New Router Mounts May 19, 2009
Posted by Ruzter in Assembly.2 comments
Spent part of yesterday making prototype mounts for the new router. This is why they are made of particle board.
Here is the drawing:
Setting up to cut the parts. The backstop is trimmed with the CNC to make sure it is square to the CNC. It also cuts the notch. The wood to be cut has a pin in the end to locate it against the backstop. This makes sure the two mounts are cut the same. Later, the pin is used to accurately align the mount to the plate it bolts to.
Here is a cut-out part (several prototypes later). The 2 round marks near the base are there to line up my doweling jig to drill the bolts holes through the edge.
Here is the router in the mounts.
The Newest Member of the Shop Family May 16, 2009
Posted by Ruzter in Electronics, Fabrication.add a comment
Here is the newest member of the shop family and the solution to the old router’s shaft wobble (among other things)
This router is great because it has constant speed control (router maintains constant speed with varying loads) and comes with a vac attachment that I can easily adapt for use. Most importantly, the router has cylindrical body that makes mounting much easier. The extra horsepower and both 1/4 and 1/2 inch collets don’t hurt either.
Now to mount it, we will just remove a few extras. This model also has the benefit of a long “neck” where the bit mounts which solves some other mounting issues.
And here is the drawing of the new mounts I will make. Best of all the CNC can make these mounts for itself!
Hole Drilling Part II May 13, 2009
Posted by Ruzter in Assembly.1 comment so far
As a follow up to my last post, I did a bunch of measuring to compare the hole drilling to the original drawing I did. This tests not only the CNC, but my drawing to code conversion.
My goal for this project was fairly ambitious, I wanted an accuracy of less than plus/minus 0.01 “. This is what I was shooting for, but I was realistic enough to be happy with less than that. So my measurements show that compared to my original drawing, I am out by 0.0014″ (1.4 thousandths on an inch), so naturally I am ecstatic! I then measured the repeatability, in other words, the holes are out 0.0014″, but are they consistently that much out. After measuring about twelve different ways, I found the variation between similar holes to be less than 0.001 (less than one thousandth of an inch). I am frankly in shock. Now here come the disclaimers.
- I could be dreaming
- I could be inept at measuring, though I have repeated the measuring many times in different ways and I though I was out more until I realized I wasn’t calculating for the right hole size.
- Hole drilling puts little or no side pressure on the machine. When cutting, there will be much greater loads. This could greatly decrease the accuracy. This, though, can be somewhat controlled by how fast you cut and such and the machine is built fairly heavily with the weak link being any stretch in the drive belts.
- I believe the smallest step the CNC can take is 0.0025″, so you are dependent of your dimensions being in multiples of a step.
- I could be dreaming
The thing is that, even if the loading decreases my accuracy, I can still make deer shaped silhouettes like nobody’s business!
Anyhow, wish me luck, I really hope I am not dreaming.
Hole Drilling May 11, 2009
Posted by Ruzter in Fabrication.add a comment
Yesterday I was testing drilling holes. These are the holes that will potentially have brush bristles inserted to made a vac shoe. I discovered (again, I think) that the shaft on my el cheapo router is bent, so turning a 1/8 drill bit at 12,000 rpm (the slowest the router goes) causes the bit to flex and vibrate to make a really crude 3/16 or so hole… These pics are of the holes I cut using a 1/8 router bit. The CNC is working well and I think I new router is all that is needed. Though I may have to lower the whole z axis as I left so much clearance I am always blocking the work pieces up off the bed.
The pictures may look like the holes do not line up perfectly, it is an illusion from the grain in the wood. I now need to double check the dimensions to see if the calibration of the steps needs any fine tuning.
Drawing the Vac Shoe May 3, 2009
Posted by Ruzter in Assembly.1 comment so far
I am designing my new vac shoe. It is going to involve drilling a lot of holes and inserting brush bristles from a dollar store broom. It will make more sense when you see it. Today I drew up the design and wrote the software to write the Gcode. Writing code to write code again…
Here is the drawing, minus all the guide lines, I drew it in Google Sketchup.
And here is a pic of the Gcode simulater (which I wrote too) to show it should work.
How to Precisely Drill Holes without Precision Equipment May 1, 2009
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Tools needed:
- Jiffy Marker
- Micrometer (ok, this is a precise but affordable tool)
- Square
- Scribe
- Centre Punch
Here is a fairly typical way I build a part:
1) Draw an area about centre on the piece of metal to be drilled
2) Using a square and a scribe, scribe a line roughly center of the piece. I leave some room so I can mill the end off later. Colouring with marker makes the scribed line show up much better.
3) Color again, but measure how far the holes are from the top edge. Gently drag the micrometer along the edge, scribing the coloured area. You would think this wouldn’t work very well, but it really does and I haven’t had problems with the line being too close to the top because the micrometer wasn’t square
4) Use center line to scribe distance of hole from center along the horizontal line you just made.
5) Centre punch
6)Repeat for all the holes
7) Drill small pilot holes. It is amazing how much even a 1/8 inch bit can wander on a press drill even if it is centre punched. Mind you I have fairly tight tolerances.
8 ) Cut to length and take off the sharp edges.
9)Clamp to a 2nd piece and drill the second one.
10) Test fit the pieces. If one or more holes don’t line up perfectly, drill out the hole to a slightly larger size. This is where my 200 piece drill bit set comes in very handy!
At this point, it is time to realize that you measured two of the holes wrong and you have to decide to start over or modify the part that was suppose to bolt on… 
11) Later I will mill the edges square in my cross-slide and drill press setup.
Vac Shoe Mounts May 1, 2009
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In prep for mounting a new vac shoe, I added these mounts. The vac shoe height stays the same as the router goes up and down.
The rods will bolt to the vac shoe and can be adjusted up or down to the height of the material you are cutting. There will be a wing nut added for adjustment without tools.
Air Deflecter May 1, 2009
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The bottom of my router is where the cooling air for the router comes out. In the interest of dust control I wanted to deflect it so instead of blowing straight down on the cutting bit, that it exits sideways. As with most things, the pictures will describe it better.
