Not really a log... LaserCut router

[Guldberg]

Here we go again... I have noticed while making my CNC lathe and my first router that i suck at updating my post. This post is going to serve as a semi log where i can ask for design input ad hoc.

Down to buisness, this is my second, and hopefully way better, router than my modified solsylva build. Here's the design





The base of the router (blue parts) are made of lasercut 10mm steel. The white parts are going to be aluminium and the whole slider system is real linear slides (no more homemade solutions). Total cost will proberly end at around 1200-1400$ assuming i can get the aluminium and the powdercoating for free. Roughtly half is salvage parts from the old router.

I would like some design inputs for the gantry if any. The base is already cut and TIG welded together, if i hadnt broken my cam i would have taken some pictures

[dz1]

depending on the span and diameter of the unsupported rails you might run into deflection problems, i used 20mm hardened rods for my x and y and ran into problems with 4' spans (i was pushing it i know but i figured they sold them in that size and length so someone was using them for something right I would guess 20mm rods are relativly safe up to maybe a 2' span given a laminate trimmer as cutter

farther down the cross slide can go away from the rods on the x the more leverage the cutting head will have to torque the rods

[Guldberg]

Way to go, i forgot some measurments. The x-rails are are Ø25mm, y Ø20mm and z Ø16mm. The cutting area is roughly the size of an A3 paper, which means the span is that + 10cm (y) and + 14cm (x). Im using a kress router and including all the gantry is about 15kg. Im planning on routing a lot of aluminium, so stability is a must

[dz1]

gotcha, those sizes sound well balanced for the size of the machine.

couple questions that usually come up

how are you going to secure the x rods in the gantry sides?

might need to add some blocks to teh outside of the frame so you have a place to secure them with a set screw

I like the offset stepper mounts, little more expensive than direct drive lead screws but nice if you are you going to gear up the steppers to teh leadscrew to get higher traversal speeds while keeping the steppers in their high torque low rpm ranges.

how are you going to mount the leadscrews to take the thrust from the cuts

if any portion of the gantry turns out to develop a resonance under a cut you can always bolt or weld on ribs in strategic spots

is the leadscrew on the Y mounted offcenter?

just a couple random thoughts cant tell from the pict

[Guldberg]

Its a little hard to tell from the pics, but the x rods are fixed to a small bracket in each end with a set screw. The holes in the brackets are oversized just a tiny bit to allow for small adjustments. The same goes for the the x leadscrew which is squeezed in between two brackets. The y leadscrew is also squeezed in between the gantry sides. It does requires som precision turning of the leadscrews.

The y leadscrew isnt directly below the rails. Jpeg coversion in pro/e sucks apparently.

Good idea on the resonace problem, thx.

Any thought on the gantrysides being 15mm aluminium, should i go thicker?

[dz1]

i would bet 15mm would be good for the sides especially if its extruded tempered stuff which should be tougher than the cast jigplate i think. (even the cast jigplate i sure woudl be fine for this size)

on the one i am doing now i used a 1/2" thick piece of 4" wide 6061t6 for the backbone of the gantry which was 49" long and even without any braces it is pretty sturdy.

[Guldberg]

Hurray, i got myself a new camera. Time for some pictures

The base has been assembled and welded. The gantry sides is of cause mock-ups. It turns out i can have them waterjet cut, proberly gonna be way better than me fumbling with that crappy mill we have at the students shop




Close up of the stepper end. To reduce size the motor will go inside contrary to the original design.


The Y bearings, 20mm


2 of the 4 X bearings, 25mm. I love the feel of these bearing, waaaay better than the rollerskate bearing solution i used on my solsylva


The Z assembly milled out of 15mm alu.


Again using linear bearings, 16mm.


Feel free to comment, i still have time for some changes:-)

[Guldberg]

Woow, 2 updates in a day.

Of cause a proper build router like this needs some decent electronic. For now i have to reuse my hobbycnc board, but in time more powerful motors properly calls for geckos. Anyway, a nice cabinet is needed. 4U 19" cabinet modified for the purpose. Everything is mounted on acrylic sheets, mainly for keeping me not electrocuting myself







The thing on top of the transformer and capacitor is a relay board featuring 8 relays for controlling things like router, light, dust extraction and air


And i bet i have the smallest workshop featuring both a cnc lathe and mill:-)

[High Seas]

AWESOME! Hey, with all that space (in the box)you could build the pc into the box - add watercooling, etc. Have a single purpose electronics cabinet.

Did you bend the acrylic yourself -- or hire it. Like the idea of mounting that way - nice clean look.
Jim

[Guldberg]

Actually its the case from my server based on a mini-itx so it could fit. But right now im using a laptop, so no need for now. Still a few things to come, a usb board with 8 outputs, 5 digital in and 2 analog (any ideas on what to use them for?:-) and a USB-to-keyboard interface to translate contack triggers into keystrokes

Water and electronic dont go hand in hand in my world:-) I dont count on adding watercooling to the router for now, spirit or cutting oil for cutting aluminium will do, else i have the cooling system for my lathe just next to.



Yes i bended the acrylic with a 30$ heatgun i just bought, nice tool.

[Guldberg]

Things are coming along quite nice, i just found out today that the mill im using is totally f**ked. The X and Y is not parallel and there is a huge play in the X plan. This explains why some of the things i made came out quite bad, i thought it was just my skills:-D

Anyway here are the 90% finished Z axis

All the parts


The Y bearings with the bolts nicely countersunk:-)


The assembled unit


For now standard skateboard bearings will have to do

[Guldberg]

Its starting to look like something...


I reused the spindles from my old machine,TZ14x4 (or maybe its 3, cant remember:-) Turned it down to size and threaded it






E-chain is mounted and the one of the x leadnut. I also reused this setup since i plan to invest in a ballscrew in a not to distance future