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Shoulder Screw Mod

PostPosted: Wed Jan 21, 2015 5:24 pm
by RameGoom
Finding a clean, unmolested shoulder bolt with a certain shoulder dimension seems to be a challenge. But, standard run-of-the-mill shoulder bolts available today will work, but don't look right when applied to a 1920's slot mechanism. So I set out to find a way to make it work.

Trying to keep the original look, I started with a socket head shoulder bolt (standard issue these days) and got to work on the grinder, removing most of the head. Sanded it down to where the hex hole was *pretty much* gone, I wound up with enough of the head that I could slot.

Using a Dremel tool with a friction wheel, I managed to put a decent slot onto the head. So now, it looks reasonably authentic for use in an antique slot.

Whaddya think?

Re: Shoulder Screw Mod

PostPosted: Wed Jan 21, 2015 6:34 pm
by TheFatman
Nice job. What machine is it in use in?
Dave F

Re: Shoulder Screw Mod

PostPosted: Wed Jan 21, 2015 6:44 pm
by Midcoast Vintage
looks good!

Re: Shoulder Screw Mod

PostPosted: Wed Jan 21, 2015 11:55 pm
by RameGoom
I needed a couple of these shoulder bolts on a Little Duke that I "engineered" a linkage to make the vender work properly:

Image

When I first put it in operation, I didn't like the socket head view on the pivot, so that's the one I needed to modify first. I used 2 different length shoulder bolts shown in the image.

Soon to be original-looking.

Re: Shoulder Screw Mod

PostPosted: Thu Jan 22, 2015 8:28 am
by RameGoom
Two more for the vender project:

shoulderscrew_modded.jpg

Re: Shoulder Screw Mod

PostPosted: Thu Jan 22, 2015 10:04 am
by TheFatman
Look at that. Wherer there is a will .... there is a way ... and a machinist.
Dave F

Re: Shoulder Screw Mod

PostPosted: Thu Jan 22, 2015 11:27 am
by RameGoom
This whole project started because I had a Little Duke without a vender that was tagged with Rockola stickers and appeared to have had its vender removed sometime during its life. Then I picked up a nice original vender assembly at the Chicago coin op show in November. I assumed the Duke had the necessary mechanism to trip the vender, but it didn't. And, it seemed the factory Jennings parts needed were next to impossible to find.

So, I put my machinist skills in force and came up with an equivalent trip mechanism to operate the vender during play. Used off-the-shelf hardware and bits and pieces of steel to fabricate the components. Then, looking at the standard shoulder screws, it got me to thinking...maybe they should have the 30's look to be period-specific looking.

Which then brought me to shaving the hardware to match the rest of the machine. This stuff is fun.

Re: Shoulder Screw Mod

PostPosted: Fri Jan 23, 2015 3:48 pm
by TJ
http://machinedesign.com/news/basics-shoulder-screws This is the place to learn everything you need to know about shoulder screws or bolts. You should be able to find the exact size you need for just about any application.

Re: Shoulder Screw Mod

PostPosted: Fri Jan 23, 2015 4:28 pm
by RameGoom
Interesting reading there. Lots of variations. Seems most present-day shoulder screws are socket head, black oxide steel finished. They work great, but they don't look authentic on the antique slots.

Trying to find a readily-available shoulder screw with a large diameter slotted head, unplated plain steel is difficult at best. I have no idea if any US manufacturer makes them. Obviously they're not too popular anymore and probably aren't used on any new products these days.

Just like the round head slotted screws; all I find are zinc plated steel or stainless steel, but not plain steel. The old slots seem to have a great amount of butchery done on the internal screw slots, and I have to resist the urge to just replace all of the screws with plated parts.

Re: Shoulder Screw Mod

PostPosted: Mon Mar 09, 2015 5:45 pm
by doc
There are some shoulder screws in this ebay auction (181686439502):

http://www.ebay.com/itm/Mills-slot-mach ... 2a4d5b0e4e

shoulderscrews.jpg