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| dmbasher:
Hi, You need to have a dog clutch with only one "tooth" then you can open the leadscrew nuts and move saddle back and re-engage nuts without worrying about pick-up as this will be automatic. Study ME/MEW forum where a very simple retractable threading toolholder is described with several different versions by various contributors. I understand that EIM magazine will be publishing in Nov or Dec a series of articles on making a quick reversing system for a variety of different lathes. This system incorporates a single - tooth dog clutch. This should greatly speed up screwcutting. Maybe you should be patient and wait til you`ve seen these. Hope above helps. John. |
| BillTodd:
--- Quote from: AcieraF3 on August 27, 2011, 03:19:51 PM ---Thanks all, :mmr: Did some practice thread cutting with the half nut engaged and using the electric brake to forward and reverse the machine.......works great. Actually I do have a manual but it is in German :bang: --- End quote --- Phone Tony Griffiths from lathe.co.uk, he may have a english manual or be able to explain how to thread with the boley system. (I suspect that, like my Hardinge, you can just reverse the lead screw without losing sync with the spindle. Bill |
| Philip Burman:
Hi Teun, I also have a Boley 5LZ. Using the brake/clutch switch (C) to stop and then reverse the spindle at 4 times speed is the correct method for threading on the 5LZ. For short to medium length sections it's faster than disengaging the half-nut and using a thread dial. I've had mine for a year and a half now and pretty much know my way around, although I'm not an expert. I'm up for trading info and knowledge if you are interested. I have a complete English manual consisting of: - Test Report BON 320/3E B1. 1 - Instruction BON 320/3 B1. 2 - Hints for fitting of Electric Multi-Disc Clutches - Leaflet De 16 - Transport Instructions BON 715-6 - Erection Diagram BON 715 -7 - Controls and structural parts BON 715-8 - Headstock assembly drawing BON 715-9 - Leadscrew bearing BON 715-10 - Cutting Speeds in meters per min. BON 703 / 1 - Register of Change Gears BON 377/93 - Lubricating Instructions BON 705/1ae - Instructions for d 32 - Wiring Diagram Phil:) --- Quote from: AcieraF3 on August 27, 2011, 03:19:51 PM ---Thanks all, :mmr: Did some practice thread cutting with the half nut engaged and using the electric brake to forward and reverse the machine.......works great. Actually I do have a manual but it is in German :bang: --- End quote --- |
| hopefuldave:
[quote Hi, You need to have a dog clutch with only one "tooth" then you can open the leadscrew nuts and move saddle back and re-engage nuts without worrying about pick-up as this will be automatic. /quote] I believe you still have to leave the half-nuts engaged, but the spindle doesn't require reversing, just the leadscrew? On the Monarch 10EE and diverse Hendeys, Holbrooks etc. the apron control allows disengaging the dog-clutch and throwing it over *to reverse the leadscrew* when thread cutting, Monarch offered a (pretty rare) high-speed electrical reverse for the leadscrew complete with limit stops etc. I'm trying to come up with one for my machine (450W DC motor, pair of bevel gears, limit switches etc.) to hang on the end of the leadscrew... After the dog-clutch (rough sketch below) which is a fair project in itself (yes, pics will be forthcoming once I get the necessary Tuits!) If the half-nuts are disengaged, particularly on "foreign" threads (e.g. anything other than tpi pitches on an Imperial lathe), although the dog-clutch ensures the same angular relationship between spindle and leadscrew (as it runs at spindle speed), releasing then closing the half-nuts could drop them into mesh any integeer number of turns out of step - fine if *and only if* the cut thread is divisible into the leadscrew pitch, not if (e.g.) cutting a Metric thread with a 6 tpi leadscrew... Dave H. (the other one) EDIT: although it may not look like it, that's a single-tooth clutch, as one dog's wider than the others... |
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