Aligning Z axis

[Ernie Martinez]

I believe that my Z axis isn't perfectly perpendicular to my table. When I flycut my spoil board I get small (.001") ridges, which indicates that the spindle is skewed in Y a bit. And when doing a pocketing cut my clear cut (.25 end mill) and my detail cut (.060 engrave bit) are at slightly different depths, which could be due to tool diameter if Z isnt perfect.

What is the best indicator/method to align the spindle?

[Jerome Stanek]

You can tram your spindle with shims to get it to where it cuts without the ridges. I use a dial indicator on a beam chucked in my spindle to check

[Ernie Martinez]

That what I thought, unfortunately my dial indicator has a 1/2" shank, and I have ER11 collets.

[Jerome Stanek]

Sorry about that I would never have bought a spindle without it being able to use 1/2 inch bits. I use 1/2 all the time for heavy sheets

[Shane Sura]

I have used a dial indicator from harbor freight coupled with a punch set in a 1/4 collet. I wish I had one with a 1/2 shank as I have a 1/2 collet. I have also heard of people using a bent clothes hanger to see which side scrapes. That is good to get it close but I like the dial for true accuracy. I would play around with a mount solution so you can get it in there.

As a side note one of my big questions I had into the CAMASTER community was what if any trimming issues they have had. The good news is most of them did not even know what trimming meant. I have the exact same issue on my home built machine and it drives me crazy.

[Ernie Martinez]

I just ordered a Shars mini pro tram system from http://www.shars.com . It has a 1/4" shank and 2 dial indicators on a beam. They also have 1/2" shank models. For around $100 I figured it was a good value if it saves me time.

[Scott Shepherd]

As a side note one of my big questions I had into the CAMASTER community was what if any trimming issues they have had. The good news is most of them did not even know what trimming meant. I have the exact same issue on my home built machine and it drives me crazy.

It's tramming, not trimming. You are tramming the head.

[Mike Heidrick]

Bumped a thread for you Ernie.

[Shane Sura]

It's tramming, not trimming. You are tramming the head.

That was auto correct on the iPad Steve. Meant tramming.

[Ernie Martinez]

I hate that auto correct! Well, I went and machined a 3" piece of .5" aluminum round stock down to .25 on one end. I was able to stick this little adapter into my .25 collet and then attach my cheapo dial indicator and holder onto the end. My beam was about 3.5" in length (center of spindle to contact point).

Error from side to side was around .080 I was able to reduce it to around .040. So based on these measurements, I have .040 over 7", or if I use the measure that Scott threw out before, about .020" over 3". Unfortunately that was the best I could get, since there wasn't any sort of adjustment cam or anything, it was basically loosen 4 allen screws and push. Not very precise.


tram.jpg

[Scott Shepherd]

That was auto correct on the iPad Steve. Meant tramming.

Not a problem, but it would have explained why no one had heard of it

Tramming a head takes a little time. I remember learning how to tram a head on a manual milling machine. I'm sure I've spent at least 1 hour on it. Get it perfect, tighten the last bolt, check it again, it's off again. Man, I hated tramming heads. After much practice, it became quite easy and now, even on some routers, it's a lot easier for me. The problems many CNC routers have is that they don't start with ANYTHING machined or square, so there is no referent point on ANYTHING to start with. Drives me crazy. Then you have raw angle iron things are bolted to. Ever see the draft angle on angle iron? Not exactly a true surface you'd want to build a precision machine on. I've always wanted to take our machine apart and machine about 4 things. Once doing that, you'd have the ability to true everything up and make everything line up with each other. Instead, we get something similar to a farm use piece of equipment in many respects.

I guess that explains why some machines cost $60K and up.

[Shane Sura]

Not a problem, but it would have explained why no one had heard of it

Lol I am pretty sure I spelled t right.

Ernie,

Don't forget now that you have trammed to resurface. What I would suggest is put another board on top of your spoil board. Surface that, retram, surface again. Once you get it as close as possible you can resurface your actual spoil board.

[Mike Package]

I used a method very similar to the one shown in the bumped thread to set up my Stinger. The only issue I have with the method as shown in the thread is where it says that the 2nd layer of MDF was surfaced, so the 3rd layer of MDF could be attached on top and doesn't need to be surfaced. I would never trust MDF to not need to be surfaced. To my mind it's one of the least stable wood or wood-like materials there is. Basically a sponge albeit a dense one. I only use one layer but if I used multiple layers I would always surface the last/top layer. And resurface often.

I had to shim the router motor in the router mount to get it as close to perfect as I could. It's certainly still not perfect but it's close enough for gov't work. I need fairly tight tolerances (guitar building) and I've got it close enough that I don't stress about it. If I paid $50k+ for a Haas and it wasn't perfect, different story...

[Gene Crain]

P1010114_2.jpg splitting hairs....if you don't have material on the table and making $$ what's .1MM difference gonna make?

[Mike Heidrick]

P1010114_2.jpg splitting hairs....if you don't have material on the table and making $$ what's .1MM difference gonna make?

Ive never had a customer complain at the way my work turns out. I am my own worst critic for sure when it comes to accuracy.

My method is just one way to do it - I am sure there are better. Just not a whole lot of cnc internet experts offering up how to write ups with pictures. Some people have never even heard of tramming and have been cutting for years. They surface and call it good. Again, you just have to make yourself happy I guess.