Member postings for chris stephens

The best design slitting saw arbour I have seen so far is Stefan Gotteswinter's

www.youtube.com/watch?v=bRQPv4AG2HQ and part two

but Robrenz comes a novel second with his superglued one when he made his micro-Ohm meter probes. If you haven't come across him yet, he is a perfectionist's perfectionist with attention to detail scales off the charts.

Hi Francis,

Take a look at Oxtool's video "surface plate calibration and conditioning"

Hi Kwil,

Curious that you say kitchen granite boards are not flat, I bought one this very PM, 16X12 under £8, and looking at a reflection of a straight line it appears flat. I have not checked it thoroughly yet and I know it will never be inspection grade, but, for my sort of hack work it should work out fine.

chriStephens

The following does not reflect well on some model engineers but I could not find ME at one of my local WHS stores so I asked at the counter only to be told that they keep it behind the counter because it was getting stolen when on show! I shall not say which store to save the thief's embarrassment, oh hell let's embarrass him, Ruislip.

There is another reason for unusual size taps, Helicoil ones. Been there, done that! :>(

Oh dear how time flies, it must be 40 years since I watched speedway at Wimbledon, still remember the smell though. Just to be super pedantic, sorry, speedway racers should be using Castrol M, the castor oil for methanol fuels.

Some thoughts come to mind, the supplied jig is not necessarily of the best design and, if used with too coarse a wheel, might not sharpen both cutting edges equally. The supplied jig is a compromise design for both turning and threading and because of this it tends to put striations along the length of one of the cutting edges which will not be as sharp as the other. A 30 degree vee shaped jig held at right angles to the wheel is, in my view, to be preferred as it puts an equal grind on both edges.

Another thought is have you put enough of a radius down the length of the tool bit. A sharp corner does not seem to cut as well as a radius one. If you put different radii on opposite corners and sharpen both ends you can select the either end for different needs.

A tangential tool will often give a superior cut on the back stroke, due to a sheering action, but should still cut forwards almost as well if ground well..

Thirded(?) nothing but good to say about Pete and his business.

Hi Neil;

You keep it up, some of us have friends that we can pass on the extra copies to and gain some brownie points in the process.

Hi Muzzer, all very good but he said it was Whitworth form not metric.

What a bunch of miseries we have, would you rather have endless cookery programs, or so it seems, or something that vaguely resembles a like minded interest?

Don't forget that we drive on the left and it is compulsory for tourists to buy a round for all when visiting our Pubs.

Hi Guys, I suspect that they kept the Imp lead screw because they could not afford to update the TPI gearbox to Metric. Towards the end of the real Myford times were increasingly hard, sadly true but inevitable.

A point of interest on the difference between Imp and Metric lathes, the Imp cross feed is in direct movement and the Metric one reads in diameter reduction. According to Mr Moore, the Myford boss at the time, this was the convention, so they followed it.

chriStephens

Hi Roger, I would expect an Email to them inquiring about solid carbide end mills might help. I suspect the reason for not having them on the web is that they are "surplus" stock and as such supply is moderately random. I only buy in person from their stand at shows, never online. They do travel the country going to all sorts of shows that have an engineering bent, last weekend Ally-Pally, today Kempton Autojumble, and shortly at Brighton Modelworld. Again an Email might reveal if they are appearing at a venue near you, if they are unwilling to sell online for some reason. My person favourite endmills are their "ripper" ones, they remove stock at a phenomenal rate (in steel, not HSS!).

Hope this helps

c

Hi Roger, Sorry, i thought everybody knew JB Cutting, they go to all the shows and sell carbide tooling at reasonable prices.

chriStephens

Hi DC1, Why ever not? It is easily done using solid carbide end mills, and they are cheap enough from JB to not matter much if things go wrong.

As an aside, one of your predecessors in the ME editors chair has been known to do it, once told it was indeed possible. Another advocate of the practice is Oxtool on youtube, and his opinion is very highly regarded by those in the know. Give it a go, it can be quicker than grinding, especially for roughing shapes.

chriStephens

Hi Steve,

I had great troubles getting my 5C collet holder to run true and mine came from the same supplier, cheap but questionable quality, methinks. If you persist you can get it to run true, undersize register and cooking foil shim stock between back plate and chuck helps. Grinding the cone is not the best answer, as it does not address the issues with the other locating surface deep inside, which must not be over size. I understand the collet holders from a certain emporium known for good service with "euro" in their name, sell better ones, bit late now though!

chriStephens

Hi Cotswoldphil,

Get yourself one of these;

http://www.mscdirect.com/product/details/09520057

Mine came over from the US as a gift from Tom Lipton, of youtube fame. Not bragging, just saying he is a very generous chap and all round good egg.

chriStephens

Just to add confusion, surely the chip breaker design defines whether an insert is positive or negative. You can have an insert seat pointing downwards (nominally negative) but with a high rake insert, it is actually positive. Or is there a flaw (again) in my logic?

Oh well if you are going to talk about modern stuff.........