Profile cutting multiple small parts

[Soapyjoe]

Hi,

I am profiling quite a number of small parts from 6mm thick Mahogany.

My problem is this...

Whilst the parts are very accurate in size I find that the finish , especially a slight burr on the top edge of the parts, requires a lot of cleaning up.
I am cutting the parts out with a carbide slot drill (two flute) at a fairly fast RPM and traverse speed and only taking 0.5mm per cut.

Any advice?

[Adrian]

Experiment with different rates and rpm along with cut direction until you're happy with the finish. When I have a new material or a new style of bit I often cut a test board with varying settings and then fine tune from the best one.

0.5mm seems a very shallow cut to me and with that number of passes I'd be concerned about build up of shavings if it's a down cut bit. I don't know how rigid your machine is or how powerful the steppers are to know if it can do more though.

[Soapyjoe]

Hi Adrian,

Thanks for your comments

My machine is quite sturdy and would , I feel, profile the very small parts out easily in one cut.

Even set at 0.5mm per cut the parts only take a few seconds each to profile (a sheet of 36 components takes about 25 minutes to machine)

Would you consider using a different cutter?

30mm Square Parts (36off).crv3d

(163 KiB) Downloaded 123 times

[Adrian]

2 flute spiral down cut bits are my "go to" tools for pretty much everything. If you're getting marks in one particular place it could be the bit flexing on plunge/retract. Using leads and ramps can sort that out.

[Soapyjoe]

Hi Adrian,

I am attaching a photograph of the parts in question.

As you will see the problem is only really on the top edge.

It is taking me longer to clean up and assemble into squares than to profile the parts

Perhaps I have to live with it..... six new 4mm slot drills have just arrived in the post .... will try these

[ger21]

+1 on the downcut bits.
Much cleaner, less tearout.

[Soapyjoe]

Hi ger21


What you you mean Plus 1 on the downcut

[dwilli9013]

Hi ger21


What you you mean Plus 1 on the downcut

He means he is agreeing with Adrian on the usage of downcut spiral bits.

[Soapyjoe]

Thanks.... I have ordered one of these cutters.... hope it works .... it was a bit expensive!

[ger21]

Try these:
https://www.ebay.com/sch/i.html?_from=R ... 4&_sacat=0

[scottp55]

+1 On Drillman1's downcut bits(pretty much all his Kyocera 1/8's)
Agree with Adrian that test cuts for YOUR finish quality is important.
Made large volume small items, and started cutting them fast....THEN found that it was taking 1.5-2 hours to sand a batch a batch of 30:(
Also were getting rejects because sanding varies with grain direction and "Rounds" were visually NOT round.
Played with it with different strategies, and found spiral ramping and playing with feeds/speeds, pass depths, and adding a TINY final pass cut finish sanding to less than 30 minutes. Yes it took more machine time, but if it saves finish time WHILE I'm finishing..win/win
Bringing material to finish grit(600G) on both sides while it was still a board, and then doing a quick 600G after cutting, left only the the sharp edges to sand on the stationary Foredom:)
scott

Oh...The small "Bonnie" buttons in last pic were cut out with Drillman1's Kyocera .25" shank 60degree VBit( it cut as well as the Vortex $38 bit we initially used)
Downcuts and sometimes other bits cut smoother with a conventional cut...check you Finish side of cut compared to the Waste side, and reverse if needed.
Also....both of the "twig" butterfly wedges were cut with his .0625" downcut(first pic is mislabeled)

[Soapyjoe]

Thanks everybody,

Food for thought!

I will make more trials before I make the next batch..... I have quite a lot of parts to make for a small Rhombicosidodecahedron that I am making.

I like the look of the cutters that Ger21 mentioned but I note that they come from America ..... is it OK to order them from the USA branch of E Bay?
I tend to only order from the U.K.

I would be interested to contact any others that model mathematical shapes.

I am attaching a photograph of a Dodecahedron that I made a few weeks ago

[Pete Cyr]

In geometry, the rhombicosidodecahedron, or small rhombicosidodecahedron, is an Archimedean solid, one of thirteen convex isogonal nonprismatic solids constructed of two or more types of regular polygon faces. It has 20 regular triangular faces, 30 square faces, 12 regular pentagonal faces, 60 vertices, and 120 edges.



Oh my.... I can see where a very small variance means it will not fit together

[Soapyjoe]

Hi Pete

This is a photograph of a shape very similar to the one I am currently making.
The sphere has Pentagons, Rectangular and Triangular parts .... I made this some time ago!
The one I am currently making is composed of Pentagons Squares and Triangles..... the margin for error is small especially cutting the side angles

Quite challenging but great fun to make

[Pete Cyr]

Very nice, very precise.