Quick question about TP keyboards

Hi...

I know that there are quite a few threads about the 3 kinds of keyboards that the ThinkPads come with and I have read them all. However, I have a question:

As I see it, the traditional (original) ThinkPad keyboards had a solid plate, while the "new and redesigned" ones (which were apparently flexy) had the perforations. It has been widely reported that the former have more of a flex than the latter and that sometime back Lenov had voluntarily changed the keyboards. The latter were said to be designed in that way to reduce weight - though how significant that weight reductions I am still to appreciate.

The question, however, that I have is this: Is it the case that the keyboards with the perforations help in keeping the temps of the machine lower than the ones without the perforations?

Thanks.

Edit: Its been a few hours since the keyboard on my machine (R400) was replaced with one with a solid backplate. I have noticed no significant change in temps - though I am just going by touch. And, the machine does not feel in any way heavier! But the typing experience with the new keyboard is excellent.

 

The difference in weight is IMO in some grams, so for sure it is not possible to notice just this change (however if you keep looking for the grams here and there through the machine, then it counts).
Those perforations are just on the backplate and don't go through the whole keyboard so it isn't like you have some wholes for the air to pass to allow better cooling. If it was so, it won't be possible to have the keyboard spill resistant.

 

@Tulip...thanks! That makes sense.

 

The perforated keyboard does improve the heat transfer by a slight margin, but i don't think most people would notice it under normal condition.

I guess i can do the test with some thermal probes when i am free in the next two week.

 

That'll be cool. Thanks. On my part, after the replacement of the solid-backed keyboard, I see no overt temp differences - by touch I mean. But I have seen some comments about the possibility of temps marginally rising on some threads, which is why I am asking.

 

I don't think there will be any measurable temperature differences, since the perforations do not allow air circulation because they do not go all the way through the keyboard back layers.

 

If you look at the heat transfer mechanism, the perforated keyboard should have a lower conduction resistance due to the less number of layers, further there is a higher efficiency for radiation heat transfer due to the preference.

You could confirm this better with an infrared imaging camera, but given that the price of these babies, i don't think many people would buy it without professional use for it.

Thermal probe is a cheaper way of testing the theory.

 

In that case, whatever increase in temperature there may be would be at best marginal and not enough to affect the workings of the machine. Also, since the solid backed keyboards were standard issue till recent times (and during the replacement program), I am guessing that any possible temperature increase would also have been factored in.

 

Everything is marginal, i would think the weight saving of the perforated keyboard would be marginal too. It is good engineering practice to even take marginal benefits into account.

But personally, i would think that the perforated keyboard design was cheaper to build (cost and weight saving would be the major design priority), while saving 50 cents may not be much for one machine, but when you build 10 of millions of these keyboards, the cost saving would be substantial.

 

@lead_org...sure! Makes eminent business sense. However, the pleasure of typing on a solid backed keyboard is incomparable! I can't seem to get my hands off it! Cumulative marginal benefits to me (the customer) too given what I have been putting up with respect to other keyboards - I have now come to truly appreciate the original TP keyboard!

 

Personally i don't like the perforated keyboard design of that generation. I still use my T41 laptop on regular basis, because it has one of the best keyboards that i have ever used (apart from some of the mechanical keyboards for the desktop machines).

 

I know what you mean. Having had the keyboard replaced with a solid-backed keyboard directly from IBM/ Lenovo was probably the best thing that happened. Tightened up the body of the machine too, which is somehow strange because I have no idea what relation one has with the other. When the keyboard was being replaced, I handled the perforated keyboard and boy, was it flimsy! The solid-backed board was much better and when fitted in is excellent. I can't seem to stop praising it!

Edit: I have a theory! I think that many of the creaks on the R400 (and possibly other machines especially in the T-class) can be addressed by putting in a solid-backed keyboard. The extra firmness of the keyboard probably lends structural firmness and makes the palmrest and surrounding areas a bit tighter...as I said, only a theory!

 

in fairness, the original TP keyboard was created over a decade and a half ago.   what you're using is good but not nearly as good as they used to be 10+ years ago.   many long-time users will say that one of the best all-time TP KBs came from the ThinkPad 600 series.   if you ever get a chance to try one, you might wish it was still 1998.

my favorite current keyboard is the X300/X301.   most X30x owners hold it in very high regard both in tactility and solid response, likening the feel to the TP 600 series.   and, get this... the X300/301 KB is PERFORATED!

everything has to do with the substructure.

 

I can imagine! Hmmm...interesting note about the perforated keyboard in the X300/301.

Could you please explain a bit about your comment about the substructure?

On the current non-perforated keyboard (which, btw, the IBM Service guy was praising while he was putting it in), the effort required to type is minimal. The sound is muted and it feels rock-solid! A completely different experience than what I experienced with the other varients from the replaced machine and the keyboard on the new machine, which has now been replaced!

In fact, the IBM service guy said that they all know about the perforated keyboard and dislike it themselves!

 

the x30x keyboard is good, so is the supporting sub structure. Unfortunately it has died a premature death at the hands of Lenovo management, since it was not a product that attracted high revenue as compared to the bread and butter T series.

The substructure that Erik is referring to, is the rollcage chassis that is under the keyboard, there is more support given to the X30x keyboards, than compared to the regular R and T series of the same generation. This effectively overcomes the problem of the plate perforation.

 

The X301 is still available...at least on the Lenovo US site! Or, are you referring to some other variant?

 

Ok. I see what you guys mean. In that case, in a strange way, my "theory" is somewhat correct right? The firmer solid-backed keyboard does lend to the structural firmness of the frame. I am experiencing this on my machine.

 

It would be stronger only when you apply a torsional load across the laptop case.

The X301 is the last machine of that design, it is better than the X300 due to the fact that it has the integrated Displayport.

 

not necessarily.   lightening holes can either add rigidity or leave it unchanged depending on the shape and dispersion of holes.   in this case, the difference in material thickness has a lot more to do with it than the perforations.

 

Hmmm...ok. This is interesting because when I handled the perforated keyboard and compared it with the solid-backed one, the former certainly felt flimsier - something that the IBM service guy also pointed out. I would hazard a guess that the perforated keyboard that I handled would have been, in material terms, less thick (but not necessarily less strong) than the solid-backed one...you see what I mean?

 

what i'm hypothesizing here is that the perforated keyboard is less rigid because it uses a thinner aluminum backplate, not because of the holes.   if the perf'd keyboard used thicker aluminum it could potentially be just as rigid as the non-perf'd keyboard.

from an engineering standpoint, one can't always assume that things with holes are less rigid.   there are many more factors involved.   in this case the major change to the design is the material thickness.   the perforations are but a secondary factor (and much less important).

 

In my opinion, there is actually not much difference between the perforated and solid backing keyboard in terms of typing experience. As erik has mentioned, the substructure is more important. If the rollcage is flimsy and flexes downwards when depressed, then no solid-backing keyboard can prevent flexing during typing, unless the plate was made of something completely stiff and rigid - like diamond haha

 

While I can see and appreciate the logic of what you and Erik (and lead_org) are saying, I can't also discount my personal experience. Thus, for example, how is it that when my laptop had the perforated keyboard, there was (1) a noticeable flex around the upper left side (near the 1,2,q,w,a,s keys) and less noticeable flex around the right hand side, and (2) the palmrest areas used to creak.

Now, with the keyboard being replaced, the flex is gone and so are the creaks and there is a certain tightness (I don't know how to describe it in any other way) to the keyboard and palmrest area. The only reason I could think of is that the extra rigidity of the (new) keyboard has contributed to this since there was nothing else done to the machine.

 

If the magnesium rollcage is that flimsy, then i don't think it would be that useful as a rollcage or structural support.

@lines of flight.

What Erik is saying is that the flexing issue of the perforated keyboard is not due to the 'perforation', but rather the back plate material on the perforated keyboard is thinner than then the non-perforated version.

 

Yup, I got that and I agree. I also think that the perforation to some extent accentuates (contributes to) the weakness that already comes with the thinner backplate material used in the perforated style keyboard. Specifically, the perforations reduces (to perhaps a very small degree) the structural rigidity of the plate (which adds to the increased flex that an already thinner backplate material exhibits).

There is one other thing that IBM Service guy told me. Apparently, the ThinkPad keyboards (when originally fitted in the factory) are made by some "unknown" entity - not Alps, Chicony or NMB. This is supposed to be a very recent development - though how recent, he could not say. When I asked him how this relates to the FRU numbers, he said that FRU numbers are country-specific by which he seemed to mean that the FRU numbers are assigned as per country of sale and are not indicative of the identity of the manufacturer of the keyboard. Apparently, this is how their parts-database is organized.

However, what was even more curious was that he said that when replacement keyboards are made, they are now made only by NMB's China-based factory. I find this somewhat hard to believe - unless there has been a consolidation of keyboard manufacturers. But then again, when I tried to lift some of the keys and see for the "blue pads" (apparently characteristic signatures of NMB keyboards) beneath them, I found that my new keyboard has them even though the FRU number of the keyboard is 42T3209 (which is apparently a Chicony keyboard). From threads here on NBR and elsewhere I know that the NMB keyboard sports (or at least used to) 42T3143 as the FRU number. But every description that I read of the NMB keyboard seems to fit the user-experience of my new keyboard!!!

Edit: I am a bit confused now. I always thought the 42T3209 FRU was indicative of the Chicony keyboard. Apparently, it is not (its supposed to be ALPS) as per post #139 available here.