looking for a dovetail cutter

Luke Rickert · Aug 27, 2017

I need a good quality but not crazy expensive dovetail cutter for making some smallish parts in cast iron. (150mm/6 inch long 18mm deep dovetails) I don't want Chinese junk but the only only other thing I have found so far is a solid carbide cutter for something over 600USD equivalent. This is for running in my Schaubln 13 mill and cutting SG cast iron so I won't be hogging out material and will cut as much as possible with end mills etc before hand. The part is unfortunately not doable with a horizontal cutter given access issues so I need to use the vertical head. I wish I had a shaper or planer for this but I should be able to do it with the mill, it just requires the correct tooling.

I have seen some people making dovetail cutters with triangular carbide inserts which I could do if there is nothing else to be found. I could also braze carbide on a home made cutter and grind it to shape with my cutter grinder but I am not going to get more than one or two cutting edges if I go that route which seems like it will make for some slow cuts.

Any ideas or suggestions?I am only prototyping a couple of parts, so figure 8 cuts total. I just can't see Chinese HSS doing the job and don't know where to look for something else that makes sense for my application.

thanks

Luke

Lumberjack · Aug 27, 2017

Hi Luke,

Long time since...

Not sure how hard that CI is but I wonder if it could be better invested $ to buy a tailor made dovetail cutter with proper cutting angles rather than a std HM mill.

Anyways, just made a quick google here in Sweden and Hoffmann´s came up with what you ask for. Should be availble in Norway too. Otherwise let me know and I can help you get it from here.
GARANT HM-vinkelfras form C 6deg TiAlN

Otherwise I´d most likely try out an HSS first, it´s like a 1/10th of the cost an they milled a lot CI back in the days before carbide. Several places to find decent quality HSS for reasonable price.

Luke Rickert · Aug 27, 2017

Thanks Lumberjack, I found that carbide on on Hoffman but in a reasonable size (remember the dovetail is 18mm high) I need to spend something like 7000 SEK which is really a rather lot of money for a single cutter. I thought getting the parts cast was going to be the expensive part

It would be cheaper for me to go buy a shaper so I can slowly cut them with a single edge that can always be sharpened.

If you have any sources for a reasonable quality HSS cutter (something with a 20mm or 22mm shaft) that would be helpful. Norway isn't good for these sorts of things and my searching techniques aren't very good for this sort of tooling apparently. All I find are those sets of Chinese cutters. I find some "cheap" insert tooling in the states on Shares etc but it isn't big enough for what I am doing and has inch dimension shafts which can be annoying with metric collets.

Luke

Lumberjack · Aug 27, 2017

Whohaa 18mm depth, I must have read it but Assumed dia...

Anyway, how wide is the slot? Could you fit something like this?
Vinkelfras 6deg o 63 mm, Hal o 16 mm

I believe the DIN norm is 842A. It´s called Vinkelfräs eller vinkelskivfräs på svenska and Winkelstirnfräser in german.

Luke Rickert · Aug 27, 2017

Thanks for the vocabulary

I might need to revisit my design and make the dovetail shorter or make it a bit wider than the current 55mm.
Luke

Lumberjack · Aug 27, 2017

Sounds like a plan to me.
And if you´ll be scraping that deep dovetail you will like it a tad wider. Anyho, just give me a ping should you want help in sourcing something on this side of the border.

Mark Rand · Aug 27, 2017

This might be 'Chinese junk' but it will do the job in three passes. Ketan at Arc Euro doesn't sell rubbish, so it will do what's needed. The price is right for the size of the project as well...

It won't do it in one cut like Lumberjack's suggestion, but it will fit within the available width.

thanvg · Aug 27, 2017

Hi whidbey,

Sharing my experience with the generic chinese 10 euro ebay dovetail cutter.
I wanted to make a custom lathe qctp holder so ordered a dovetail cutter as describes above. Not a critical part and no time pressure so I thought it made sense to try. Made the part out of an old huge mill clamp. Not super hard but not soft by any means, took the best of two quality angle grinder disks to part the piece off the 'stock':

Was amazed by the performance of the humble cutter. Pics don't do the finish justice but it was acceptable at least. Took the cut without strange sounds, just worked and lasted for both cuts without getting tired.

Of course I ordered a couple more cutters after this, it might worth trying.

Br,
Thanos

bentley1930 · Aug 28, 2017

Hi All,

Luke,

I have some good old British HSS cutters That you could borrow but they are for use in a Clarkson Autolock chuck as they have an imperial thread on the end of the imperial shank. Do you have a chuck that can handle these type of cutters? You could also borrow my chuck but it is 2MT using a 3/8" Whit drawbar, probably not compatible with your machine.

I will check sizes when I can get to my workshop on Wednesday.

Alan

Luke Rickert · Aug 28, 2017

Hi Alan, I was just thinking I should get in touch. We should get together again before long.

I have an autolock chuck for the mill but only metric "collets", Ole might have some, I know he has an extra iso30 autolock he doesn't need. I love autolock by the way, totally antiquated I know but it works well and the cutters never move. Let me know what you find, there is no hurry as I haven't sent the patterns off the the foundry yet, I am just trying to make sure I can actually machine the part I am designing. Given the cost of the castings is rather high I don't want to end up with an impossible part and a very expensive lump of iron as a doorstop. I do need a rather large cutter with a depth of near 3/4 of an inch.
thanks
Luke

bentley1930 · Aug 28, 2017

Hi All,

Luke, i`m pretty certain that I have the size that you require I just need to double check.

I needed a dovetail cutter for the FP1 Riser project and bought several cutters from "Home & Workshop Machinery" during my recent stay in the UK, if you are ever in the UK it`s worth a visit, they are situated in Footscray in Kent near the Thames crossing. Steve is very helpful and he will send to anywhere in the world. They have so much stock that it`s a daunting task to look round their premises and find what one needs! The stuff can be a bit pricey but it`s there. (home&workshop.co.uk). Unfortunately they don`t handle Deckel or Swiss stuff.

Where were you thinking of having the castings made?

Alan

Luke Rickert · Aug 28, 2017

Thanks Alan, that would be helpful for sure. I can always order some chinese wonders and try my luck but better tooling is never a bad thing. I am also going to cut at least the accessible part with horizontal tooling which is so much more robust and stable than vertical tooling on a light machine like the Schaublin 13.

Alan I should have checked with you but the only foundry I was able to find that would work with me is Specialised Castings in Scotland, I wanted to find someone in Sweden etc but haven't had any luck. Here in Norway there are small non-ferrous foundries but the iron guys only work with big offshore stuff from what I could find. I am providing 3D printed patterns but the setup costs are still significant and the casting itself isn't cheap. I do need ductile iron which makes things a bit more complicated I think. Coming from aerospace engineering I don't have much background in cast iron so this is educational

Luke

MattiJ · Aug 28, 2017

whidbey said:
Alan I should have checked with you but the only foundry I was able to find that would work with me is Specialised Castings in Scotland, I wanted to find someone in Sweden etc but haven't had any luck. Here in Norway there are small non-ferrous foundries but the iron guys only work with big offshore stuff from what I could find.

Luke

Here in Finland Tevo-Lokomo, Karhuvalu oy, Karhulafoundry and Ulefos Oy are all making ferrous castings.
(Sacotec and Miilucast also but those are either precision tool steels or bigger scale parts.)
Not sure of minimum quanties but part sizes are from couple of millimeters to submarine hulls.

michiganbuck · Aug 28, 2017

For a one up job(dovetail )you cant beat doing it on the surface grinder. Tip the part on 45* or so to get in...cutter rough and then then SG finish is also good as it can save much scrapping if close is needed. Dovetail cutter because of the longer cut may need better holding support..shear angle better than a straight flute for better finish and less cutting pressure IMHO... but yes a little harder to sharpen.

Best way to sharpen is to spin on the angle to a small circle land , then back off clearance primary to just make sharp. With not using a riding finger one may have to bump angle to make edge length ..the error will be in tenths so the part will not know the difference.

Lumberjack · Aug 28, 2017

Hi Luke,

There are several foundries in Sweden, some specialised in short runs.
Have a look here, I´m sure they can guide you in the right direction.
Engelsk sida
They have a member list but I only found it in swedish, if you need I could mark up those most likely of interest.

michiganbuck · Aug 28, 2017

For a few parts a good name HSS cutter may do. Perhaps a little more time but at a savings. WELDON 6 DEGREE DOVETAIL ANGLE CUTTER ENDMILL, HSS, 2-1/4 DIA. 1" SHANK

but yes cast iron loves carbide and a small negative top edge land or circle land under top edge is often best..any sand on cast iron surface kills a HSS cutter..

for longer life on a production cast job a small bump top edge to a wire or abrasive soft wheel may add life time.also a small negative hone with a very fine diamond hone (wet).

Back spin the last tickle makes a better circle grind land. A circle grind land is a small portion of the grinding left abous the primary clearance.. Yes not up to sharp perhaps .002 to .015"(or so)

bentley1930 · Aug 31, 2017

Hi All,

Luke,

Had a look round the workshop today and this is what i found.

The two cutters on the left are on a 5/8 shank and can cut a depth of 9/16".

The cutter on the right has a 3/4" shank and is 1.5" dia with a depth of 5/8". This diameter shank will not fit the collets supplied with the small Clarkson chuck which has a max size collet of 5/8" or 16 mm.

I hope that this larger cutter will suit you but it will need sharpening.

Talking about Clarkson chucks and collets, I got both the small and large chucks with my FP1 and the shanks of these were marked with the Deckel ID. Unfortunately the collets are missing from the large chuck and I will have to find them on Fleabay.

It was the availability of cheap throw away cutters that sealed the fate of the clarkson chucks although the cutters are still readily available for them.

In the above photo you can see how Clarkson tried to embrace the throwaway cutter threat by designing adapters so that the throwaway cutters could be held in the existing Clarkson chucks.
You can see on the left an insert that could be screwed into the chuck in place of the nut. This adapter takes 1/4" dia cutters held in place with an Allen grubscrew.

The two adapters shown on the right have 5/8" dia shanks and take 1/4" and & 6 mm dia cutters. they are held in the chuck exactly the same way as the normal clarkson cutters.

Alan

michiganbuck · Aug 31, 2017

As I mentioned before a good if not best way to sharpen such a cutter is to spin grind the angle to a small land .. then bring up the clearance to just sharp.. that takes away all error due to old grinding and variance in the flutes.. you may need not clean up every bit of cutting edge to absolute clean-up to save life of the cutter..Often 75% and better clean up will be as good as 100%.

nitromarsjipan · Aug 31, 2017

If you're still looking to buy one Öberg verktøy in Skien has one almost your size. It is 60° 38mm dia on 16mm shank and a depth of 16mm:
http://shop.obergverktoy.no/produkt...halefres-hss-co-6-skjærs-wdd60380-p0000018030

Their price is 859 NOK excluding VAT. (This is with a 30% rebate. I'm not sure anyone pays their list price.)

Dimensions can be had on page 199 here:
https://obergverktoy.no/sites/default/files/catalogue_-2011.pdf

Luke Rickert · Sep 1, 2017

thank you nitromarsjipan I will get in touch with them. If not for this they could be useful of other tooling.

Thanks Alan, I will be in touch offline. I can always hold a 3/4 shank in a 19mm collet (an ER32 should have no issue with the 0,05mm oversize with a 19mm collet). I will see if my design will work with a 15mm depth (5/8ths is 15.8mm)

I also found a swiss made 63mm diameter 60 degree dovetail cutter in a drawer of stuff that came with my Schaublin mill. It still has the protective dip on it so it should be good and sharp although it is too big for the internal side of the dovetail as currently designed.

Luke

looking for a dovetail cutter

Hot Rolled

Hot Rolled

Hot Rolled

Hot Rolled

Hot Rolled

Hot Rolled

Diamond

Hot Rolled

Hot Rolled

Hot Rolled

Hot Rolled

Hot Rolled

Titanium

Diamond

Hot Rolled

Diamond

Hot Rolled

Diamond

Plastic

Hot Rolled

Similar threads