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Problem with z-axis when using 90°v carve bit

#1

Hi all, im having trouble with my z-axis not cutting to the depth i want.

My son hand drew a picture that i scanned and converted to an svg file. I uploaded this file to easel and set it out as follows

Bit: 90° V CARVE
Depth: 6mm
Feed rate: 760mm
Plunge: 760mm
Pass depth: 3mm
Safety height: 2.5mm

The problem is when sled moves to start position, z-axis lowers to work surface but does not penetrate timber. It also seems like z-axis is making micro movements up and down as it progresses.

I changed projects and was successful through the cut. I have also used the v carve bit on other projects.

Im wondering if its a problem with the design or g-code?

Any help very much appreciated :blush::blush:

1 Like
#2

do you have a bungee cord holding down the router against the Z axis? if not,
the backlash is going to give you lots of problems.

David Lang

1 Like
#3

Thank you for replying. My z-axis is mounted with 3d printed part with lead screw on a bosch router.

Everything functions properly on the z-axis normally. Would it be helpful to upload video or design file?

1 Like
#4

a video of it misbehaving and a copy of groundcontrol.ini would be good.

David Lang

2 Likes
#5

a servo system like the maslow (encoder + motor) does have a tendency to seek a
little bit, it’s not like steppers that can stay motionless (unless you
microstep).

On a standard maslow, the resolution of the encoders is extremely high and so
wandering a little bit isn’t measurable. Since you are using a different setup,
it could be that the steps per mm for the Z axis just isn’t high enough and you
notice the wandering.

David Lang
k

2 Likes
#6

Thank you again. I will be able to get video in about 3hrs when i get home. Will upload both video and groundcontrol.ini :+1::+1:

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#7

I just noticed probably the same thing today. It was my first time using a 90 degree V bit.
The problem is that the wide bit angle doesn’t fully dig into the wood before the AX moves start. You can actually see the sled tipping back and forth a little as the moves are started. I tried slowing down the feed rate to 400mm/min and it helped but didn’t eliminate the issue. I was only cutting 3mm deep. I also found that reducing to 2mm deep helped but again didn’t resolve the issue entirely.

I’m hoping to pick up a new bit to try tomorrow.

1 Like
#8

You may also need to account for calibrating the thread/lead screw pitch on your set up if it’s not the Ridgid.

Thank you

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#9

In my case it’s the recommended Ridgid router.

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#10

Thank you for the advice much appreciated. Unfortunately ive been called to work and wont get a chance to get back to my maslow for about a week now so cant upload video or ini file :cry:

The more i think about it the more im convinced it is the design im trying to cut, along the lines of what @terry1769 has mentioned.

When I do get a chance to use the maslow again i will upload the design file along with video.

Again thank you wonderful forum members :blush::blush:

1 Like
#11

@terry1769

Are you using a bungie to pull the router into the work?

Thank you

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#12

Im in australia and the router that was most suited here is the bosch 1200 ae. It uses @Ned 3d printed coupler and a lead screw to pull the router down. So no bungie cord. I have measured z travel and adjusted step back when i calibrated machine. I have also checked z travel and have around 55mm.

1 Like
#13

#14

These cuts were completed with out issue after i experienced the problem using the v carve bit.

3 Likes
#15

@Bee, Yes, I’m using a bungee.

#16

Got a new 1/4" vee bit and it definitely helped.

2 Likes
#17

Can you share - before and after pics? That might help someone in the future.

Thank you

#18

I had the similar problem and after intensive trial and error I found that the bit was actually lifting the router away from the timber. The plywood had soft spots and hard spots so I had to change the angle to accommodate this. Good Luck!!

#19

Ok sorry i have not had a chance to upload video for this problem. Im home now and have taken some video. It is hard to video the problem at the router unfortunately. If a different angle or video of something else will help let me know and i will try that :blush:

I feel like @terry1769 might have identified the problem. Maybe i need to tidy up design more?

#20

Grr wont upload video, is there size limit?