| The Craftmans Shop > New from Old |
| The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20) |
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| Sea.dog:
--- Quote from: Pete W. on October 09, 2020, 05:56:20 AM --- --- Quote from: awemawson on October 08, 2020, 04:38:53 PM ---I’ve a couple of Avo 8’s but my ex WD Avo 40 recently died from a fatal fall onto concrete --- End quote --- The 15 volt dry battery (high ohms range??) is getting a bit hard to find these days. Easy to source and a lot cheaper than when I last looked - https://www.ebay.co.uk/i/273806052629?chn=ps&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&itemid=273806052629 --- End quote --- |
| Muzzerboy:
There are certainly times the AVO has its day, like observing things starting up. By the time a digital meter has got its knickers on and the display settled down (assuming it does), the smoke may have come out. When I was developing SMPS supplies, we used AVOs and panel meters a lot. The DVMs were reserved for precision, static measurements. At one time I used those little miniclip probes with voltmeters. It was when holding both of them onto a 3 phase supply that I was able to experience the feeling of 3 phase across my hands. Could have killed me I suppose but here I am. I have to say it hurt like f***. Little strands of wire hanging out at each probe aren't clever. Back then we were allowed to sign equipment out for home use. But we had brain dead a hole managers who thought standing outside the factory door at 5:29pm would motivate the engineers. I signed out an AVO 8 for a homer project and one of said a holes gave me a dirty look on the way out. Consequently I kept it longer than I'd planned and then the company was bought out and closed down, making everyone redundant. On the upside, the all a holes also got made redundant and I still have the AVO 8 in my workshop. |
| awemawson:
Sometimes you just get lucky :ddb: Advertised on eBay a couple of months ago were a pair of PCM swiss made powered tooling holders - a straight one, and a 90 degree one. The description was vague, and although they looked to be VDI holders the seller couldn't say if they were VDI 20 / 30 / or 40. A search on the PCM part number of the straight one (as it showed in the advert photo) implied that it was VDI40 as I need but was no means definite. However the drive end of these holders looked to be identical to the Beaver ones that I had had to modify on my existing holders. Anyway no point in getting too excited - he was asking silly money and had already rejected a more reasonable off that I made a few weeks back. Well, he went through the hoops of re-listing the items four times so last week I made a slightly increased offer and to cut a long story short they have just arrived. A quick inspection shows the bearings to be reasonable and although they need a clean up they are in infinitely better condition than the previous ones that I got that were seized solid and needed new bearings and seals. The straight holder fits 'as is' directly on to the tool turret with no modifications needed, and the drive engages nicely. The 90 degree one will need to be modified (as I had to with the previous one) as the heel of the mounting face fouls on the centre disk on the turret. About 1/4" needs to be removed - perhaps a bit less - to clear the disk, but I've done it before so can do it again! . . .so I'm a happy bunny today :clap: |
| tom osselton:
You have to love that! :ddb: |
| awemawson:
Since I bought this CNC lathe I've hankered after a collet chuck, which saves all the hassle of soft jaw turning etc. Problem is that the way chucks work on this lathe is rather unusual. Most hydraulic chucks, be it collet or jawed, have a draw tube co-axial with the spindle which is pulled or pushed by a remote co-axial hydraulic cylinder. On the Beaver the chuck has the cylinder built into it, and has two ports (open & close) in the face of it's rear surface that mate with similar holes in the spindle nose where an O ring is trapped to seal the oil. Now my main chuck is a Pratt-Burnerd 1749-02780 which I very much doubt was a special for Beaver so it must conform to some spindle nose standard (I assume). The lathe spindle 'seems' to be an "A2-6" standard spindle shape with the two hydraulic ports added. Anything conforming to this standard is remarkably rare - in the last few years I've found one chuck like mine in the UK that the seller wanted really silly money for, and one rather beaten up collet chuck that was a fair price, but no collets and being in Canada transport killed the deal. So when a collet chuck using this same system turned up on UK eBay complete with an almost complete set of collets I got quite excited. Conversations with the seller revealed that it was off a Beaver lathe - excitement raising to fever pitch - soon to be dashed when I find that it was off a Beaver TC10 lathe (mine is a TC20) that has an A2-5 sized nose so not directly compatible. Explaining to the seller how limited his potential market was persuaded him to release it to me at a very reasonable price (£200 inc carriage) which is worth it for just the collets. So LOADS of googling shows that at least two firms make a converter plate from A2-6 nose to A2-5 nose - they don't have the bores for the hydraulics but if the adaptor plate is fat enough there might be room for some drilling of oil galleries converting from the collet chuck's 60 mm PCD to the spindle noses 84.2 mm PCD. Both are 6 mm diameter. I envision drilling blind holes into the two mounting faces of the adaptor at the two PCD's with a cross drilling joining them which can be blanked of with a sealed grub screw, but this depends on the adaptor plate being fat enough and actually managing to buy one! Absolute 'back to the wall' solution is to make the adaptor plate myself, but it has rather a lot of precise features and needs to be absolutely concentric so not something to knock up in a wet weekend. I have thoughts of 3D printing a model to prove the concept. . . . the other issue is actually handling the original chuck - nowhere above to put a block and tackle and it weighs 47.2 kg :bugeye: |
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