Cutting Observations of a Newbie

[Tex_Lawrence]

If a different diameter bit shows a different depth, then that suggests that the Z-zero is not being maintained at bit change. The grooving around the letters suggest that to me.

You are suggesting that tramming is not the issue, but some photos suggest that, but its hard to say.

Or you might have a problem where your stock is moving up and down under the bit on the spoil board.

[Adrian]

Not sure what you mean by "there was NO load on the router when it cut." There is always load on the router when cutting unless you're cutting air.

Your feed rates seem very, very slow to me for MDF especially at such a high RPM. As an example I cut MDF at 360 ipm at 11250rpm but I have absolute no idea what your machine is capable of.

Another thing to be aware of is the varying pass depths you have set on the tools. In the pocket toolpath you have the pass depth set to 1" on the 1/4" but and 0.5" on the 1/8" bit. Yet on the profile toolpath you're using a pass depth of 0.125" for the 1/4" bit.

At the moment it looks like you had the toolpath calculated with it set to 3 passes using the Edit Passes field but that can catch you out if you change the cut depth. Change it to 0.5" for example and Calculate and all of a sudden you're trying to cut 0.5" with a 1/8" bit.

That's all by the way to your issue but I thought I should point it out.

I agree with the previous reply as to the most likely causes of the actual issue. One thing to bear in mind is that a spoilboard flattened with a router that is out of plumb in the cut direction is going to be flat but not perpendicular to the router.

[KevinC]

Not sure what you mean by "there was NO load on the router when it cut." There is always load on the router when cutting unless you're cutting air.

Your feed rates seem very, very slow to me for MDF especially at such a high RPM. As an example I cut MDF at 360 ipm at 11250rpm but I have absolute no idea what your machine is capable of.

Another thing to be aware of is the varying pass depths you have set on the tools. In the pocket toolpath you have the pass depth set to 1" on the 1/4" but and 0.5" on the 1/8" bit. Yet on the profile toolpath you're using a pass depth of 0.125" for the 1/4" bit.

At the moment it looks like you had the toolpath calculated with it set to 3 passes using the Edit Passes field but that can catch you out if you change the cut depth. Change it to 0.5" for example and Calculate and all of a sudden you're trying to cut 0.5" with a 1/8" bit.

That's all by the way to your issue but I thought I should point it out.

I agree with the previous reply as to the most likely causes of the actual issue. One thing to bear in mind is that a spoilboard flattened with a router that is out of plumb in the cut direction is going to be flat but not perpendicular to the router.

I'm not fully following you on your post Adrian. You are correct it was under load just minimal load. My router is a variable speed DeWalt router so I had the speed set to 1. I had found a chart tailored to that router with feed rate, plunge rate and router speed. SUGGESTIONS. This was the first time cutting MDF so I went with those settings. The router never dipped in RPM while it was cutting. Meaning I wasn't feeding it so fast that it could have altered the bit position while it was cutting. If that makes since. I'll speed it up next time. But Adrian if you could please elaborate on your post I will adjust those settings. Thanks.

Kevin

[KevinC]

If a different diameter bit shows a different depth, then that suggests that the Z-zero is not being maintained at bit change. The grooving around the letters suggest that to me.

You are suggesting that tramming is not the issue, but some photos suggest that, but its hard to say.

Or you might have a problem where your stock is moving up and down under the bit on the spoil board.

I thought the same thing Tex however I used a touch probe. The method I'm using to anchor the workpiece is the tape and superglue method. There was no movement in the material while cutting. So you a leaning to a tramming issue? How do I correct or test that?

[Adrian]

But Adrian if you could please elaborate on your post I will adjust those settings. Thanks.

If you edit the toolpaths and look at the tool settings you will see the pass depths there. Select the tool in the list and click the Edit... button.

Note that when you create a toolpath the link between the tool and the tool database is "broken" so don't assume that when you see a tool used in one of your files that the settings are the same as you last had them in the database. I was just pointing that out as something to watch for rather than the cause of your problem.

Another thing that I noticed that you should really change to get clean pockets is the stepover. You have it set to 80% which is likely to leave small nibs of material in some circumstances but it depends on the design really.

There are also quite a few areas one that design where the 1/8" bit won't reach so you'll have joined sections between letters as well. You can that in your picture of "Is".

Here are some threads on tramming a spindle/router:

viewtopic.php?t=25136
viewtopic.php?t=21172
viewtopic.php?t=34311

There are many more on the forum that you can find using the Search box.

[KevinC]

But Adrian if you could please elaborate on your post I will adjust those settings. Thanks.

If you edit the toolpaths and look at the tool settings you will see the pass depths there. Select the tool in the list and click the Edit... button.

Note that when you create a toolpath the link between the tool and the tool database is "broken" so don't assume that when you see a tool used in one of your files that the settings are the same as you last had them in the database. I was just pointing that out as something to watch for rather than the cause of your problem.

Another thing that I noticed that you should really change to get clean pockets is the stepover. You have it set to 80% which is likely to leave small nibs of material in some circumstances but it depends on the design really.

There are also quite a few areas one that design where the 1/8" bit won't reach so you'll have joined sections between letters as well. You can that in your picture of "Is".

Here are some threads on tramming a spindle/router:

viewtopic.php?t=25136
viewtopic.php?t=21172
viewtopic.php?t=34311

There are many more on the forum that you can find using the Search box.

Awesome Adrian Thanks.

I wondered about my step over it is set wrong and was going to ask when I check my thread this time. But you brought it up before me.

Thanks for the links too... I'll do some checking into tramming and see if that can help.

Kevin