FC3, TC3, Plain shank, weldon shank and too many tool holders?

[PekkaNFParticipant @pekkanf]

Hello,
 
I’m new here.
 
I have mostly ER25 collets and MT3 ER-chuck for milling cutters.

ER collets seem to do a good job with plain shank tools,. But I have aqquired quite a few threaded shank (Clarkson?) cutters and Weldon cutters. Also FC3 cutters seems to work pretty well for me.
 
The problem is: I don’t feel comfortable using threaded shank/weldon/FC3 on ER collets.
 
For Weldon there are some End Mill Holders, such as:
http://www.arceurotrade.co.uk/Catalogue/Cutting-Tools/Milling-Cutters/End-Mill-Holders

I wonder how End Mill Holders  work with FC3?
And often I would need longer tool holder.
 
I might better of with MT3 arbor,  ream 6 mm h7 hole  to it, and cross drill a crub screw?
 
There seems to be many Clarkson type holders on the market, but they limit me only to threaded shanks, don’t they?
http://www.axminster.co.uk/axminster-axminster-auto-locking-milling-chucks-prod23576/#bottomsection

What about the TC3, they look good on paper. I haven’t got any yet, but how to chuck the “right” and is there anything I should know about them, before buying a good selection?
 
Many questions, but if I don’t try to rationalize my slot drill / end mill / chuck  situation now, I’ll end up with 1000 pcs puzzle in no time…
 
thanks,
Pekka

[PekkaNFParticipant @pekkanf]

Slot drill, end mill cutters and holders?

[Ian S CParticipant @iansc]

Hi Pekka, I have a Clarkson type chuck, and I made a collet that takes plain shank end mills. The collet has a grub screw to hold the cutter. I’v only one collet for 1/4″ at the moment, but no doubt, if the need arose I could make other sizes. You can buy 3MT collets, tapped for a draw bar, and what ever size you want. My only problem is a lack of metric collets for the chuck, but I over came that for an emergency job with a 6mm screwed shank cutter by making a shim of aluminium drink can, the thread seemed near enough, and the job went well.

even after rationalization you will proberbly still end up with 1000 pcs puzzle. Ian S C

[David Clark 13Participant @davidclark13]

Hi There

Chances are the ER holder can hold on the plain shank.

The thread will be inside the body.

To extend the FC3 cutters, do as you suggest, turn a bit of bar and then drill and ream the 6mm or 1/4 hole and drill and tap for a grubscrew.

Do it all at the same setting and all should be true.

 

Weldon should not be a problem with the light cuts taken on hobby machines but Arc Euro Trade do do some excellent holders with side locking grubscrews.

regards David

 

[David Clark 13Participant @davidclark13]

Hi There

I think the Clarkson thread is the same on imoperial and metric.

Just the diameter that varies.

I think it was 20TPI from memory but could be wrong.

regards David

 

[PekkaNFParticipant @pekkanf]

Thanks,

 

You are right on Clarkson/Osboure thread. These chucks have Whithworth 20tpi thread on all diameters. Checked it on WPS#2.  Not too keen on doing Whithworth on metric master/slave collets.

 

Checking if can butcher a MT3 “GROZ” blank. The stub is 25,4 mm by 38 mm. A little big on 6 mm FC3 and a little small on 16 mm master/slave. I probably would turn OD down to 16 – 18 mm.

 

I’m a bit apprehensive about the 6mm h7 hole tough. I could drill and ream it, but I’m afraid it won’t be concentric and parallel. Boring it? Hole this small would be first time for me. It would lead me to a major HSS grinding excercise.

 

I probably will do inventory on my weldon bits, by most needed MT3/weldon holders from Arc and try to manufacture this problematic FC3 holder.

 

What is the main difference/use FC3/TC3?? Can’t really figure it out.

 

Pekka

[John Stevenson 1Participant @johnstevenson1]

I use these here.

 

http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collets-Collet-Chucks/ER11-Collets-Collet-Chucks

 

Item at the bottom of the page ER11 collet chuck and hold them in a 16mm collet in either an ER32 or using the adaptor three up from the bottom these then fit in a standard Clarkson chuck.

 

Holds any size up to 7mmdrills or cutters and are bang on for concentricity.

 

John S.

[Sub MandrelParticipant @submandrel]

I use my ER collet chuck for FC3, Clarkson-style and plain shank cutters – even my slitting saw holder. I have a plain arbor reamed for FC3, but I find the ER collets work fine in the ER collets so I rarely use it.

 

I understand ER collets are meant for tool holding, they are designed to collapse parallel so they grip for the whole length of the collet, not just at one end.

 

Neil

[David Clark 13Participant @davidclark13]

Hi There

They are classed as throwaway cutters, which is why I think they are TC3.

Can’t remember on FC3.

regards David

 

[David Clark 13Participant @davidclark13]

Hi There

If you are worried about making an FC3 holder without runout, drill and ream the hole, drill and tap for the grubscrew.

Turn a bit of bar to fit the holder, fit the holder to the bar with the grubscrew and skim true.

regards David

 

[PekkaNFParticipant @pekkanf]

Posted by David Clark 1 on 17/09/2010 20:21:03:

Hi There

If you are worried about making an FC3 holder without runout, drill and ream the hole, drill and tap for the grubscrew.

Turn a bit of bar to fit the holder, fit the holder to the bar with the grubscrew and skim true.

regards David

 

 Had to read this twice, before the coin dropped! Pretty obivious on hind sight. I have pretty good metric drill rods, just perfect for a good mandrel.

 

This just prooves that it was a good idea to ask studio team, before rushing into garage and make hash up of things.

 

Thanks,

Pekka

 

I have been toying up with the idea of buying some smaller ER sets and shank holders, but then again – it would add more pieces to my puzzle!

Edited By PekkaNF on 17/09/2010 21:33:58

[Ian S CParticipant @iansc]

Yes David 20 tpi all sizes is the standard for the shank of milling cutters. Ian S C

[PekkaNFParticipant @pekkanf]

Hello again,

 

Tried to drill hole exacly to centre and parallel. Long story short: I got all the mistakes on the book. Not too bad individually , 0.01 mm or under each, but the mistaks add and the end result was that the FC3 tip has about 0.004 mmwoble. Clearly too much for 3 mm three fluted cutter.

 

 I toying with the idea of making a small booring bar. I just need 6X18 mm hole.

 

Probably I should order a couple of spot drills, booring bar and a h7 reamer.

Bugger,

PekkaNF

[David Clark 13Participant @davidclark13]

Hi There

Centre drill, drill slightly undersize and finish with a size drill.

Drill and tap for grubscrew.

Turn size mandrel, fix holder to mandrel with grub screw.

Skim od.

All should now be true.

regards David

 

[PekkaNFParticipant @pekkanf]

Jup. Finaly a partial success of having less than 0.02 mm throw on short FC3 business end.

 

I didn’t want to skim OD, so I was limited to booring. Made a nominally 6 mm booring bar out of M6 thread tap, shank OD is 6 mm, shaft arounf 5 mm and it was broken, only three teeths left to save a lot of grinding. Made a booring bar holder for it and gave last finish with a diamond lap. Worked out fine.

 

Probably will make one OD 12 mm holder with bottom hole just to practice. I don’t feel proficent yet.

 

I know that one tooth of threading tap is not ideal, because of the 60 decree from, but on the positive side, the tooth has almost all the right angles. I could have groud half a teeth further to introduce more traditional form, but this small tap has very small teeth and regrounding the whole would have been a lot of extra work.

 

Extra lazy bit on this one was to bolt the holder in place and step drill with the lathe chuck to 6 mm shank size. I can almost guarantee centered hole and correct edge height with tap/booring bar!

 

Went fine into 5,8 mm hole, but needed careful aligment, high RPM and SLOW feed.

 

PekkaNF

 

[John OlsenParticipant @johnolsen79199]

You can measure .004mm of wobble on a 3mm cutter? Or is that a typo? Even the .02mm in the later post sounds pretty small. Or was it 0.2mm, which would be about 8 thou.

 

I too have a boring bar made out of a very expensive gun tap!

 

regards

John

[PekkaNFParticipant @pekkanf]

This 0.004 mm was a typo. I would have been overly happy with that and it’s also pretty hard to measure accurately these magnitudes. The correct figure was 0.04 mm of “throw” on 6 mm shank cutter at 15 mm away from the adapter face. I was making a holder for 6 mm shank, 3 mm short FC3 cutter. I was expecting it to get even worse when in use, because the hole was a little bell-shape, a litlle too big, a little inclined and off-centre!

 

0,02 mm woble was after few experiment later and I’m happy with it, the hole is of proper size, hardly can push most of the FC3s in. I made a hole trough to allow brass drift to push FC3 out if they get stuck. The hole  looks pretty straight and close to centre.

 

What size is your tap booring bar? How do you use it? I used this to take overly small cuts. My finishing cuts were in order of 0,02 mm and there was a noticeable spring on return, althoug it seem to cut on return stroke as well.

 

Tried to make another adapter and I was hurrying up – I botched it right there. The hole for FC3 came out too big! Should have learnt by now.

 

PekkaNF

Edited By PekkaNF on 28/09/2010 09:04:01

[KWILParticipant @kwil]

It is standard practice to cut on the return pass until  there no further cut on the forward pass before setting another cut when you are working with fine tolerance boring. There is always spring in the tooling which must be allowed  to work out. Cuts of 0.02mm? thats nearly a whole thou! Do you mean 0.02mm radial or diametral?

[PekkaNFParticipant @pekkanf]

I was trying to take a 0,02 mm cut i.e. radially this much on one go. It didn’t seem too much to ask. This cutting tool is pretty rigid for it’s size, I think. Anyway I’m familiar with the spring of the the boring tools, but it was still a bit more than I though of. Then again, material is about silver steel and 30 decree leading edge is not ideal.

 

You feel I should have tried cut less deeply? I was more worried of cutting too litle and only rubbing.

 

PekkaNF

Edited By PekkaNF on 28/09/2010 19:30:14

[John OlsenParticipant @johnolsen79199]

My tap boring bar is made out of a 6mm tap that “just came apart in my hand”. It broke near the bottom of the cutting section, leaving a piece that stuck out on one side that suggested a boring bar to me. So I ground away what I had to and now have a cute little boring tool that will go into a hole about 4mm diameter. It is really useful for those tiny bits that need to be concentric, although I have never tried to measure the runout I get, I just know it is lots better than a drill will give after it has wandered about.

 

regards

John

[PekkaNFParticipant @pekkanf]

I know the feeling when something just suddenly snaps off…always manages to surprice me.Happens a lot with no-brand carbide inserts. Specially some parting-off tools crumble like a cookies.

 

I had this problem of small boring bar and I was staring just what was at hand and I was trying to see what could be made to to work.

 

I’m having trouble too of drills wandering off centre. lately I have used very short carbide drill to make pilot hole. It’s a slight improvement on start. Nevertheless the hole comes inclined later when drilled to full depth. I now the drill, have to measure tail stock again…

 

Found center drill / spot drill thread earlier here and I ordered some spotting drils and such.

 

Does anybody makes stiff enlarging drills (those three flute, thick core affairs) anymore? Or drils that does almost as good as cheaper reamers? These used to used after normal two flute drills (that make triangular hole) to prepare it for reaming. I go ask this tuff to local tool shop and get an empty stare….

 

Made another attempt without boring i.e. just step drilling and it produced 0,05 – 0,1 mm woble at 20 mm 6 mm dia! Fitted that sob to drill rod with set screw and skimmed it outside with carbide insert…phew…not duly impressed but it came workable at 0,03…0,04 mm woble at same conditions. I really don’t understand this process completely – set screw at the other end of the adapter can do only so much to keep all 50 mm of OD 16 mm shank still – even when this 6 mm mandrell is drill rod and supported with revolving centre and adapter has reamed hole. OD came out around 15,85 or thereabout.

 

I’m almost giving up on using drills on tail stock and startting to consider using tool post to drill, enlarge and ream….

 

PekkaNF

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