[davtuner]

Hey everyone, I recently built a 4x4 Joes Hybrid machine, rack and pinion, using a 2.2kw spindle, and have been trying to cut out an e chain unsuccessfully. As you can see in the pictures, the edge definition is very poor regardless of my speeds/feeds and what bit I am using it seems.

In photo 1, the three lines are cut using a downspiral Freud bit carbide 2 flute 0.25" diameter, 0.125" depth of cut, 8000 RPM @ 100 IPM.

In photo 2, everything is cut using an upspiral carbide Maritool 2 flute 0.25" diameter 0.125" DOC, @ 8000 RPM and 100 IPM.

The lack of edge definition is preventing me from properly assembling the parts. I am using EMC2 as the controller, and the machine seems to move accurately and keep up to speed relatively well. I have also tried slower/faster speeds and faster RPMs, different depth of cuts, but nothing changes the results. Do I need a different type of bit? Is the MDF just too poor quality? Similar results occur on baltic birch plywood... this is just ruining my week

[jckstrthmghty]

How much moisture is in the air? Is the saw dust fine particles or chunks?

[ger21]

Those bits must be extremely dull. Even a dull downcut should be giving you a clean edge, or very close to it.

Can you take a picture of the bits?

Also, try upping the rpm to 10,000-12,000.

[aarongough]

I've had good results with 1/4" 2 Flute endmills running at 8K RPM and 160IPM, maybe try increasing your feedrate and reducing your depth of cut.

[davtuner]

Thanks for all the fast replies!

How much moisture is in the air? Is the saw dust fine particles or chunks?

Humidity is at ~50%, the dust is clumps of particulates, fluffy clumps of loosely aggregated particulate mdf.

Those bits must be extremely dull. Even a dull downcut should be giving you a clean edge, or very close to it.

Can you take a picture of the bits?

Also, try upping the rpm to 10,000-12,000.

The bits are brand new, bought the downspiral yesterday specifically for this purpose after researching these forums and the internet. The Maritool bits are brand new, and Maritool has a good reputation everywhere I have been. I have tried running the bits at 16000 RPM (max speed) and had the same result.

I've had good results with 1/4" 2 Flute endmills running at 8K RPM and 160IPM, maybe try increasing your feedrate and reducing your depth of cut.

The shallower cuts were done as g0 moves, at 300IPM, 8000RPM, and 0.01" DOC

[jckstrthmghty]

Seems to me like the mdf is very low density. Those cuts looks like cutting cardboard. What perplexes me is the plywood. That should cut clean unless it's wet. Have you made any clean cuts with this machine?

[osphoto]

Looks like you are "moving" the material and not cutting it.

I've used burr mills and have had better cuts then what you are getting.

This may be silly but, I'll ask it. Is your spindle running clock wise or counter clock wise? Are you turning the bit in the proper direction? Even at a shallow cut, you should be getting a cleaner cut.

[ger21]

I was going to say, if those bits are sharp, it looks like they're spinning backwards.

[ger21]

Seeing that you're using a spindle, I'm almost positive it's spinning backwards.

[aarongough]

Interesting, I wasn't sure what else it could be and the idea of the spindle going backwards hadn't occurred to me as I'm used to using routers...

If that's the case then you are going to be like 'oh boy!' when you see what your machine can do when spinning the right way!

[ger21]

I actually have some experience with the spindle spinning the wrong way , as we used to use left handed bits quite often, and someone would occasionally use the wrong one.

[osphoto]

Wow. To think I might have finally contributed something useful!

Perhaps I'm learning something after all

[aarongough]

Wow. To think I might have finally contributed something useful!

Perhaps I'm learning something after all

Haha, I know how you feel! I haven't gotten there yet, but I'm getting close!

[davtuner]

So guess which one was cut spinning the right way?

Apparently I miswired the vfd and it switched the rotation direction last time I moved... thanks for the help everyone

Also, if anyone has any questions about the vfd, spindle, or machine, I'd be happy to answer

[ger21]

The upcut was spinning the right way.

That MDF does look like it's very soft, though.

[davtuner]

Sorry Gerry, that was actually a trick question, all the ones previously listed were spinning the wrong way, I forgot the new attachment haha

The far right was cut with the downspiral 8000 RPM 100 IPM at 0.125" DOC

[aarongough]

Nice! Looks very clean!

[neilw20]

Building hay shed roofs, the boss, who was a total know it all, just do as I say was swearing and tossing self drilling screws 30'
We all new the power wrench was running backwards, and waited till after smoko to tell him.
It was quite a performance, but we had all learned to keep quiet and watch, as instructed, then told him he always wanted it that way.

He was much nicer the rest of the week. Age did weary him, somewhat, he had to admit, but it was really the new technology he couldn't handle.

[CarveOne]

Building hay shed roofs, the boss, who was a total know it all, just do as I say was swearing and tossing self drilling screws 30'
We all new the power wrench was running backwards, and waited till after smoko to tell him.
It was quite a performance, but we had all learned to keep quiet and watch, as instructed, then told him he always wanted it that way.

He was much nicer the rest of the week. Age did weary him, somewhat, he had to admit, but it was really the new technology he couldn't handle.

And just which one of you onlookers kept reversing the drill when the boss wasn't looking?

I used to do that in the engineering lab I worked in. I loved the new cordless drills when they first appeared.

CarveOne

[ashleywilson]

Try using a different blade. A steel blade with that many teeth is designed for thin plywoods, like paneling 1/4" or less. A carbide tipped blade for a 7" - 7 1/4" size can be found with a 40 tooth blade, which will work very well. Have the good face down when cutting.

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