First Build looking for tips and advice.

Hello All. First post for my first build. I hope you don't mind a bit of background. I am 44 years old and recently purchased a CNC router to create a water cooling distribution block for my daughters new computer build. I immediately knew the machine I bought was not going to last long. I wanted to upgrade ASAP. The machine I purchased was a BobsCNC E3 which performed wonderfully once I understood how to use it. The concerns I have are with the flex in the gantry and the size of all 3 axes. I would like to build a machine with the capability of milling large cabinet doors and the precision and power to mill aluminum blocks roughly 12" x 12" x 4". I will need the z axis clearance to use a vise. I have created a part list below which is by no means final but gives me a jumping off point for more experienced users to help steer me toward a good choice. Cost is a factor for me, This will be a hobby and I have a family so please understand some of my choices will not be premium or new.

The base size for the table I have decided to make is about 1500mm x 1500mm ( roughly 5' x 5') with about 200mm (8") of gantry clearance from the spoilboard which should allow the use of a vise.
I am undecided between ballscrews and rack and pinion.

Stepper motor Nema 34 Dual Shaft 878oz.in 2A
DM860A stepper driver
nvcm6v2.1 breakout board
2.2kw vfd and water cooled spindle er20 24000 rpm

These items are all on ebay and put me at around 850.00 and if at all possible I would prefer to stay under 2000.00 to keep my current wife.
I will most likely try to build the frame work from aluminum square tubing and 1/4" plate steel.

Thank you for any help, Really.

1) Do NOT buy those motors.

Any motors over 450-500oz should be rated at least 5a-6a for best performance.Look for motors with an Inductance less than 3mH. High inductance motors will run very slowly, and have little power at higher speeds.
Cheap chinese kits are often the worst performing options.
Do not choose motors until you've made you ballscrew or rack and pinion choice. The screw pitch, or R&P gear ratio has a lot to do with motor selection.

2) Do NOT buy a chinese Mach3 controller. Most do not support all of Mach3's functions properly, and they have no support. I don't recommend Mach3 at all, as it's obsolete.


What material are you building the machine with? $2000 is a very low budget for a good 5x5 machine.
Very few CNC Routers are rigid enough for high quality cuts in aluminum. You'll still need to take very light passes. A 12"x12" block will take a long time to machine.

Are you planning to cut 4" thick aluminum slabs or just mill the top?

Hi Monki - You are getting well into mill territory here. A 4" deep tool is a serious tool to hang from a router. If its just a router for the timber work all good. A Mill is a serious undertaking. You will need ballscrews for this machine... or find a small manual mill and retro it... Peter

Quote:

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Originally Posted by peteeng

Hi Monki - You are getting well into mill territory here. A 4" deep tool is a serious tool to hang from a router. If its just a router for the timber work all good. A Mill is a serious undertaking. You will need ballscrews for this machine... or find a small manual mill and retro it... Peter

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The mill can't be too small if it's going to accommodate a 12"x12"x4" block of aluminum. Most conversion mills (the usual suspects) don't have anything close to 12" Y axis capacity. Also, Most benchtops won't do well trying to handle a vise large enough to hold the stock he's talking about. That has to be one serious vise.

Gary

I think you're going to have a tough time with the budget, I spent more than that on the electronics alone. If I were you I would look out for a used machine off eBay or Craigslist or similar sites. If I would have had the space for a 4x8 that's the direction I would have gone. But realistically you need to be more in the $5k range. You also need to be realistic about machining aluminum with a router, you really are limited unless you have a router with a big spindle. Even then I'm not sure people are machining 4" blocks of aluminum, that's really a job for a VMC.

Ok I can see how this is looking so allow me to be a bit more specific to help out. I hope to start a small business building water cooling parts for pc's. The bulk of the work will be with cast acrylic so no big issue there, although milling holes for m5 taps and cutting grooves for gaskets will need to be precise. As for the aluminum I overshot the size without realizing how much difference it would make. In truth the aluminum will be milled down to a size roughly 100mm x 100mm and around 20mm thick. The aluminum will transfer heat from a processor which will circulate through a cooling system. On the other side my wife is big in to crafts and wanted the size to create 3 dimensional signage and things of that nature. I hope this helps get you honed in to my needs.

Please recommend motor sizes,electronics and whatever helps me to get started. I will be buying a little at a time and building from scratch. I would love to buy a machine outright but I have the patience to get it done properly. If I could get a recommendation for a proper business to buy from it would go a long way.

Also considering you get a better idea of what I want to do, I hope someone could advise me toward ball screws or rack and pinion.
I really appreciate your responses. I will check back tomorrow.

Hello Monki - It is really not a good way to go buying things as you go. This means you will make lots of mistakes or commit to things that you will not use or need. You need to design the entire machine to resolution then get everything in one go. It will need to be a ballscrew machine. You had better look at commercial machines that will do your job to establish a benchmark. It will take some months to design a machine, select parts and resolve the design doing it part time. Look at avid cnc machines and see what they have to do your stuff. Turn on your PM's Regards Peter

Quote:

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Originally Posted by Monkiskin

Ok I can see how this is looking so allow me to be a bit more specific to help out. I hope to start a small business building water cooling parts for pc's. The bulk of the work will be with cast acrylic so no big issue there, although milling holes for m5 taps and cutting grooves for gaskets will need to be precise. As for the aluminum I overshot the size without realizing how much difference it would make. In truth the aluminum will be milled down to a size roughly 100mm x 100mm and around 20mm thick. The aluminum will transfer heat from a processor which will circulate through a cooling system. On the other side my wife is big in to crafts and wanted the size to create 3 dimensional signage and things of that nature. I hope this helps get you honed in to my needs.

Please recommend motor sizes,electronics and whatever helps me to get started. I will be buying a little at a time and building from scratch. I would love to buy a machine outright but I have the patience to get it done properly. If I could get a recommendation for a proper business to buy from it would go a long way.

Also considering you get a better idea of what I want to do, I hope someone could advise me toward ball screws or rack and pinion.
I really appreciate your responses. I will check back tomorrow.

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The best advice I can give you is spend the money on your products if this is for a business. Just find a local shop and get some quotes with different price breaks then do a short production run and start selling parts. Once you make some dough weigh it out on weather or not it's more cost effective to invest in the proper equipment to manufacture your products. You need to decide if you are starting a business or if you just want a project. If you still just have to have a router and you have a 2k budget you should save yourself the frustration of trying to build one from scratch unless you have access to a lot of equipment and have the ability to design and build one.

Check out Franco's little router he just built, something like this would be in your budget or possibly a 6090 Chinese router.
https://youtu.be/nzUXw05h83o

Edit
I just went back and reread your original post that you already have a small kit router, so I would suggest if you really want to go down the road of building a new one to spend some time looking at the hundreds of examples on the forum. Eric, David, and GME have some nice examples of extrusion machines which would probably be the easiest to build.

You can get a UC motion controller: CNCdrive - motion controls
You can use Mach3, Mach4 and UCCNC, their controllers work with all 3 softwares.

https://www.youtube.com/watch?v=d7YKPYwatfE

Pm's are on now.

As other have indicated I see it as being extremely difficult to get a large format router in the size you indicated that can also do a credible job of drilling and tapping or even thread milling for that matter. The problem is that low cost machines are generally not stiff enough for such usage. The only way you might come close is by finding used components that can be retained for your build. If you get lucky at the rightsort of auction you might be able to get good hardware for 10 cents on the dollar often less. But these auctions are rare and you will end up buying a lot of scrap material to get that stuff you need.

Your best bet is to focus on one need or another. Even a large format wood working router quickly ends up costing money. You might be able to hit your $2000 budget but you might not be happy with the results. The important thing here is to understand your expectations, your wife’s expectations and how a large format router might address them. Then you need to understand what type of build is needed to meet your goals.

As for routing Aluminum heat sink blocks the lowest cost route here might be to do a small mill conversion. This will still put you over $2000 for a decent conversion but if you choose the right mill you can get kits that greatly reduce your effort. The reality though is that these conversions are still very limited in capability due to slow spindles and the mechanical skill needed to maintain plain bearing ways. However more than one guy has started a business with such conversions and a good portion of them quickly upgrade to Haas type mills. To put it bluntly most businesses can not afford to be dicking around with machinery. The ability to compete demands high performance machinery that is reliable. There are some low end machinery such as the Tormach line that might be a better place to get started. How expensive that hardware is is likely in flux due to tariffs so a $7000 dollar mill could easily become a $12000 mill.

The third possibility here is to build a bridge mill type machine. This is a router built more robustly and smaller than most routers. If you keep the work area small, say 250mm it is far easier to achieve a stiff machine with all the axises properly aligned. Ideally it would be a moving table design. You would also need machining help to get the critical parts right. This is another advantage of a small bridge mill, much of the machining can be handled on tool room equipment like a Bridgeport or small horizontal. You will need that machine support so that needs to be factored in cost wise. If you find somebody in the neighborhood with a Bridgeport you may be able to save some dollars there.

If you are wondering about the references to machining it is because I don’t believe it is possible to build a suitable machine out of extrusions. Thermal blocks like you are looking to build require a funky machined mating surface with the processor package. That means flat and a high quality surface. The rest isn’t as big of a deal unless you get into channelized paths for the water flow, then you have matting parts to consider. There are all sorts of considerations here, for example a fly cutter might give you that surface finish but you need to be concerned with spindle RPM. Small cutters would require excellent tramming of that spindle.