View Full Version : Shopbot ?s

Richard Wolf
10-11-2007, 6:13 PM
Thinking of adding a shopbot to my shop. Is the alpha model worth the extra money? Is a spindle worth the extra money over the router?
Any comments on the learning curve?



Keith Outten
10-11-2007, 8:17 PM

The old PRTalpha has now been replaced in the top spot by the new PRSalpha but I doubt anyone can answer your first question other than you, the value of each model is relevant to an individuals needs.

I have the PRTalpha 48 by 96 with the router in my shop and the same machine with a spindle that I operate at CNU. The spindle was an additional $2,800.00 and is worth every penny if you plan to run your ShopBot all day long five days a week or if you have sensitive ears. The spindle produces less noise...but that depends on the material you are cutting. For instance when you are cutting plywood it doesn't matter since you couldn't hear either over the noise of the bit. Cutting MDF or Corian is a different story as there is less noise from the bit you can actually hear the router whine but barely hear a spindle. Personally i don't give a hoot about the noise as I am going to be wearing head phones either way.

A spindle is more accurate in that it has less run-out than a router motor, this can be a big deal of of no concern depending on the work you do...do you care about a few thousandths of an inch? The spindle will definitely last longer but is expensive to rebuild, a router is cheap...throw them away when they are worn out or replace the bearings for just a few bucks depending on your situation.

I run them both and don't have deep feelings either way but when it was my wallet that had to provide the funds I went with the router. The only thing I would do different would be to pass on the Porter Cable router and go for the Milwaukee motor.

The learning curve is relevant to your knowledge of graphics software and the level of experience you hope to attain. There are so many levels you may never see the top but many are happy to function at the lower end of the scale doing simple machining jobs and never consider doing high-end 3D type work. The good news is you will never outgrow your ShopBot.

Whatever you decide you will love your Bot, it is very close to the vortex situation that wood turners are always talking about...except it makes money :)


Richard Wolf
10-11-2007, 9:24 PM
Keith, thank you for taking the time to answer some questions.


Keith Outten
10-12-2007, 7:32 AM

No matter what decision you make concerning the make or model most would agree that V-Carve Pro software is a real bargain and it makes it so much easier to get started. VCP is relatively easy to learn and provides a preview that shows your mistakes before you start up your CNC router. When the preview is right the part will machine as expected and this will save you time and money. I'm still a novice but I have managed to machine some nice parts and signs with just a couple hours invested in learning VCP.

Some of the best advice I ever read was from a ShopBotter who said that 90% of the money made is done with the free software that ships with a ShopBot. This is probably more true today as I heard that ShopBot is including VCP with each machine now.

I was invited to speak at a ShopBot Jamboree a couple of years ago in Durham and also at several ShopBot Camps. My message was to the CNC nubies who are worried about getting started and wondering how they can make money to pay for their new router. I try to assure them that they shouldn't worry about learning to do the high end machining right out of the gate and that even simple machining can be very profitable in the first week you own your machine.

Imagine that you were a power user and spent four to five hours on a design. Then you spent 8 to 16 hours machining a very detailed sign plus the costs associated with painting. Your sign will be beautiful all right but very expensive. At the same time I can cut hundreds of door signs and probably produce more income at the end of the week with very little experience.

The cabinet makers are in a similar situation, since many cut the same parts all day long they often realize more profit from their ShopBot than the 3D sign designers. In time I hope to be able to increase the detail of the signs I make but I don't feel rushed to get to that level because I have bills to pay. I know that even simple jobs can produce the kind of income necessary to pay the bills and I can take my time learning advanced techniques without having to worry.

It took me two years to pay off my laser engraver but only one week to pay for my ShopBot. In all fairness I have to admit that I had a very large sign job in my shop when I ordered my ShopBot so I didn't have to market or bid new work. I put the Bot to work as soon as I got it assembled and it only took a couple of days to complete machining the remaining sign blanks for the project. The time savings was astronomical and the quality went through the roof over making blanks in manual mode with a band saw then sanding the edges on a spindle sander.

At CNU our ShopBot only runs an average of two days per month. It can produce more signs in two days than I can process and install the rest of the month. These are mostly mass produced sign blanks for facilities but I often get requests for custom ceiling access panels, moldings and other fancy machining jobs as well. The bulk work of making door signs pays the bills and makes a profit, the high end work has little or no cost involved other than material. Scraps from projects can add up fast, for instance I have enough material left over from a custom Corian molding job to make all the door signs for our new Library construction project. A $15,000.00 sign job will be done for about $500.00 in material in three weeks time using mostly scrap Corian left over from another job.

Food for thought.


Richard Wolf
10-12-2007, 8:30 AM
Thanks again, your insight is very helpful.


Bob Reda
10-12-2007, 8:46 AM
I purchased a used 48x48 prt a few years ago with a twin z. If you want one to go faster get the alpha but the prt has been really great for me. My machine doesn't run 8 hrs a day, so the routers are just fine. Like Keith said, shopbot is starting to use vcarve pro and also cut 3d. Don't worry about trying to create 3d models, there are plenty out there to buy from 10-75 dollars each if you want to go that way.

Richard Wolf
10-12-2007, 8:59 AM
Thanks Bob, maybe you could explain the use of twin Z axis?


Ed Lang
10-12-2007, 9:21 AM
Hello Richard,

I will add that I have a PrtAlpha and started with a PC-7518 router. I upgraded to the 4HP HSD spindle and speed control. I can now set the spindle speed via software. I also upgraded my stock motors on the X and Y to the current 7.2:1 motors that are shipping on current machines. I have more resolution and torque. I will also say that vacuum is a real good way to hold material on the cnc. The upgrades were well worth it to me. The stock machine is fantastic.

If you let me know what your plans are for your machine, I will try and do better than saying the ShopBot will work great.


Bob Reda
10-12-2007, 5:31 PM

Twin z's are two routers that are independent of each other. If I can figure out how to set it up I could have different bits on each and call each one in as I want to use it. For example, a v bit on one and a end mill on the other.
Also, look on the shopbot web site, there are quite a few good used machines that can let you do other things with the money saved.


Richard Wolf
10-12-2007, 9:05 PM
Thanks for the help.
Ed, with the slow down in the home building industry, I have extra time on my hands to help my wife with her craft business. She is a painter, and signs are a big part of her sales, so I was leaning in that direction.


Tom Galzin
11-27-2007, 12:00 AM
There are a number of machine builders that would be worth a look. FactoryNEW.com has a nice machine for the money.