Need a good table top scrolling CNC!

[RoboChair]

Originally Posted by Aboudy Dairi

Do you see any flex in the gantry when plunging, especially with the drill? How much did you end up spending on the router? I'm extremely impressed just by the footage you took.

I want to mention that the videos are typical of the performance we have observed. I have pushed it far harder than that, but I have to keep my fingers at the controls and jockey the feeds at least until I find somewhere that it likes.

The gantry is absolutely solid, no flex. The Z-axis head and spindle does flex away from the gantry under heavy axial load, a result of the head geometry common to almost all routers. Because the head is cantilevered off the gantry it has a good amount of mechanical advantage to cause deflection, due to the spindle axis being offset from the X-axis linear guides. It's only really been an issue for us when drilling larger than 3/16" holes because of the force required to pull a good chip is a little much for it. The problem goes away when you do a lot of peck drilling or pre-drill the holes with something smaller first. We solved the issue by just using a smaller than 0.250" endmill and helical boring any hole size over 0.1875", which has the happy side effect of one less tool change. For gearboxes and the like we bore the bearing holes 5-15 thousandths under size and post-ream them on our drill press to get the perfect fit.

We spent $6,000 on it but only because we knew which options that we could skip and do ourselves cheaper, what we picked up from Velox wasn't exactly ready to plug and play.

We dropped the following features
No table top surface -$649 (Surfaced ours with extrusion from my work's old router table)
No CAD software -$189
Supplied our own computer -$725
No dust hood -$315
No table legs -$1695
I drove down on a business trip and picked it up on the way back, so shipping was free. -$625
What we did get was as follows
Vectric Cut2D Pro for CAM +$450 (highly recommended, dirt simple to learn and use)
Mach3 License +$210
3.5HP Porter Cable router for spindle Default
1/2" Precision Collet +$100
4-Axis Smooth Step Default
Quick Manual Tool Change tool holders x3 +$260 (Lets you run as if you had a tool changer with pre-zeroed tools)
5% Educational Discount
5% Promotional Discount (for asking them nicely to sponsor us)

The reason we worked to bring the cost down so hard was because we got a 6000 dollar grant for buying a CNC router. I would have liked the Velox table extrusions and the proper spindle, but I was fine for the listed reason and I knew I could buy a spindle from China for about a tenth the price.