Member postings for Ajohnw

I don't know how big these are but lathe tool post grinders don't need a lot of power, neither does tool post mounted milling arrangements either really for key ways and other light jobs.

John

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Given my choice of drill it would be an elderly tool room type which I might have to refurbish hoping that the rotating parts ran in races of some kind and also that the quill hadn't worn loose. They are extremely heavily built and the drill will be very square to the table which means that they can produce round holes. These still tend to fetch high prices at dealers but some neglected ones sell for very little money.

I have to be realistic though. I recently changed drill to one that has a back gear in the hope that it will help drill true stainless in case I ever have to do that again. My other drill was also beginning to show some signs of bearing wear which could be changed of course. Not sure it will help really with stainless as at low speeds the feed needs to be correspondingly low too.

In terms of the table arrangement my previous one has a round table that can be rotated and also swung around the column. Very useful as any drilling position can be reached when work is clamped to the table or in a vice. I will miss that and am wondering if I can arrange for the old ones bits to fit the new one.

John

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My tool checks were plastic but still had name and number engraved on them. Allowed 3 but there was a sort of black market in them. Who ever did the engraving did some spares.

For larger sizes I have a vernier calliper with a 0-25in scale and metric on the other side. Marked 27.5in by Starret. It's in a bit of a state but still zero's perfectly. Workshop grade though so not marked n degrees F. I have needed it a couple of times.

John

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By the way compound slide is the UK term, top slide the N.American one.

John

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Screwfix have an excellent set of circlip pliers in stock at local branches. Way better than the prices would suggest. Not available mail order but many of the local stores seem to have them in stock.

Circlips, internal or external have 2 holes in the ends that the pliers fit into..

Silly thought for you - is there a saddle clamp screw to lock it into position some how? I did have one for a time but can't remember. Watch how tight you fit tools - the screws are perfectly capable of cracking the tool holder casting - as the next owner of mine found.

In my experience it would be very unusual to have a lead screw nut jam but if you disengage the screw cutting and can't turn the handle on the end of the lead screw it is or the saddle is locked.

John

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People may find that they have local suppliers tucked away some where. Most will cut to the size that is wanted. Finding them can be tough. Google can help with suitable search terms but searching for say stainless steel probably wont help. Searching for non ferrous metal suppliers might. As might steel. They seem to be a strange breed and don't advertise much especially the smaller ones. Cost I suppose. They generally don't care how small an order is or how many pieces need to be cut.. If there is an industrial estate near by people on there may know where they are as well.

It's a pity some one doesn't maintain a map of them. I keep some "stock" 3ft length and often find that I don't have the right sizes or material. If they happen to be the right size I cut them down on the cheap version of the horizontal band saw. These are ok but the cut length stop on them isn't too good - or isn't on the version I have so I use a tape on every piece. To be honest though this was an early purchase. Given a supplier at a reasonable distance I would let them do the cutting.

John

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On a 0-25mm and other they usually come with a spanner that is used to rotate the inner barrel to precisely align the zero mark. Ones above 25mm should come with a setting gauge as well. The spanner from one make sometimes fits others.

I did come across a micrometer spindle that had the spanner but the barrel was fixed and wouldn't rotate at all. The spanner was probably added to fool people it could be adjusted in the normal way. Also when I unscrewed the anvil part completely I found there was no ring nut to adjust the fit of the micrometer screw. I looked as I thought it was a little too loose. Turned out that the feel of it was mostly determined by the grease they had put on the screw.

Not sure you will find ratchets work out as well as you might think. They can be ok when everything is spotlessly clean but the trouble is that when the zero is set the whole area of the anvils is in contact where as when say measuring on a diameter it isn't so pressures tends clear away any oi,l grease or atmospheric gunk. It doesn't when measuring say blocks so slightly more pressure is needed to be sure of correct readings. The safest thing really is to clean the area being measured and the mic.

Even when setting a new micrometer it's best to grip some printer paper between the anvils and pull it through just to make sure there are no residues of this and that on them then check the zero.

John

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I assumed you meant slide rest tools Bob. I have had a passing interest in watch clock work done that way. Parting off tools look just like the usual type and there is another type where on side is flat and the other slopes back forming a sharp point. There is a google book that can be viewed on the web.

M2 should be ok providing it's not over heated when grinding - the video mentions wet grinding but I suspect we have all used that on an ordinary grinder without tempering it. I've ground silver steel d bits without tempering them further. I wanted the cobalt HSS bits for slide rest tools and larger diameters than typical watch / clock sizes. Due to the once and maybe still use of tool steels for gravers I don't think that the surface speeds are that high really otherwise this type of tool would blunt very quickly. Some years ago there was some argument about even carbide reaching the same level of sharpness as tool steels can.

Nosing around - old book on the internet archive - it reckons tools can be given a high surface hardness by quenching in a KOH solution. It suggests keeping quenching liquid in a glass stoppered bottle which I would assume had a narrowish neck - no one would want to get hot KOH on their skin. It even has problems when cold - sort of soapy feeling due to it slowly detaching skin cells.

John

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John

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I didn't have much of a problem finding the silcon grease I mentioned

**LINK**

John

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I understand air guns have exploded due to hydrocarbon type problems. I have even seen photo's where the air reservoir on a gun had exploded. This was some time ago when my son was younger so must be 14-15 years ago and most people were using silicon grease from dive shops where any was needed. I'd guess some places still offer silicon grease.

John

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Edited By John W1 on 10/06/2015 21:24:34

I'm not sure Bob but I once bought a Boley of some crooks in London and one muttered at levels he didn't expect me to hear that he would love to see my face when I tried to part off with it. Little did they know that it has adjustable bearings - slight taper on the spindle so has to be set in precisely. Going on that with slides a rather fine parting off tool but I believe a simple pointed tool is used at times. I'll be interested in any other answers.

I have the tool height problem on my Pultra but indexed 4 way tool posts and I don't like using packing. I have used a different type of tool holder on rather large lathes. A holder with a square hole drifted into it at an angle to suite back rake. It struck me that the same thing on lighter lathes could be done with a block with a slot to suite the tool bits milled at an angle in the side. The slot has to be positioned so that the tool tips stick out a sensible distance when on centre. Fine adjustment is made my moving them in and out. The angle saves weakening the tool by grinding on back rake which is often a pain to do while keeping the cutting angle as wanted.

I also came across an interesting tool height gauge. Face of a length of bar. Place it in the cross slide and scribe a line round it with one of the centres. Face that end until the scribed line is split to just remove. Then set height by touch - should be sensitive to microns,

I also needed some decent 3/16 or 4mm toolbits. Cromwell have some in their clearance section. They also list 5% cobalt HSS bits. I could only find M2 on Ebay and that needs real care even when grinding.

John

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Yes they are nice knobs. I must have jumped in on the dp knurls before that was posted. I bet that you enjoyed doing it the way you did.

John

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If you want to use silicone grease the best source is probably a dive shop (scuba etc). It has to be the pure real thing just like grease used in air rifles, in the later case some greases explode. In the other it's probably more related to fuming but on the other hand some one who fills tanks for them told me he had to use a very similar oil to the one F1 use in his compressor - complaining about the cost.

I wouldn't use silicone oil. It migrates and gets all over the place.

I'm still curious about what part on a lathe is made of plastic and needs lubrication?

John

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Edited By John W1 on 10/06/2015 18:29:49

Plastic is tricky. I have microscopes and a common problem on a Nikon type is plastic gears shrinking, breaking etc because some one has used the usual microscope grease on them or something out of the cupboard. Nye lubricants springs to mind but might prove expensive. They also do a huge range. There is an ebay.de seller that sells suitable grease. It's used in optical stuff so mustn't fume at all. Not sure if this would be suitable for your use but what parts are you lubricating that are made of plastic?

John

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There is a lot of anti on moly grease and oil additives from the motor industry in particular. This didn't stop Ford from using the grease when they noticed parts were not getting through warantee. There has also been claims about poisoning engine sensors when a typical engine hardly had any at all. Could be true these days but some how I doubt it. I will always remember a test the AA did on a mini a long time ago. Treated engine so emptied the oil out and then drove it a considerable distance considering that it was like that. Stripped the lot and only found signs of slight overheating. Might be folk law but I doubt it. I stripped an engine that had done over 100,000 miles that had always used it on every oil change - no signs at all of any wear on any crankshaft associated bearings and sub 0.002in on the bores. 6 cylinders and it ran fairly well for 2 days with with one cylinder not firing - bang and a hole in the piston which blew all of the oil out of the exhaust. I didn't realise until I checked and filled it up - the lot came out in a few minutes just ticking over. I did one trip home from work, around 10 miles and a further 25 miles at high speed that night before I found this was happening.

Lathe head stock bearings of the rolling kind should be preloaded so I don't see how they can stop rolling, balls or rollers. it seems the stuff works by changing the surfaces of the metal it's in contact with - a sort of boundary lubricant effect. Can't say I would use it in the engine of a modern car. I probably would if I could on wheel bearings or anything else suitable. These days some one else services my car. I do ask them to put copper slip on the correct part of single pot sliding callipers and hope they do and that's about it.

John

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I'm a Boxford owner John so may be inclined to jokingly pass comments about Myford. Some do. I have owned a Myford too. it started as an ML7 and later turned into a Super 7. Sold before it was fully sorted out because the Boxford came up with a lot of tooling.

Personally I would be more worried about the effects on the head stock bearings than the slides due to the number of times the cut starts. The relief has to be generated slowly, not in one go. I run my slides fairly tightly anyway which would help. I do this for finish and very light cuts when needed. I'm a finish fanatic I'm afraid.

John

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It pre dates MEW. I believe it was in Model Engineer. Personally I feel that the method I linked to is an easier option and 4 points is a lot better than a fly cutter with a form on the end of it.

One thing about Eureka is that it's not that easy to see how it works from the detail I saw in a mag some time ago. The video helps a lot.

So Myfords shouldn't be used for interrupted cuts. I know they have limitations but didn't think it was that bad.

John

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Your probably wise to avoid the ones reading to 1um. Many of the digital ones that read to that have very rigid and heavy frames which can make them cumbersome to use. I'm glad I bought mine used as I soon went back to my mechanical ones.

On the callipers I feel the ones you have linked too are a good choice. A lot of people like that style. One thing I should point out is that eventually I bought some that read to 200mm. The extra range can prove useful. They are available on this page

**LINK**

The ones I use are these

**LINK**

So far the batteries have lasted a couple of years plus and they are pretty precise. That just leaves the problem of using them that accurately when work is on machines etc. The extra length probably makes that a little more difficult than the 150mm ones but I'd say there is nothing in it really. The problem with callipers is ensuring they are dead square to the work when a measurement is taken, they also are not as accurate as a mic. The usual bore measurement is also very iffy. The older style that didn't use knife edges are better but they limit the min size that can be read and their width has to be subtracted from the reading.

John

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It does cut the form as well Andrew so that they can be ground back. Not much point using one otherwise.

John

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They specify the accuracy of 2 of them so I would pick one of those, a bit dearer than the last one.

Personally I wouldn't rule out Starret and Shardlow although I think Shardlow are defunct now. My 0-1 is by Starret chosen because it has a vernier scale as well so reads to 1/10 thou and due to that they made the frame a little heavier than normal. I would most definitely say Mit Absolute Coolant proof for callipers - the best they do or at least they were when I bought mine.

I agree about batteries. These mic's tend to get much heavier and the 1um reading really is a bit of a joke. The problem I find with mine is that the batteries go flat at the most awkward time.

Out of interest I understand that Black and Decker have owned Mitutoyo for a long time now. That would make me a little wary of any cheaper offerings.

John

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