discussion on pad molding that somehow came from a bug post

1 - load project
2 - create multiple sequences
3 - enter song mode (seqs should already be in sequential ordeR)
4 - hit play start
5 - allow song to play out
6 - BUG - after last sequence, UNUSED sequence begins playing
7 - BUG - "stop" does not work while UNUSED sequence is playing

can anyone confirm this?
i just loaded 4.44B for the first time in ages, my mpc was still running 4.35
it may have been my headphones but i seem to be noticing some weird glitching audio sometimes while adjusting a sample's start/end points in TRIM mode

nothing earthshaking. i do really like the new song mode/qlink assignment page.

works fine with me. you say 'multiple sequences', by that how many do you mean? does this happen with just two for example? also, no 'unused' sequence appears in song mode for me. just the ones i've put in there, and '(end of song)'.

weird. it just happened to me again, happens every time.
i'll maybe take a couple screenshots and try again later
meanwhile i'm working on casting this rubber

have fun with the bubbles.

don't scare me like that - but since we're on the subject what would you suggest for avoiding getting bubbles? egg beater? (joke)

i'm using vytaflex 20 shore A. the pads are gonna be 6 mm thick, 2 more mm than the akai 4 mm thick pads. the color of the rubber is "clear amber" but you can of course put different pigments into it, which i will do on the request.

my mold is a real stroke of brilliance. ramshackle, but man, i put sweat and blood into it. i'll scan it soon.

i'm also proud of the way i get the sensors attached to the frame. i was having a hell of a time figuring out how to do it without losing more than 1 mm of space in between the metal cover and the pad frame. the answer is surprisingly cheap and very simple. i consulted an engineer who also is a model train hobbyist for this one.

the sensors get applied to a strip of thin, clear vinyl - not like in-cupboard vinyl, but more like the clear sleeves that record covers sometimes come in at the library. it's tough and thin, which is what i need.

i then adhere the sensors to the strip of vinyl with silicone glue on the sensors backside. i then push em down against the vinyl so they don't sit up on the silicone. the result is great - they do not move. i have been playing just on the sensors (no rubber pads yet) for the last several days, and i've been loving it - the feel/velocity sensitivity is AWESOME and the only issue is that i can't do corner hits since i'm aiming my fingertips at this:



you see the 4 screwholes in the corner? silicone goes in there too, providing "liquid nails." this is the cheapest, flattest, and most durable answer i could find in terms of securing the sensors to the pad frame. that much silicone glue won't break from downward force, especially once it's dampened through soft rubber. i've tried excessively to damage it and make it fall off, but it just won't happen.

i know i'm going on a bit of a rant here but another reason i used silicone glue (and why i'm so amped on it) is because while it's permenant, you can also remove the sensors if you want - by prying them off. you have to apply force from the other side in order to take these sensors off, which is great, because A, there's a hole on the frame under each sensor, and B, this means that's the only way the sensors will come off - intentionally.

so amped about this, modnar. the sensors feel better already than the original sensors and there aren't even any PADS yet. a VERY lucky find.

getting rid of bubbles? you need an evacuation tank. very expensive. it's the only way to do it properly. short of that, if your mold is 'open' as in, there's no undercuts where bubbles could get trapped when rising to the surface. then you should be okay just leaving it, you may get a few bubbles on the top (which i assume will be the underside of the pad sheet, and hence will not matter).

also: are you sure you could not have these sensors screwed down? it's not quite clear from what you say, but it sounds like you have a sheet of vinyl with 16 sensors stuck to it, and this sheet is free-floating inside the mpc. personally, i'd mark and drill holes in the pad frame, unless of course there's big holes right where you need to drill, in which case, i'd put some kind of additional frame either on top of the existing one, or underneath, depending on space. i doubt the silicone's adhesion to the sensors (and possibly to the vinyl) over a long period of time. i understand that it passes through the holes in the corners of the sensors, but it may start giving less than optimal hits after the silicone comes free.

another reason i'd like to see a more 'industrial' approach to attaching the sensors is that it would impress the guys in charge at the uni you are going to apply to. to turn up and say 'yeah i kinda stuck the sensors on' would go down rather worse than 'this sh!t is fukking been-through-the-sun-twice-and-still-works kinda tough.' but that's just my opinion. the silicone may be the cheapest easiest way forward to getting this whole show on the road, but at the end of the day, you're doing this for yourself as much as the rest of the 1000 community. while i'm not saying that you should say 'fuk you lot, i'm doing mine, and that's it' i'm saying that you should possibly take a step back and try and see how an outsider may view this project if you end using 'No Nails' to stick the sensors down, i mean: akai used screws, didn't they?

yes good points indeed. i intend to keep testing extensively this silicone solution. as for drilling into the pad frame, that's a possibility as well but seems unlikely in the short term. one thing i forgot to mention is that these little sensors have clasps on the back which hold that metal frame in place:



these clasps aren't held rigid agianst the fiberglass, they have a little space in between. this gives the silicone a little more nooks n crannies to grab rather than if it was just adhered to the fiberglass itself.

what you said is right - i will probably do more to my own than i do to the kit which i send out, but then again i wouldn't send out anything that i wouldn't use myself. i'll give a lot of advice for beefing it up, and probably make some sort of wiki so people can post their own ideas.

as for it being free floating, there's nothing to worry about there. the rubber pads will be locked down against the vinyl, not allowing it to go anywhere since the rubber will itself by held down enthusiastically by the frame (customizeable by actually raising the entire pad frame via a couple small washers under the screws holding it in place)

however, you could also put double sided tape just to hold it in place. seems shoddy, but when you think about it there's no moving parts relying on the tape, so there's no real reason to worry about it losing adhesiveness. it's just to hold it in place until you'd put the rubber pads on/screw back on the cover - at this point, nothing will be going anywhere, and the ONLY moving part will be the rubber pad.

screws would be good, but i've had a difficult time thinking about a way to screw the sensors in without raising them up closer to the surface of the machine, which would put them up above the surface of the mpc cover frame. this in itself wouldn't be bad, but the mold would have to compensate for it and you'd end up with slightly less thick rubber. alternately, i'd worry about the screws actually cracking the fiberglass of the sensor with an excited enough hit about as much as i'd worry about the silicone glue giving out after a long time.

i was suspect of the silicone glue before trying it, too, since shaky silicone gluing was the problem with the first pad sensors in the beginning of this fairy tale - but as of now i'm pretty confident that it's gonna hold up - if not, there are other options.

what would you think about some quickset epoxy? that certainly wouldn't let go.

i was gonna do that first, but that was before i thought of putting the sensors on four horizontal 1 by 4 strips of vinyl which gets secured onto the pad frame as described above. epoxy sure would be tougher than silicone glue. thoughts on that?

yeah epoxy sounds good, although it'd probably need reinforcment as it's brittle. the only problem with that is 'replaceability' of the sensors.

re: the screws

i shouldn't think the screws would crack the pcb, as these are reinforced with glass-fibre.

if you find the time, could you measure the gap between the top of the pad frame, and the underside of the top panel, and i'll see if i can come up with something. thanks.

about 4 mm, probably 4.2 mm or so. not a lot of maneuvering room. the sensors themselves are just under 4 mm tall, as well.

ahh ok, i see the issue now. i'll get back to you. thanks

also - according to james seiler, the guy at CUI who knows most about these things, replaceability shouldn't be an issue in the forseeable future. lots of actuations on these things and that's under more force. but, i did want to keep options open - so that's why these 1 by 4 strips of sensors (horizontal) would be good. i mean, if one were to go bad you could always just snip it out (if using epoxy) or peel it off (if using silicone) and replace it.

i don't envision that happening though - force transducing rubber has a very long lifespan.

sudden thought: you could embed the sensors in the rubber, any movement would be lost, which could help increase longevity, and sensitivity may be more like what you're looking for?

yeah there's not a lot of room in there. that's why the mold is so important. it's awesome though because the sensors themselves have a rounded actuation point - the dome - which means the pad underbelly themselves don't hhave to be domed for corner hits. saves me a LOT of trouble. the underbelly of the pad can be flat - but since the sensors are nearly the height of the space in between, the mold has to have negative space to fit the sensor and give appropriate hit-space. vytaflex has excellent resistivity to tearing - it can stretch to 100% its original before tearing - so the rubber will complement the design and be very durable.

in short, they're gonna feel niiiiiiiiiice especially since they're shore 20A

another thing: the contacts on the sensors, are they on the top surface only?

i'd thought about that, and it'd solve so many problems if i could figure out how to make that work

the issue is space. if the underside of the pad sits directly on a hard space, there's noplace for it to go besides compressing itself. this'd be great for dead on hits, since all the force is directly transferred to the sensor, but corner hits would either not register or they'd register far more quietly than they should have.

i think i'll try it though - it'd make for even more solid feeling pads since there'd be no "space underneath." i think people'd like that, myself included. it's worth a try, but like i said the real issue is preserving those corner hits.