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.

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[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!

[robe_uk]

thanks for the comments lads,
Yes Metallica rocks and I love the color too, although I had planned to get the steel powder coated I went and used hammerite, wish I had stuck to my plan of powder coating as the finish with hammerite is a bit sh*t, oh well it'll have to do now

As for shims I have found that i did not need to for the rails to run straight with no binding, I still have to test for accuracy and final tuning but as things are running smooth i hope to be ok.

I still have to bolt my 18mm mdf table to the unistrut and come up with a way of having hold downs for the work, have been thinking of T-track but its a bit pricey here in the UK, once I have this down i'll be able to surface my spoil board which should leave the bed true to the router.

Rob

[robe_uk]

Here is a few photos of my control box, things can get rather messy once you start adding things.
The PicStep drives are along the top with fan cooled heat sinks on the driver chips. I run the EMO and limit switch circuit at 24v (mainly due to the fact this was the type of relays I had) When powered up the reset button has to be pressed to latch the EMO relay on, this can only happen if all limits and EMO are closed (safe), the limits relay is currently linked out as I have still to install the limit switches on the tool, the over-ride function means that if the tool hits a limit I can hold the button in to by pass the limits and jog off, the over-ride will not bypass the EMO buttons.
The EMO relay is a mutlicontact relay and the enable signal has to pass though it so if the tool is EMO'd the drives will disable right away, I know mach will do this also but I don't want to trust only software.
The enable relay also is mutlicontact and once active will disengage the Z axis brake and also allow the spindle on signal pass through to the spindle relay when required. I have a problem with the Z dropping down when I enable the drives as the PicStep only becomes active once it gets steps even if it is enabled so I'll have to look into a solution that releases the brake once the drive gets steps, at the minute I have to jog up as soon as I enable the drive for the drive to hold the stepper, I also had to load on the no time out firmware onto the PicStep so it wouldn't timeout a drop the spindle when I wasn't expecting it
The circuits at the bottom are opto isolated inputs for inputs to the computer breakout board, currently only the EMO is going in but will add limits and probe in future, I have two parallel ports on my computer so lots of room for expansion. Another board is opto isolated drivers for output signals to drive the enable relay and spindle.
I do have some circuit/wiring diagrams which I have to update for recent changes and will post once I get this done.

Hard to explain so if you have any questions I'll do my best to answer.

Rob

[robe_uk]

Not had too much time lately for my cnc and I've had a some ups and downs, The down is that am missing steps on my Y axis, am sure its from my step up on this axis, the gearing to the pinion drive was 2:1 couple with the fact it was made using bits i had laying around, the belt was too long so i had to retro fit a idler pulley added to the missed steps, lowering accel & velocity didn't help much so i have had to bite the bullet and order new belt and pulleys (budget limits my spend at the moment). The gearing am going to use will be 4:1 so hopefully my old steppers keep up.

The up is that Alan the creator of the PicStep drives modded the firmware for me so that when the z drive is enabled the motor locks and i do not have the router dropping Nice one Alan.

So am now waiting for my parts to arrive and hopefully the end of lost steps.

Sorry for the lack of pictures, will add later.....

Rob

[robe_uk]

bollox, received my new pulleys and I tried to drill out the smaller one to 1/4'' and made a mess of it didn't drill straight and its now useless... new part reordered, I think i'll take the new one to a local engineering firm and get them to do it for me.

to be continued........

[robe_uk]

Been a while since I updated this thread, build logs and me don't go well together

Well what have I been at you may ask, well just a few bits, not as much as I'd like, usual story, anyway.

Installed 2010 screen set, best upgrade you could make as its enabled my to;

Installed a touch plate which I can use to zero my cutter to the top of the work piece, also a fixed plate for tool change.

Cross hair laser for zeroing X&Y axis,

Just installed home switches, X A & Y axis have their own pc inputs and Z shares with the probe input so I have to make sure the probe/home is clear before using either function. I thought when I homed it would move all axis at once but it does Z then Y followed by X+A.
The independent home switches will allow me to square the gantry once I work out if its out of square to start with, loads of testing to do yet.

Also x-box controller for remote pendant control.

oh also drilled a grid pattern into the router worktop and screwed in threaded inserts then the spoil board goes over the top with matching holes so work can be bolted down.

I'll add pictures soon, be aware they'll be in no particular order.

Rob

[robe_uk]

X axis home switch ramp

[robe_uk]

Drilling the hole pattern in the worktop, I turned the end of a drill bit down to fit into the router, I wouldn't recommend anyone doing this

[robe_uk]

Tried a bit of V carving onto a cheap chopping board, my V bit is not great quality but for a learning exercise its not bad, its a Celtic knot with the names of my wife and kids around it.