Question Which Insertion tool to use?

Hi,

I'm completely new to CNC.

I want to design prototypes of airducts for racecars.
See below for an example what I want to make.





I want to create it with an 840, but I'm confused which drill bit (insertion tools) I should use.

So, can any of you guys tell me which drill bit I should use to shape 18mm MDF.
I know I need one (6mm?) for the first pass and another (1mm?) for the second pass.
But I do not understand the difference between downcut and upcut, when to use single flute, when fish??

Is it correct to use this one for the first cut
www.stepcraft-systems.com/en/accessories/insertion-tools/2-flute-fish-upcut-d-6-mm

and this one (as 1mm) for the second cut?
www.stepcraft-systems.com/en/accessories/insertion-tools/end-mill-diamond


Thanks,
Gerry.

Diamond is used for materials that can't be cut very well (for example CFK or GFK). Diamond works like filing or rasping.
One fluted endmills are important for materials where chips tend to get stuck in the flute.
In general having more flutes is better for the cut itself, less stress for the cutting edges, less tendecies for vibrations, smaller chips but still higher feed rate.

Your choice for the first run is ok.

For the second run I'd choose a ball end endmill. If the picture shows the whole truth, no more sharper edges hidden in other parts, I'd also use a bigger endmill. The rule here: As big as possible, as small as needed.
The 1mm endmills are short and you might get problems when cutting too deep.

hi gerry,

- for his kind of shapes you need ballnose bits like this: bits

- mdf material is usually machined with diamand-toothed bists or with helix-toothed bits (you get a better surface)

these kind of bits are all upcut-bits (the machined material is transported out of the drill while rotating)

- down-cut bits are only important while using very thin material which you can't climb totally on your machine table - usually you fix it with a vacuum table or you use something like spray glue

the down-cut bits supports the fixing force instead of up-cut bits.

disadvantage: the machined material can block the drill - you have to use the hoover continuously to prevent broken bits

Hi,

OK MagIO2 and drilldevil for the clear explanation.

So my orderlist looks like this :



Do all this pieces fit together?
Missing something?



Thanks.
Gerry.

Don't forget:
"For the application of the tool with a STEPCRAFT or a third-party router additional ER-collets are necessary."
(That's what SC says on the Spindle page)

Of course you can spend much more money. An aluminum t-slot machine table is -from my point of view- a must-have for a SC840 because the original machine table is not very stable. A vice like these ?

Endmills you can't have enough, but it's OK to start with a limited number, find out what your needs are and buy more with the next paycheck. (If you stop smoking you can spend the savings for endmills ;o)

For more advice we would need to know what you want to mill.

PS: oh ... ok ... you told us ... how big are those airducts? Maybe no vice needed for that, but believe me ... when you have the machine you'll start milling other things as well.

I wouldn't buy the tool length sensor. You won't use it a lot in my opinion, it's 40 euros to skip a 20 second manual measurement. Not worth it.

The 6mm bit from stepcraft needs to have 6mm ER collet too, so add that to there. Also make sure you get spare nut for the HF500. It is much easier to just change the whole Clamping Nut than to remove the clamping nut, exchange the 3.175mm ER collect with 6mm ER collet when changing from the 6mm endmill to those smaller ones. So add following to the cart:

www.stepcraft-systems.com/en/accessories/system-accessories/milling-spindle/clamping-nut-spare-part-for-hf-spindle

www.stepcraft-systems.com/en/accessories/system-accessories/milling-spindle/er-collet-for-hf-spindle

and for the second add both 3.175mm and 6mm ER collets. I think the HF500 does not come with any ER collect automatically so you need to get one to be able to use it.

I think the 6mm bit from stepcraft is the only one with 6mm shaft (i.e. requires 6mm ER collet), and I think all others use 3.175mm shaft (note, not 3mm shaft), so that is the other one you need.

I would add some 2-flute fish tail end mills too. I have 1mm, 2mm, and 3mm downcut versions, and few upcuts too. Downcut will make the top surface better, i.e. if you pocket a hole in the middle of piece, the upcut can rip the corners of the cut upwards, and make uneven cut, downcut will push the cut downwards in to the material, thus the top of the material does not rip. This is important if cutting something that has subject of ripping (soft material or something that has thin layer attached or something like that).

Also I would remove the cut3d from the cart, and download vcarve and cut3d demo versions from the vectric.com site, and check out which of those you want to use. Cut3d is very limited what it can do, it can only take precreated 3d models and make toolpaths for them. VCarve have same features, but also allows makeing 2d toolpaths etc. Only thing Cut3d has that is not in the VCarve desktop is the easy to use wizard type interface and easy way to generate two (or four) sided toolpaths. You can do those in vcarve too, but there is more manual work needed for those.

Note, that neither of those can actually generate 3d objects, they can just take one 3d object created using some other program and generate toolpaths for those. If you need to create 3d objects you need aspire, but that software is quite pricey, and you could use blender or similar to create the 3d objects and then only use vcarve or cut3d to generate toolpaths.

I myself have both cut3d and vcarve, mostly because kickstarter came with cut3d, and then I realized it does not offer features I need so I had to buy vcarve to be able to do things. I have used cut3d once, and for all other works I have used vcarve. I have only the desktop version of the vcarve, which is limiting my max size for the projects to smaller than what 840 can do, but I have not needed that big jobs yet, and vectric allows upgrading to pro version by just paying the difference.

Anyways go to the vectric.com and download the demo versions and test them out before buying any of them. You can also buy them directly from their web site, and you get immediate download from their site, so there is no hurry to pick your software now.

Btw, I did just got the tool length sensor and T-slot table, and I have to say that I am very happy with both of them. I have done several jobs where I have lots of tool changes (3mm EM 2f ft dc for main pockets etc, then some ball nose rounding some inside corners, then V-bit for adding some texts, then finally 3mm EM 2f ft dc for cutting piece out etc), and there it really helps.

MagIO2 wrote: Don't forget:
"For the application of the tool with a STEPCRAFT or a third-party router additional ER-collets are necessary."
(That's what SC says on the Spindle page)

Of course you can spend much more money. An aluminum t-slot machine table is -from my point of view- a must-have for a SC840 because the original machine table is not very stable. A vice like these ?

Endmills you can't have enough, but it's OK to start with a limited number, find out what your needs are and buy more with the next paycheck. (If you stop smoking you can spend the savings for endmills ;o)

For more advice we would need to know what you want to mill.

PS: oh ... ok ... you told us ... how big are those airducts? Maybe no vice needed for that, but believe me ... when you have the machine you'll start milling other things as well.

Thanks for the tip for the ER Collets.. I did not know this !

Indeed, a vice is not big enough. And yes, maybe I want to make some other stuff too. Stop smoking ?? I did that 10 years ago.. it was a wise decision

A T-slot table has to wait for the next (or the next-next) paycheck.

jvalencia wrote: I wouldn't buy the tool length sensor. You won't use it a lot in my opinion, it's 40 euros to skip a 20 second manual measurement. Not worth it.

OK, I thought about it.. but I'm going to buy it anyway. It is some money indeed, but as unexperienced as I am, all the help is welcome. This tool will help me a little bit to configure my machine..
Thanks anyway.

Whow man . Your post is really great ! Thanks for taking so much time to explain all this to me.

Kivinen wrote: The 6mm bit from stepcraft needs to have 6mm ER collet too, so add that to there. Also make sure you get spare nut for the HF500. It is much easier to just change the whole Clamping Nut than to remove the clamping nut, exchange the 3.175mm ER collect with 6mm ER collet when changing from the 6mm endmill to those smaller ones. So add following to the cart:

www.stepcraft-systems.com/en/accessories/system-accessories/milling-spindle/clamping-nut-spare-part-for-hf-spindle

www.stepcraft-systems.com/en/accessories/system-accessories/milling-spindle/er-collet-for-hf-spindle

and for the second add both 3.175mm and 6mm ER collets. I think the HF500 does not come with any ER collect automatically so you need to get one to be able to use it.

I think the 6mm bit from stepcraft is the only one with 6mm shaft (i.e. requires 6mm ER collet), and I think all others use 3.175mm shaft (note, not 3mm shaft), so that is the other one you need.

OK, clear !! I understand and I will do so.

Kivinen wrote: I would add some 2-flute fish tail end mills too. I have 1mm, 2mm, and 3mm downcut versions, and few upcuts too. Downcut will make the top surface better, i.e. if you pocket a hole in the middle of piece, the upcut can rip the corners of the cut upwards, and make uneven cut, downcut will push the cut downwards in to the material, thus the top of the material does not rip. This is important if cutting something that has subject of ripping (soft material or something that has thin layer attached or something like that).

Makes sense !! Done !

Kivinen wrote: Also I would remove the cut3d from the cart, and download vcarve and cut3d demo versions from the vectric.com site, and check out which of those you want to use. Cut3d is very limited what it can do, it can only take precreated 3d models and make toolpaths for them. VCarve have same features, but also allows makeing 2d toolpaths etc. Only thing Cut3d has that is not in the VCarve desktop is the easy to use wizard type interface and easy way to generate two (or four) sided toolpaths. You can do those in vcarve too, but there is more manual work needed for those.

Note, that neither of those can actually generate 3d objects, they can just take one 3d object created using some other program and generate toolpaths for those. If you need to create 3d objects you need aspire, but that software is quite pricey, and you could use blender or similar to create the 3d objects and then only use vcarve or cut3d to generate toolpaths.

I myself have both cut3d and vcarve, mostly because kickstarter came with cut3d, and then I realized it does not offer features I need so I had to buy vcarve to be able to do things. I have used cut3d once, and for all other works I have used vcarve. I have only the desktop version of the vcarve, which is limiting my max size for the projects to smaller than what 840 can do, but I have not needed that big jobs yet, and vectric allows upgrading to pro version by just paying the difference.

Anyways go to the vectric.com and download the demo versions and test them out before buying any of them. You can also buy them directly from their web site, and you get immediate download from their site, so there is no hurry to pick your software now.

You are right again ! Before buying I should use and test the trial versions, so I know what the differences are. The thing I absolutely going to need, is the possibility to make slices from an object, as some of my objects ar going to be 30 a 40 cm thick. So I have to cut them in various slices.
Is this function available in VCarve?

Kivinen wrote: Btw, I did just got the tool length sensor and T-slot table, and I have to say that I am very happy with both of them. I have done several jobs where I have lots of tool changes (3mm EM 2f ft dc for main pockets etc, then some ball nose rounding some inside corners, then V-bit for adding some texts, then finally 3mm EM 2f ft dc for cutting piece out etc), and there it really helps.

Thanks again !
Gerry.

Updated orderlist :



All comments are welcome

Gerry

The CNC cookbook has some articles about the bits, you might want to check those too:

blog.cnccookbook.com/2012/04/06/cnc-router-cutters-types-and-how-to-use-them/

I have not used those spiral end mills yet, so do not know how they will perform. Currently for wood (pine, ash, and acacia) I have only used those 2-flute end mills downcut (pocketing, cutouts, leveling of surfaces, rough cuts for 3d objects), V-bit 90deg (great for making text using the V-Carve tool in Vcarve), Ball Nose 1/16" and 1/8" (finishing cuts for 3d objects) and the 6mm upcut (for material removal, i.e. big pockets, and deeper cutouts).

You said your objects are 30-40 cm thick, so that is really lot to mill if you are going to make that big objects, or was it supposed to be 30-40mm thick?

The V-carve do know how to splice the object in pieces, i.e. you can take 3d-model in there, and slice it to for example 1cm height slices, and run each of those separately through the cnc-machine.

The 6mm end mill has cutting length of around 40mm, so cutting down 30mm should be ok. The smaller end mills usually have only 20-30mm of cutting depth, and if you want to go 25mm deep in the material the bit will not be too much in to the collet... The total length of the smaller end mills is 40mm or so.

The 6mm end mill do tend to start vibrating when doing deeper cuts in climb direction, so I did change some of my cuts to use conventional direction (i.e. where the bit moves in such direction that bit does not try to climb out from the wood, but instead is pushed in to the wood), and that did help with vibration quite a lot. When doing that the surface quality is not great, thus I use 3mm EM 2f ft dc to clean up the job.

Hi Guys,

I've ordered my Steppi, it has been delivered, and I assembled it. I've had no problems assembling it.
I've made a few test pieces in foam (so nothing can go wrong thanks to my stupidity). Everyting turned out OK.

Wanted to thank you all for the advice.

Gerry.