Here is a list of all the postings Ajohnw has made in our forums. Click on a thread name to jump to the thread.
Thread: why spider? |
04/10/2015 11:50:22 |
I saw an interesting gadget that can do something similar on youtube. Just a ball race on a piece of metal in the tool post. Lightly tighten work in the chuck and run the ball race against it while moving the saddle or compound to true the work up. The poster also mentioned using the same idea for an edge finder. John - |
Thread: A rather reduced price 75-100mm 3-4" micrometer |
03/10/2015 23:49:57 |
What I can say about the gauge is that it's ends and the anvils of the mic are pretty square but the gauge does look a little naff. The screw driver looks a bit M&W.
John - |
Thread: Any idea what inserts this takes? |
03/10/2015 22:09:22 |
I wondered about the comment - I can see the images even though I run Linux. I'm using a purely open source version of Chrome rather than the Google one. John - |
Thread: Is it time for ME friendly inserts resource? |
03/10/2015 22:03:46 |
APT Carbide brake down the material groups which I find helps. Their prices aren't bad either but come in packs of 10 apart from a few they sell for hobby use in smaller numbers. I've used several types over the years on a lathe. One thing I am certain of is that loose head stock bearings don't do tips any good at all even causing them to chip at times. Another thing I have learned is not to trust ebay bargains. I'm sure some have been used. I don't buy that way any more but to be fair some list now with no mention of either new or used. Some state new but having been bitten and disappointed with performance I just don't buy them from this source any more. Personally I feel rigidity is more important for finish than speed. I actually wonder if some people find that speed must be high are getting better results because their lathe head stock bearings will heat up more and more quickly the faster the lathe is run and this will tighten them more as a result. Not an approach that suites me as I adjust on the basis that the lathe wont run much over circa 500 rpm. In any case max speed is circa 1300rpm. One pet hate I have is model engineering suppliers that sell tooling with no mention of the tip type reference number or even sizes. Eg I recently bought a 25mm parting off blade and holder from RDG. From the onset as there is no info on the tip fitted I have mostly bought it for the holder as I can easily buy another blade and tips to suite. The tip supplied looks unusually short too. I'm looking at face mills at the moment. As raked inserts look best on a lathe to me I suspect I will go for APMT1604. However a Chinese listing mentions that APGT1604/APKT can also be used in these. That will mean spending some money to find out. John - Edited By John W1 on 03/10/2015 22:05:27 |
Thread: Any idea what inserts this takes? |
03/10/2015 18:45:39 |
Posted by Bandersnatch on 03/10/2015 17:31:03:
Triangular insets are usually defined by the inscribed circle .... probably 10mm in this case. TCMT or TNMG probably. You could always ask the eBay vendor. They are prefixed with the length of one side of the triangle - If the mounting faces for the inserts are "square to the end" so that this type of insert could be fitted I'd like to buy the 50mm.
John -
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03/10/2015 17:24:07 |
Posted by Vic on 03/10/2015 16:35:58:
The inserts on my milling cutter don't have any rake, it all seems to be on the tool? RDG do one with what is probably a 16mm flat insert Some of the newer face mill holders use an oblong tip. On these the clearance angle looks to be in the normal range for carbide and rake is added by changing the shape of the top surface of the tip. I'm not sure how this applies to triangular tips but there does seem to be some low diameter face mills about, more end mill size that use triangular tips with rake. I've not seen any on ebay. I assume that the raked ones are fitted to square shoulders on the holder. I've no idea what they do on the RDG ones or similar but would assume they have very little if any rake. If anyone buys a face mill I would suggest looking at the tip prices. I've been toying with the idea of getting one and had a bit of a shock when I checked the tip price, ?? £7 each. Some types are a lot cheaper so I'm having another look around now and again as the rake does make a difference on a lathe. John - |
Thread: Universal Grinding machine construction series? |
03/10/2015 14:25:28 |
I for one would be unlikely to buy 31 editions of any magazine for a project. I have mixed feelings about more than one really. In this case I suspect that the design and build will eventually finish up in a book so often think that it would be better if things started that way but this isn't good for a magazine which needs designs in order to continue to exist. Magazines could also shorten the number of issues needed rather than often containing a lot of bits of some particular projects. I suppose this is needed in order to broaden the range of interests covered in a single issue but maybe some rationalisation would be possible. Maybe the answer in this case which would allow a lot more detail to be included is people like these who will publish subjects that come down into the fringe interest category. I found them via a couple of detailed books on some aspects of microscopy. They aren't available from any other source. Conventionally published works on the subjects they cover are very expensive due to the limited audience they are aimed at. They appear to publish to order even one at a time but the books arrive pretty quickly and they have been around for some time now. A blog on the web would be sufficient to give an over view of the machine etc. I'd guess the author also gets some payment for their efforts without prices going over the top. John -
Edited By John W1 on 03/10/2015 14:27:50 |
Thread: Any idea what inserts this takes? |
03/10/2015 13:12:46 |
Looks like 16mm triangular tips would fit. As I use 11mm triangular on my lathe I've been hoping to find a milling holder for those but no luck so far even for 16mm. You might find that TCGT work better as they have more rake, John - |
Thread: A rather reduced price 75-100mm 3-4" micrometer |
03/10/2015 11:30:07 |
The battery in it was dead on mine too. These things can spend years lying about in storage so that doesn't concern me at all. A very quick check suggests that they can read size accurately to better than 0.0002" but that's too quick to be certain. It could be better or worse. The frame is more rigid than some which surprised me. All in all not bad at all really.
My usual work horses are a shardlow 0-1" and a starett 1-2" both with 0.0001" verniers that I have owned from new plus some used M&W. I also have digital that cover the same range and feel in some respects they are a waste of time and money other than being dual reading, mitutoyo's finest. These can be bought at greatly reduced cost if people are prepared to wait until they crop up. 3 point bore mic's too. I also have a pair of 200mm 8" Mitutoyo absolute callipers. If people want accuracy these in my view are the ones to go for as the readings are meaningful but still only to +/- 0.02mm. Some are much worse. John - Edited By John W1 on 03/10/2015 11:32:16 |
Thread: New lathe arrived today : The ongoing saga |
03/10/2015 10:33:28 |
Posted by Brian John on 01/10/2015 10:53:53:
I bought an aluminium cutting wheel today ; it is twice as thick as the steel cutting wheels. I am not sure why that is but I will use it next time I have to cut aluminium or brass. I seem to be using mostly the RH cutting tool since I bought the lathe. I am using the carbide tip tools (not indexable) for roughing cuts and using freshly sharpened HSS tools for taking finishing cuts. This is giving a very good result. Hopper's cutting tools are VERY sharp ! What sort of results should I expect with indexable carbide tips such as these ? The 2nd link types are fine Brian. I use them but on the 10mm / 3/8" holders. You don't want to buy that set though. Look for ones that come with a torx wrench. The tip fixing screws are far to fine for a modern poorly fitting hex key and the keys round over in no time at all. I would suggest 10mm holders too if they can fit your lathe but from the spec you would need to buy a new tool holder. The one that comes with the lathe seems to be aimed at 5/16in tooling but an odd metric equivalent that comes out at 0.309" +0 -0.012". The tips on them are old hat though now. You should find a source of tips like these to replace them with at some point. The triangular tips can be used to work up to and finish shoulders - not so the square ones. The rad on the tip is pretty small so the shoulder can be relived by plunging the tool in a little. The same style for stainless finishing works well on all materials too but those are coated and the finish does fall off when the coating wears. I intend to try the micro polished aluminium ones on other materials and don't see what they shouldn't work out. Not done yet as I am in a no more work phase until I have completed a very thorough clear out and tidy up. There is some brass work in my photo album done with the stainless ones and no polishing etc. Also the same tip on silver steel showing micro tearing that would polish out very easily. The marks are only a couple of micron deep. It's pretty junky silver steel. The place I bought it off where getting rid of it. I've found that a 60 grit green wheel is fine for braised tip carbide tools if the tool is moved side to side to finish off. I don't use these much now but did use them a lot. I have green grit on one wheel and a medium grit ordinary wheel on the other for hss and also relieving the tool steel under the brazed tip carbide tools when these were reground. John -
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Thread: What did you do today (2015) |
27/09/2015 21:35:11 |
Posted by Neil Wyatt on 27/09/2015 20:34:57:
I've got an EQ34, but on an EQ5 tripod. Works best when I keep the weight down. Neil I've long suspected that the tripod is more important than the head. Far more than people seem to realise. John - |
Thread: Vertex |
27/09/2015 20:09:19 |
Jon makes a good point about final thickness when rigidity matters. It relates to weight as well. Manufacturing costs are complicated. The company I worked for generally had tooling made in the USA (by the USA wing of it* ) It would then be used for production in the far east, generally China. As an experiment they did the tooling design and then had it made in China. The cost saving over having it made in the USA was relatively small, circa 10% or under from memory. This was for producing rather precise pressure die castings that would require a minimal amount of machining. Going on this where precision is needed costs aren't all that different. This is probably down to the cost of the equipment used to make the tooling. Labour costs are a drop in the ocean compare with that. These days development costs are also very high on many items. Often the most significant one of the lot. Where labour costs are significant is in cases such as the one that started off a lot of use of far eastern manufacture. Electronic items without surface mount and reflow soldering etc. All parts were put in by hand and then hand soldered. DIY machine prices have similar problems. It can be amazing what huge 5 axis cnc machines can do with hardly anyone going near them. They cost a fortune and that would have to be passed on to the person that buys them so they use separate machines to do the job. These still have to be paid for and the accuracy they have to work to will have a bearing on cost. Not just the machine used but the amount of consumables it uses and how often quality is checked and corrected and to what level. More and more people are needed so labour costs get more significant. The other factor is the final cost. As the cost goes up fewer and fewer people will buy them so costs have to go up even more. I feel there is another factor as well in the west probably more so in the UK. Business needs money. It's way way simpler for some one to buy in and sell than it is to manufacture and sell so the "smart" money goes into that area as life is so much simpler. *The UK wing had tooling manufacture locally and went for the lowest of lowest costs. I lost count of the number of times they had to retrieve something quickly because the company they used had gone bust. Another problem with manufacture. No one wants to pay for it so even if the business is good profits are low so that far too many people can buy them in and sell them on often along with pretty dramatic price mark ups so that they can earn a good living. No point bleating about this, it's a fact of life. John - |
Thread: What did you do today (2015) |
27/09/2015 19:24:42 |
Which telescope mount to you use Neil. Those aren't bad results. John - |
Thread: Wabeco 4000 back plates |
27/09/2015 19:16:38 |
Just on the off chance has anyone come across a source of these ? It's fitted with 125mm chucks which are on a back plate to bring the fitting down to what I think is DIN 100mm chuck size but I suspect these will have been made by the chuck manufacturers - Bison. They are a light interference fit on the register which I can do but having a number of other things to do I'd rather buy if I can - depending on price. John - |
Thread: New lathe arrived today : The ongoing saga |
27/09/2015 19:03:50 |
John - |
Thread: Lathe Milling Attachment - Disadvantages? |
27/09/2015 18:57:36 |
The boxford vertical slide is a bit different to others as is the boring table. Both fit in place of the compound slide which I feel limits their use more than you might suspect. They did it this way because most of their lathes apart from an ME10 don't have a T Slotted cross slide. It is possible to fit a T slotted cross slide to all of them via this man who is so busy it can be hard to get hold of him. He will also make T slotted cross slides for some other lathes. This still leaves the vertical slide as a bit of a problem. The best option is probably a Myford one that might benefit from packing up to account for the difference in centre height over the cross slide. I'd go along with others. A separate miller is the best option really. In general the only use I make of the T slotted cross slide on my ME10 is for a slotting attachment. Mainly for keyways. It's based on castings intended for Myfords as many things are. Easily remedied by fitting an aluminium plate under the casting to increase the centre height. I feel you have made a good choice in lathes. If you need help understanding it, parts and etc I would suggest you join the yahoo boxford group. There are plenty of people on there with detailed knowledge of the lathe. Also parts lists and other bits and pieces.
John - |
Thread: New lathe arrived today : The ongoing saga |
27/09/2015 18:22:43 |
I'd take care about cutting the pin Brian in case it's slipped back for some reason. The end should go well past the centre line of the part carrying the groove it fits in. One trick I use to remove things like that is either a drill chuck or the lathe chuck. They will grip tightly and not mark significantly. A twist and pull with a bit of care often gets bits like that out without bending them. John - |
Thread: Arc Euro boring and facing head |
27/09/2015 16:26:36 |
I really don't see why Michael as just like me trying to help others your posts might as well. One of your posts did help anyway - my existing head. A link you posted showing how I could face with it on my miller. My brain was stuck in a different way of mounting the see saw on it. Graham Howe has sent me a copy of his design as well mentioning a good point. Think about the headroom available on the miller. There is plenty available on a Dore Westbury even without the extreme column some fit but will need to check. It would be interesting to see the design in the book that was mentioned. My problem in that area is that I would be buying the book for just one design. The rest would be of little if any interest. That's just me being mean really but any design I see is likely to be modified for my own use anyway. John - |
Thread: New lathe arrived today : The ongoing saga |
27/09/2015 15:10:09 |
If you do lever the pin and it does come out all you are likely to need is some loctite retainer. Something you will probably find of use later for other things.
John - |
Thread: Lathe Chuck Questions |
27/09/2015 14:59:45 |
Rotagrip may be able to get the original jaws for it but they are very pricey. They also stock a range of soft jaws. Pretty sure you will find dimensions on their web site. I've found that they sometimes need a bit of fitting to get them in the chuck. Easy to do providing that some care is taken to see which areas need a few thou removing. I find it's best to use a 10in flat file with a safe edge and rub the jaw against the file - lot easier to keep the surfaces flat and get a perfect fit. You don't say what you want to machine. If it's heavy work 4in in a 5in 3 jaw is pushing it and an independent 4 jaw would be better. They grip work very tightly and in real terms for moderately accurate running don't take long to set up. They are usually bigger than the 3 jaw for any given lathe as well. Often they can be usefully bigger than the standard size that normally comes with a lathe. Just be sure saddle etc clears if needed and allow for a bit of jaw projection. John - |
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