[GreenKeys] TD gears for the dual head 28 ASR

[gfmurphy at earthlink.net]

Thanks to George for sharing that trick about getting the dual head
tape reader to work with the normal TD gears.  Problem solved.

Jerry Murphy

-----Original Message-----
>From: "George B. Hutchison" <w7tty at centurylink.net>
>Sent: Feb 4, 2013 5:46 PM
>To: jack hart <wa2hwj at att.net>, Greenkeys <greenkeys at mailman.qth.net>, gfmurphy at earthlink.net
>Subject: Re: [GreenKeys] TD gears for the dual head 28 ASR
>
>Well, time for the old guy to rattle on a bit and divulge a not too 
>closely kept secret.
>
>The simplest way to make that dual head base useable is to go down 
>to your local industrial supply and buy a length of 3/8" diameter 
>centerless ground rod.
>
>Borrow a good shaft from a single head TD, remove the rear to front 
>shaft from the dual base, take yer handy-dandy dial caliper and do 
>some measurements and make a new shaft which will be just a bit 
>longer than the one you removed from the dual base, and turn a new 
>shaft for the dual head.
>
>The shaft has to be cut a bit longer than the original, and you'll 
>have to cut a new C-clip groove for the bearing in the new one, and 
>machine the new end to fit the gear from the single head shaft, 
>positioning said gear to mesh properly with the drive gear on the 
>inner TD head.
>
>Power from the new shaft will drive the inner head, and inasmuch as 
>the inner head is engaged with the intermediate shaft in the dual 
>base, it will drive the outer TD just fine.
>
>I've made about six of those shafts in my lifetime, and on a good 
>lathe takes no more than about fifteen minutes.
>
>And it works spiffy, and you can use all of the standard 28 TD gear 
>sets.
>
>W7TTY
>
>
>
>