Build Thread- Rob's 'Evolution' router

[robe_uk]

Hi all,
Well to say that this is a build thread would bending things a bit as the router is 'mostly' built, in fact I purposely avoided starting a build thread as that seems to be the death nail for any project I start anyway a little bit of background story;
This is my forth build, the 1st and 2nd builds I logged here, the 2nd machine was used of cut some parts for this machine, the 2nd machine used 8mm threaded rod for lead screws and was slow, plus the fact it wasn't on a stand and sat on the floor making it a pain to use meant it never got much use.
My 3rd build (picture attached) was a mini router 20cmx20cm, rough and ready but worked nicely, never made a log for this one and its scheduled for an upgrade to A4 size.

ok ok enough waffle lets get down to business.

Why 'Evolution'? well as far as i can see these machines are never truly finished and continue to evolve with upgrades/rethinks etc.

I was lucky enough to salvage some 25mm nsk rails 1600mm long plus supported round rails 1200mm long so the machine was designed around these.

[robe_uk]

Trying to make some sort of plan rather than jumping straight in like my usual style i made up some plans in cad and sketchup

[robe_uk]

Here is the frame during the build, the legs are 40x40mm steel box, the gantry and main side supports are 50x100mm steel box section. The table bed is unistrut.
The box in the bottom will hold the electronics

[robe_uk]

To ensure the machine is solid the bed unistrut is bolted down to the base frame and also bolted using right angle brackets.
The main side section is bolted down to the bed unistrut and also with 50x50mm right angle.
The bed is held square by the 10mm threaded rod that can be seen crossing under the bed.

[robe_uk]

The gantry runs on the THK rails which are bold onto the top edge of the side box section, a lot of drilling and tapping I have read a lot about people grinding the top surface flat or using epoxy to give a surface for the rail to sit on but i found it worked well enough without.
I made the sides sit up like this so that the gantry side risers could be as compact as possible to help keep everything solid.
The risers are 80x80mm profile, the THK bearings are bolted to a Alu plate which in turn is bolted to the profile.
The gantry is bolted down to the profile and also has right angle support brackets on each side to avoid it twisting.

[robe_uk]

The gantry axis is supported round rail bolted onto the top and bottom edge of the steel box section. You can see in the pictures how the z axis all bolts onto the Alu plate which is bolted to the bearing blocks, the z uses 20mm rails.
The z uses a 4 start screw, the weight of the router causes the z to drop when power is removed from the drives so i have a brake attached to the bottom of the screw.
The z motor mount is held in place by having the z rails extend up and hold the mount with shaft supports, nice clean solution i think.

[robe_uk]

For this machine i decided to use rack and pinion for the main drives as they will be more forgiving for any misalignment (i hope).
The rack is MOD1.0 15mmx15mm mounted to 20mm right angle which in turn is mounted to the steel box sections.
The pinion drives were cut on my last machine and are made out of mdf, these will be upgraded over time but for fast prototype it works for now.
The pinions are held onto the rack using springs, the tension can be adjusted by tightening down the screws.

The motors, belts and pulleys are all salvaged so may not be the best for this application, dual drive on x geared at 3:1 and single y geared about 2:1. Budget prevents buying new drive components for now.

[robe_uk]

I have no pictures of my electronics yet but i am running 4 picstep boards running at 40v. I have EMO circuit setup and will be using limits and home switches but this is to be done, i'll update at a later stage

[robe_uk]

OK that was a very quick over view of my machine to date and i still have loads to do.

But in the mean time here is a couple of things i have done,

My son managed to break the slats on the bottom of his bed ( his sister and him jumping on it ) so i got that correct size of plywood and used the router to cut out slots to let air circulate.

My videos appear jerky as they where taken with my mobile

[robe_uk]

another small project was a lamp, more just an exercise than a practical use. Made with mdf, I had to slow the feed to 1000mm as i was losing steps, found cause to be one of my drive pulleys was rubbing one of the side walls of the drive on the y axis.

Also can be seen my dust shoe which does a good job, although am cutting with a striaght flute bit the dust is not ejected fully from the cut.

[joshendy]

Nice job on the router, looks really well made. Love the Kill Em' All style colours you got going on the CNC.

[PaulRowntree]

This looks very nice. Did you need to shim the X or Y rails much to get the track straight on the rectangular tube?

Cheers!