[GreenKeys] 180502 Parts

[David Tumey via GreenKeys]

Rob,

Wayne and I noticed during the design phase that there is a considerable amount of variation in the dimensions of the hammer from machine to machine and in particular, the grove beneath the "face" of the hammer.  Because of this, the fit of the part will also vary from hammer to hammer.

On the tight-fitting hammers, a thorough cleaning is essential and the addition of a little silicone (sprayed onto a fingertip and applied to the bottom of the rubber head) or WD40 will permit easier installation.  Once installed if you twist the part several turns in either direction, it should seat properly.

In all the tests we carried out, the hammer did stay in position correctly and the wear pattern was acceptable.

Also, we had to increase the durometer of the part to make it more durable which also makes it more difficult in some cases to seat it correctly.

What is certain is that of the 4-5 iterations of the part we tested (each with small dimensional tweaks), the current part is the best fitting we could find across all the test machines - Wayne you might want to chime in on this as you did the bulk of the in-use testing.

thanks.
--dave


________________________________
 From: Robert Jarratt <robert.jarratt at ntlworld.com>
To: David Tumey <davetumey at yahoo.com>; "greenkeys at mailman.qth.net" <greenkeys at mailman.qth.net> 
Sent: Monday, September 8, 2014 2:52 PM
Subject: RE: [GreenKeys] 180502 Parts
 


I tried one of the early test samples at the weekend. My Model 33 still had the original hammer head which turned out to be a strange mixture of gooey and hard. It was messy getting it off, I  ended up with black goo under my fingernails, some of it is still there 24 hours later.

The rest of the cleaning I did with Isopropyl Alcohol. First using a paper towel for the bulky bits, a small screwdriver to get into the corners, and finally some string and some dental floss soaked in Isopropyl.

Getting the new part installed was ok, but it didn't go on really snugly until I used a bit of WD40.

Regards

Rob



________________________________
From: David Tumey via GreenKeys
Sent: ‎07/‎09/‎2014 17:12
To: greenkeys at mailman.qth.net
Subject: [GreenKeys] 180502 Parts


I am shipping Rob Jarratt 100 pcs for distribution in Europe.  Will try to get them out this week.

We will see how that works.

thanks.
--dave
W5DT
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