Re: DEC H9xx rack parts needed

[Paul Koning via cctalk]

> On Sep 16, 2017, at 7:44 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 09/16/2017 03:21 PM, Steve Malikoff via cctalk wrote:
> 
>> Yes I agree they both appear to be simple machining jobs. As a substitute 
>> for drill rod...
> 
> I'm unclear why the recommendation has been for "drill rod" (i.e.tool
> steel) for the parts that essentially hold the parts to a hinge together.
> 
> It would seem that a plain 1018 cold-rolled steel would be strong
> enough.  For easy machining, even 12L14 would seem to be preferable,
> although I don't know if that's legal in the EU, given the slight lead

I just meant it in the sense of steel rod that's available in many sizes to 
good tolerances.  You're right, for this application mild steel is certainly 
strong enough.

Re: DEC H9xx rack parts needed

[Jon Elson via cctalk]

On 09/16/2017 03:47 PM, Ethan Dicks via cctalk wrote:
Worst case, if I can't resurrect the PC, I'll probably 
throw an Arduino on it and use modern Open Source tools 
for driving it (the LMC box has a DB25 with all the step 
and direction and endstop signals on it for Mach3 or Grbl 
or whatever). This sort of project would be perfect on 
this wee lathe. The pins would be trivial (just need to 
grind an HSS cutting bit with the profile you described), 
and the bushings not much harder (ordinary bit for the 
main diameters and the taper, then cutoff, then rechuck 
and cut down the face to get down to final length). -ethan 

There's also LinuxCNC for machine control.  ( linuxcnc.org )

Jon

Re: DEC H9xx rack parts needed

[Chuck Guzis via cctalk]

On 09/16/2017 03:21 PM, Steve Malikoff via cctalk wrote:

> Yes I agree they both appear to be simple machining jobs. As a substitute for 
> drill rod...

I'm unclear why the recommendation has been for "drill rod" (i.e.tool
steel) for the parts that essentially hold the parts to a hinge together.

It would seem that a plain 1018 cold-rolled steel would be strong
enough.  For easy machining, even 12L14 would seem to be preferable,
although I don't know if that's legal in the EU, given the slight lead
content.

Anyone care to shed some light on this?  And if "Drill Rod' is the
preferred material, what *kind* of steel?  i.e.  O1, S7, A2, D3, W1, M2?

Just curious--unless the application is for a shaft subject to torsional
loads or needing a cutting edge, I generally use cold-rolled mild
steel--it's inexpensive and machines well.

--Chuck

Re: DEC H9xx rack parts needed

[Steve Malikoff via cctalk]

Paul and others said
>> On Sep 16, 2017, at 4:10 PM, Paul Koning via cctalk  
>> wrote:
>>
>>
>>> On Sep 16, 2017, at 9:52 AM, Noel Chiappa via cctalk 
>>>  wrote:
>>>
 does anyone have any spare "pivot bushings" for the DEC H9xx series
 cabinets (H950, H960, etc)? (These are the short pieces with a conical
 top which fit over the hinge pins, at the bottom.)
 ...
 I could also use some more of the pins (particularly the kind with the
 hole drilled through them to take a roll pin)
>>>
>>> Someone asked for an image of these; here:
>>>
>>> http://ana-3.lcs.mit.edu/~jnc/tech/jpg/H9xxPinBushing.jpg
>>>
>>> is one. The pin in the picture is the kind without the hole at one end, but
>>> they are otherwise identical. (Ignore the retaining ring on the pin; those
>>> are easy to get, my local hardware store has them.)
>>
>> If you have a lathe, this looks like a very nice beginner's project.  Start 
>> with a rod of the right diameter; a simple way to get such a rod is to buy a 
>> long bolt, because those are mostly not threaded.  Failing that, get a 
>> length of "drill rod" from a metal supply outlet.  Then all you need is
to grind a tool bit (high speed steel) to form a narrow screwdriver-like tip to 
cut those grooves.  Hold the rod in the lathe, cut the grooves in the right 
spots, cut the thing to length, done.>
> Ok, I read that wrong.  You were talking about the short thing.  Still, 
> that's an easy project.  Same idea.  Start with a rod, grip in the chuck, 
> drill, cut bevel, cut the two diameters, then cut to length.  Elementary 
> lathe operation books are easy to find; the South Bend Lathe manual that used
to be reprinted by Lindsay Publications is very good.  It's probably still 
available even though Lindsay unfortunately retired some years ago.>
>   paul

Yes I agree they both appear to be simple machining jobs. As a substitute for 
drill rod (although not the same quality steel) you can
use shafts out of old printers and photocopiers, I have a bunch of them I saved 
for just this sort of purpose. Often they have
circlip grooves in them already, so some of the work is saved, but a fine tooth 
hacksaw will make a circlip groove whilst the lathe
is spinning (frowned-upon workshop practice, I know). or just place it in a 
vice, saw, rotate the pin for the next few degrees and
so on. Check the circlip for fir every so often.
The bush looks pretty straghtforward. Between the one-off and the full CNC 
route is the form tool approach where the profile is
ground in a piece of tool steel and then fed into the job. For very low runs a 
piece of drill rod can be cut then hardened, sure
saves a lot of effort grinding.
If some micrometer or digital caliper measurements of the pin and bush are 
available I'll draw it up for the list. :)

Steve.

Re: DEC H9xx rack parts needed

[Ethan Dicks via cctalk]

On Sat, Sep 16, 2017 at 4:57 PM, Chuck Guzis via cctalk
 wrote:
> On 09/16/2017 01:47 PM, Ethan Dicks via cctalk wrote:
>
>> This sort of project would be perfect on this wee lathe

> You'll still need to center-bore the hole through the thing, which,
> while not hard, does require some skill and a set of centering drills.

Right.  There's that part too.  Easy on a "real" lathe, not easy on
the specific CNC lathe I have (it has a simple tailstock and no chuck
for drill bits).  I do have access to a 12" x 36" manually-operated
screw lathe that would be able to do all the steps, but I have to pay
$15/hr to rent it (not terrible, but also not free and the tool time
is much greater cost than the material cost).

> Personally, I'd probably find a friend with a home machine shop and buy
> him a suitable quantity of his beverage of choice to do the job.
> machinists don't own a shop because they *hate* machining.

Right.  You want a couple, and it's no big deal.  Some beer and
company and conversation and a chance to show off the tools.   A box
of a bunch of the same thing though, that's work.

-ethan

Re: DEC H9xx rack parts needed

[Chuck Guzis via cctalk]

On 09/16/2017 01:47 PM, Ethan Dicks via cctalk wrote:

> This sort of project would be perfect on this wee lathe.  The pins
> would be trivial (just need to grind an HSS cutting bit with the
> profile you described), and the bushings not much harder (ordinary bit
> for the main diameters and the taper, then cutoff, then rechuck and
> cut down the face to get down to final length).

You'll still need to center-bore the hole through the thing, which,
while not hard, does require some skill and a set of centering drills.

Personally, I'd probably find a friend with a home machine shop and buy
him a suitable quantity of his beverage of choice to do the job.   Home
machinists don't own a shop because they *hate* machining.

--Chuck

Re: DEC H9xx rack parts needed

[Ethan Dicks via cctalk]

On Sat, Sep 16, 2017 at 4:16 PM, Paul Koning via cctalk
 wrote:
 does anyone have any spare "pivot bushings" for the DEC H9xx series
 cabinets (H950, H960, etc)? (These are the short pieces with a conical
 top which fit over the hinge pins, at the bottom.)
>>>
>>> http://ana-3.lcs.mit.edu/~jnc/tech/jpg/H9xxPinBushing.jpg
>>>
>> If you have a lathe, this looks like a very nice beginner's project.

I was thinking much the same.  I recently came into a 1990s vocational
school CNC lathe (neighbor by my younger brother moved out and gave it
to him on the way out), 3" x 6".   Light Machines Corp made the
control box and proprietary 8-bit ISA cards.  This one came with an
AT/Olivetti PC6300 that looks like it was an a car wreck (I needed a
prybar to open the case).  The disk was an ST251 on an 8-bit
controller and, surprise, isn't readable.  Worst case, if I can't
resurrect the PC, I'll probably throw an Arduino on it and use modern
Open Source tools for driving it (the LMC box has a DB25 with all the
step and direction and endstop signals on it for Mach3 or Grbl or
whatever).

This sort of project would be perfect on this wee lathe.  The pins
would be trivial (just need to grind an HSS cutting bit with the
profile you described), and the bushings not much harder (ordinary bit
for the main diameters and the taper, then cutoff, then rechuck and
cut down the face to get down to final length).

-ethan

Re: DEC H9xx rack parts needed

[Paul Koning via cctalk]

> On Sep 16, 2017, at 4:10 PM, Paul Koning via cctalk  
> wrote:
> 
> 
>> On Sep 16, 2017, at 9:52 AM, Noel Chiappa via cctalk  
>> wrote:
>> 
>>> does anyone have any spare "pivot bushings" for the DEC H9xx series
>>> cabinets (H950, H960, etc)? (These are the short pieces with a conical
>>> top which fit over the hinge pins, at the bottom.)
>>> ...
>>> I could also use some more of the pins (particularly the kind with the
>>> hole drilled through them to take a roll pin)
>> 
>> Someone asked for an image of these; here:
>> 
>> http://ana-3.lcs.mit.edu/~jnc/tech/jpg/H9xxPinBushing.jpg
>> 
>> is one. The pin in the picture is the kind without the hole at one end, but
>> they are otherwise identical. (Ignore the retaining ring on the pin; those
>> are easy to get, my local hardware store has them.)
> 
> If you have a lathe, this looks like a very nice beginner's project.  Start 
> with a rod of the right diameter; a simple way to get such a rod is to buy a 
> long bolt, because those are mostly not threaded.  Failing that, get a length 
> of "drill rod" from a metal supply outlet.  Then all you need is to grind a 
> tool bit (high speed steel) to form a narrow screwdriver-like tip to cut 
> those grooves.  Hold the rod in the lathe, cut the grooves in the right 
> spots, cut the thing to length, done.

Ok, I read that wrong.  You were talking about the short thing.  Still, that's 
an easy project.  Same idea.  Start with a rod, grip in the chuck, drill, cut 
bevel, cut the two diameters, then cut to length.  Elementary lathe operation 
books are easy to find; the South Bend Lathe manual that used to be reprinted 
by Lindsay Publications is very good.  It's probably still available even 
though Lindsay unfortunately retired some years ago.

paul

Re: DEC H9xx rack parts needed

[Paul Koning via cctalk]

> On Sep 16, 2017, at 9:52 AM, Noel Chiappa via cctalk  
> wrote:
> 
>> does anyone have any spare "pivot bushings" for the DEC H9xx series
>> cabinets (H950, H960, etc)? (These are the short pieces with a conical
>> top which fit over the hinge pins, at the bottom.)
>> ...
>> I could also use some more of the pins (particularly the kind with the
>> hole drilled through them to take a roll pin)
> 
> Someone asked for an image of these; here:
> 
>  http://ana-3.lcs.mit.edu/~jnc/tech/jpg/H9xxPinBushing.jpg
> 
> is one. The pin in the picture is the kind without the hole at one end, but
> they are otherwise identical. (Ignore the retaining ring on the pin; those
> are easy to get, my local hardware store has them.)

If you have a lathe, this looks like a very nice beginner's project.  Start 
with a rod of the right diameter; a simple way to get such a rod is to buy a 
long bolt, because those are mostly not threaded.  Failing that, get a length 
of "drill rod" from a metal supply outlet.  Then all you need is to grind a 
tool bit (high speed steel) to form a narrow screwdriver-like tip to cut those 
grooves.  Hold the rod in the lathe, cut the grooves in the right spots, cut 
the thing to length, done.

paul

RE: DEC H9xx rack parts needed

[Henk Gooijen via cctalk]

Van: Noel Chiappa via cctalk<mailto:cctalk@classiccmp.org>
Verzonden: zaterdag 16 september 2017 15:52
Aan: cctalk@classiccmp.org<mailto:cctalk@classiccmp.org>
CC: j...@mercury.lcs.mit.edu<mailto:j...@mercury.lcs.mit.edu>
Onderwerp: Re: DEC H9xx rack parts needed

> does anyone have any spare "pivot bushings" for the DEC H9xx series
> cabinets (H950, H960, etc)? (These are the short pieces with a conical
> top which fit over the hinge pins, at the bottom.)
> ...
> I could also use some more of the pins (particularly the kind with the
> hole drilled through them to take a roll pin)

Someone asked for an image of these; here:

  http://ana-3.lcs.mit.edu/~jnc/tech/jpg/H9xxPinBushing.jpg

is one. The pin in the picture is the kind without the hole at one end, but
they are otherwise identical. (Ignore the retaining ring on the pin; those
are easy to get, my local hardware store has them.)

Noel


Got the pivot bushing here in front of me, it’s yours.
I am pretty sure I have one or two pins *with* a hole at one end,
but I remember they are not perfectly straight. You will have to
hammer them a bit to straighten them.
I will check whether I can find those two pins, and send them
to you in a “bubble envelop” marked as “old metal pivot parts”.

Greetz,
Henk

Re: DEC H9xx rack parts needed

[Noel Chiappa via cctalk]

> does anyone have any spare "pivot bushings" for the DEC H9xx series
> cabinets (H950, H960, etc)? (These are the short pieces with a conical
> top which fit over the hinge pins, at the bottom.)
> ...
> I could also use some more of the pins (particularly the kind with the
> hole drilled through them to take a roll pin)

Someone asked for an image of these; here:

  http://ana-3.lcs.mit.edu/~jnc/tech/jpg/H9xxPinBushing.jpg

is one. The pin in the picture is the kind without the hole at one end, but
they are otherwise identical. (Ignore the retaining ring on the pin; those
are easy to get, my local hardware store has them.)

Noel

RE: DEC H9xx rack parts needed

[Henk Gooijen via cctalk]

Van: Noel Chiappa via cctalk
Verzonden: zaterdag 16 september 2017 01:04
Aan: cctalk@classiccmp.org
CC: j...@mercury.lcs.mit.edu
Onderwerp: DEC H9xx rack parts needed

Hi, does anyone have any spare "pivot bushings" for the DEC H9xx series
cabinets (H950, H960, etc)? (These are the short pieces with a conical top
which fit over the hinge pins, at the bottom.) I need at least one to hang a
back door which I have.

If nobody has any, they'd be easy to machine, so I might look into having a
run made by some local machinists.  (I do have a lathe, but have little lathe
experience, so machining one of those myself is probably out of my range.)  If
it's someone with a CNC lathe/etc, I could probably get more made for little
more than materials cost. If none turn up in response to this, I'll ask on the
list about interest before I set off to find a machinist.

I could also use some more of the pins (particularly the kind with the hole
drilled through them to take a roll pin), if anyone has any of those spare.

Thanks!

Noel

Hi Noel,
I am going to my “museum” this afternoon, and will check.
I am prety sure, I can help (and return a favor)  

Greetz,
Henk

RE: DEC H9xx rack parts needed

[Ed Sharpe via cctalk]

or find some one with a brown and sharpe... screw machine...  keep them 
employed!

Sent from AOL Mobile Mail

On Friday, September 15, 2017 Noel Chiappa via cctalk  
wrote:
Hi, does anyone have any spare "pivot bushings" for the DEC H9xx series
cabinets (H950, H960, etc)? (These are the short pieces with a conical top
which fit over the hinge pins, at the bottom.) I need at least one to hang a
back door which I have.

If nobody has any, they'd be easy to machine, so I might look into having a
run made by some local machinists. (I do have a lathe, but have little lathe
experience, so machining one of those myself is probably out of my range.) If
it's someone with a CNC lathe/etc, I could probably get more made for little
more than materials cost. If none turn up in response to this, I'll ask on the
list about interest before I set off to find a machinist.

I could also use some more of the pins (particularly the kind with the hole
drilled through them to take a roll pin), if anyone has any of those spare.

Thanks!

Noel