[Adamj12b]

This build is something I wanted to do to try and put some of the machine parts I have to use. A few years ago I salvaged a few truck loads of parts off of 3 industrial pick and place machines. (2 chip shooters and 1 reel feed machine)

Photo Gallery: https://goo.gl/photos/Ua1YPN6hhGPEqawB6

YouTube Playlist: https://www.youtube.com/playlist?lis...86GiVKspfpeDIP

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I am currently in the process of building another machine, much more heavy duty , but needed a small machine for a job I have a chance to make a good profit on. I figured I had mostly everything I needed, so I would build another machine and make some money with it. My goal is to build the machine without spending anything except for the plywood for the frame. The machine will be used to mill circuit boards for large power stages (12"x18") as well as copper sheeting for electrical bus components. I also figure I will use it to make parts out of delrin, and of course, I will see how it cuts aluminum.

Here's what I came up with and where I am now.

I spent 3 days drawing up what I had in mind. I wanted to use what I had which included 2 1/2" pre-loaded ground ball screws about 24" long, 4 - 34" 1/2" round supported rails as well as bearing blocks to go with them, and a Haydon linear actuator which is just a nema 34 stepper with a captive nut inside it. The nut spins and moves the screw in 0.0005" per step increments. I will use this for the Z axis. For the X and Y, I will use the servo mounts that were left on the screws, and I will couple 400w AC servos to each screw. The motors are a little large for this, but I have them already and the mounts... I might try and use some 200W servos I have, but will have to adapt the mounts to them. Travels end up being around 22" for the X and Y and 6.5" on the Z.

Here is a cad view of the machine open and closed.

Attachment 303988Attachment 303990

The external dimensions of the machine are 36" x 36" and 29.5" tall. The Y axis servo will most likely protrude from the left side, but Im still finishing some of the ball screw/mounting details as I go.

The spindle is a Porter Cable router. Specifically a 7539. Now, if you google this, you will find out its a plunge router. This was another thing somebody gave me about 10 years ago. It had been dropped off a shelf and the frame was cracked. I ended up taking it apart and putting the body in my lathe and turned the handles down to a round body like a 7519 router. It will still need a custom mount, but it has 5 rpm speeds and is rated at 3.25HP, and didn't cost me anything. Here is it sitting next to a 1-3/4HP porter cable router.


The table and rails are what determined the size of the machine. The table frame is a cast aluminum grid that was the table on the chip shooter. I will cover the top of this with a piece of Mic6 eventually, but for now, its original aluminum top will be installed and an MDF spoil board installed. I plan to close off the bottom of the frame and plumb in vacuum lines and valves to activate each of the 9 chambers individually. I will use venturi vacuum pump feed from my compressor to create vacuum for the table.


The wooden frame of the machine is made of 3/4" poplar plywood I bought from Home Depot. My goal is that this will be the only thing I spend money on. I spent $120 on 3 sheets, mostly due to the extra material needed to create the front of the enclosure.

The base of the machine is a torsion box design using 1.5" pieces of plywood, in a grid pattern, 6" on center. Everything is glued and screwed together using Kreg jig and screws. This assembly method is continued through the uprights and the gantry beam. The gantry beam is made out of 7 ribs, and 3 cross braces that align the ribs. This is then wrapped in 3/4" plywood.

The Y carriage and Z axis are made out of 3/8" aluminum plates. The Z rails are THK SR20V linear rails and bearings, with the Haydon stepper mounted in the center.

That's it for now. My next posts will go into detail of the build, with videos

Once completed, If there is interest, I will share the model openly for anybody else that is interested in building something similar.

Hope you enjoy.

-Adam

[Fluxion]

Sounds like you have scrounged for some nice parts! I'm along for the ride and awaiting another post.

[Devastator]

Looks like a cool project. I'm tuned.

[Adamj12b]

The router has been progressing over the last week. Slower then I had hoped, but Its coming along.

As I said before, the size of the machine was determined by the rails I had on hand and the table frame I wanted to use.

The rails are Thompson 1/2" supported rails 34.25" long. I picked up 4 of these a number of years ago for something like $20 a piece. I ended up buying 10 SPB8OPN blocks for the rails on Ebay shortly after I bought the rails. All of this has been sitting on the shelf in the garage since 2008.

The table frame was what the circuit boards would mount on in the chip shooter. It is cast aluminum 21" wide and 19" deep. The top and bottom of the frame was machined parallel and flat to better then 0.001". One side of the frame has a boss where the side of the linear bearings are aligned against. Im not sure if I will be using this, as I still have to put some spacer blocks between the bearings and the frame.

I started the build with the base. I ripped enough pieces of plywood, 1.5" thick, to create the grid of the torsion box to from the base. This grid is on 6" centers with 4 extra ribs (2 pairs) located under where the linear rails will screw to the base.



These were notched using a dado blade to interlock, then assembled. I glued and screwed the 7 vertical ribs to the bottom side of the base top first, using the horizontal ribs for alignment. After these were dry, I went back and glued the horizontal ribs to the vertical ones and the base top and screwed those in. I ended up using 104 Kreg screw in this part alone.



Next I started on the gantry beam. This is made up of 7 ribs, with cross bracing and then wrapped with plywood.

I cut the first rib then traced them using a router and flush cutting bit. This gave me 8 identical copies, with the master as a spare as it had some saw over-cuts that I wanted to avoid using if possible. After assembling the base, I liked how well the cross ribs aligned everything, so I decided to do the same with the gantry ribs. I set up a jig on the table saw again with the dado blade, for each cut of the ribs, and made 3 more interlocking cross braces for the beam.



I started assembly with the bottom piece of plywood, and the back face. The mating edges of these were cut on a 45 degree angle, glued and clamped with special 90 degree degree clamps to give me a square edge to align the rib frame with. After drilling the ribs with the Kreg holes, I screwed them to the base, pulling all them tight against the back square edge using the screws. I worked my way up from there, screwing and gluing the cross supports to the ribs.I continued to the front and started fro, the bottom up, wrapping the ribs with the plywood. I used the Kreg jig and screws to secure as many of these pieces in from the back, but some had to be screwed in threw the face. These will be removed and replaced with countersunk screws.






After that, I started with the uprights for the beam. These are just simple boxes, with internal ribs for strength. The bottoms are notched to interlock with the base ribs and will be glued and screwed together to make the base and uprights one piece. Here is a shot of the partial beam sitting on the partial uprights.



After I got to this point, I started mocking things up with he rails. I found that the base section is not as flat as I hopped. I was afraid of this, but thought the ribs would flatten everything better then they did. So, time to try something new.

I had been researching using epoxy for linear rail seats for a larger machine I am building out of steel. Progress on that one has been slow, as Its made with the same quality screws and servos as this, but is using 35mm IKO profile rails. I didn't want to rush into that one and weld up a frame that's not worthy of the quality components im going to mount on it. Since grinding it was out of the question, I was looking for alternatives. I came across this thread: http://www.cnczone.com/forums/cnc-wo...60948-cnc.html where Fluxion had used a special epoxy to level and flatten the surfaces of the frame for the rails. This is the route I will go with that machine, but decided this machine might be a good test.

Since I didn't want to spend a ton of money on epoxy for something that might not work out, I tried something else. I ended up using a bar top epoxy that I got from home depot. I have seen this stuff before, that once cured, is extremely hard. It is meant to create a smooth level surface as well. I leveled the base the best I could, then created a set of channels to keep the epoxy to just the locations of the rails. Across the middle, I put down a strip of packing tape to keep the epoxy from sticking. This section will be discarded, but allows the 2 channels to equalize so both channels are on the same plane. I heated the 2 bottles of epoxy in hot water to lower the viscosity and make it flow easier, promoting the best leveling action. I whipped together a vacuum degassing chamber using the venturi pump that I will be using for the table once completed. This was just a gasket-ed electrical enclosure. It would only hold 12in of mercury and as you can see, it deformed the side causing the gasket to leak. I'll use this again for the big machine, but I'll add some bracing so I can get closer to 30in next time.



The pour went well, and the base was covered to cure. Full cure is 72 hours. Tonight will be 48. Ill wait the 72 to remove the forms.



While this was curing I turned my attention to the Y carriage and Z axis. Some quick milling on the Bridgeport and some drilling, I had both 3/8" plates done and did a test assemble. I drilled the required holes in the Z plate, and spotted 42 holes on a 1in grid in case down the road I want to mount different spindles.



I'll end with a quick preview of the Z axis first moves. 40IPM, with limited stroke as there are some clearance issues with the spacer blocks and stepper mount.

Enjoy!

https://youtu.be/pZMcDMDnrco