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domino11 Sat 23 October 2010 18:43

If that little gaff is the worst you did with a stick on that thin stuff, I congratulate you. I would not have tried that without a mig. Even then it is not that hard to get burn through on thin stuff. :)

JamesJ Sat 23 October 2010 18:46

Steve, I impressed that you can even use a stick welder on that thin stuff! :)

timberlinemd Sat 23 October 2010 19:41

Well I have retooled the pinons with 1/4-20 grubs. Used a 3/8" ratchet to tighten them. The motors have a slight movement/slop by themselves. The pinons appear to be solidly attached to the motors shaft. Using a dial indicator with the motors turned on and grabbing the router collet by hand and applying some force, I get a .005" slop up and down in the Z axis, a .030" in the Y-axis and a .010" in the X-axis. Can anyone tell me if I should be getting better values?

timberlinemd Sat 23 October 2010 20:33

I read about the .005" backlash that my motors have built-in. So, measuring with the dial indicator placed on the gantry and touching the Y-car, it indeed would move the .005" only, therefore confirming that there is no loose pinon in the Y-motor. I also noticed that I measured this from a different location than before, so I measured the Y-slop at the router collet at this position. At this location I only get .010" slop instead of the .030".

Regnar Sat 23 October 2010 21:59

Steve, are you pushing with your hand to figure out the backlash?

If you are pushing you are measuring deflection. This means all your doing is fight the spring that is attached motors. This is also the reason for ruff cutting a finishing passes.

To measure backlash you would need to move the axis under power. Similar to this

If you are measuring under power and you are still ending up with these numbers something is loose or your steps per is off a little. You will not end up with zero but you should be pretty close to the factory's .005

By the way great looking machine you built there. Looking forward to seeing what you make with it.

Just out of curiosity how long did it take you to paint all the nuts, bolts and washers. :eek::D

jhiggins7 Mon 25 October 2010 09:18

Builder's Log Update

Thanks for the information.

Here's the Updated Builder's Log

timberlinemd Wed 27 October 2010 18:40

Thanks for the reply. Yes I was pushing by hand. I spent some time ajusting and then learning enough G-code so I could run some cut tests. I ran a 45 degree diagonal line and a circle. The line and circle showed no chatter!:D The circle came together exactly wher it began! Gerald your design is so sweet!:)

timberlinemd Wed 27 October 2010 19:15

I'm trying to get my head around the way some people decide to set up a large wood cutting CNC. When looking at the Mach and CNCzone sites I find that there are many that operate metal mills, not so much wood routers. So some of the assumptions I have made may be in error. The author/programmer/user of the CAM software I have chosen to use has made the software to default to following...

1) A spoil board will need to be used.

2) The 0.0 Z plane is at the surface of the spoil board.

3) The values for the different tool path levels are “inverted”, meaning negative numbers are above 0.0 and positive numbers are below 0.0 or down into the spoil board.

Also, he has defauted to using absolute coordinates instead of relative.
He has provided the means to change these settings, but looking at his approach, it seems to make more sense in panel processing with a spoil board than the Mach3 method which I assume again was written more for the metal mill CNC. e.g. dosen't have any spoil board.

In reading the Mach3 docs I'm assuming that the Z-axis 0.0 setting is on top of the work piece and sending the cutter down into the work uses negative numbers.

These two approaches would produce very different G-code.

I would like any thoughts on these different ways to process panels.


Gerald D Wed 27 October 2010 21:04

Originally Posted by timberlinemd View Post
The author/programmer/user of the CAM software I have chosen to use has made the software to default to following...
Which software is that? It sounds very unconventional.

timberlinemd Wed 27 October 2010 23:36

The software is VCamm and intergrates with VCadd, the CAD software I have used for my drawings for years. This is the first time I have used VCamm.

timberlinemd Wed 27 October 2010 23:39

Also, by your response I assume that this is not the method you would recommend using? :confused:

Gerald D Thu 28 October 2010 00:34

I am not recommending anything - simply observing that Vcamm is apparently forcing you to be the opposite of 99% of other CNC operators.

Greg J Thu 28 October 2010 14:41


I've been using Vcarve Pro for a year or so. Great program, in my opinion. I set my Z = 0.000 at the top of the part I'm making. All cutting is in the negative Z direction. Just my preference. Vcarve Pro lets you set it where you prefer.

You might want to checkout Vectras site and their tutorials for another reference.

You'll get it. :)

timberlinemd Thu 04 November 2010 19:17

Dust Foot
7 Attachment(s)
Among other things I needed to make a dust shoe for my machine. My router is the Makita model 3612. First generation. Have had it for 28 years. As ‘Scotty’ said in an episode of Star Trek NG, “No B, No C, No D”.

The type of dust system I decided to implement is the ‘fixed’ style of dust shoe. The problem with that is the router’s massive body size. It isn’t round so I had to come up with a design that would allow it to go below the base of the dust foot. I chose the brush Gerald recommended in his post on building his dust shoe. I wanted to keep the entire length of the brush, which is 4”, so it would be sure to ride over any clamps. The photos that I show of the sheet metal prototype was modified smaller, because in the end I had to cut away some of the router’s body parts otherwise the shoe would have been a sasquatch (big foot).

After the sheet metal work I set up to do my first real cut part on the MM. It was the stiffener for the sheet metal dust foot. I decided to make the first one out of ½” Baltic birch ply. I used a ¼” cutter with a ½” shank and two straight carbide tipped bits. The tip measured .008” under the ¼” diameter. I’ve had it for a long time so I’m sure it has been sharpened over the years. Anyway, I set the material in the machine, loaded the G-code and let her rip!

The part that came out is amazing! The dimensions I measured with a veneer caliper are only off by .002”, if you consider the undersized cutter and that I cut the part without compensating for it. The finish is pretty flawless. There is a slight run-out on the smaller of the two inside circles, the fillet on one side only shows a little chatter and the rest of the part fine. I haven’t checked the X-Y axis for square nor the Z axis yet. I haven’t surfaced the spoil board yet either. I’m very pleased with the machines ability to keep this kind of tolerances! In no small part due to Gerald’s design and this groups refinement of critical steps in the making of the beast.

I also added the shelf Gerald suggested over the control box to protect the G-540’s DIN plugs.

PS. A 3' long brush ended up being too short so I'm awaiting McMaster-Carr for a longer one

mrghm Fri 05 November 2010 04:25

very nice cut quality

timberlinemd Sat 06 November 2010 17:25

Z-Slide final ajustments
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Hey Gang,
I need some advice. I have adjusted my Z-slide according to the post Gerald made using a sheet of glass, framing square and trammel. In my case I swung a dial indicator around with a 6" radius. After 'squaring' the Z plate, I mounted the router. I do not have a precision router holder. I made one like that shown in one of Geralds posts because I have the Makita 3612. It does have the steel dowel locators which will position router holder in the exact same spot every time it is remounted to the Z slide. I used 'stand-offs' like Gerald, but mine are removeable when the router is removed from the holder. I set my dial indicator up and swung it around on the sheet of glass. The first reading showed .150" height difference in the diamater (12") in the Y direction. No difference in the X direction. Using my CAD program I caculated how much material I needed to remove from two of the stand-offs to right the router in the holder. After I had obained a difference of only .030" in 12" I remounted everything to do an experimental cut. I should mention that the reason I settled for the .030" is because the amount that I would need to take off of the two stand-offs would .001". I could remove that amount by placing some sandpaper on a flat surface and gently sand the base of the stand-offs, but I wanted to see what would happen first.

The pictures below show the before and after. I cut a rectangle pocket using a Mach3 wizard. The cutter I had to use was a 13/16" WKW 68604 straight double flute with NO flat bottom. I'm ordering the Onsrud surfacing cutter, but I haven't decided on the spiral cutters yet.

So, after this long intro, here is my question. How close is close? Are most of the machines set-up so that the 'lawnmower' effect is non existant? The second photo, the adjusted Z, has slightly visible lines in the cut. You cannot feel any 'steps' when you run your hand across. Where the cutter 'turned' the corner 'steps' are a little more noticable than anywhere else. I'm I wasting my time at this point because the cutter I'm using is wrong for this kind of cut? Should I go back and take out that .030" travel in the 12"?

Any thoughts would be appreciated.

Before: 1st Pic

After: 2nd Pic

Gerald D Sat 06 November 2010 20:16

Steve, I think you have done particularly well and can stop trying to get it better.

Greg J Sat 06 November 2010 20:22

That's better than my setup. :o

Nice job Steve.

timberlinemd Sat 06 November 2010 20:42

Gerald, Greg... Thanks for the kind words and advice. I will move on the final squaring of the X and Y.

timberlinemd Sat 06 November 2010 20:48

Gareth... sorry, thank you also for your kind words!

timberlinemd Sat 06 November 2010 21:10

I just wanted to update the progress that was made last week with the problems I was having with the CAM software I was using. I contacted the provider of the software and they were very eager to hear about my suggestions in regards to how their software worked with my machine. They have been marketing mostly to 'Multi-Cam' users as a third party alternative, I believe. Anyway, for a week now they have been sending me revisions of the program to test on my machine! At this time the last revision is doing everything that I want! They told me that they were going to use allot of the changes that they made for me and include it into their software.

Gerald D Sat 06 November 2010 21:12

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This is the "shelf" I had in mind:

Attachment 10592

BlueFeather Sat 06 November 2010 21:34

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Couldn't you use an air vent cover like the one below. It's adjustable and magnetic. But you could also use double sided tape to adhere it to the box? If it's only to keep the dirt out maybe use the idea and make a metal one. Might be a lot more durable than the plastic. Just a thought.

MetalHead Sun 07 November 2010 04:32

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Here is a simple option. I have one of these and they hang on real strong.

timberlinemd Sun 07 November 2010 08:19

The cover of the panel is aluminum. It acts as a heat sink, not too magnetic.:rolleyes:

timberlinemd Thu 23 February 2017 18:45

Vacuum table
1 Attachment(s)
After having my share of botched parts from moving while being cut I finally decided to add vacuum holddown.

A big thanks to Gary Campbell over at the Shopbot forum for his wisdom on vacuum systems.

I designed my 'black box' based on Gary's with my own modifications. If anyone has questions, post them here and I will try to answer them.

Now for some pics...

Cutting the parts.

timberlinemd Thu 23 February 2017 18:50

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Then asssembly...

timberlinemd Thu 23 February 2017 18:52

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The control box and another pic of the 'black box'.

timberlinemd Thu 23 February 2017 18:54

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Then on to the plenum..

timberlinemd Thu 23 February 2017 19:07

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