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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W1TTL on November 01, 2021, 10:27:31 AM



Title: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: W1TTL on November 01, 2021, 10:27:31 AM
Hi everyone,

I am restoring a Johnson Thunderbolt that's missing its square rubber feet.  Does anyone have a rubber foot substitution that you recommend or some spare rubber feet that I could purchase?  I am trying to make everything look original. 

Thank you and 73,
Tony W1TTL


Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: WB6NVH on November 01, 2021, 02:21:11 PM
This doesn't help you much but back about 4 years ago there was a guy on eBay selling repro exact feet.  I needed more recently and can't find him now!


Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: W2PFY on November 01, 2021, 02:36:13 PM
What I found after a lot of looking is plastic corks at Home despot. They have them in all sizes.  I glued them on with the large end to the chassis. I think I used a hot glue gun to affix them?

They call them rubber stoppers and here is a link. Go to the hardware section and you'll find them in the pull out drawers with all the other misc items..

https://www.homedepot.com/b/Hardware/Hole-Plug-Cork/Indoor-Outdoor/N-5yc1vZc21mZ1z0zteaZ1z11evg (https://www.homedepot.com/b/Hardware/Hole-Plug-Cork/Indoor-Outdoor/N-5yc1vZc21mZ1z0zteaZ1z11evg)

   Let me know what you think about this solution?

Terry


Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: Pete, WA2CWA on November 01, 2021, 03:04:03 PM
I went through this several years ago with my first T-Bolt. The original feet are no longer in production.
I opted for these shown below from Grainer, 5 for $10. They also sell a similar one, same diameter but not quite as high.

https://www.grainger.com/product/16ZD79?ef_id=CjwKCAjwoP6LBhBlEiwAvCcthJG1V5v-PDzjfXYL3QZg-5R57FTEN8A3y3u-G8HFfJhTK1hMZt7QsxoCC7IQAvD_BwE:G:s&s_kwcid=AL!

(https://static.grainger.com/rp/s/is/image/Grainger/16ZD79_AS01?hei=804&wid=804)



Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: W2PFY on November 01, 2021, 06:19:33 PM
Those look nice Pete! I guess I should have come here first rather than looking at everything in HD?


Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: KA2PTE on November 01, 2021, 09:31:40 PM
Mine had round feet with I think #10 threaded screws, they looked original.
Make sure when you replace you put those screws back in so they dont stick up
on the rail. The screw head ought to be on the rail side. Otherwise a little thread portrudes
and makes it hard to slide the chassis in on the rails.

I put some fine oil on the rails to make it slide a little easier.
Also check out the IO group I made for the Johnson Linears,
someone there may have some.


Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: MikeKE0ZUinkcmo on November 03, 2021, 10:51:31 PM
I have a fair number of heavy transmitters, amplifiers, and receivers, and I rotate onto and off the ops bench fairly regularly, so having rubber feet that "grip the road" so to speak, are certainly not an asset, since they virtually prohibit moving the monsters around on the bench.   

I install self adhesive Felt pads to either replace the rubber feet on the bottom of the cabinet, or attach them on the underside of the rubber feet.   They are available in a variety of sizes and shapes and easily cut to size if needed.    These big heavy old BA's are certainly heavy enough that even with the felt pads they don't move without a fair amount of push being applied, but they move fairly easily so that positioning them on the bench doesn't require calling for reinforcements.

(https://photos.smugmug.com/Miscelaneous-/BIGGIES/i-RhqvLPZ/0/3493b22a/L/feet3-L.jpg)


Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: K4NYW on November 04, 2021, 01:05:42 PM
For future reference - McMaster-Carr sells a variety of "bumpers", also for use as equipment feet.
https://www.mcmaster.com/bumpers/heavy-duty-unthreaded-bumpers/
https://www.mcmaster.com/bumpers/unthreaded-bumpers-6/


Title: Re: Recommendation for Rubber Feet for a Johnson Valiant or Thunderbolt?
Post by: W1TTL on December 31, 2021, 01:35:25 PM
Hi everyone,

Just thought I'd post a follow-up on what I ended up doing.  

The original Valiant rubber feet have the following dimensions.  They are a trapezoidal prism in shape and are around 9/16" (14mm) thick.

Bottom Area: 1.5" x 1 5/16" (38mm x 33mm)
Top Area: 1 3/16" x 1 5/32" (30mm x 29mm)

A suitable replacement are some rubber feet I found from RubberFeet.us that are a rectangular prism and 0.59" thick and have a base area of 1.5" x 1.5".  They are non-marking and quite rugged and hard with a durometer of 87.  I was able to use the screws similar to the originals, which are 10-32 x 1/2" screws with #10 washers and 10-32 hex nuts.

I hope that helps someone else looking for the same thing.  Attached are some side-by side and photos of the old and new rubber feet on a Valiant.  I used these feet for my Thunderbolt project.

73,
W1TTL
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands