I use a glass "fastener", of sorts, in one of my products.
It's small, inexpensive, reasonably durable...

But, there's a large variation in terms of how "informed"
users want to be before they start trying to put things
together! As it's glass, it *can* break if abused.

[I've not been able to break one "carelessly" so I think
you'd have to be pretty aggressive to do this.]

As they are inexpensive, it is probably easier to just
include a spare (or three?) in with each item -- just
in case. I figure the sort of user who carelessly
breaks one is likely also going to be impatient as to
getting a (free) replacement... projecting his failure
onto others rather than owning it.

But, including too many seems like it sends the opposite
message; that these are fragile.

So, *0* spares may be too few and 2 may be too many?

[E.g., when you buy an item of clothing, you often get
*one* spare button with it to save you the hassle of
locating a matching replacement. But, not *two*!
Yet, if you managed to lose one, why wouldn't you
be likely to lose a second??]

Anyone take this sort of proactive approach? Perhaps
specialty fuses or mechanical catches or connectors...

On Sun, 2 Oct 2022 13:32:17 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

>I use a glass "fastener", of sorts, in one of my products.
>It's small, inexpensive, reasonably durable...

What is it?

On 10/2/22 14:02, John Larkin wrote:
> On Sun, 2 Oct 2022 13:32:17 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
>
>> I use a glass "fastener", of sorts, in one of my products. It's
>> small, inexpensive, reasonably durable...
>
> What is it?

Its a button.

On Sunday, October 2, 2022 at 4:32:26 PM UTC-4, Don Y wrote:
> I use a glass "fastener", of sorts, in one of my products.
> It's small, inexpensive, reasonably durable...
>
> But, there's a large variation in terms of how "informed"
> users want to be before they start trying to put things
> together! As it's glass, it *can* break if abused.
>
> [I've not been able to break one "carelessly" so I think
> you'd have to be pretty aggressive to do this.]
>
> As they are inexpensive, it is probably easier to just
> include a spare (or three?) in with each item -- just
> in case. I figure the sort of user who carelessly
> breaks one is likely also going to be impatient as to
> getting a (free) replacement... projecting his failure
> onto others rather than owning it.
>
> But, including too many seems like it sends the opposite
> message; that these are fragile.
>
> So, *0* spares may be too few and 2 may be too many?
>
> [E.g., when you buy an item of clothing, you often get
> *one* spare button with it to save you the hassle of
> locating a matching replacement. But, not *two*!
> Yet, if you managed to lose one, why wouldn't you
> be likely to lose a second??]
>
> Anyone take this sort of proactive approach? Perhaps
> specialty fuses or mechanical catches or connectors...

I think that you often overthink some things. I would include one spare with a note explaining why it is there. Indicate if they lose that one or need more, they can contact you.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

On 2022-10-02, Don Y <blockedofcourse@foo.invalid> wrote:
> I use a glass "fastener", of sorts, in one of my products.
> It's small, inexpensive, reasonably durable...
>
> But, there's a large variation in terms of how "informed"
> users want to be before they start trying to put things
> together! As it's glass, it *can* break if abused.
>
> [I've not been able to break one "carelessly" so I think
> you'd have to be pretty aggressive to do this.]
>
> As they are inexpensive, it is probably easier to just
> include a spare (or three?) in with each item -- just
> in case. I figure the sort of user who carelessly
> breaks one is likely also going to be impatient as to
> getting a (free) replacement... projecting his failure
> onto others rather than owning it.
>
> But, including too many seems like it sends the opposite
> message; that these are fragile.
>
> So, *0* spares may be too few and 2 may be too many?
>
> [E.g., when you buy an item of clothing, you often get
> *one* spare button with it to save you the hassle of
> locating a matching replacement. But, not *two*!
> Yet, if you managed to lose one, why wouldn't you
> be likely to lose a second??]
>
> Anyone take this sort of proactive approach? Perhaps
> specialty fuses or mechanical catches or connectors...

Hammond do with their exruded aluminium enclosures,
there's four non-magnetic M2 screws (which can easily
disappear into carpet) to secure each end. So they ship
9 screws with each case.

--
Jasen.

On 02/10/2022 21:32, Don Y wrote:
> I use a glass "fastener", of sorts, in one of my products.
> It's small, inexpensive, reasonably durable...
>
> But, there's a large variation in terms of how "informed"
> users want to be before they start trying to put things
> together!  As it's glass, it *can* break if abused.
>
> [I've not been able to break one "carelessly" so I think
> you'd have to be pretty aggressive to do this.]
>
> As they are inexpensive, it is probably easier to just
> include a spare (or three?) in with each item -- just
> in case.  I figure the sort of user who carelessly
> breaks one is likely also going to be impatient as to
> getting a (free) replacement... projecting his failure
> onto others rather than owning it.
>
> But, including too many seems like it sends the opposite
> message; that these are fragile.

I'm inclined to think that including a single spare might be the way to
go (and if they are penny items also be geared up to stuff one in a
envelope and mail first class to anyone who needs a third one). A note
to the effect that they should read the instructions more carefully
before attempting to fit the spare (or keep it safe for future use).

My furniture comes with a lifetime guarantee on the door handles. One
failed during a house move and the company were as good as their word.
>
> So, *0* spares may be too few and 2 may be too many?
>
> [E.g., when you buy an item of clothing, you often get
> *one* spare button with it to save you the hassle of
> locating a matching replacement.  But, not *two*!
> Yet, if you managed to lose one, why wouldn't you
> be likely to lose a second??]
>
> Anyone take this sort of proactive approach?  Perhaps
> specialty fuses or mechanical catches or connectors...

I have seen one replacement fuse provided with things that sometimes
fail (and had plenty of stuff in my time that was DoA).

I lucked out once with a colour laser printer that was virtually
impossible to assemble correctly unless you were very strong, had
excellent mechanical intuition and read all the instructions before
attempting to put it together. There were an insane number of pull tabs
that had to be removed in a specific order. Miss one and fire it up or
scrape the transfer bed on the case and it was ruined. I was able to buy
up starter toner from written off main units for more than a year!

I even got a refurbed second unit print engine for next to nothing too.

--
Regards,
Martin Brown

On 10/2/2022 9:28 PM, Jasen Betts wrote:
> On 2022-10-02, Don Y <blockedofcourse@foo.invalid> wrote:

>> Anyone take this sort of proactive approach? Perhaps
>> specialty fuses or mechanical catches or connectors...
>
> Hammond do with their exruded aluminium enclosures,
> there's four non-magnetic M2 screws (which can easily
> disappear into carpet) to secure each end. So they ship
> 9 screws with each case.

Yes, and likely don't draw unnecessary attention to the fact
that they've "miscounted".

While one could likely live with a missing screw *or* obtain
something comparable from "local stock/suppliers", one would
likely be annoyed to have LOST one of the EXACTLY 8 that had
been supplied.

So, the supplier avoids an annoyed/inconvenienced customer
for the low price of a spare screw.

And, a customer need not feel obliged to SAVE the extra screw
in the event that he doesn't need it, now.

On 10/3/2022 1:29 AM, Martin Brown wrote:
> On 02/10/2022 21:32, Don Y wrote:
>> I use a glass "fastener", of sorts, in one of my products.
>> It's small, inexpensive, reasonably durable...
>>
>> But, there's a large variation in terms of how "informed"
>> users want to be before they start trying to put things
>> together!  As it's glass, it *can* break if abused.
>>
>> [I've not been able to break one "carelessly" so I think
>> you'd have to be pretty aggressive to do this.]
>>
>> As they are inexpensive, it is probably easier to just
>> include a spare (or three?) in with each item -- just
>> in case.  I figure the sort of user who carelessly
>> breaks one is likely also going to be impatient as to
>> getting a (free) replacement... projecting his failure
>> onto others rather than owning it.
>>
>> But, including too many seems like it sends the opposite
>> message; that these are fragile.
>
> I'm inclined to think that including a single spare might be the way to go (and
> if they are penny items also be geared up to stuff one in a envelope and mail
> first class to anyone who needs a third one). A note to the effect that they
> should read the instructions more carefully before attempting to fit the spare
> (or keep it safe for future use).

We initially planned on including a spare to cover the possibility
of the user needing to *remove* the item and then replace it. The
thought was that the removal would be more likely to break the
item than the installation (think: resort to pliers!).

We then thought that the prospect of it being damaged on insertion/assembly
could be addressed by this same spare. But, then the user has no OTHER
spare to cover the removal risk case.

> My furniture comes with a lifetime guarantee on the door handles. One failed
> during a house move and the company were as good as their word.

Yes. Many firms will actually provide these sorts of items "for the
price of a phone call". E.g., we have "Decora" style light switches
throughout the house, most with dimmer capability. The large plastic
"rockers" are flimsy and fail, over time. A replacement switch assy
is ~$25 so a costly failure!

But, a call to the manufacturer will have a few replacement spares
at your doorstep in a few days.

OTOH, there is a cost to the manufacturer for doing this as a separate,
post-sale activity; someone has to answer my call, interact with me,
jot down my name/address and arrange for replacements to be shipped
(postage).

OTOH, including a spare in with *each* switch sold seems like it would
alarm users ("Is this thing expected to break? How soon?") as well as
inconvenience them ("Now where the hell am I going to store this for
the failure that is EXPECTED?")

The guy who's been looking at regulatory/safety/liability issues had
suggested some changes to the parts -- as well as the addition of a
(cheap, disposable) tool to reduce the chance of "flesh" being in contact
with breakable glass during insertion/extraction.

But, telling the user "please put the insertion/extraction tool in
a safe place in the event that you need to disassemble the unit puts
a burden on the user -- you KNOW it's going to get lost!

OTOH, shipping a second tool+fastener in with the original product
(in it's own "tool+fastener" packaging) seems more likely to
result in the tool AND fastener finding a home (nothing says you
can't use the SECOND tool to remove the FIRST fastener!)

>> So, *0* spares may be too few and 2 may be too many?
>>
>> [E.g., when you buy an item of clothing, you often get
>> *one* spare button with it to save you the hassle of
>> locating a matching replacement.  But, not *two*!
>> Yet, if you managed to lose one, why wouldn't you
>> be likely to lose a second??]
>>
>> Anyone take this sort of proactive approach?  Perhaps
>> specialty fuses or mechanical catches or connectors...
>
> I have seen one replacement fuse provided with things that sometimes fail (and
> had plenty of stuff in my time that was DoA).
>
> I lucked out once with a colour laser printer that was virtually impossible to
> assemble correctly unless you were very strong, had excellent mechanical
> intuition and read all the instructions before attempting to put it together.

The instructions are the pisser. If too lean, then they likely don't
add any value AND convince the user that assembly is easy so they can be
ignored. If too lengthy, then they discourage reading -- esp if the first
3 pages are disclaimers about all the ways the user could hurt himself
(to help indemnify the manufacturer)

I try to design so things are "obvious" and "hard to screw up/break"
cuz the user will, at best, be annoyed at his mistakes and, more commonly,
project that "failure" onto the manufacturer/designer!

> There were an insane number of pull tabs that had to be removed in a specific
> order. Miss one and fire it up or scrape the transfer bed on the case and it
> was ruined. I was able to buy up starter toner from written off main units for
> more than a year!

I would rummage through discarded pallets in the hope of finding the
"right" cartridge(s). Our B&W lasers have enough "free" toner rescued
in this way for *several* years of normal use!

The same is true for paper. I once cut up several reams of "linen" (high
rag content) stationery just to make little 3x3" slips of "note paper"
to have on hand! This week, I'll be bidding on a pallet of ~80 reams
of paper at a *computer* auction -- likely not to see much competition
for that! Given that I'll need to BUY a case (10 reams) of paper, soon
($50), it may be better to put those monies towards an auction bid!

But, as with the spare toner cartridges, then you've got to find a
place to store all that stuff until you NEED/consume it! <frown>

[I'm scanning books for discard to rid myself of this sort of bulk
so hoarding ~8 cases of paper really is contrary to that goal!]

> I even got a refurbed second unit print engine for next to nothing too.

I rescued an entire imaging unit for my first color laser, thinking that
I *might* need to replace it, someday. When I finally tired of the laser,
the imaging unit was still new, in its box. <shrug> Some spares never see
use (but, Murphy suggests failing to preserve a "gift" can lead to regret,
later)

I ran solid ink phasers for a while. You'd drool over the camera-ready art
they'd churn out! But, they were a bitch to maintain in a low use environment.
And, the house always smelled like burnt crayons when they were used. :<
So, I now let a service bureau print proof and the local library for any
"run-of-the-mill" color laser work. At 10p/double-sided page (I can route
my output to the printer from home!), it's hard to beat -- and, no hassles
with maintenance!