1st machine rebuild

[multiplex]

I built my first router back in october of 2007. It was built specifically to help out with a large production job i had at the time. Luckily i got the machine up and running with very few issues, but there were always some weaknesses in the design.

I've been running the machine weekly since that time, and finally have a break in my work which should allow me to fix some of the issues.

two things i'm going after.

1. Gantry rigidity. I largely underestimated the impact of cutting forces. The gantry was fabricated out of 3/4" pvc due to its price and its machinabilty. Poor choice for obvious other reasons.

2. Travel speed. I'm stuck at around 80ipm

Here are some pics of the current build. I will be keeping the base, which is very sturdy and welded up out of 2"x2" angle iron. Underneath are two VXB 25mm linear rails for Y axis









Plans are as follows..

One.

Keep the same machine layout and design concept. Replace / rebuild entire gantry out of extruded aluminum channel.

for the plate that connects the Y axis bearings under the table, i will use 2.8" x 10" x .5" aluminum channel.

On either end will be 1/2" or 3/4" 10" wide aluminum by about 18" tall.

From there i will mount a piece of 2.5" x 8" x .5" aluminum channel vertically where the X axis linear rails will mount.

I will also use some of the left over 10" wide aluminum to made the trolley for the router.

example of the channel



Two.

Switch out the X axis linear rails to 60" lengths to give me an X travel of 49" (verses 44" i have now)

Three.

Switch out my 1/2-10 2 start screws for 5 start to help improve my IPM's.


I just ordered the aluminum today, so hopefully things will be underway shortly i can post back up some progess.

Please let me know your thoughts / comments on this!

thanks

[multiplex]

just got in my aluminum channels today, so work is about to pick up.. started laying out the design and had two options to go with for the gantry. not sure how much of a difference there would be, but wanted to throw them out there for opinions

here is the current setup



layout 1 - just like old setup.



layout 2 - carriage straddles the x axis channel



shifts some of the weight behind the channel. based on the size of the channel being used, and the 3/4" aluminum that will connect it all - do either of these variations matter?

any input would be appreciated!

[multiplex]

anyone?? its lonely in here

for what its worth, i'm leaning towards version 2. started machining up a few parts last night that would work either way

[CarveOne]

I'm leaning toward #2 also. Go for it!

CarveOne

[multiplex]

thanks!

did a little bit of work tonight. getting the support frame for the z axis going. The y axis linear bearings will bolt to this, along with the backlash nut.

waiting on a huge piece of 3/4" aluminum to arrive

notches are for linear rails and screw.. still needs mounting holes drilled for other items

[multiplex]

doublepost

[FandZ]

I was going to say go with option 2 also but for somereason never got around to posting.

So how did you mill out that part? Did you use your old cnc machine?

[multiplex]

i used a standard bridgeport to machine these so far. for the larger spanning pieces, i'm going to make a drill jig to drill the ends - too long to setup on the machine.

[multiplex]

made some good progress tonight. my new 60" linear rails came in, along with all my stuff from dumpstercnc, and my big piece of 3/4" aluminum

router cart is complete minus a few small details. need to add in limit switches and whatnot.





with the 60" rails i should finally get my 48" travel. actually more like 49.5

[FandZ]

Yep that looks solid. I know this is a noobish question, but how do you go about getting those vertical round rails in the front to stay in. How come they just don't fall out the other side? Are they tapered holes? I'm sorry for the lame question but I gotta know.

[multiplex]

totally valid question! well that is one aspect i did not complete yet. However i'm going to make a vertical slice in the top and bottom plate, and put a screw in perpendicular to the slice essentially making a clamp what will hold the rods in place

when using rods like this, its really important that the ends are clamped firm otherwise they can flex more than normal (i learned this on my first build, and later switched to supported rails)

[FandZ]

Thanks for the explanation. Makes since. And I could see where clamping it would make a sturdier rail than just screwing the ends in. I'll keep checking back for updates.