Hello everyone, first post disclaimer. Ive recently purchased a Workbee 1520 and started with the recommended design. DeWalt router, belt drive, etc. However, I’m eventually planning on beefing it up as I’m sure a lot of you all do. Here are a few upgrades I'm considering: Dewalt to Spindle Belt to Lead screw Stepper motors to servos For upgrade #1(Dewalt to Spindle): I really want to be able to quickly cut through thick aluminum and potentially cut mild steel(slowly). For this I’ve determined a 3.0 rated FVD and 2.2 rated Spindle could do the trick. However, I’ve read some articles on 1.5kw spindles and that seems to be what most use, but a 2.2kw would clearly be better. It seems the main reason people pick the 1.5kw over the 2.2kw is because of the rumored weight being too much for the build. Do you all have any perspective on this? Do you know of any builds using a 2.2kw? For upgrade #2(Belt to Lead screw): Once completing some version of #1 I’m going to need to upgrade the drive system. I’ve looked into better belts, but haven’t found any solution that I feel could handle difficult loads. For the previous reason and for improved accuracy and improved strength I’d like to upgrade to using a lead screw design. As I’m sure you are aware if you are still reading this is that when you use a lead screw over too much length you can get a lot of whip in the lead screw. My understanding is that at longer lengths the lead screw diameter is too small(for what openbuildspartstore.com offers). If I were to go with a 1/2” lead screw with 8 starts, do you think I could eliminate a majority of the whip/bouncing? Would I run into issues of accuracy when I comes to timing travel with the steps the motor is capable of because of the new threads(or will software address this? What about a 3/4” lead screws at 6’ lengths? I know there is a big cost difference but that aside, what is best suited to work? For upgrade #3(Stepper motors to servos): If I were to implement some form of #1 & #2 then I would likely need to upgrade the stepper motors. This is the area I know the least about so please don’t assume I have a preference. I know higher power stepper motors exist, but I’ve also heard servos can be really good too. Given the context of #1 & #2 what would you all recommend? Lastly, I know that if I were to do all of these upgrades(and I don’t kill myself in the process) then the frame will become the weak point. I have considered this and plan to improve the frame when the time comes. Thanks for reading and any answers! James
I will be brief. Spindle - The deciding factor is usually the weight. This is primarily dependent on your machine, in the strength of your gantry/ x Axis that will be holding the router/spindle, and the motor that will be holding the router/spindle. I went with a 800 Watt Water Cooled Spindle. I can not say that I have been disappointed. I have cut a significant amount of aluminum without issue. My recommendation however would be for the 1.5kw spindle. Personally I have not been able to find a 110v 1.5kw 65mm water cooled spindle, otherwise, if I did, I would buy it. Screws - I am a fan of screws. The biggest limitation if what you can fit into the machine without total revision. I started with the 8mm leadscrews that Openbuilds sells, but have since moved on to 16mm ballscrews. Steppers/Servos - This section can just be called Money$$$$. 1) Nema 23's will take you pretty far. 2) Once you get to Nema 23 High Torque you will need stepper drivers, or a new controller. 3) Servos can cost about $250 a motor, plus the power supply, so servos could be well over a $1000. My advice would be to work on upgrade 1 & 2 first.
Thanks CNCMD very helpful! When it comes to the aluminum you have cut, what is your typical material thickness? Depth of cut? Bit size? As for the 16mm ball screw, what build setup do you have? Why did you decide to upgrade? Would you upgrade again?
I have cut up to 1". Typical is .25 - .50". DOC is usually .5mm for roughing. Bit size is 1/8". Build is completely custom, you should be able to find it in the build section. Decided to upgrade for a handful of reasons. First I hated the wheels, between balancing the eccentric nuts to be equally tight, the inability to adjust them easily, dirt and chips getting into the wheels and ruining them. This was on a Sphinx. I would point out more could have been done to isolate the wheels from chips. So I went with linear rails to replace the wheels. Screws - takes a real understanding of the machine to eliminate backlash. I was able to remove most of the backlash in the system by going to lead screw clamping collars. Now, keep in mind, my old machine was used to build the new machine, so it was certainly a decent, capable machine.
I'm not sure where you are located, but a 1.5kw 110v can easily be had. However, many have stated that going 110v is a waste. Voltage in any kind of motor is a big deal. Looking through all of the posts from cnczone and other forums, everyone is saying that the 110v variants are just dead weight. Not only that, but they are pulling double the current (P=IV) from the mains. Also going from the 65mm to the 80mm doubles the weight, even though they may have the same 1.5kW rating. The limitations I encountered on my 500x500 (extrusion length) Sphinx were the wheels. Not too far after that was the router though. That was with a Bosch Colt Palm router. An 800W spindle is supposedly a good upgrade over the similarly rated router, so I don't see a 1.5kW on such a large frame to be of much use. It's still going to be ER11 with the 65mm, which means there is no end mill advantage either.
