Newbie- "Acrylic" Carbide Endmill ?

[yngndrw]

Hi,

I thought a carbide endmill was a carbide endmill, however there are some that state Acrylic in the name, for example:
http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=150328691654

I'm just wondering what makes these endmills for Acrylic and if they are usable on other materials, such as Aluminium ?

Thanks,
-Andrew.

[gleas]

Originally Posted by yngndrw Hi, I thought a carbide endmill was a carbide endmill, however there are some that state Acrylic in the name, for example: http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=150328691654 I'm just wondering what makes these endmills for Acrylic and if they are usable on other materials, such as Aluminium ? Thanks, -Andrew.

Andrew,

I know of no end mills ground for acrylic. Router bits yes. I have been machining plastics for over 30 years and the most important consideration is that your end mill be brand new and not used on any other material like Aluminum. If you use a cutter that has been used on metal even though it appears sharp, it will not cut plastic well.

Hope this helps, -Greg

[yngndrw]

Thank you for your reply Greg.

In that case I'll just have to try them out on Aluminium when I can.

Also thanks for the advice about keeping plastic-cutting endmills separate, I would have never known about that and would have ended up just using the same endmills for all materials.

[Geof]

I had a look at the larger picture and it clearly says carbide endmill and Acrylic.

It also says micrograin carbide which is what you want, this can be ground to a razor sharp edge which is what is needed for acrylic.

It is almost certain that these will work fine on aluminum with the limitation that they are three flute so chip clearance might be restricted. They may also have a low helix and a high helix cutter normally gives best chip evacuation for aluminum.

Incidentally the high helix micrograin carbide end mills made for aluminum also work very well on all plastics so it is a case of buy whichever is the lowest cost.

[Boots]

The word Acrylic appears in the name because this is the type of material it is designed to cut. Not wood, metal, foam or Corian. Just Acrylic and it is made of carbide. Just my advise but I wouldn't be buying any tooling off e-bay. Get it from a reputable dealer or it may not last very long or even cut. Depending on your Machine you will need speed and feed information as well as depth of cut.

[gleas]

I'm with you on the EBay thing. It's a gamble unless you absolutely know what you are getting. Not to say that you can't get a great deal though.

-Greg

[yngndrw]

I was just looking for something cheap to get started with - I'm not doing any production so these should be fine for me. I'll keep in mind the quality if I do ever get into any kind of production though.

They are actually two flute so hopefully they should be fine with the chips.

I've also learnt what the 'micrograin' part means today so thanks again.

[MechanoMan]

My carbide supplier showed me single-flute bits too, saying they were designed for acrylics. Given the difficulties in designing a single-flute which has no symmetry, I assume this actually must have some good benefits.

[Geof]

With acrylic, or just about any plastic, the things that cause problems is rubbing and heat build leading to softening of the plastic. With plastics generally the best approach is to have a moderate cutter rpm and a fast feed to generate a thick chip which tends to carry away the heat in the chip. Sometimes especially with routers the spindle speed cannot be slowed enough or the feed run fast enough to get suitable conditions for a thick chip and also a thick chip needs lots of flute clearance so the single flute cutter is the solution; only one cutting edge means twice the thickness of chip compared to two flutes, there is plenty of flute clearance and half the rubbing.

[tobyaxis]

Geof mentioned Razor Sharp Edges already so I can only suggest that you buy tools without coatings and a High Polished Flute.

[yngndrw]

Cheers guys, there's some great advice and information in this thread. I've learnt a lot and I'm sure some others will too.

[tobyaxis]

Originally Posted by yngndrw Cheers guys, there's some great advice and information in this thread. I've learnt a lot and I'm sure some others will too.

That is the specific intention of this Forum Fro all to share information.