Member postings for Jon Gibbs

Seems to be borne out from the scale.

Since weight will follow volume, and given that the cube root of 2 ~= 1.26, the ratio looks about right for the lines 1/2 -> 1 & 1 -> 2 & 11/2 -> 3.

Edit: Also from 1 -> 1 1/2 and 2 -> 3 will be ~1.145 which looks pretty close to me too by eye.

Jon

Edited By Jon Gibbs on 24/11/2017 13:29:00

I have a fair few HSS end mills, including some roughers, and means to sharpen them.

I don't have any carbide end mills though and I just wondered whether it might be a cheap and handy alternative for cast iron roughing to save too much resharpening or bu99ering up my decent roughers.

Jon

Murray,

Thanks for the warning. My machine's an RF25 which might not be rigid enough although it probably has the speed.

Do you think the interrupted cut problem is because the longer cutting edge is not mounted helically for side cutting, like an end-mill would be?

Jon

Hi All,

Thanks very much for your advice. At that price it's just below the threshold for VAT and so has to be worth a punt.

Jon

Edited By Jon Gibbs on 15/11/2017 19:31:38

I'm looking at one of these (**LINK**) ...

...and wondering whether it would be useful with my round column mill for roughing out. It's not going to work for plunging cuts but for hogging material.

It's obviously wrongly labelled and this one's got a 14mm diameter and so may be better after shortening and turning down to fit 1/2" or 12mm collets.

Any value or a waste of time? - Any or all opinions welcome.

Many thanks

Jon

I take the point about vehicles but they are clearly not as efficient when used as weapons and have other, slightly more utilitarian, applications...

Armed incidents -

Las Vegas - 58 people dead and 546 injured

Paris Bataclan - 130 people dead and 413 injured

Vehicle based -

Westminster Bridge - 4 people dead 50 injured

Barcelona - 13 people dead and 130 injured

On the whole, I accept that firearms do have some practical purpose, but I don't think it's unreasonable to say that in their main use these days is recreational.

I don't buy the claim that markmanship will be useful when we have our next war. IME most marksmen I know will be well beyond recruitment age if a war comes. 

Jon

Edited By Jon Gibbs on 15/11/2017 16:55:06

I'm sympathetic but comparing the carnage that one gunman in the US was able to achieve in Las Vegas with that possible by any of the Islamist terrorists in London, who thankfully weren't able to get hold of a firearm of any kind, I know which democratic government I'd rather continue to live under.

Jon

Edited By Jon Gibbs on 15/11/2017 16:19:39

Hi Dave,

In theory brass expands more than steel with temperature and so if you use a brass plug it'll get tighter at higher temperatures **LINK**.

The only doubt I have is whether the plug will drop out when the temperature goes down again.

Not sure this helps

Jon

Stovax black grate graphite polish is still available for woodburners - see **LINK**

A small amount gets everywhere - just like marking blue

Jon

As NDIY says one way is to buy yourself a digital metric/imperial set of calipers or micrometer and use the in-built function

...but if you want to keep the grey cells working I have found that it's just as easy to buy yourself a metric micrometer or even just continue to work in metric and as you're approaching the correct dimension in diameter or length multiply the amount you need to remove in mm by 40 to give you the number of 0.001" (thousandths) you need to take off using the dials - Simples.

The actual conversion is slightly less at 39.37008 but since cuts of more than a mm or two (in diameter) on a Myford lathe can be challenging it's close enough and when you get below a mm the approximation is pretty good.

Once you get the hang of it, it becomes second nature to multiple by 4 and shift the decimal point appropriately.

[Edit: I have an imperial mill and an imperial lathe and work in metric often - It's no bother at all. For the Myford ML7, I bought two 21 tooth change wheels from RDG which give access to almost all of the usual metric pitches - within a gnats piccolo of the correct one and probably well within the accuracy of my worn old feed screw.]

HTH

Jon

Edited By Jon Gibbs on 07/11/2017 09:13:00

This graph reminds me of the dot com bubble - Greedy investors jumping onto a band-waggon that rolls for a while before something causes a realization that the valuations are overstated and then there's a readjustment to reflect more sensible valuations. Predicting that point near to the peak is pretty much impossible for your average investor.

I'm reminded of the adage "it's never a bad time to take profits".

Jon

Lubetech oil on ebay are reliable and cheap IME.

No affiliation just a satisfied customer **LINK**

HTH

Jon

I've used ER collets for this job and they do work.

I have two suggestions; make sure the cutting edges are horizontal and parallel when mounted and this is much easier with a bearing collet nut which won't move the collet and drill as it's tightened.

HTH

Jon

According to my calculations, Sin(8) - Sin(7.9984) over a length of say 1" results in a diametric error of 5/100ths of a thou and ER20 collets are probably less than 1" long.

For 1 thou diametric error over 1" length I think you need an angle within about 0.028 degrees of 8 or 1.7 minutes.

HTH

Jon

Hi Steve,

Harold Hall provides this diagram of a set-up similar to Clive's to achieve as close to 8 degrees as makes no difference...

**LINK**

It's part of a description of an ER collet chuck here... **LINK**

HTH

Jon

I'm really interested in these posts - there's certainly more than one way to skin this particular cat.

Like Carl Wilson though I bought HH's book and thoroughly enjoyed making my own T-nuts, strap clamps and parallels amongst other stuff.

My mill came equipped with quite a lot of miscellaneous stuff - some good, some less useful but it gave me a start and I think I was pretty lucky.

Jon

Many people have such thin skins these days and take offense at the slightest thing.

I'm proud of my hobbies but I'd quite like to be able to poke fun at others' hobbies too e.g. like watching reality TV, stamp collecting, playing computer games, gambling etc etc which ought to be fair game IMHO. (I'd also be tempted to include religion in this list too - but perhaps with the caveat that the participants live in free countries where it represents a lifestyle choice).

So if its just poking fun at our hobby then why not try to just treat it as a joke?

Jon

+1 - At the end of the day it depends how much you can afford and what's available to you when you want it.

I bought an old ML7 but that was just what came my way at the time. I then bought a second hand Taiwanese round column mill.

Neither of them are perfect but then I don't suppose any other machine I could afford would have been perfect either. I might have done better if I'd waited but then again maybe not.

Do I ever wish I hadn't bought them? - No!

Over analysis never achieved anything.

Jon

Hi Peter,

Yes, I had that trouble too until I saw the dodge recommended by Steve Jordon. You need to put some leather, rubber or other conformant packing underneath the join between the two ends of the rubber strap. That makes all the difference.

Jon

I use neat cutting oil which I know isn't strictly a coolant but check out these folks... **LINK**

5 litres postage free for £20. I use them for my slideway and headstock oil too - similar prices.

Usual caveats - just a satisfied customer.

Jon