Issues with linoleum

(F B) #1

I’m trying to figure out why cutting linoleum works great with my 1/8 endmill and gives nice edges, but with my 1/32 bit it is fuzzy.

With 1/8 (carbide3d #102) @ 60IPM 12plunge .06/ deep I had great results.

When did my detail pass with 1/32 2 flute (this one) 30IPM 9 plunge .05 deep, the edges are fuzzy. I tried over riding the feed up 20% and down 20% at various speeds on the makita, with no improvement. Is this the wrong cutter for this?

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(William Adams) #2

Most likely it’s a matter of balancing feed and speed.

For the 1/8" endmill, calculate out your SFM and chipload, then compare with what you’re achieving for the smaller endmill.

One technique for testing feeds and speeds here: https://www.precisebits.com/tutorials/calibrating_feeds_n_speeds.htm

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(F B) #3

I haven’t done this before, so bear with me

I think

The 1/8 SFM is 18000 (RPM) X .125 (diameter) X Pi / 12 = 589
The 1/8 Chipload is 60 (feed rate in IPM) / 18000 (RPM) X 2 (flutes) = .0017

The 1/32 at current settings is

SFM is 18000 (RPM) X .03125 (diameter) X Pi / 12 = 147
Chipload is 30 (feed rate in IPM) / 18000 (RPM) X 2 (flutes) = .0008

SO

If I want to increase the SFM, the max I can get to on the 1/32 endmill at 30K RPM would be 245 (only half of the 1/8)

And for the chipload i could double the feedrate to 60IPM to match. Would that be advisable to try? Is there something else i can do to increase the SFM?

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(William Adams) #4

For the hobbyist machines, it can’t be purely about numbers — you have to go by the feel of the machine as it’s cutting.

More information (some of it contradictory) at: https://wiki.shapeoko.com/index.php/Materials#Linoleum and the balance of that page.

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(Richard Cournoyer) #5

Ummm, can I just leave this here: (PS there is one more video to this series)

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(F B) #6

Timely!

However, based on this, my settings outside of DOC are pretty close for the 1/32 mill.

He recommends

1/32" 2FL Endmill @:
10k RPM
25 Inches per Minute
0.02" Stepdown

My settings were (at one point)

1/32" 2FL Endmill @:
10k RPM
27 Inches per Minute
0.05" Stepdown

In this case, will .03 DOC and 2 IPM make the difference? He did mention that not cutting as deep would help with chip clearing, but I’m thinking the type of linoleum we have might be more of a factor. I’ll have to do some more experimentation.

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(Csaba Horváth) #7

I have not worked with linoleum yet but what I have noticed with this small end mills that a slight increase in DOC can cause a lot of troubles. So I would start to reduce that first.

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(F B) #8

I’m definately going to try less DOC. There are some people on the inventables forums saying the gray lino that i purchased is not great for carving and can have this issue, but the tan lino doesn’t.

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(Jesse Glessner) #9

Some of your problem might be the age of the linoleum. If it has any age at all, say a year old, it could have hardened.

You might also try a ball nose bit if that will work for you.

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