[bonesbr549]

Any suggestions would be appreciated and if in wrong section sorry. I've got this Urn project for my brother and ran test piece in poplar yesterday and got ghost lines. I'm using an amana bit that is 1/16" carbide ball nose bit, and 10% step over. Feed/spped = 45 ipm/18000 (per mfg doc).

It's smooth in most places. Is there something else I should look at?

Running V'carve pro 8.5 & crp4896 800 built in March
Attachment 331526

[ericclinedinst]

Id say you're out of tram.

Any suggestions would be appreciated and if in wrong section sorry. I've got this Urn project for my brother and ran test piece in poplar yesterday and got ghost lines. I'm using an amana bit that is 1/16" carbide ball nose bit, and 10% step over. Feed/spped = 45 ipm/18000 (per mfg doc).

It's smooth in most places. Is there something else I should look at?

Running V'carve pro 8.5 & crp4896 800 built in March
Attachment 331526

[ger21]

If you're cutting this at that angle, then it's most likely lost steps on the Z axis.

[bonesbr549]

not cutting on an angle, square to y. Don't see the lines in all areas. I surfaced the spoilboard and looked for ridges to indicate the spindle may not be plum but it was in good shape when I cut the piece. I could be missing something of course.

[CNCMAN172]

It appears that your Tram from Vertical to horizontal is off a good deal. This happens when the edge of the router bit is touching the surface of the material and the other side is up in the air, so it causes a line. If you can get a dial indicator on a bar that can attach to the spindle so it looks like of like an L you can rotate the spindle slowly and see how much the height varies when touching the surface. There are many tram gauges on ebay.

Here is one for over $100 but you can also make them and they don't need two indicator but that does speed up the process.

01 Pro Tram Bridgeport Head Square Knee Mill Spindle CNC Router Milling Endmill | eBay

Russ

[bonesbr549]

It appears that your Tram from Vertical to horizontal is off a good deal. This happens when the edge of the router bit is touching the surface of the material and the other side is up in the air, so it causes a line. If you can get a dial indicator on a bar that can attach to the spindle so it looks like of like an L you can rotate the spindle slowly and see how much the height varies when touching the surface. There are many tram gauges on ebay.

Here is one for over $100 but you can also make them and they don't need two indicator but that does speed up the process.

01 Pro Tram Bridgeport Head Square Knee Mill Spindle CNC Router Milling Endmill | eBay

Russ

Thanks for the link! Probably it. I found some youtube videos and the symptoms pretty spot on.

Thanks again to all

[DaveCNCnewb]

Did you solve the problem? Inquiring minds want to know... BTW I bought one of those tramming units from Edge Technology in anticipation of needing to tram my system accurately. I haven't used it yet so can't provide any guidance. Hope you've solved your issue.

Dave

[CNCMAN172]

If you go to the Edge Technology site they have a video showing you how to use their tram unit. You might find it easier to watch the video, but it is pretty straight forward and ensures the Spindle is perpendicular to the table to both X and Y.

Russ

[bonesbr549]

Mines arriving tomorrow. I'll let you know. Sadly Its for my brother's URN that is required Sunday. I'm hoping I solve it by tomorrow night. Otherwise, I'm just going to sand them out of the real final cherry piece.

[DaveCNCnewb]

Sorry for your loss.

You'll figure it out. As CNCMAN said it's a pretty straight forward device.

Sent from my SM-G930V using Tapatalk

[CNCMAN172]

Very sorry for you loss tough to work on a project like this period, let alone having difficulty during a difficult period. I think when you adjust your spindle with shims after checking it with the Tram gauge you will solve your problem. I am sure your brother would be very proud of you. Hang in there man.

Russ

[bonesbr549]

OK, got the gauge today! Thanks so much to them for getting it the mail. Thanks to the USPS that got it from AZ to PA in two days!

I checked it and it was .020 out on the Y (along the gantry). It was about .0015 out on x length.

I used this guy's vid and it worked like a charm.

https://youtu.be/DmuipSuDNAs

Luckily there is an ecentric nut on the spindle mount to make an adjustment so I'm dead nuts on on the Y and .0005 on the X. When I got more time I'll do some shimming on the one x to get it perfect, but I just don't have the time. I've got to get one cut tonight and that only leaves me sat to assemble and finish. Memorial is Sunday. Dang I've been woodworking for 30 years and this little box is the dang hardest project i've done.

Thanks again for the help guys!

[DaveCNCnewb]

Glad to hear that you got it sorted out in time. That video helped me understand the process as well. Did you use the glass and cards or go directly from your spoil board? I am still a bit confused about the cards. Guess when I do it next week I will figure it out.

Sent from my SM-G930V using Tapatalk

[CNCMAN172]

Yeah the interesting thing about the playing cards is they can vary several thousandths themselves, the glass idea does allow you to run the indicators on something very smooth so the readings don't bounce a great deal. His table was a little rough so I assume the cards keep the glass just above the roughness of the table as least that would be my guess.

Russ

[DaveCNCnewb]

I was wondering about the glass as well. Doesn't it vary in size or does glass generally have consistent thickness?

Sent from my SM-G930V using Tapatalk

[CNCMAN172]

Well if you ever what how they make glass it is actually pretty uniform. While it might vary by 2-5 thousands it tends to be uniform over a pretty large area. It is probably much flatter than using his worn table top to take the measurements. There are many theories on the best way to align and tram a machine. There are actually special optical machines that do this on commercial machines they are very expensive and back in the day you could pick one up on ebay for say $600, but like everything else on ebay things have skyrocketed and it is hard to find deals these days. Basically the optical system used some electronics and lasers and it could measure perpendicularity to .00005 or something depending on the model. They typically use a system that is 10X more accurate than you need to be or something to that effect, but for hobbyist making machines that is out of the question and most of us don't have all the component in a given machine to achieve .0001 precision, we are jumping for joy to get .001 and that is a darn good machine. LOL

Russ

[ger21]

I'm still confused about how an out of tram ballnose bit can cause the issue that he's seeing.

If you're machining a flat surface with a ballnose tool, an out of tram spindle should not cause any issues at all. The bottom center position of the ball never changes with direction changes, so it shouldn't be cutting deeper in some places than others.

Maybe I'm wrong here, but I would guess that the machine is flexing during direction changes, causing the tool to dive deeper.

[bonesbr549]

Well, I ended up getting it pretty close, but not perfect. It will just take some time and scrap to get it just perfect. Unfortunately, time is not what I had. I did a couple passes and finally had to just go with it. Finished up spraying the lacquer this morning. Leaving right now. I will working on it and get it right. I have the CRP upgrade to linear bearings to do so I will do it after that. I just need a little time to decompress.

Thanks again for all the help! I'm close!

Attachment 331992

[DaveCNCnewb]

It's beautiful and a wonderful tribute...

Sent from my SM-G930V using Tapatalk

[CNCMAN172]

Absolutely beautiful job, you did your brother proud.
Russ