BuildLog CNC Router?

[bdring]

In my opinion that is fine. There is only side load on that and it is only as much as the stepper can put out (10-12lbs max). That is the strongest axis for that part. It is placed before any torque increase via pulleys and lead screws. It is a .125 Thick 6061-T6 Plate.

[cpdude]

I now know what I'm going to do with my MakerSlide parts! I've already have a DIY router but this will allow me to go a bit bigger. Bigger is generally better!

Brian

[bdring]

Here is a quick conceptual rendering of where I was going when I was talking about "scaling" the earlier design. That "reference" design will work fine for a lot of people, but I already have a much bigger router already.

The CNC router is my favorite tool in the shop. I think it is the most versatile CNC tool I have access to. All machines have their limitations and sweet spots, but I can usually make do with in more areas with the router. So why are they so rare in hackerspaces and labs? I think it is because they are so noisy, messy and scary.

I hope this design is a first step towards addressing that. This will be a fully enclosed mid sized router. There will be a fitting on the rear for a dust collection system. It will eventually have a dust hood on the spindle and a general enclosure fitting to suck out the rest. Some shop vacs like the Festool line are extremely quiet (a little expensive too). It will support several spindle options, but the one shown is a 0.8kW VFD based spindle. These are amazingly quiet. The brushless DC hobby motor based spindles are another option to look at. The skins might be lined with acoustic panels.

The lower section houses the electronics in the rear and the front is a pull out shelf for tools, etc. I used MakerSlide for that too. Many people use drawer slides as linear bearings. I am using a MakerSlide linear bearing as a drawer slide.

I am still up in the air on the access doors and what panels are clear. Right now there is an upper door and a lower door and a single clear panel in the upper door. The basic router ties into the outer frame to add a little more rigidity. I'll see how that goes. I don't want that to cause the skins to vibrate like a drum. I think the right acoustic material laminated to the skins would prevent that. Maybe some rubber bushings would attenuate the upper frequency noise. I need to figure out the best way to vent it too.

It has a long way to go, but I thought I would share my progress.

[cpdude]

I like the fully enclosed route, however, I cut mostly thin sheets of plywood and the parts always seem to want to lift up. I usually use a "chicken" stick to keep the parts in place. Does anyone have a better way to hold down thin (between .4mm-3mm) sheets of plywood?

Brian

[BenJackson]

I think the left side of the 2.x router should open like the front of that router...

[dirktheeng]

I like the fully enclosed route, however, I cut mostly thin sheets of plywood and the parts always seem to want to lift up. I usually use a "chicken" stick to keep the parts in place. Does anyone have a better way to hold down thin (between .4mm-3mm) sheets of plywood?

Brian

Brian,

I'd look into setting up a bleeder board (spoil board), and a vacuum hold down. This is basically mdf that a vacuum is applied to the underside. The actual spoil board is porous so the vacuum can move right through the board and suck your part to the board. If your area isn't too large (say less than 2 ft by 2 ft ) you may be able to get away with a single shop vac to hold down your work. This kind of hold down system is what the pro's use to process sheet goods. it works well as long as you aren't trying to mill small, thick parts. You can always leave an "onion skin" in place when you do your cutout (that is leave a thousandth or two of material to keep the piece in place and not break vacuum), and clean that up by hand after your part is cut. That helps keep your part from moving and keep the whole sheet sucked to the spoil board. You can cover any unused area with plastic or wax paper to increase/maximize your hold power as well.

There are plenty of home-made solutions using this kind of method detailed online. I would seriously consider doing this as it isn't hard to setup especially if you already have the router.

Dirk

[dirktheeng]

Bart,

Have you considered making the y-axis move the bed and have a static gantry? I'm just thinking that the maker slide would be perfect for doing the same kind of setup that the shopbot buddy has. In essence, this gives an infinate y axis length. They use an integrated track that has a slide and rack on it so they can bolth them together and attach more cutting surface to it to extend the bed as needed. It moves by rack and pinion. The maker slide would be perfect for this kind of setup as well.

Basically, you would want to put the v-groove bearings in place in the gantry frame to hold the track and then use some roller blade wheels to make the bed float as it moves away from the gantry. The bed only needs to be precision aligned right benieth the gantry.

The only disadvantage to this kind of setup is that you need 2x the room to move the bed. that is is your bed is 4 feet long, you need 4 feet on either side of the static gantry for clearance.

It could really reduce the cost to getting into a large format cnc without having to bulk stuff up and get to a size where the maker slide would not be any good.

[J45on]

I am drooling over this Bart
I would love to replace my tiny home made MDF router
with one of these in the future but how big is it ?
Is it a desk top machine like the 2.X ?

[bdring]

The work area is still being tweaked. Right now is is about 650mm square. The outside dims of this whole thing are 1 meter square. I have it shown as a table top style, but it is a little deep for a standard table. I would suggest custom table or a cart for it.

Easy open sides is something I am thinking about. My first smaller router had open sides and that is handy. The screwed on the sides add a lot of rigidity. I was thinking of sides that open just in the work zone.

I often use a chicken stick too to keep small parts from flying, but for the high volume work I do, you need to find other strategies, even if a vacuum system is out of the question. If there is not other way around that, I will mill down to a small fast last path or use tabs. That way 90% of the job is done before the chicken stick gets used. Otherwise you end up babysitting the whole run. Hopefully, even partially open, this will be cleaner than an fully open router. I thought it would be nice to have an extra vacuum port built in where a standard hose could hook up for cleaning out the corners or dust stuck in the work piece cuts.

The fixed Y is a neat idea, but I don't think it is appropriate for this one. The Z Makerslide is fixed in this design. This will allow me to run a large cable carrier from the Z top the back of the enclosure. This could be a traditional chain style or simply three hinged bars. It could be large enough to carry the vacuum hose too.

[cpdude]

@Dirk-I've got vacuum hold down system on my current router and it's a big improvement, however, it's far from perfect. When you're cutting dozens of small parts out of a 18" x 30" x 1/64" sheet of plywood the vacuum will usually fail at some point and the sheet will lift. I guess that why I my lasers are my favorites! The router is definitely less suitable for these jobs but better suited than a laser for other things.

Brian