55 Degree dovetail cutter, Where from?

I need to cut some female dovetails in aluminium. The slot will be about 30 wide and 6mm deep so a cutter head diameter of 15 would be ideal. The 55 degree angle is to match some existing camera equipment which incorporates the locking mechanism so the angle has to pretty close.

I can find lots of 45 and 60 degree cutters but 55 degree ones are either very expensive of have to come from distant shores.

Can anyone recommend a UK supplier or have a cutter lying around that I could buy?

Ian P

Hi Ian,

You could easily make a dovetail cutter for this application. I made a 60 degree cutter using a TCMT insert as shown here:

http://mikesworkshop.weebly.com/dovetail-cutter.html

If you cut the recess for the insert so that the bottom of the insert makes an angle 5 degrees to the horizontal than the cutting face will be at 55 degrees.

Alternatively you could cut the 55 degree dovetail using a 3 mm straight milling cutter with the work mounted at the appropriate angle. This will give a slight undercut to on the base but unless the material is very thin this will be of little consequence.

Mike

Why not make one from silver steel, very easy and cheap. Have made quite a few over the years mainly for gun sight dovetails . John

Chris

Kirjeng dont seem to have a catalogue or a website that I can find. Please could I trouble you to see if 55 degrees is a cutter angle they show in the catalogue you have.

Mike

If it was 60 degrees a standard triangular tip would make it easy (but then 60 degree cutters are plentiful) If I tilt one as you suggest the bottom face of the channel would not be flat. That also stops me using small diameter endmill at an angle.

Johnf

Whilst silver steel suitably hardened would be OK I dont have the skill and patience to make a multi edged cutter.

I dont have a vast quantity of dovetails to cut (10 females about 60mm long) so all in all its not a vast amount of metal to remove but I want to achieive a nice repeatable finish without having to cut very slowly. I have done similar profiles before using woodworking router bits, they are not ideal in aluminium but often very good value for the money.

Based on what Michael said I could use s ready made 45 degree dovetail cutter and tilt it 10 degrees, It would mean I had to tilt the head of the mill and that really is too onerous for me to do, ever! (Loose shims in two planes means precise tramming take hours)

Ian P

Hi,

Why not make a cutter as Michael Cox suggested, but use a 55 deg DCMT carbide insert.

Barry

Hi Ian,

try www.freud.com or co.uk (or google it), I think they were in Hamel Hampstead.....they do various cutters for Ally and wood...don't remember them being mad expensive....

they do have a good on-line catalogue.....If u get stuck I do have a couple of other places to try but I'm not at home to get the details......but home soon, just ask if u need them.....

get lucky...

Frank in France

Frank

I did think of Freud, there are none in an old catalogue I have so I looked on the website. I actually doubt they do one at 55 degrees but I had to go through hoops just to find the angle of the ones they do make! The indexing and search on their site might be OK if you know the shank diameter of the cutter or what industry the cutter is used in, but you cannot choose by cutter shape, just weird.

If you need router cutters, I can recommend 'Wealdentool.com' I have found their cutters and prices good.

Barry's idea is one I had not thought of. I'm not sure if I could make a holder (for two tips preferably) to the required accuracy but its got me thinking of buying a pair of the super sharp, polished aluminium cutting inserts and having a go.

Ian P

A small flycutter will do dovetails, I often use them to do the latched on hit & miss governors

I looked through my Wealdon catalogue when I fiorst saw this post but they don't do such steep angles

Edited By JasonB on 23/09/2014 07:24:59

Hi Ian, again.....

check out "Trend", they sell there own and other ally cutter's.....

sorry can't do more as I only have a tablet at the moment and I need some new eye's....hahaha'''

get luck, Frank in France....

Nothing in my Trend pro or hobby range catalogues

Sounds like a job for a shaper if you know someone with one.

Hi Ian, just a thought.....

what about one of those cheap and cheerful Chinese tipped cutters......thinking, don't laugh...

what about putting it in a drill press then touch it with a 4" grinder to get the angle whilst it's spinning then just grind back the back edge...there'll only be a few to do......I'm sure it'll do as a throw away...

get lucky....Frank in France.......

Thanks for all the ideas. I have some DCMT (11) tips and I think a single edged cutter using one would work. Using two tips would make the overall diameter too large because the back halves of the trapezoidal shapes would clash. Using smaller than TCMT11 maybe OK but the holder would be more fiddly to make.

Another idea that I cannot use because I dont have a cutter grinder, is to modify a 60 or 45 cutter to 55 degrees but I may investigate getting a sharpening company to grind one.

I have two of the Lidl/Aldi Chinese 12 router cutters selection boxes, I think he first one cost me £5.99. They have proved very useful when I needed a special shaped TC cutter, rarely used for woodworking though.

Ian P

Or you could search for a Whitworth dovetail cutter

http://www.ebay.co.uk/itm/30mm-x-55-Degree-HSS-Dovetail-Cutter-End-Mill-/120937175863

hi ian,

i have a suitable cutter if you want to borrow same. what depth?

cheers,

julian

.

Vic,

Interesting ... that cutter looks like it's 55° from the vertical; which would make the internal angle 35°.

For no particularly good reason, I had assumed that Ian's requirement was for a 55° internal angle.

Which makes me wonder ... is there an agreed convention for the way dovetails are described, or is it something we need to be wary of ?

MichaelG.

.

P.S.  Harvey Tool lists an enormous range of small Dovetail Cutters ... and refers to the Included Angle.

P.P.S. ... and here is Harvey Tool's very useful Angle Conversion Chart !!

Edited By Michael Gilligan on 23/09/2014 07:02:19

Edited By Michael Gilligan on 23/09/2014 07:07:07

Vic that was one of the cutters I saw but the distant shores put me off, price is OK though.

Looking at it again now the angle does look very steep, it might just be the photograph but its ruled out anyway because the diameter is too large as the finished slot is only 28 wide.

IanP

Julian

That is a very king offer. I will see if I can buy a cutter first just in case the parts I have been asked to make turn out to be a regular requirement.

The female dovetail I am cutting (to suit existing male) is 28mm wide and 6mm deep and needs to have fairly sharp internal corners as the male part only has about a 0.5mm flat.

Ian P