[basskitcase]

I am getting towards finished with my first build, which is a chain drive steel framed moving gantry design with open linear bearings on supported rod. I still need to reinforce the base, build the table top (sheet of plywood on the top til i can get that done) and level everything up.

[basskitcase]

[basskitcase]

Well, i tried to link to the pics. Any idea why they might not be working?

edit: well i was trying to upload files that were too large. I got them working now.

[whiteriver]

Make sure size is correct. Click upload in the Manage attachment screen after selecting which pics you want.

[basskitcase]

Any comments...concerns???

[basskitcase]

I just made my first cut out yesterday, which was the very popular roadrunner in mach 3. Today i am hoping to reinforce the base and hopefully get the MDF table with countersunk nuts done. I will post pictures soon...

[gmfoster]

Thatis a nice looking router. I suspect you will find you might want to incorporate some triangles in the gantry but they will be easy to add. Looks as if you are a very handy fabricator.
Garry

[nofx]

How do you find the rigidy of your tube frame? I'm planing something with sqUARE TUBE myself and was curious how it is. I like the design alot. Hows the backlash in the chain drive on ur zaxis?
Jon

[basskitcase]

If i had to do over, i would have used 2" steel, but overall its pretty good. I have a little bit of racking in my x, but thats more a factor of not having the bearings very far apart (might fix this in the future, or go with a moving knot, or both). Having two layers of steel is much better, and if you notice from my pictures, there are two layers on the vertical part, but only one on the horizontal, which i plan to change (i think this is giving me a little bit of flex).

Honestly, I'm still fine tuning it right now, so i haven't evaluated the backlash of the chains, but since i'm using a 10TPI screw, the lash should be very miniscule in terms of gantry movement (this is why i decided chains would be acceptable). Really, if you keep the chain reasonable tight, there really isn't much visable lash (i know this adds some inefficiency, but I'm willing to accept that for how easy it was to implement on my machine compared to building the structures to direct drive it).

[basskitcase]

I used the machine to cut out holes so i can bolt work down from the top. I cut hex slots for the nuts and drilled the hole through the rest of the way. Worked great!

Also, i used the router to cut out a wooden piece i used to make a cyclonic dust separator for my machine (which works but I'm not quite done tinkering with it yet)

[basskitcase]

As mentioned before, i had planned on changing out the wooden z axis bearing support for a steel one. I used my router to cut out 3/4" spacers out of MDF to go from the 1.26 OD of my bearings to the 1.6 ID of my pipe. I then disassembled the machine, removed the bearings from the old support and pressed them into the steel pipe. I put these back onto the rails, and tack welded the pipes to my bolt on support frame. After making sure everything was level, square, and not seizing, i did a final weld. Its now smooth as glass!

You can't see it very well in the pics because it's not orange like the rest of the frame, but on the bottom of the gantry, i welded a second horizontal support to the bottom frame, so as to help add some stiffness.

I also started my conversion from 1/2-10 single start to 1/2-8 2 start screws with dumpsterCNC delrin nuts. All i need to do now is make the pieces to connect the nut flanges to the framing, and I'll be up and running again.

I also made a vacuum attachment to help eliminate all the dust that was filling the basement! So far, it works pretty good, as i was able to do about a half hour of constant cutting this morning with much less dust than 2 minutes of running it before holding the vacuum hose up to it.

Once i get all this done, I'll start making a new and improved holder for the router that will also hold the vacuum attachment (right now i have to bolt the vac attachment on and off when i need to change tools).

[hemsworthlad]

Hi Basskit,
Nice upgrade should work a lot better! . . . I was just wondering how does that block of wood affect the cooling of the router.? . . . would think it act's like an insulator and would over heat bearings.?

[basskitcase]

I imagine if i used it for hours it might, but so far the longest i have used it is 1/2 hour, not at full speed, and cooling hasn't been a noticable problem (then again, its probably 55F in my basement). Once i get the other upgrades done, i will hopefully be making a better router holder out of aluminum that i can integrate my vacuum system into. I admittedlly took some shortcuts when building the thing, just to get it running, with the intention of doing it right once i had satisfied the "i want to see it work" voices in my head. There for awhile, my wife must have thought i was planning on taking up residence in the basement, but since i've got it running, i have been able to slow down and think about how i want to improve it.

Once i get it running again, i think i'll try my hand at making some e-chain. Oh, the fun never ends...

[RomanLini]

Nice solid looking machine basskitcase!

Can you tell a bit more about your cyclonic dust filter design and the mods you made to it? I take it your whole bottom container is under vacuum too?

[basskitcase]

I can't really take credit for the idea, as there is a comercial product called the dust deputy that is very similar, and i saw another member here (can't remember who it was) make one out of old plastic food containers, but here's my un-expert take on it...

I formed a cone out of some spare sheet metal i had. didn't really measure anything, just eyeballed it and pop rivited it together then sealed the seam with hot gue. In the top of the cone, i took a 90ish degree angle vac attachment and glued it into a hole in the cone, so that air entering it would be deflected sideways (the other member just ran a straight pipe in at an angle). The outlet comes in at the top, and the pipe for that extends a few inches below the inlet. The concept is that the outlet sucks in air, and the air entering is forced into a vortex, which gives particles enough momentum to pass the suction stream and continue down the cone into the bucket. I guess i should mention the open bottom of the cone is sealed into the lid of the bucket, so the whole system is under vacuum (any leaks will reduce your suction)

I should also add a word of warning that sucking particles through a plastic tube creates static, which can result in a dust explosion if you're not carful, so the whole shebang should be grounded, which i haven't taken time to do yet. (touching the cone while running it usually gives me a little static shock)

Google cyclonic dust sepeartors and you will probably be able to see a little better how they work.

[hemsworthlad]

Google cyclonic dust sepeartors and you will probably be able to see a little better how they work.

I did just that and guess wot it returned just 1 reply.!! . . . . this thread. LOL(nuts)

Edit: I know why now .? . . . . . You missed spelled separators and i just copied n pasted. . . Doh

[basskitcase]

I did just that and guess wot it returned just 1 reply.!! . . . . this thread. LOL(nuts)

Edit: I know why now .? . . . . . You missed spelled separators and i just copied n pasted. . . Doh

My spelling has been known to be questionable at times :rainfro:

I have gotten the new lead screws going with the dumpster nuts, and now i just need to fine tune the alignment to get the best speeds (former speeds have increase about 1.5x at the moment, and backlash is down to zero)

On a different note, i am in the process of taking some positive steps toward improving ridgidity. After a good deal of studying, i have determined the table is flexing more than i originally thought it would, which is causeing my whole gantry to flex slightly. I am going to first try to reenforce it with steel to get it more solid, but if that doesn't work, i might just bite the bullet and weld up a steel frame for it.

[basskitcase]

It's been awhile since my last update, but i have more photos for you! After making the previous mods, i tore the whole thing apart, painted it, made a rolling base for it, and moved it into the garage so i could wheel it outside to cut so I wouldn't have to worry about dust in the house. After tuning the linear shaft and lead screw alignment, i have gotten the top x speed up to 220 IPM and the Y up to 230 IPM. I backed these down to 180 for reliability. I still have to get the cable carriers made and make a better mount for the router, but otherwise, I'm happy with it. The modifications helped stiffen it up, though it does still have a little flex as a result of the gantry being so tall (the gantry itself isn't flexing its the open linear bearings flexing with the leverage applied due to the tallness of the gantry. I made this trade off so that when i use it for putting designs on furniture, i can fit the pieces in without too much fuss.)

More to come!







View My Video

[Ernie34]

Nice Job!

Im in the final stages of design on my machine. I am ordering the steel for the base tomorrow. Its all 3in square tube for a 5x7 frame to give me a 4x6 cutting area. It is based on CarveOne's machine since he did such a amazing job! I am VERY exited about building my first machine.

[basskitcase]

As promised, i replaced the wooden router mount with an aluminum one (sourced from K2CNC). To mount it onto my existing frame, i made a steel bracket, but tried something rather unique. Instead of buying a 7" x 4" chunk of 3/8" steel for $20, (and since i have access to a sheet metal shop with free scrap sheet metal) i made many sheets of 7"x4" and welded them together (welded the edges). It actually turned out quite sturdy, since it has bolts going through the edges and center.

I also bought some used IGUS cable carriers on ebay and installed those.

I got my home/limit switches installed and wired (as a side note to anyone using the hobbyCNC board, i had to increase the debounce setting in Mach3 to 2000 and add a 0.01uF capacitor between the input and ground of each limit switch to keep the noise the lines picked up from interfereing with the signal)