Chris Gragson | 14/01/2022 21:13:48 |
44 forum posts 25 photos | Hello all, I have not posted for a while, I appreciated the information I got on my wee Hobbymat lathe and since then I bought a bit of a basket case Hobbymat mill which I have restored to working order and now working on making a mill base for it which is going well. But, I am looking for some help on getting any information on my not that recently aquired Pollard 12 AX, does anyone have any leads to getting a user/parts or service manual for one of these? - or the FX as it is basically the same apart from the pedestal. I did get a reply from Tony at lathes.uk but they only have the 13AX which could be very different unless anyone know otherwise. Apreciate any help. Best Chris |
Clive Foster | 14/01/2022 22:32:45 |
3630 forum posts 128 photos | Chris 13 AX manual will be of no help to you, that is a direct drive machine with a 4 speed pole changing motor directly above the spindle / quill assembly. See the pictures of the 15 AX in the catalogue on that makes up most of the Pollard section on Tony's Lathes.co site. Tony actually gives that information in the pre-amble but its not obvious unless you have some familiarity with Pollard products. As you know yours is a more basic belt drive machine. Fortunately very little to go wrong. I have a 15AY with 6 speed gearbox. Clive |
Chris Gragson | 14/01/2022 22:39:26 |
44 forum posts 25 photos | Thanks a lot Clive, appreciated, I will post tomorrow on some basic questions re the J2 chuck and some photos. I want to know how to get it out without damaging the chuck or the arbor and if the spindle would accept an MT2? Cheers Chris
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DiogenesII | 15/01/2022 08:41:32 |
859 forum posts 268 photos | Just realised it's a Corona - the spindle nose has a male Jacobs taper machined directly onto to it, remove the chuck using taper wedges - My example used a JT2 taper (if there's room to get calipers in, about 0.57 or so imm. above the chuck) - tho' I imagine they're all the same. The spindle in these machines is solid and of small diameter, so there's no room to fit an internal taper. There's a thread here with some info and pictures of wedges for chuck removal; |
Clive Foster | 15/01/2022 09:20:43 |
3630 forum posts 128 photos | Chris Spindle diameter is probably insufficient for MT2 adaption. Minimum diameter for MT2 seems to be around 1 1/8" inches, 1 1/4" sounds safer. Yours is probably about 1". Picking up on the mention of Corona models by DiogenesII it looks like these, later machines, were fundamentally an update of your drill with muti groove vee belt drive, silly skinny looking thing, and a few, mostly cosmetic changes. The Corona 100A/1 I owned before I getting the 15AY was fitted with an MT1 taper in the spindle. Generally the Corona versions appear to have been for woodworking use with appropriately higher speeds. Pollards made a huge variety of machines and there is lots of commonality through the ranges. I suspect the sliding carrier for the quill & spindle assembly is the same as that used for the metal working machines with MT2 and, possibly, MT3 spindles. Easily checked by measuring quill diameter. If so it would be mechanically practical to chop the end of your spindle off and weld on an MT2 carrier. Something I considered for mine when frustrated by the inability to use larger drills. Plan A being to operate on an MT2 jump up sleeve. Never summoned up the courage to try! Sleeve is still kicking around here if you fancy a go! I'd previously asked Pollards, who were still supplying limited spares at the time, if an MT2 spindle could be obtained and fitted. As I recall it they said that although an MT2 spindle could theoretically be fitted the job was impractical because the splines wouldn't match my pulleys. Clive |
DiogenesII | 15/01/2022 10:19:08 |
859 forum posts 268 photos | It is confusing - if you do an image search for 'Pollard 12AX pedestal drill' a number of images turn up, a 1930's style massive CI-bodied machine that used flat belts - that's the machine to which I am referring.. .. I see a dark blue one, a light green one, and a single picture of a red one.. In the example I had, the business-end of the spindle is 5/8", the driven tail is 1/2" with opposed key slots that reduce the core to 3/8" - all driven by a sleeve of suitably modest dimensions. As Clive notes the speeds indicate it was most firmly intended for woodwork.
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Clive Foster | 15/01/2022 13:47:39 |
3630 forum posts 128 photos | DiogenesII I think the 12AX was current up until the mid 1960's or so when it was replaced by the Corona 100/A that I had. Which basically gained more boxy styling, a larger spindle and multi-vee belt drive. Lost the screw feed belt adjuster tho' for a simple permanent spring loading system. Push the motor against the spring to shift the belt. Pretty much the whole Pollard range got re-vamped to more modern styling in the 1960s -1970s but little change in the innards. I suspect that Chris will find a Corona 100/A manual adequate for general what goes where and how does it go together information subject to a bit of engineering experience to sort out detail differences. Clive |
Chris Gragson | 15/01/2022 13:49:29 |
44 forum posts 25 photos | Thank you for the replies, good info there. Yes it is a Corona 12AX pedestal, quite a substantial floorstanding bit of kit, with the flat belt setup, the FX I think is the bench type of the same model. I have seen variations in pictures of the same model also. That's a a bit of a blow on MT compatability, the idea of welding on an MT2 carrier is an interesting one, my MIG welding is as accurate as a scud missile so I would have to get that done by someone better. The longer plan was to slow the machine down to be able to use bigger drill bits on metals. It has been converted to single phase and does work smoothly but I want to convert back to 3 phase motor with a VFD. Are these J2 wedges still available? I would rather not wreck the chuck or the arbour for now as they are fine. |
Chris Gragson | 15/01/2022 14:04:56 |
44 forum posts 25 photos | Thanks for the tip Clive, I will search for the 100/A manual - spotted on lathes.co.uk just now, a bit spicy at £55! Best Chris
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DiogenesII | 15/01/2022 18:32:45 |
859 forum posts 268 photos | MSCDirect - Chuck Removal Wedges Set JT2 ..there are a few problems with adapting for bigger holes in tougher metal, in particular the rather small proportions of the driven part of the spindle, it's keys, and drive sleeve - if the necessary reduction in speed is arrived at by altering the gearing, the torque applied to these components will be multiplied by an equal amount.. It's certainly been my experience that adapting machinery intended for woodworking for use on metal can easily result in spending much time (and even money !) to end up with a machine that becomes somewhat unsatisfactory for either as a result of all the little compromises that have to made along the way.. Whilst it's not hard to affect a change of speed, it can be very troublesome to make things suit the heavier duty requirement.
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Chris Gragson | 15/01/2022 22:00:08 |
44 forum posts 25 photos | Sage stuff Sir, I could be chasing my tail and wasting time/money. Surprising though, that at 400lbs total, it's ideal use is drilling through softer material, but what you say makes sense regarding the relatively weedy spindle, the length of spindle drive and the high speeds. I put a bit of work into this but given the space it takes up, I think I will probably end up selling it as it won't suit my needs. Shame. Thanks for the link on the wedges, appreciated. Best Chris |
Clive Foster | 16/01/2022 08:57:02 |
3630 forum posts 128 photos | Chris Professional woodworking shops are hard on their machines. Pro equipment has, historically, been hefty and strong to put up with it. Just because the material is soft it doesn't mean that a light duty flippity flop machine will be up to producing accurate results. If you aren't in the trade or don't know someone with a higher end wood products workshop its easy to overlook the standards of accuracy and repeatability needed to ensure things fit together with snug joints without lots of hand fettling. A, now unfortunately deceased, friend who had a small high end wood workshop reckoned he would be generally working to 10 thou or better if he was set up to measure it rather than just making things fit. He built a small traction engine and considered the accuracy needed no more onerous. Clive |
AlanW | 16/01/2022 18:16:03 |
92 forum posts 12 photos | Hi Chris, I adapted a Corona 12FX for milling and the article I produced to describe the saga appeared in MEW issues 216 & 217, if I recall correctly. My original adaptation of the spindle for milling involved machining a bespoke ER32 chuck incorporating a female J2 taper. The spindle end drilled readily to accept an axial screw to keep the thing attached. The closing nut was bought in. This arrangement worked fine but anything other than fine cuts (< 0.1mm) led to sideways deflection. I half expected this because the 72mm chuck length produced far too much overhang from the bottom bearing. I should quickly add that I replaced the ball race with a tapered roller bearing ground down to size to fit the existing bearing housing. Eventually the lack of rigidity became too much to live with and I tried a different approach; one that may suit you better than welding. I cut the end off the spindle, and fitted a sleeved and bored ER32 collet chuck extension, glued using anaerobic adhesive and pinned through with a roll pin. This runs in a much larger tapered roller bearing in a housing with a spigot that fits into the original bearing housing. Retention is via the existing three screws (not equi-spaced, incidentally; I spotted through the original retaining plate. I allowed sufficient 'hollow' length of the spindle extension to accommodate a MT1 to parallel adapter in one of the larger collets to make use of some imperial taper shank drills I have. Larger drills are held directly by collets and smaller ones in a Jacobs chuck on a 19mm diameter straight shank arbor. The original three-speed flat belt drive has been replaced with a two stage poly-vee system, giving eight speed from approximately 160 to 2,500 rpm from a 2,400rpm single phase motor (the original was 3 phase. Although it could never compete with a proper mill, performance is not bad at all and edges produced by side-milling are square, so no deflection as before. The slim (around 5/8" Alan |
DiogenesII | 16/01/2022 21:16:39 |
859 forum posts 268 photos | Pleased to be proved wrong by such an interesting conversion! |
Clive Foster | 16/01/2022 21:20:32 |
3630 forum posts 128 photos | Chris Further to what AlanW has said it doesn't seem unreasonably difficult to come up with a functional equivalent to the spindle on my 15AY which has a similar style of large diameter bearing carrier to Alans modifications. Mine has an MT 3 taper. The exposed spindle is 1 1/2" diameter and the quill carrying it only 1 5/8" diameter so the main body of the spindle must be rather smaller to allow adequate quill wall thickness. I imagine a inch or so. The bearing carrier is around 3 1/2" in diameter. If you obtain an MT 2 to parallel sleeve it could be joined to the spindle by a simple tube having the appropriate diameters to accept the sleeve at one end and the spindle at the other. I imagine a couple of inches or so overlap on both would be plenty for high strength loctite bonding. Even without the pin used by Alan. The joining tube will need slots cutting in opposite sides to take the ejector drift. Obviously you will have to accept some loss of quill travel and clerance between table and spindle to accommodate the bearing mount and MT taper extension. Fitting the bearing on the joining sleeve would be the most rigid arrangement and minimise the reduction in spindle to table clearance. I suspect Pollards used an angular contact ball bearing to take the loads. In your position I would use it as is and decide what to do later to make it exactly what you want. Start wih a 3 phase motor and VFD. Clive
Edited By Clive Foster on 16/01/2022 21:22:51 |
Chris Gragson | 24/01/2022 20:26:26 |
44 forum posts 25 photos | Hi Alan, would you have a link or could you send me some more info on your 12AX project? - I am really interested in details of how you achieved the v-belt system on your single phase motor, the RPM on mine is rated at 1425rpm, and if I can convert that and reduce speed via v-belt cones it would be much more preferable. My aim is larger slower drilling not milling, simpler in that respect I hope Hi Clive, I did not intend to knock the woodists Does anyone have any J2 wedges for sale or that I can borrow? - I still can't find them available anywhere. Many thanks Chris
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Chris Gragson | 24/01/2022 20:37:12 |
44 forum posts 25 photos | Just to add, I had to drill 4 holes through 60mm 5083 ali plate yesterday to the max drill bit the Pollard could take, on the lowest 3000ish speed it gummed up with lube, dry it ripped through I then had to swap to the ok pillar I have to get them out to 12.5, but the Pollard did the hard and accurate work. |
AlanW | 28/01/2022 15:54:39 |
92 forum posts 12 photos | Chris, I have answered your pm but photos of the conversion are in my albums. Also in my albums is a photo of my spindle mod. Alan Edited By AlanW on 28/01/2022 16:14:45 |
Chris Gragson | 28/01/2022 21:31:28 |
44 forum posts 25 photos | Hi Alan, thanks a lot, and I have PM'd you back. Hope to hear from you In case it is of any interest re the JT2 wedges, a really nice guy has lent me a pair of "Smallbone" made wedges which worked a treat with just a few hefty taps either side. Meaty things, not like those weedy ones advertised on ebay which cost 25 quid each! the ones pictured are about 18mm at thier thickest and about 50mm across. Having googled the company https://archive.commercialmotor.com/article/27th-may-1966/93/wedge-extractor-tool I see that they made ball joint splitters -> so something like this could be adapted as they are 18mm down the inside which would fit - > https://www.ebay.co.uk/itm/154367635664?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
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Chris Gragson | 24/08/2022 20:12:44 |
44 forum posts 25 photos | Hi all, in the end I went 3ph & VFD which meant could keep the original pulleys, although the driven pulley had to be bored to suit the motor drive. I made a 10mm thick backplate to mount onto the OE plate which also does the belt tensioining, getting that central and height correct took some working out with MDF before I commited to cutting and drilling/tapping the plate. I needed to bring the motor closer than the woven original belt would allow or the hood did not sit right over the TEC 3ph motor, I could have cut and rejoined but went for a shorter belt from BB which was perfect. It's working great, left to do is a remote with reverse/jog etc and wiring up the tacho.
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