Tool post height

[brian jones 11Participant @brianjones11]

Having invested in an RDG QC tool post system – very nice too – to be fair RDG was totally up front in saying that while the tool post could accept 12mm shanks these are too high for a Myford – 10mm or less ok.

What isnt said is that 12mm is far more common than 10mm. however a brave Myfordian had this solution

Video Link Deleted see CofC

drastic maybe?

I tried a simple way and milled out the slot of the holder 3mm deeper

this is the result

 

 

 

 

 

Edited By brian jones 11 on 06/07/2021 16:50:34

Edited By JasonB on 06/07/2021 18:37:05

[brian jones 11Participant @brianjones11]

[brian jones 11Participant @brianjones11]

OBTW I wish there was a way to save a post in hand, cos if you stray from the page then your work is lost

yes i could save a txt fill to notepad

also once a pix is inserted you cant move it or get below it for further text ?

[old martParticipant @oldmart]

You could have just milled the base of the tool 2mm, it would have been easier. The Smart & Brown model A at the museum has a centre height of 17.53mm. All of the inserted tooling is 20mm with the base milled down. No shims are required for any of the three toolposts that are available.

[Tony Pratt 1Participant @tonypratt1]

Much easier to mill the tool base.

Tony

[brian jones 11Participant @brianjones11]

Indeed a good thought, i have to get one of those solid carbide 10mm end mills and ive no power feed on my DW

i admit it was a fiddly job and strained my eyesight – dont know if i want to do it again

[brian jones 11Participant @brianjones11]

But back to my topic, I lashed out another 20 quid for a 10mm set and blow me, I got 7 tool holders and the LH holder was omitted from the listing )(*&*&^&%^

so it will cost me £17 for one from RDG as they are not commonly available on EB – like buying a car and one wheel missing

All the listings are like that from PRC., dont they do RH direction cuts in CNC world?

OBTW watch out for the treachery when buying 10mm index tool sets – THEY LIE when you specified 10mm in the small print they are actually 12mm shanks (give away is in the part coding 012 insted 010)

I feel sorry for the likes of RDG who no doubt strive to provide a good service but they are totally flooded out by repetitive EB listings from dodgy PRC sellers making it very difficult for a buyer to find the reliable goods – such time wasted.

For example trying to find a LH tool holder as above, it wont show up in the listings

[jimmy bParticipant @jimmyb]

I've not had any trouble with tooling.

If I need to reduce the height of any tooling, I take it from the bottom of the tool, leaving the head as is (this part of the tool is not in the toolpost).

Jim

[Dave HalfordParticipant @davehalford22513]

Posted by brian jones 11 on 06/07/2021 16:49:29:

Having invested in an RDG QC tool post system – very nice too – to be fair RDG was totally up front in saying that while the tool post could accept 12mm shanks these are too high for a Myford – 10mm or less ok.

What isnt said is that 12mm is far more common than 10mm. however a brave Myfordian had this solution

 

drastic maybe?

I tried a simple way and milled out the slot of the holder 3mm deeper

this is the result

 

 

 

 

 

Edited By brian jones 11 on 06/07/2021 16:50:34

I would expect chatter issues taking so much of the insert support away like that.

Edited By JasonB on 06/07/2021 18:39:15

[bernard towersParticipant @bernardtowers37738]

Why would you weaken the tip holder?

[brian jones 11Participant @brianjones11]

isnt skimming the base of the tool holder the same thing

in the pic i actually went 1mm lower than I wanted to because my auntie dore Westbury had a blonde moment

[old martParticipant @oldmart]

lowering the insert pocket would certainly leave the main body of the tool stiffer than taking the same ammount off the base, but is harder to do. I have not tried it because the pocket sides should be angled to match the inserts 7 degree sides. That may have changed since I bought a small milling vise with multiple movements.

I would look at the way the toolholders are held in the post, do they touch the top of the compound when set at their lowest height? I would also measure the exact centre height to find out if the possibility of skimming the top of the compound was feasible. The toolholders might be lowered if they were thick enough, and you had the means to mill hardened steel. A little bit off several parts could add up to the total ammount without noticably weakening anything.

[CalumParticipant @calumgalleitch87969]

Posted by brian jones 11 on 06/07/2021 16:53:35:

also once a pix is inserted you cant move it or get below it for further text ?

If you have a keyboard, keep pressing the down key till you can't see it, then press enter (it will have been hiding on the right of the pic). Fiddly if you're using a tablet or phone, I suppose.

[brian jones 11Participant @brianjones11]

indeed its 6 of one and half doz of another, maybe the lad who milled 3mm off his top slide wasnt so daft after all

he started off grinding a step off the face of the slide (facing the work) but realised he couldnt rotate the tool post

Its all shown in his excellent vid above.

I balked at this as it seemed like a Bridgeport job but the way he used the Myford as a milling machine showed me its quite feasible – i even have a vertical slide – which ive never used but i havent got a shell end mill like he had, and the one he links in Ali is no longer available.

While on this – any advice on end mills. I found the offerings on EB mostly dishonest (from PRC of course). Ive got a HSS fly cutter but would only have considered this for al or brass. I assume the top slide is CI

I dont have much experience of vertical milling (other than a bridgeport) but carbide tips seems to have opened up another world

What spec should i look for – solid carbide? index tips, flutes? hardness (HRC 45?) dia 10mm shank (i have a jacob 1/2 chuck or an MT2 offering on my DW, dia of cutter as my DW only goes to 1650 rpm.

this needs some chutzpa, cojones, bushellam guts

[Pete.Participant @pete-2]

What are you planning on doing with the 1/2 Jacobs chuck?

[brian jones 11Participant @brianjones11]

stick a straight shank end mill in it

take the surface of the top slide with 1mm cuts

bad idea?

[Pete.Participant @pete-2]

Do you own a Dore westbury milling machine? How do you normally hold milling cutters?

[brian jones 11Participant @brianjones11]

yes DW 2 but Ive only ever drilled holes or made small slots <1/4 dia, never tried surfacing

[Pete.Participant @pete-2]

No, don't use the Jacobs chuck to mill, the end Mill will almost certainly slip and damage your compound slide.

An er20 or er25 collet chuck would probably be suitable for your size machine, buy this type of tooling from a reputable seller as the eBay stuff is often factory rejects the Chinese sell to stupid tightfisted foreigners (us).

[brian jones 11Participant @brianjones11]

Thnx 10^6 Pete Im on it.

Its going to be much more rigid and is probably why I only ever had mediocre results and only used small mills

[JasonBModerator @jasonb]

Same goes for any cutters you buy get them from a reputable source as they are unlikely to be dishonest. Items may well still come from the same part of the world but be to a better standard which you will have to pay for.

[Martin KyteParticipant @martinkyte99762]

Posted by brian jones 11 on 06/07/2021 20:03:46:

isnt skimming the base of the tool holder the same thing

in the pic i actually went 1mm lower than I wanted to because my auntie dore Westbury had a blonde moment

Not if you leave a step at the front. You only have oreduce the underside of the tool holder for the portion that fits in the toolpost.

regards Martin

[JasonBModerator @jasonb]

Though reducing a 12mm holder in height either way is still going to give you a more rigid tool than going down to 10 or 8mm square one

[bernard towersParticipant @bernardtowers37738]

You could also mill the bottom inside edge from the toolholder, I believe they used to sell them already modified.

[SillyOldDufferModerator @sillyoldduffer]

My advice is to ditch the QCTP and oversized shanks for the time being. Learn to use the lathe with the standard 4-way tool-post and buy a set of tools to fit it and arrange to height with shims. Keep it simple. Although 12mm tools are common, it's not difficult to find smaller sizes. Have a look at ArcEuro; although Ketan doesn't sell sets (I think), he does individual holders in 6, 8, 10, 12 and 16mm. Rather helpfully, Ketan's web site also identifies the inserts that fit the holders, removing another aggravation.

Exactly why is it necessary to fit a QTCP? Their advantage is fast tool changes and easy height setting without shims, which is particularly useful with HSS cutters. Indexed holders with pre-set shims are almost as fast, and hobbyists rarely work against the clock. I don't care if it takes a couple of minutes to shim a re-sharpened HSS cutter to height. An experienced machinist, who works rapidly with HSS has good reason for fitting a QCTP, but that's not me. Risky to buy a QTCP and shanks to fit a lathe before understanding the tool-height requirements.

Faced with this sort of problem, I think it's better to cut ones losses and go back to basics. Buy tools that fit rather than modify holders, or even worse, hack into the lathe itself.

Beginners have a lot to learn and there is no shame in making mistakes. But a good deal of trouble can be avoided by buying a few books and learning the ropes with a few simple projects before rushing to fit accessories and make changes. I recommend books rather than Internet videos because it's difficult to tell the difference between a twit who is good at making videos, and competent machinists who bumble in front of a camera. Quite a lot of fun to be had on the forum by pointing out bad-practice found on youtube.

In the absence of learning and experience problems are likely to spiral due to poor technique. I wonder how many lose interest in hobby machining due to making a false start? (I came close myself.) For example, Brian mentioned 'fixing' his problem by milling with a Jacob's chuck, which is a classic way of spoiling work. It's almost bound to end in disappointment and a misplaced rant about the quality of Chinese tools. In the early stages best to avoid tricky stuff like milling the unknown steel of a tool-holder with a floppy chuck. (Warning: lots of metals don't machine well! Don't imagine a lathe or milling machine will cut anything made of metal.)

Doesn't take long to get a feel for machining and materials. Apprentices have the advantage of starting with tools in good order, cutting metal that machines reasonably well, with an experienced mentor offering robust advice! Takes longer to teach oneself and mistakes will be made – don't rush it. Think months rather than hours. Three sources of error: machine out of order, poor choice of material, and the operator. At first, the operator is chief suspect when stuff goes wrong, especially when a novice accidentally gets into deep water.

Dave

 

 

 

 

Edited By SillyOldDuffer on 07/07/2021 09:33:48

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