Thanks for the link, Mike. You made me look. The “Flanged Compression Springs” are similar to the original shape, but the smallest part is too big and heavy: 5/8-inch long with a 1-inch flange and 33 pounds per inch spring rate. The original is more like 3/8” long, 1/2” flange, and a couple pounds per inch rate. That’s more like you might see in e.g. an optical disk transport, that doesn’t seem to be M-C’s market.
I’m still looking at RC-copter camera mount balls. There seem to be about a half-dozen sizes, but it’s hard to get dimensions - sellers can’t comprehend using them for anything but their intended purpose. “Tektronix? What kind of quadcopter is that?” <facepalm>
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mike Dinolfo via groups.io
Sent: Sunday, June 20, 2021 10:11 AM
Subject: Re: FW: [TekScopes] Another interesting Tektronix web site
Don't know if they have shock mounts that will work for you, but I
recently came across shock mount-type items at mcmaster.com. Tryhttps://www.mcmaster.com/bumper-cushions/
I'm not the first to suggest Mcmaster.com; other Tekscopes group members
have previously suggested Mcmaster as a source for bumpers, hardware,
raw materials, tools, etc. Good outfit to deal with (but I don't know
if they will ship outside of the US).
Mike Dinolfo N4MWP
On 6/20/21 11:30 AM, Dave Wise wrote:
Closeup photos available off-list.
I don’t know how to cast something hollow. Anyway, my goal is to come up with something cheap and easy. Can you suggest phrases to search for? “Shock mount” and “vibration isolator” mostly pick up mike stands and heavy automotive/HVAC stuff.
The shape is a hollow ball with a flange at each end and a hole through the axis. You squeeze the flanges through the mounting holes in the chassis. With 348-007 (used in Type D and H from the 1950s, now deteriorating) you finish up with screw-washers-nut through the hole to prevent a big shock from tearing the cushion apart. 348-0087 (used in Type 1A6 and 1A7 from the 1960s and may outlive me) is a different material, stiffer, and instead of a screw, it is secured with a plug at each end. I think 348-0087 would fit in a D or H.
If I had access to the PISL (Purchased Item Source List microfilm “window cards”), I could determine who Tek bought them from - if they bought them - but they’re surely gone now anyway.
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Harvey White via groups.io
Sent: Saturday, June 19, 2021 7:38 PM
Subject: Re: [TekScopes] Another interesting Tektronix web site
Could you make a mold and cast some sort of rubber?
On 6/19/2021 10:10 PM, Dave Wise wrote:
I performed this procedure on one of the chassis cushion mounts in my Type D plugin. (Tek P/N 348-0007-00. 348-0087-00 might work too.)
Must be a different rubber.
Unless someone has another idea, I will look at cushions made for RC helicopter camera mounts.
This one caught my eye:
HONBAY 24pcs RC Anti Vibration Rubber Balls for Fright Controller Gimbal
On closer look, it's far from ideal. The parts are 13mm overall height, 8mm overall diameter, 6mm hole diameter, approximately 7mm chassis spacing.
The mounting holes in Type D are themselves 8mm diameter (5/16") so the cushions will slip free unless the chassis and subchassis are modified, perhaps by gluing down washers with 6mm ID.
Also the Type D chassis are spaced on approximately 10mm centers, not 7mm, so glue the washer on the bottom side of the upper and the top side of the lower.
I'll report results in a month or so.