Here is a list of all the postings Pete Rimmer has made in our forums. Click on a thread name to jump to the thread.
|Thread: Buying lathes direct from China|
The CE compliance mark and the China Export mark are deliberately similar to fool unsuspecting people into thinking they have bought a CE-marked item. Once you know, it's easy to tell them apart. Quite simply if you continue the C around to make it an O, on the CE mark the edges will meet but on the China Export mark they cross over each other.
|Thread: Filling defects in slideways|
I would use Araldite 2013 and iron powder as a filler. It's not cheap but it's very good. Cures at room temperature (20deg nominal).
Edited By Pete Rimmer on 13/02/2019 06:22:01
|Thread: Blacking engraved lines|
I was experimenting with this today. The graduations on my HLV cross slide are rather faint and I wanted to make them stand out. I rubbed some fine magnetite powder into the surface and it brought the marks up beautifully. Unfortunately I have not managed to find a way of fixing it into the engraved markings.
|Thread: Tapered gibs on a mini mill (SX2.7)|
The answer for you is to re-make the adjuster screw with a fatter head that fills the slot. If the slot sides are not properly parallel they will need filing or machining first and the new screw made to fit very closely. I had to do this with my own Warco milling machine.
Edited By Pete Rimmer on 09/02/2019 16:24:44
|Thread: Motorcycle General Discussion|
|I've been well north of 200mph on my home built bike without really worrying about it but the thought of swinging a leg over that monster scares the hell out of me. Fair play to the guy who rides it.|
Edited By Pete Rimmer on 07/02/2019 09:34:39
|Thread: Milling slide for sale|
More like a bed fitting for a HBM I'd say.
|Thread: Colchester Bantam|
I would install GearDXF on your PC and use it to produce DXF of both pressure angles for a gear tooth count you already have. Open the DXF in Draftsight (or other CAD drawing program), print at 1:1 scale and simply put the gear on top of the printed DXF. Closest match wins.
|Thread: Metric thread cutting in a lathe|
Last time I bought a m12 x 1 nut for a ballscrew it was left hand thread. Glad you didn't find that out after making one.
|Thread: Cast Iron Straight Edge|
VERY variable Anthony. Rarely a perfect square and often not even square-sided. Ok for rough stuff but I'd put a mic across each end of each pair to check they are actually parallel.
Can't argue with that philosophy Mike. You work with what you got and there's often an enormous gap between perfect and adequate. You wouldn't strip and scrape a machine for 2 or 3 tenths wear so if that's the best your tools can get it you're no worse off than if it was that much worn.
The sensible person would always check their straight edges before use especially if there's been a long interval since last use. I have an as-new 48" cast iron straight edge that I don't use but check the others against. The only thing that tells me that this 48" is not moving is that the other straight edges all check against it. If one day one of them didn't, I would check another. Two straight edges are not going to move the same so the second check would identify which part has moved.
Really though if they are correctly stored a commercial straight edge should stay straight fairly indefinitely. It's tools you make from cast iron that you should be careful with checking before use. As for granite moving over time, I never experienced that nor met nor talked with anyone who did. worn, yes but warped no.
Another supplier is United Cast Bar they also do GD250. Call them up and talk to one of the sales team, they might have a piece on the shelf. They also have a Kendall milling machine so they can pre-finish any part you order. I bought 3 metres of iron bar from them for the scraping class and they did give a good service.
United Cast Bar (UK) Ltd
|Thread: Harrison milling machine play|
Sorry Marcel I mis-read your opening post, plus I wasn't familiar with the arrangement despite David George's description .
Anyway, looking at the photos the inverted vee controls skew on the y-axis slide so if you're getting some then it suggests that the slide is not sitting fully on the vee. I would strip off the table and the cross-slide, clean it up and inspect the y-axis slideways. Could be it's riding on debris or might simply be wear in the vee ways. If it's wear you're going to have to scrape it some.
|Thread: Thread locking|
I was going to suggest similar - a grub screw and lead pellet.
|Thread: Cast Iron Straight Edge|
Last weekend I had a visit from a Norwegian friend who was over for the Ally Pally show and we were discussing this very thing (the difficulty in finding used straight edges). He told me that by far the easiest place he knew of to find cast iron straight edges was Sweden.
If you're in Sweden and struggling to find them I don't know what I would suggest.
Edited By Pete Rimmer on 23/01/2019 20:57:58
I did that, it bent like a banana though I did try to mill it from round, not square. I then got hold of some dovetail pieces which were slideways off an old machine and scraped one of those as a prism for doing cross-slide dovetails. That worked well but 6 months later it had developed a 2 tenths bend. Didn't take much scraping to fix it but I remind myself to check it on my plate each time I get it out to use it.
Edited By Pete Rimmer on 23/01/2019 19:17:28
|Thread: Precision Level or Precision Frame Level|
|Setting the bed straight - level or not - is fundamental to the alignment of the lathe. It's such a trivial exercise (if you have a sensitive level) that there really shouldn't be any argument against it. |
J Bennett - I'd you happen to be in N Kent you could borrow one of mine, then you can check your lathe without the expense of a seldom used tool.
A lathe bed can be twisted and still cut parallel. The headstock might not be square with the bed and someone shimmed the legs/bed to make it cut parallel in the chuck then set the tailstock over to cut parallel between centres (for their test piece) but a twisted bed means that the saddle isn't sitting fully on the ways which means more wear in the ways and in the saddle and a less rigid machine overall.
It's quite important, though some machines are immune to it. Hardinge state that there is no requirement for levelling the HLV for example. The bed is spring-mounted to the cabinet.
The frame levels have all sides finished square to each other so you can use it to check perpendicularity and parallelism if you like. They come into their own when working on a milling machine or other machine with vertical ways.
|Thread: Cast Iron Straight Edge|
Parts are heated in a stress-relieveing oven to a specified temperature over a specified time period then controlled cooling. Any good heat treatment place will do it.
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