if you use a counterweight to lighten the load on the needle.

[Marco Gilardetti]

No need to say that a bad "swinger" record would trigger the mechanism although the record hasn't yet finished!

Just as a side (useless) note, in my experience this autobrake is so insensible to backward movements, that in some cases even the eccentric locked end groove is not enough to trigger it (most HMV records will trigger it, but with other brands I'd say it's 50% or less). I would then classify as "impossible" that an off-centered record - for how badly off-center it may be - may have any chance at all to trigger it.

[HMVDevotee]

I am familiar with how these brakes work, having serviced them on both 163 and 193 machines. I asked for clarification because when Nostalgia said, "It does not stop the turntable when the record is finished playing, and I have tried several HMV records from around 1925-1930, ...) it was unclear to me if the brake was being tripped by any records.

In looking at Nostalgia's video, it appears that he manually trips the brake by moving the tone arm to the extreme left, perhaps beyond the normal distance of a run-out groove's track. When I have adjusted these in the past, I measured the distance from the spindle to width of the run-out pattern of a record. I then removed the platter and moved the soundbox back and forth, approximating the movement generated by the record. Then I was able to examine at what point the "pawl" should engage the toothed rack. In one instance, I re-positioned the rack, in another, where the engagement was inconsistent, I took the brake apart and cleaned and lightly lubricated any engaged surfaces including the friction plate under the little three-legged flat spring. The mechanism that moves the pawl then worked freely and reliably thereafter.

For Nostalgia's sake, I hope records, for the most part, are tripping the brake. What I described above was tedious and time-consuming.

Robert

[nostalgia]

Thank you everyone. Barry, Inigo, Marco, HMVDevotee ! It rightly was the leather pad! It was too short to hit the rim of the turntable correctly, to test it, I used a pliers and carefully pulled it 1 cm to the right, and then everything worked. It runs at correct speed too, with no uneven playing. I don't know why it run at uneven speed when the leather pad was not correctly attached, but all is good now.

I did not show on the video how the record was not engaging the brake when the record was finished playing, before making the video I have tested 3 different records from the correct period. When testing it yesterday evening with another HMV record, the mechanism worked as it should, meaning if now the mechanism is not engaging, it is because of the record, and not because of the auto stop mechanism.

HMVDevotee, I will save your words thank you, since I understand you have actually disassembled the mechanism in the past, and adjusted it. Luckily it was not necessary on this particular auto stop. As we can see it really also works smoothly, and is looking like new really, like the rest of the machinery on this machine ( and well, yes also the cabinet).

I believe the leather pad was the reason why this machine was sold in the first place. The seller pointed in the direction of the auto stop when I bought the machine, trying to explain it was not working well. To me it looks like the complete gramophone has recently had a total service on the motor and springs, and also maybe have had a new leather pad installed. The fact that the past owners have not been able to reason out why the machine was running at uneven speed, and also one could hear a noise from the leather pad constantly disturbing the motion of the turntable when it was incorrectly installed, and also causing the autobrake to kind of live it's own life, havE created a state of constant annoyance and nuisance.