Hi All, I have been playing with a small 3018 CNC for over a year now and have been doing some great work. Getting my daughter involved as well has made it even more enjoyable! We have got to the stage where small signs and things are getting a bit boring and we want to be a bit more adventurous. I have looked around for ages and been tempted by some of the offers that you see for a large machine but to be very honest, spending about £1000 is not ideal as we can't really afford it. I work for an engineering company and last week we had a job to do for a new customer. There was a lot of large aluminium extrusion left over from the job that was going to be thrown away so I persuaded my boss to let me have it along with all the leftover fixings and brackets etc. In theory, I now have all of the framework needed to make my own machine that can cut around 1200 x 1500 if I wanted. I already have a palm router at home as well so am I right on thinking I only need the below to get up and running Ball screws / Rails for the motion Stepper motors Router Bracket GRBL Controller / Power supply Waste Board Is there anything that i am missing?? Can it really be that simple now to get a physical machine made up? Many thanks Paul
Well, that's the general stuff, but there's a lot more that goes into it. Wiring, motor couplers, nuts blocks, etc. The Openbuilds machines have parts list or you can find public builds here and look at their parts list. Maybe even watch some of the OpenBuilds assembly videos to get a better idea of what you are missing.
Excellent. As I work for an engineering company I can easily get hold of nuts bolts etc. brackets can be made from scrap material we have around but the more critical parts I think I’ll need to buy. ill start my shopping list!! many thanks
Good luck! There is a TON of little things that go into these machines. I was initially thinking about building my own, but in the end, I went for a LEAD bundle. To be honest, the aluminum extrusion is probably the least of it. Just at a quick glance, if you take a look at the LEAD 1010, without the router, it runs about $1900. The v-slot extrusions and c-beams make up about $220 of this cost, so you're still talking about $1680 in additional parts and components. You'll want to put some thought into making sure you have appropriate brackets and connectors to give you the rigidness you'll need, especially in a machine that size.
Thanks for the info. Been looking at the rails and ball screws and i am comfortable that these can be covered for all axis for a reasonable price. The biggest outlay i can see is the controllers. The 1 thing i am struggling to see is what size steppers these larger machines are using? Is it the Nema 23 or Nema 34? or bigger? They both look like they could handle the weight and power but can't really see the proper requirement. I'll keep looking. Was also looking at a complete controller setup like this https://www.sainsmart.com/collections/genmitsu-cnc-replacement-upgrade-parts/products/cnc-4-axis-kit-wtih-nema23-motor-driver-board-power-supply i can see similar kits as well which seem a good price at the moment. Got my list going so see what kind of costs i end up with Thanks for all your help, really appreciate it!
If you are considering the $229 one the link went to, I think you would be overcharged by nearly $60 for that kit. You are getting four $10-$12 TB6560 stepper drivers, four $20 Nema 23 270oz motors, a usb cable (of unknown quality), a power supply of unknown quality (an equivalent Meanwell 24V 10 amp power supply is $40) and an $8.99 breakout board which requires you to purchase Mach 3 software, or use LinuxCNC (there may be other choices). You can not use GRBL with that board so it is basically a throw away unless you want to use Mach 3 or LinuxCNC. I have purchased some Sainsmart electronics components before and can not think of any issues I have had, so I can not say first hand what their customer service is like should something not work.
OK, Appreciate the comments. What would be the ideal GRBL setup for a custom build? I definitely want to use this as I have a lot of easel files saved which I want to continue using as well as some from carveco which is what i am starting to use instead. I have looked through some of the custom builds on here but not many people go into the detail around the electronics. The electronics side is my weak area, all the structure and mechanical i can do myself with a bit of help from the engineering team at work! Many thanks Paul
Thanks, I did initially spec this up and it's around £350 of kit with cables and steppers etc. Hence why i initially asked about the cheaper 1 from Sainsmart. Can i just ask about the steppers? There is a high torque option for the Nema 23. Would the high torque be needed for a larger machine? The main cutting would be wood. Thanks
Not really needed, but do make for a good upgrade Be weary of the 3rd party steppers - ours are premium spec - custom made for us - ideal voltage/inductance/resistance values to be perfect match for the stepper drivers too - we actually care that the things all work together too (;
Always makes sense to buy as a package. I can see that even the connectors are pre-configured for the black box controller so it's a good choice. Appreciate the help Paul
While I understand the need to stick to a budget you’ll find there is nothing more expensive than trying to go cheap. Buy right, buy once. As for the steppers you’ll need to select the ball screws first. The heavier the screw the more desirable the high torques become.
If you do go with ball screws be careful of what pitch you select. Many people go with 1605s because for some reason they are sold everywhere. However, the nut will only move 5mm/rotation. Whereas the lead screws OpenBuilds sells will move 8mm for every rotation. What people that select the 1605s soon realize is that their machine may be a lot slower than they hoped. 1610s would be a better choice.
