Here is a list of all the postings Philip Cooper 1 has made in our forums. Click on a thread name to jump to the thread.
|Thread: Warrington Model Engineering Developments|
Some photos below of the solution that I arrived at, using the 17T gear that Rod very generously made. The mounting stud is 0.375" and the standard Myford change-wheels are 0.625", so I bored the 17T to 0.500". This was then Loctited and pinned to a stepped sleeve, the other end of which was milled for a keyway to take the standard gears as required. Seems to work fine, usable on Stud 1 and Stud 2. Thanks to Brian's mathematical prowess I also have a set of alternative gear combinations to make finding a suitable set-up even easier.
Thanks to all for your help, the generosity of Forum members is amazing. I hope to be able to make a similar contribution at some time.
And in place on Stud 2:
It was fascinating to read the patent application, thanks Michael for tracking it down. Unfortunately no clues about using the smaller gear, metric seems to get only one brief mention.
Below is a picture of the stud/sleeve/key arrangement. It might be possible to make a stepped sleeve that would allow the use of a gear with a reduced bore.
Still going to be tight, but worth investigating. Rod has very kindly made a couple of 17t gears, one of which is un-bored so could be adapted for use on a stepped sleeve, so I may now have a potential solution that would retain the originality of the unit.
Brian - Thank you for the offer to recalculate the ratios. I'll try and establish the constraints on gear size for each position to see if this could be an alternative way forward.
Thanks again to all for your inputs.
Hmm, I did wonder if it might be a bit tight, the smallest standard part is 20t.
Rod, many thanks for looking at this, I appreciate you taking the time. I’ll play around with some of the combinations that have been suggested, plus those from the Martin Cleeve book on screw cutting. Most of my metric stuff Is just a few standard pitches, so I should be able to find some workable solutions.
Thanks again to all.
Thanks for your comments. You are correct, the second set of gear wheels are bought into use when fine feed is selected.
I unfortunately don’t have any more information on the unit, it was fitted by the previous owner, a friend who was selling due to ill heath. I suspect that he bought it secondhand, as he meticulously documented all aspects of his workshop but I can’t find any reference to WMED. As you suggest, supplying a 17t as part of the kit would have made sense.
Thanks for the 1.5mm pitch calculation. I’ve completed the current job using a Die, but will certainly try your suggestion.
Please see below a few pictures of the unit:
As can be seen from the above chart, the change wheel combinations differ from the original Myford suggestions. This may be because the increased complexity limits the gear combinations that can be accommodated. 1.25mm pitch can be done using 30:38 + 25:50, but none of the recommendations for 1.5mm (at least, those that I've tried so far) will fit. Finding a 17T gear would be the ideal solution.
Thanks all for your responses. I’ve today joined the forum as it’s clearly a great resource. When I’ve figured out how it’s done I’ll post some photos of the WMED unit.
A fellow VMCC member made me aware of this forum, looking at the amount of information on here I should have joined a long time ago! Main interest is old motorcycles, but I also refurbish the odd clock. An ML7 and Dore Westbury mill are the workshop basics.
I look forward to getting involved with the forum.
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