Cutting pockets with a machine.How small can we go ?

Newton

Newton

AzB Silver Member
Silver Member
I have had a run on our works CNC/engraving machine and have made some
test inlays. However I ran in to the problem doing pockets where the machines cutter was to big (3mm). Doing pockets with a machine requires a very small bit/cutter and I guess many of you have ended breaking them.

What is the smallest cutter bit which people has manage to use for cutting pockets? 1mm? Are we able to go smaller with increased spindle speed and lower cutting speed/motion?

I was just curious and was hoping to learn the easy way and not spending big
bucks on a bucket of broken bits :)
N
 
Newton said:
I have had a run on our works CNC/engraving machine and have made some
test inlays. However I ran in to the problem doing pockets where the machines cutter was to big (3mm). Doing pockets with a machine requires a very small bit/cutter and I guess many of you have ended breaking them.

What is the smallest cutter bit which people has manage to use for cutting pockets? 1mm? Are we able to go smaller with increased spindle speed and lower cutting speed/motion?

I was just curious and was hoping to learn the easy way and not spending big
bucks on a bucket of broken bits :)
N
Click to expand...

I've finished pockets with cutters as small as .010 thou. (.25mm). I was spinning them 60,000 rpm though.
 
Ho ho ho. That?s really small!! I guess you then has a really low cutting speed even if you use 60K Rpm? Using a pantograph and
a Dremel tool would for sure not work out I understand.. What type of mill is giving you that performance ? Custom made ?

Our machine at work has a belt drive to the spindle, which I have been told may cause vibration and break small cutters.
The only option for me seems to be to invest in something like this http://www.alfredjaeger.de/frameseiten/englframestart.html
to modify our machine, but that set?s me back $6700!!!

N
 
Newton said:
Ho ho ho. That?s really small!! I guess you then has a really low cutting speed even if you use 60K Rpm? Using a pantograph and
a Dremel tool would for sure not work out I understand.. What type of mill is giving you that performance ? Custom made ?

Our machine at work has a belt drive to the spindle, which I have been told may cause vibration and break small cutters.
The only option for me seems to be to invest in something like this http://www.alfredjaeger.de/frameseiten/englframestart.html
to modify our machine, but that set?s me back $6700!!!

N
Click to expand...

This little machine right here with a auxiliary spindle since the main only goes to 12K.

http://www.murraytucker.com/mazak.htm
 
Newton said:
Ho ho ho. That?s really small!! I guess you then has a really low cutting speed even if you use 60K Rpm? Using a pantograph and
a Dremel tool would for sure not work out I understand.. What type of mill is giving you that performance ? Custom made ?

Our machine at work has a belt drive to the spindle, which I have been told may cause vibration and break small cutters.
The only option for me seems to be to invest in something like this http://www.alfredjaeger.de/frameseiten/englframestart.html
to modify our machine, but that set?s me back $6700!!!

N
Click to expand...

The smaller the cutter you use then the more speed and accuracy is needed in the router or spindle. A 1 mm cutter is approx. .040. I use .0312 in a CNC Gantry machine with a Precise high speed grinder for a spindle. To get tight radiuses, you must use a small cutter. The smaller the cutter , the tighter the radius. Most inlays are put in with a 1/32 or even a 1/64 end mill. A Panto-mill and a CNC use the same cutters and can do the same work with the same results but With a CNC you can move the cutter at it's optimum cutting speed without breaking bits. Since a Panto-mill is moved by hand movement you can't move at the best speed that is needed. The day that the first CNC mill was invented sounded the death nell for Panto-mills.

Dick
 
NSK is the way to go. Call Blud... He will be able to get you the set up cheaper than you can buy it form NSK. Air cooled 50000 rpm. Quiet and precise. If you are looking at spending that much money buy the whole machine from Blud..
 
I had really not planned to spend that amount of money on this type of equipment. Our Gravograph
IS 400 in stock shape actually do a pretty good job on normal size inlays, but if you ad something
like a start or other shapes with sharp edges I?m off the track.

RHNCue; You confirm what I was told by the supplier of cutting tools - Crown. Our
Gravograph IS400 is strictly not accurate enough I was told, so I think I leave it at that.
The smallest bit recommended was 2mm, so fairly large and curved inlays must be designed.
I?ll do a test run on a blank and see how it goes.

Murray; I?ve seen you posting in respect of CNC machines earlier linking to you?re machine,
and since this seems to be repeating I guess you must be very proud of it :-) I would however
never spend that amount of money on a machine like that, since I?m a hobby cuemaker and
have no big plans on going commercial. Happy building with you?re big $ machine ;-)

RocketQ; I have read about Blud and seen pictures of his machines, but I?m living in
Europe and we do use 220V. Shipping something like Bluds machines over here
would most likely cost me the same as a regular payment on my mortgage :-)
The NSK air head do however look good and I?ll keep an eye one Ebay.
If the sellers only would ship to Europe...

N
 
Newton said:
How about fitting a NSK on one of these :
http://www.cnc-router-routers.com/html/prices_about_cnc_router_engrav.HTM

I'm not sure if the machines frame is rigid enough thoug, but it should at least have enough travel ... Maybe this post should be in the cue machinery section now..

N
Click to expand...

Any Gantry type machine will easily work as the weight doesn't affect the travel. The weight (cue and set-up for holding cue) is stationary and the tool moves. Those machines don't have much travel but with a little ingenuity in making a set-up for the cue, one of them would be fine.


Dick
 
Thank?s Dick.

I'll certainly have a closer look and see what I can figure out. Maybe I end up building my own machine with a high RPM spindle head :)

N
 
Cutting pockets

A couple a different comments so excuse the jumping around. I'm another user of the precise spindle( ebay purchase) I have cut with as small as .010 but not very often. I can run a .0312 cutter all day long. .020 has to move faster so it doesn't get hot. That's what kills carbide, heat and heat changes. The stiffer your machine the better, same with tolerances on ball screws and rails. Any slop or vibration and forget the cutter. Comes down to precision costs money it's up to you to decide what level you want to take it to.
Most gantrys aren't that stiff. My techno will flex a little bit on a rapid change of direction. Another factor is accel/decel ramp programs in the software. Those who think CNC takes no skill have never gotten down to the nuts and bolts of what it takes to get these machines to do what you want. Sure you can hog out big round inlays all day long, same as a panograph. But get into the delicate work and it takes some time in the saddle until you can get nice delicate and repeatable work.
 
Newton said:
Murray; I?ve seen you posting in respect of CNC machines earlier linking to you?re machine,
and since this seems to be repeating I guess you must be very proud of it :-) I would however
never spend that amount of money on a machine like that, since I?m a hobby cuemaker and
have no big plans on going commercial. Happy building with you?re big $ machine ;-)
Click to expand...

You do understand that I am in the machine shop business for a living don't You? I don't make enough cues per year to even be called a hobby cuemaker.
 
You should look here:

http://www.precisebits.com/

for all your needs with small milling cutters. Steve is right about the speed thing. Moving cutters too slow and letting them heat up is the single largest killer of small carbide cutting bits. This site has allot of information on this subject, and if you still don't have the answer, call them. These people have been helping cue makers for years.

Royce Bunnell
www.obcues.com
 
cutter said:
Those who think CNC takes no skill have never gotten down to the nuts and bolts of what it takes to get these machines to do what you want. Sure you can hog out big round inlays all day long, same as a panograph. But get into the delicate work and it takes some time in the saddle until you can get nice delicate and repeatable work.
Click to expand...
Well said!
It's almost another case of: "It ain't the arrow, it's the Indian."
 
Thank's all of you for the feedback.

Cutter; I had the same "idea" so to say.If the Gantry is not sturdy enough
I had a feeling that this might flex a little bit. The weight however would just be
the bracket for fixing the high speed router and the weight of it?s own materials.

Does anyone know which pitch would be the best to use to get the best out
of this? 5mm, 10mm,16 or 32mm? Accuracy and speed wold be linked to this..

Tucker; I'm sorry, I thought you was just a cuebuilder. I would have loved to
combine my passion and work :-)

Royce; I had a look at that page and it was really nice. I'll see what I end up
with.

For me CNC is just a part of the job. You save some time on the cutting but
manual work is for sure needed, which makes the interesting part of this.
Using a knife and saw, painfully making something which looks OK is for sure
interesting , but in a daily life this takes simply to much time. No big
production runs is demanded, doing this as a hobby is what?s drives me.

I have currently not made one single cue, but I'm investigating the needs
to be able to do it. I would for sure be back for more discussions with you
master cuemakers with tons of experience ;-)

N
 
merylane said:
holy shitz mister tucker:eek: how many cues can that spit out an hour?
Click to expand...

My highly automated process has allowed me to complete three cues so far this year. :eek:

Sometimes I have to use the big mill though.

merylane said:
i like how youz subliminally stuck the steady rest in the last pic.... tricky:D
Click to expand...

That's used for precision joint work.

Unfortunately that lathe (36" swing and 17' between centers) is either getting put in cosmoline or sold on Wednesday. Not enough industry around here anymore to support it. A new Mazak VTC is going to take it's place. I'm really sad to see it go but it's only had two jobs this year so I have to use the floor space for something that pays the bills.
 

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