Help with first V carve project

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SIBUD
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Help with first V carve project

Post by SIBUD »

Using 1/2" 90 degree V bit. Have selected right tool. Have run this more than once and every time it looks like this.

Image

Notice the line in the left hand side. The right hand side has a ridge also but, on the left hand side the ridge is because the second cut didn't go as far left as the first. On the right had side the ridge is because the second cut went farther right than the first. Here is a line drawing to explain what I mean.

Image

So as I'm typing this, inserting images and previewing, it occurs to me that it may be a machine problem. From the drawing it would seem that the machine, on the second depth was not keeping the same X reference point.

Hmmmmmmmmmmmmm..........



Two passes. Depth of cut is 0.22.

I previously had more shallow depth of cut. For every pass the bit went deeper, it left that line.

Does this have anything to do with step over?

Shape of letters look good.

Letter is 3" tall.

Any ideas?

I haven't run the bit test yet to see if it is something other than 90 degrees.

I'm tired and not going to do any more tonight so you all have some time. :mrgreen:

Thanks.

Sometimes answers come to me in my sleep. :D
Bud Meade
Nashville, IL

I don't own too many BMW motorcycles, I just have too little time.

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SIBUD
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Re: Help with first V carve project

Post by SIBUD »

Oh, and a related question on V carving letters.

Is the depth of the letter dependent on the width? In other words, would a finer font produce shallower letters than a wide/bold font?
Bud Meade
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I don't own too many BMW motorcycles, I just have too little time.

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SIBUD
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Re: Help with first V carve project

Post by SIBUD »

More information is always helpful.

Here is an earlier cut that had many shallow passes.

Image

Notice the line every time the bit went deeper?
Bud Meade
Nashville, IL

I don't own too many BMW motorcycles, I just have too little time.

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Re: Help with first V carve project

Post by Bob Reda »

In V carving the depth of cut is in direct proportion to the width of the vectors and the degree and size of bit used. You can limit the depth by checking the flat area clearance box and setting in a depth. In the photo it looks like the machine is losing steps.

Bob

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Re: Help with first V carve project

Post by 4DThinker »

It looks like your router may not be perfectly perpendicular to the table. Stick a long straight dowel or rod in the router and check to be sure it is 90 degrees from the table in every direction.

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Re: Help with first V carve project

Post by Xxray »

Could you in fact be using a 60 degree bit .. Or maybe try selecting 60 just to be sure that isn't the problem ?
Doug

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Re: Help with first V carve project

Post by SIBUD »

Bob Reda wrote:In V carving the depth of cut is in direct proportion to the width of the vectors and the degree and size of bit used. You can limit the depth by checking the flat area clearance box and setting in a depth. In the photo it looks like the machine is losing steps.

Bob
Thanks for the info Bob.
Bud Meade
Nashville, IL

I don't own too many BMW motorcycles, I just have too little time.

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SIBUD
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Re: Help with first V carve project

Post by SIBUD »

4DThinker wrote:It looks like your router may not be perfectly perpendicular to the table. Stick a long straight dowel or rod in the router and check to be sure it is 90 degrees from the table in every direction.
Thanks for the tip. I will check it out.
Bud Meade
Nashville, IL

I don't own too many BMW motorcycles, I just have too little time.

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SIBUD
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Re: Help with first V carve project

Post by SIBUD »

Xxray wrote:Could you in fact be using a 60 degree bit .. Or maybe try selecting 60 just to be sure that isn't the problem ?
Thanks for the suggestion. I have checked, and it is a 90 degree bit.
Bud Meade
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I don't own too many BMW motorcycles, I just have too little time.

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Re: Help with first V carve project

Post by Leo »

1) The MOST likely cause is that the angle of the bit is NOT exactly 60 degrees.

2) Another possible cause is that the center-line of your router spindle is not exactly 90 degrees to the table.

I will place my bet on #1

Can you do the letter is ONE step down to full depth? Don't do it in step down increments --- IF you can - the line will go away. Number 1 though is still a strong reality.
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SIBUD
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Re: Help with first V carve project

Post by SIBUD »

Leo wrote:1) The MOST likely cause is that the angle of the bit is NOT exactly 60 degrees.

2) Another possible cause is that the center-line of your router spindle is not exactly 90 degrees to the table.

I will place my bet on #1

Can you do the letter is ONE step down to full depth? Don't do it in step down increments --- IF you can - the line will go away. Number 1 though is still a strong reality.
Thanks Leo. The bit is a 90 degree bit but it may not be exact.

I'm going to check on #1 today

The depth is too great for one pass.
Bud Meade
Nashville, IL

I don't own too many BMW motorcycles, I just have too little time.

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SIBUD
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Re: Help with first V carve project

Post by SIBUD »

Bob Reda wrote:In V carving the depth of cut is in direct proportion to the width of the vectors and the degree and size of bit used. You can limit the depth by checking the flat area clearance box and setting in a depth. In the photo it looks like the machine is losing steps.

Bob
A follow up question. What causes a machine to lose steps? And why are the lost steps so regular and related to change in change in tool depth?
Bud Meade
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I don't own too many BMW motorcycles, I just have too little time.

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Re: Help with first V carve project

Post by mezalick »

I have found lost steps are cause by asking the machine to do more than it can.
Move too fast, cut too deep, trun a sharp corner too fast, too much resistance, etc.
Finding what the limits of your machine are is an important step in this process.
I have also heard talk that a machine will lose step if the motor is going bad....
Just so ideas.
Michael
SIBUD wrote:
Bob Reda wrote:In V carving the depth of cut is in direct proportion to the width of the vectors and the degree and size of bit used. You can limit the depth by checking the flat area clearance box and setting in a depth. In the photo it looks like the machine is losing steps.

Bob
A follow up question. What causes a machine to lose steps? And why are the lost steps so regular and related to change in change in tool depth?
Michael Mezalick
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mm@mezalick.com

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Re: Help with first V carve project

Post by 4DThinker »

Good luck getting this figured out. I've seen several bits that were not 90 degrees despite being sold as 90s.

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SIBUD
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Re: Help with first V carve project

Post by SIBUD »

4DThinker wrote:Good luck getting this figured out. I've seen several bits that were not 90 degrees despite being sold as 90s.
Thanks. Later today I will run the program included in http://www.vectric.com/forum/viewtopic.php?f=3&t=2164 which should help determine the correct bit angle to use V carve pro
Bud Meade
Nashville, IL

I don't own too many BMW motorcycles, I just have too little time.

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