Myford Super 7 screw cutting gears (metric)

[John Stevenson 1Participant @johnstevenson1]

Simon,

Thanks for that chart, no doubt it will help other users of the early gearbox's but only if they can do a 30 /17 and 29/16 cluster.

I went back and examined the 14.5 and 20 degree differences.

Quite a difference. The one on the right is 29T corrected but at 20degrees PA with the original No 4 cutter at 14.5 PA superimposed. As you can see nothing like.

The one on the left is using a No5 cutter 21T to 25T range and cut 0.0065" deeper. Again loads of under cutting but the flanks are a good match.

[Simon Williams 3Participant @simonwilliams3]

Thanks John, looks like the couple of thou I added on to the DOC "just to be sure" were well invested.

Best rgds Simon

[Steve BowerParticipant @stevebower42241]

Quite late to this post, but I've just acquired a Super7. Are the metric gears still available? Thanks

[Roderick JenkinsParticipant @roderickjenkins93242]

Steve,

If you have the standard Myford gear box, 33 and 34 teeth gears are available from Myford **LINK**

HTH,

Rod

[Steve BowerParticipant @stevebower42241]

Posted by Roderick Jenkins on 12/11/2017 22:04:04:

Steve,

If you have the standard Myford gear box, 33 and 34 teeth gears are available from Myford **LINK**

HTH,

Rod

Brill, thanks

[9fingersParticipant @9fingers]

Does anyone know of a source of either a set 21, 33 and 34 tooth gears or just a 34 that will get me out of a current problem please.

TIA

Bob

[Simon Williams 3Participant @simonwilliams3]

Bob (9fingers) – I have sent you a PM.

Rgds Simon

[9fingersParticipant @9fingers]

Just a public THANK YOU to simon for sending me an extremely professional 34 tooth changewheel.

What a Gent!

Thanks

Bob

[Andy GParticipant @andyg]

Test

[SteviegtrParticipant @steviegtr]

An old thread but I am still slightly confused as said on other threads. I am about to buy the 2 gears 33 & 34 tooth. Someone posted a picture but I was still not sure. Mine is a super 7B 1977. Does the new gear go below the 2 tufnol gears on the gear that you can remove one gear from it. A actual picture would be great if anyone has one.

[SteviegtrParticipant @steviegtr]

Bump. I have ordered the 33 & 34 gears from Myford. I now think from reading posts that they fit on the shaft below the pair of tufnol gears. The shaft that holds 2 gears. So if correct do I turn that gear around for screwcutting so the 33 or 34 which I put on is to the inside, with larger gear to outside. Also anyone got an idea what year my QC gearbox is. No QC137956, my lathe is circa 1977.

[john fletcher 1Participant @johnfletcher1]

Hello steviegtr, I've got Brian wood's excellent book and its all explained in the book, together with good clear photos. The shaft you are referring to has a pair of gears on it, which are keyed together. So you can change the outer gear, but you do have to lower the quadrant as the replacement is larger in diameter. In the book, it shows the shape and gives the dimension of the gear adapter which needs making. Brian also suggests making a little tool which makes adjusting the quadrant an easier task. Then you will need the tables of which there was a lot of discussion about in Model Engineer Workshop, when some errors were discovered, not pointing a finger anywhere,. Anyway, I think the book is worth buying. John Steviegtr

[SteviegtrParticipant @steviegtr]

Thanks for that. I have copied the charts which were put on here some time ago showing which setting of the quick change for each pitch of metric thread. Not heard that I need a gear adaptor. What is that for.

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