New CNC build - AVID 4848Pro with GCnC Electronics
Hi All,
Figured some of y'all might be interested in this build as it seems to fit the size and budget requirements that get posted here often.
Back in October of 2020 I put an order in for an Avid Pro4848 machine with the 'Pro' legs, proximity sensors, Auto Z plate and the 3HP spindle + mounting plate. After asking a few users here and on other forums I decided to go with an Acorn control setup from Gary Campbell instead of the Mach3/4 electronic package offered by Avid (more on this later).
Gary was very helpful, but it turns out that he has sold his business to his business partner Matt DeVincentis. After speaking with Matt through email and on the phone a few times I decided to go with the upgraded package he offers, a Closed Loop control package with an integrated 40amp relay for full automate control of the spindle.
Fast forward 3 months and I just got the call from Avid this week that they're about ready to deliver their part of the system. Fortunately I live close enough to Avid that I was able to save a few hundred dollars on shipping by picking up the system from their warehouse (they charge reduced shipping for the extrusions and no shipping for the spindle / custom parts). Building the GCnC electronics package has also been slowed down significantly by COVID, but I'm hopeful that the whole package will in my shop by the end of the month.
My plan is to post some build updates as well as thoughts on the entire system as I go along. Although there are plenty of glowing reviews on the GCnC setup, there isn't much information about a closed vs open loop setup or about building a combined system (Avid + GCnc; I think I've seen 1 or 2 others on any forum).
That being said, a few Q&A items I hope help others:
Why Avid Pro4848? Why not bigger or another mfg?
First off I really wanted a 4x8 ft machine to start, but after a lot of thought (well over a year) and multiple re-orgs of my shop I decided that although I could technically fit a 4x8 machine, it really wasn't going to be comfortable. I didn't want to go any smaller than 4x4, so that narrowed down my options. From there I liked the ease of moving an Avid machine over the other options. I know it comes at the trade off of rigidity, but I've moved my shop twice before and I'm sure I'll do it again in the future. My wife will probably kill me if I need 3 truck loads to move next time (last time was 2). Finally, Avid is local and I'm sure I'll need their help once or twice in the future, so having somebody nearby was a nice selling point.
Why GCnC and not the Avid electronics?
I've never run a CNC, so all of my knowledge is third hand - but the reviews for Mach 3 are bad and the reviews for Mach 4 seem to be incrementally better. That never really made me feel great. I get that Mach 4 is supposedly a better, but 'better than bad' isn't necessarily great. Acorn on the other hand gets much better reviews and so does GCnC (Gary) as an integrator. I was glad to talk with 2 knowledgable people who have clearly built many systems in the past.
Why Closed vs Open?
An Open loop system would obviously have been much cheaper, but between talking with Matt and watching some videos of (much smaller) CNC machines lose steps and ruin work / catch pieces on fire, I decided to go for the more professional option from the get go. It's no secret that most, if not all, professional level machines use closed loop control systems and upgrading from open loop motors to closed in the future wasn't an economical solution. Basically I'd be looking at near full system replacement, so I decided to spend the money upfront instead.
We'll see how this goes - this will be my first CNC machine. Hopefully it'll also help some other buyers in the future either make the right choices, or not make the same mistake I'm inevitably going to make!
Ben
