Milling on Myford

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

Is there any chance some of the more learned members would give me a ‘real life’ example of milling – for instance:

Using a Myford Super 7 (no auto feed)

1″ FCMS mounted (securely!) on vertical slide (across bed)

1/2″ Rippa cutter in Clarkson Autolock.

Decent coolant system.

Using cutter at (eg) 1/2 diameter

Slides adjusted and locked appropriately.

* How deep a cut can I take (not millipedes if poss please)?

* What sort of speed would you use?

* What speed feed would you use?

I have read until I’m ‘blue in the face’ getting more bogged down as I go 

If I haven’t worded this clearly I won’t take offence if the first reply is “what the … are you talking about” 

 Any help appreciated – I have such big dreams 

Regards,

Ruaidhrí 

 

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

A real beginner!

[David Clark 13Participant @davidclark13]

Hi There

I would not use a rippa for milling in the lathe.

regards David

[John LadlowParticipant @johnladlow78959]

Any chance of telling us what you would use?

 

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

I should, perhaps, have pointed out that most of my scant information on milling comes from T.D. Walshaw’s “Milling Operations in the Lathe”, Sparry’s “The Amateur’s Lathe”, Bradley’s “Series 7 Manual” and GHT’s books.

Excellent stuff – but I’m still foggy (SWMBO says that is nothing unusual).

As a long time woodturner I never had the sligtest problem grinding up a cutter and doing a Bill Jones routine, but I haven’t the confidence yet with metalsand would prefer to have the ‘Ladybird Version’ if possible.

Cheers from a rainy (as usual) Dublin,

Ruaidhrí  

[David Clark 13Participant @davidclark13]

Hi There

Probably a slot drill.

If milling a flat surface, put a small chamfer on the corners of he slot drill.

regards David

[CirclipParticipant @circlip]

Ya need to give us a few more clues Ruaidhri, we’re driving a Taxi, but you’re not telling us where to go.

 

    Yer 1″FCMS,  – Flat? Round?Square?Hex??

 

   1/2″ dia cutter, are you slotting, stepping, flattening??

 

   Bu**er, this ingineering thing is full of questions.

 

   Something to read? Try H.H’s book on the right of this page, simple explanations and I ain’t patronising, Most of the printed data supplied with cutters by the manufacturers is for PRODUCTION manufacture (Used to have a manufacturing industry in Britain hard as it is to belive).

 

   We’re doing it as a HOBBY, chill and relax, don’t bother about auto-feed cos you’re hand can stop turning a darn sight faster than fighting to find the knock off or off switch. You need to be able to Feel whats happening, when you’ve mastered that, then start thinking about automating it.

 

      Regards  Ian.

 

  

[Peter G. ShawParticipant @peterg-shaw75338]

Hi,

 

I would concur with Circlip re HH’s (presumably Harold Hall) book “Milling, a complete course”. I would also suggest a look at Tubal Cain’s (Tom Walshaw) “The Model Engineer’s Handbook” which contains a table of materials in machinability groups and tables of feed rates and speeds for turning, slot drill milling, end milling and drilling.

 

I would also agree re manual feed because then you can adjust both up and down as you go along.

 

I don’t have a Myford, but I have tried milling on my lathe – with not very good results. Except for the last time when I locked the saddle (which I don’t like doing because it’s a bolt straight onto the dovetail slide, managed to get the cross-slide very tight (there’s actually no facility for locking the cross-slide on my lathe) and fed quite carefully taking reasonably fine cuts at an axial depth of about 10mm or 3/8ths inch. I used a 10mm end mill  running at either 500 or 710 rpm. This worked perfectly, I suspect due to the locking down of two of the three slides.

 

Also, I only apply coolant with a brush – which goes against Tubal Cain’s/Tom Walshaw’s advice.

 

Good luck,

 

Peter G. Shaw

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

Thanks folks.

 

The 1″ FCMS is only hypothetical – meant as and example, but possible my wording could have been clearer. I am speaking in general terms here.

As mentioned I’ve waded through a ton of books (and taken the point about production speeds vs our speeds), and also tried out a couple of bits of FCMS.

What bothers me (he said trying to be clear) is that most writers seem to warn about taking too fine a cut – but I am wary of overdoing it 

 

I’ll be in the ‘shop in a couple of days and just have a …. good muck about.

 

If there are no more posts from me by the end of the week it will be because I have done something truly ‘orrible!

 

On the plus side of things I got a copy of the latest SOT membership today and discovered there’s another OT nutter in Dublin – as our American colleagues would say – Yeehar LOL

 

More whinging anon,

Ruaidhrí

[ChrisParticipant @chris16039]

Hi

Not a note of advice I’m afraid but one of encouragement.

When I started to find out about tooling up my Clark mill as attached to the lathe I couldn’t even get my head around collets, clarkson threads, end mills, slots etc etc. The guys from Chronos at the Harrogate show were very helpful and got me tooled up and roling at a very good price. They have a question section on their website and I have used it several times with a rapid and useful reply within the hour.

Try,  chronos.ltd.uk. (Usual disclaimer, my only association with Chronos is their share in my plastic card!!)

As for speeds etc, I’m on trial and error as I don’t know what speed my mill is running at. See my other contributions on this site. Am I the only owner of a clark 500?

[BobParticipant @bob17059]

Hi Ruaidhrí

 

Try this for starters,

 

Set the block of FCMS true across the lathe and approximately at centre height. Make sure all is secure. A strip of normal A4 typing paper between the vice and the work often improves grip on the work..

 

Set your 1/2″ cutter in the collet. Make sure your drawbar is in place and that there is daylight between the backface of the closing nut and the body of the Autolock. Nip it up tight, but no need to flog it tight with a hammer!

 

Set the cross slide so the work is between you and the cutter, then advance the carriage until the cutter will take between 1/16″ and 3/32″ cut.

 

Now lock off the carriage. Disengage the leadscrew drive and engage the claspnut (If you have a handwheel on your leadscrew you can use the to apply subsequent cuts, very useful. Also use the nut that pinches down on the bed to lock things up while you are milling.

 

Set your lathe to bottom speed direct drive ( not backgear).

 

Put your safety glasses on, check the spindle is clear to revolve and start up the lathe.

 

Cautiously advance the work towards the revolving cutter. Listen and watch progress carefully. As long as the noise sounds ok and the swarf is coming off cleanly carry on until the entire cutter clears the work leaving a shallow slot in the steel.

 

The swarf should be bright and shiny, not blue. If the swarf is coming off blue then stop at once. You will neeed to reduce the speed of the cutter.

 

I am aware that these shallow cuts are unkind to the corners of the teeth on your cutter, but the poor rigidity of the set up means that you cannot drive the cutters hard. As others have pointed out, a small chamfer on the corners of your cutter will greatly increase its life especially if you are using it for facing work.

 

As you gain experience you can experiment with different speeds and feeds, but remember, the speeds and feeds quoted by cutter manufacturers are for industrial production on massively rigid machines and that these figures maximise the rate of metal removal at the expense of tool life (After all, they are trying to sell cutters!)

 

Your rippa should be OK for this job, but I would choose a four flute end mill as I don’t need to plunge it into the work. You won’t cut an accurate half inch slot this way. If you want to do this then start with a smaller diameter cutter in the middle of the slot. Then when the slot is almost to full depth machine first one side and then the other to dimension. Remember always to advance the work towards the cutter tooth.

 

You mention woodworking, just think about the rules for feeding a router around a piece of wood, its the same for milling. Trying things the other way (Climb milling) is not suitable for the type of setup you describe.

 

Bob

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

Thanks Bob – I’ll have a try at that over the weekend(and report back)

 

Cheers,

Ruaidhrí

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

Just so you know I haven’t forgotten my manners –

 

Intended to try out a couple of the above suggestions but son is getting married tomorrow and the happy couple decided they wanted four candle holders for the wedding – two smallish, one medium and one on a standard (for absent friends). This has taken care of my workshop time

 

More when I actually get to try some milling!

 

Cheers,

Ruaidhrí

[DugsonParticipant @dugson]

As a general guide for home use and HSS cutters a surface speed of about 60 Feet / minute is a good start, that is for a 1/2″ dia cutter = about 450 rpm.

Once you have the speed and the number of teeth in the cutter – say 4, the feed rate is calculated by multiplying the teeth per minute in this case 450 X 4 = 1800 by the cut per tooth, .002″ is a good start so 1800 X .002 = 3.6 or about 3 1/2″ per minute, this is .06″/second or around two seconds per turn of the cross slide handle. It’s all a bit of a guess and with hand feeding can be adjusted as you go.

Have fun

Dugson

[Alex DU PRE 1Participant @alexdupre1]

Going back to the original question, you are unlikely to get away with a depth of cut of more than half a mm at a single pass using a half inch cutter in slot cutting mode in the Myford.  Probably much less.  This is based on my X3 milling maching (similar motor power) which would really start to struggle under these loads.  I hope this helps.  As a beginner, I had wildly high expectations of the depth of cut my mill could cope with.

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

Wow, what a year!

I have been to far too many funerals since I last posted here.

 

Finally back – slightly shamefacedly about manners.

 

Thank you all for the advice and help.

 

Took courage t’other day and bunged in a piece of CI – the base of GHT’s centre gauge as mentioned in his MEWM.

 

Using the 1/2″ Rippa, speed 740,  cutting dry, I experimented with feeds and cuts and discovered that, as some of you mentioned, it is just a matter of checking one’s facts first, then ‘having a go’.

 

I was really pleased with the results and will be a lot more confident in future such operations

 

Thanks again folks.

 

Ruaidhrí

 

BTW – I’ve posted a pic of the finished item in an album (Ruaidhr&#237 for dem as wot is interested.

[Ian S CParticipant @iansc]

Good on you Ruaidhri, it always helps one when things go OK, I’d tend to halve the speed though, about 350rpm is what Arnold Thorp suggests In Vertical Milling in the Home Workshop, this is the book I go by, I imagine that milling in the lathe would not be that different to a light V mill.Ian S C

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

Thanks Ian. I may have been confusing feed rate with cutting speed. I have gone back through Tubal Cain’s book “Milling Operations in the Lathe” and made myself up a quicky spreadsheet which may avoid this in future

 

More experiments will need to be undertaken

Cheers,

Ruaidhrí

[Ian S CParticipant @iansc]

At least your getting clearer advise than I got when I bought a 2″ three tip carbide cutter for the mill, the chap how sold it(supposed to be the company expert on machining)said when I asked him about using the tool, Put on a mm or so, give it 900rpm and crank like hell. In those days I was at about the same stage as you are now by the sound of it, but no one to ask what to do.Ian S C

[Ruaidhri MurphyParticipant @ruaidhrimurphy46564]

Again quite a gap between posts

 

Turns out (after much poking and prodding) that I have a new item in the workshop – Coeliac Disease

Back to the point – THANKS to you all I plucked up courage again and attacked several bits of assorted junk.

Have tried milling, cutters, slot drills, slitting saws etc., all with some success after a bit of initial faffing about.

Even got ambitious and made up a cutter for the 0.1cc comp. ign. engine I have just started – and it worked!!

 

It would appear that asking questions, listening to people who Know Stuff, and practice, is the way to go.

 

Thank you all,

Ruaidhrí

 

[Author]

Posts