-------- Original Message --------
Subject: RE: Broken map drawers
Date: Wed, 11 Aug 2004 15:05:54 -0400
From: Mark A. Thomas <[log in to unmask]>
To: 'Maps and Air Photo Systems Forum' <[log in to unmask]>

------------------
I'll second what Brian Bach says regarding loose bolts and lubrication.
We've done similar maintenance on some of our cabinets.

The wheels on our old Maylines are held in by a bolt with a flat Philips
screw head (I think it uses a big #3 Philips screwdriver, with a nut
that I think takes a 7/16" head, 28 threads per inch).  The bolt is
recessed and there's very little clearance, so I don't know if you could
get any off-the shelf replacements. I couldn't find anything that fits
down in the recess enough to provide clearance. If someone has a spec on
this so I could get at a hardware store, please tell me.

The nut loosens over time and the wheel wobbles and eventually the
drawer binds up. The threads on the bolt get all worn and stripped since
it's loose in the mounting hole instead of tight. Usually you can fix by
removing the drawer and tightening the bolt tightly. (There are two
wheels on the drawer and two in the cabinets in these models.)  Just
force the nut over those stripped threads. I've even taken the entire
wheel unit off and worked on the nut back and forth a little further at
a time over the stipped part of the bolt to sort of re-thread the bolt.

Mayline/Hamilton will sell replacement wheel sets: the wheel plus the
bolt and nut. That's overkill because all you usully need is the bolt.
I can't remember the price they gave me. Maybe $10-15 each.

Lubrication is important and I've used automotive wheel bearing grease.
You should pack the bearings in the wheel as you would auto bearings ...
Push grease with your hand into all the cracks between the ball bearings
until it squeezes out the other side. As you turn the bearings, the new
grease will dissolve the old hardened stuff and it will start to move
smoothly.  (i.e., I didn't bother to clean the bearings first as I would
have for a car.)  You'll need lots of paper towels.

Since the axle grease is smelly and messy, I think vaseline would work
fine.  The forces shouldn't be as much as in the front wheels of your
car (although some of our drawers are pretty overloaded!).  As a couple
of people said, I'd avoid WD-40, which would certainly dissolve the
hardened grease but isn't good for a long-term lubricant and may drip,
as would a light lubricating oil like 3-in-1.  Mainly just collect dust
over time and gum up much faster than a solid grease.

I always pull my hair when I see people spraying WD-40 into keyholes.
That will just gum up the lock after a while and make it worse.  You
should use powdered graphite or rub a soft pencil on your key and insert
into the lock to lubricate it.

--Mark
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Mark Thomas / [log in to unmask] / 919-660-5853, fax:919-684-2855
Economics, Geology, Geography Bibliographer
Map and GIS Librarian / Public Documents and Maps Department
025 Perkins Library / Duke University, Durham, NC 27708-0177

> -----Original Message-----
> From: Maps and Air Photo Systems Forum
> [mailto:[log in to unmask]] On Behalf Of Johnnie D. Sutherland
> Sent: Wednesday, August 11, 2004 1:25 PM
> To: [log in to unmask]
> Subject: Re: Broken map drawers]]
>
>
> -------- Original Message --------
> Subject: Re: Broken map drawers]
> Date: Wed, 11 Aug 2004 09:03:49 -0700
> From: Brian Bach <[log in to unmask]>
> To: [log in to unmask], [log in to unmask]
>
> ------------------
> Ilene,
>
> Having achieved a sort of mechanical apprenticeship tinkering with old
> DeSotos and Chrysler Imperials in my youth, I consequently feel
> confident enough to effect nearly all map drawer maintenance myself.
> Most problems have to do with the guide wheels, as you have
> pointed out.
> I've found that the screw or bolt that mounts the wheel to
> the framework
> has sometimes come loose, so that the wheel wobbles and
> causes all sorts
> of mayhem, including scraping (metal filings are a telltale sign!) and
> misalignment. Solution: tighten said screw or bolt - firmly. There
> should be some sort of lock washer in there to keep it tight.
> Otherwise,
> it's pretty much a case of lubrication.

...