Thinkpads Forum

I hope one of the experts here can solve a minor mystery.

On the base of the X61s, near the hard disk cover, is a small rectangular foot - or there WAS a small rectangular foot, because it keeps falling off. My question is: what was its original purpose? When the machine is sitting on a table, it doesn't touch the surface. What do I gain by having one on there, and what do I lose (if anything) by not having one?

Thanks for any insight into this long-standing mystery.

To ensure ventilation if a battery is not installed. There should be a foot on the other side as well.

precip9 wrote:To ensure ventilation if a battery is not installed. There should be a foot on the other side as well.

Thank you for the suggestion, but I'm not sure that can be right - for two reasons:

1. The lower case of the X61s already has two feet on either side of the battery near the back edge, and these (together with the other two feet near the front edge) hold the machine off the surface when no battery is present - and hold it higher off the surface than the rectangular foot would do.

2. There is in fact no second rectangular foot on the opposite side of the machine - there is only one, on the left, near the HDD door.

Perhaps you're thinking of a different model, not the X61s?

You can see all this in the picture here:

https://www.dropbox.com/s/wspp3pv6er7k0 ... erCase.jpg

(The picture is from an eBay sale of X61s lower cases.)

So I'm still puzzled - what is the purpose of that small rectangular foot near the HDD door?

(I thought the answer might be that the foot fits into the small rectangular opening in the UltraBase, but in fact the foot is about an inch away from that opening.)

No idea what for.
But 'your' extra foot sits further outward than on both X60s and X61s that I have!
Mine both sit inside the square for the label that sits to the right of it.
See the right X61s on this eBay item: http://www.ebay.com/itm/Lenovo-Thinkpad ... 1217874505
Looks like newer model-year cases have it inside (like mine) and older model-year cases (like yours) have it on the outside.

Interesting! The foot that's on the label - in the machine on the right in the photo - does look as if it fits into opening in the UltraBase (though I can't be sure).

But the one on the right in the photo isn't an X61s, it's an X61. If you look at the photo that shows the screens, you'll see that the one on the left is badged X61s below the screen, while the one on the right is badged X61. And the labels on the back show that the model number of the one on the left is 7666, which is an X61s, while the one on the right is 7674, which is an X61.

There are other differences between the two lower cases also; for example, the X61s has a wider battery opening that requires attaching a spacer to the battery, while the X61 has a narrower opening and doesn't need the spacer, because the corresponding half-cylinders are part of the lower case itself.

You can see the differences here:

X61:

http://www.ebay.co.uk/itm/Lenovo-ThinkP ... 0939342242

X61s:

http://www.ebay.com/itm/NEW-Oirg-IBM-Le ... 1203404980

So the mystery deepens: why is that foot in one place on the X61s and in another place on the X61 - and what is it doing there in the first place??

Whatever, mine are both of the -s variety:
- Frankenpad X601s (X60s 1702-A11 chassis, with an X61s 7666-3EU motherboard)
- Thinkpad X61s 7667-C54.
Both have their "foot in it" (that label).
Maybe it's different factories, that changed the design...

Fascinating! I've accumulated three X61s machines, and all have that foot near the HDD door. You must be right about the different factories; I can't imagine what else could account for the difference.

Maybe there was some idea that the UltraBase design would change also - or, for all I know, there might be two different UltraBase designs, one for each location of that foot? Just guessing here...

And here, a picture that confirms exactly what you said, is a 1702 (X60s) lower case, with the foot in the label:

http://www.ebay.com/itm/IBM-ThinkPad-X6 ... 3f34bcd4c6

I must have a lot of serious work to do, or I wouldn't be avoiding it by researching this question.

Lenovo seems to have been inconsistent even in the same model number. Your 7667-C54 has the the rectangular foot on the label, but here's the exact same model number with the foot in the same position it is on my machines:

https://www.dropbox.com/s/et1xd2aszcqoo2s/7667C54.jpg

Edward Mendelson wrote: So the mystery deepens: why is that foot in one place on the X61s and in another place on the X61 - and what is it doing there in the first place??

Open the hdd door and notice the foot perfectly aligns with the frame's internal bracing.
The 'mystery' foot adds support to a weak segment of the frame.

The magnisum frame is unsupported across the length of the hard drive door cover.
The frame of earlier x-series thinkpads (sometimes) snapped in this unsupported section.

Edward Mendelson wrote:(I thought the answer might be that the foot fits into the small rectangular opening in the UltraBase, but in fact the foot is about an inch away from that opening.)

That foot (on both my X60s and X61s) fits indeed in that rectangular opening.
But even if it were NOT there, it still doesn't do anything!
Even without a battery, that rubber foot does not touch the table/surface it is standing on.
Methinks that foot should probably have been thicker AND touch the surface to (literally) support jaspen-meyer's theory!

Sure, it the machine's flat on a table, with all 4 feet touching the 'floor', the 5th foot isn't supporting diddly-squat - it's just a useless appendage much like the extra set of wheels on (some) dump trucks.

But the x61s isn't always laying flat on tables.
For example, lay the machine on a book, or another thinkpad(!), whereby the hdd-side's front foot isn't supported and the weakness is exposed, which is to say the weak area of the frame is now under load.
Now stack a few thinkpad's atop the x61s and watch the frame collapse.

Another analogy, the dump truck was the first.
Have you every watched someone, trying to change a flat tire, place their jack smack in the middle of the door well then started jacking up their car?