[Ironman1952]

I have been a cabinetmaker for 40 yrs. all highend residential and furniture pieces.
I have been researching cnc routers and am leaning towards a DIY machine.
Mainly for carved pices for furniture. I am thinking a 3X6 machine. Double ballscrews in Y and single in X and Z.
AC servo motors with encoders, (not sure what type of encoder yet, any thoughts?)

I want to use steel frame, probably bolt together for fine tuning, and maybe aluminum gantry ( not completely sure here)

I am looking for articles and reference material to study. I also am pretty green on the controls part :-(

Any help would be appreciated. In the meantime I will continue to read all that is on this site.

I wish Katran would speak with me as I like his design concepts.

Anyway I am in Soap Lake , Wa. USA

Great job everyone :-)

My website is. creativecraftsmanwa.com

Joe

[wizard]

I have been a cabinetmaker for 40 yrs. all highend residential and furniture pieces.
I have been researching cnc routers and am leaning towards a DIY machine.
Mainly for carved pices for furniture. I am thinking a 3X6 machine. Double ballscrews in Y and single in X and Z.
AC servo motors with encoders, (not sure what type of encoder yet, any thoughts?)

Going with Ac servos is OK if the rest of the machine is good enough to justify the additional expense.

I want to use steel frame, probably bolt together for fine tuning, and maybe aluminum gantry ( not completely sure here)

Aluminum isn’t cheap, at least it hasn’t been. The unfortunate thing in many DIY machines is poor gantry design. There is a good thread in the stickies than covers some of the more important aspects of gantry beam design. Before locking in a design I’d review that thread carefully. In general though a square steel beam is often very cost effective.

As for the rest of the steel frame bolted up frames can work well but there are places where overall it might be better to fabricate steel weldments and have them machined. The gantry supports come to mind here. You could also use an epoxy grout to avoid some of the machining expenses.

Epoxy leveling is another option for the larger frame. You need to do something because structural steel is nowhere near as straight or flat as is needed for linear rail mounting. There are lots of discussions in various threads focused on addressing this issue. The reason many avoid having the machines frame machined, is the high cost when you find a shop with a big enough mill. One option to moderating the cost is to have the frames beams macined before the frame is completely assembled.

I am looking for articles and reference material to study. I also am pretty green on the controls part :-(

There are few really good books or apps or web sites on this subject. You kinda have to read every thing you can findand digest all the good bits. There are some really great build threads here though. Controls can be tough if you don’t have a basic electronics background.

Any help would be appreciated. In the meantime I will continue to read all that is on this site.

I wish Katran would speak with me as I like his design concepts.

Anyway I am in Soap Lake , Wa. USA

Great job everyone :-)

My website is. creativecraftsmanwa.com

Joe

Best of luck with your quest! Just realize that if you don’t have a lot of machine tool experience there is a considerable learning curve. It take a lot of time to do a decent build. There are also many different approaches to a good build.

[he1957]

Joe, your 40 years of cabinetmaking shows - beautiful work! :-)

There can be a lot of work in a DIY machine. There are quite a few kits out there and of late it seems of increasingly variable quality. Research this forum to see lots of different approaches of folks who have designed and built their own or others who have built from available "kits" or just used various part assemblies from suppliers (eg: Z axis assemblies). Looking at your work implies you are looking for high accuracy and repeatability possibly with some higher performance (speed) so any machine you choose is going to need high rigidity and I'd agree to go with servo based motors.

It is difficult to compete with the mass production of some of the Chinese kit available these days. Viewing a lot of machines seems to indicate very similar components with varying degrees of assembly along with quality (or lack thereof) of workmanship from various suppliers. It looks to me like there is a big factory that makes various components and these are then used by the different suppliers to build their "unique" machines. Model numbers seem quite similar generally referring to the X/Y dimensions of the work envelopes.

I recently purchased a 4 axis 2400x1200x200 machine from China with stepper motors, fully welded frame, case iron gantry with 16mm steel supports, rack and pinion dual drive on Y, single on X with ball screw on Z. The machine itself is built like a brick s*thouse weighing in at just on 1000kg. With a different spindle I could probably cut mild steel but don't intend to.

The accuracy/repeatability is very good along with very good performance overall. My usage varies from general sign making to more intricate carving such as I saw on your web site along with custom parts or other items.

When I said "kit" what I mean is a complete and functional machine however, along with the comment about workmanship it seems to be that much of the Chinese kits have reasonable to good quality components, somewhat assembled to somewhat unfinished workmanship.. For example, uncleaned cuts, unground or unfiled mating surfaces and so-forth. So what I've found is that these machines need to be finished after delivery and testing. Cleanup edges, and go through a finishing phase to complete what should have been done, including fine tuning. For examples:

a. The T-Slot table was wider by 3mm at one end and not parallel to the Y axis
b. The gantry was not perpendicular to the table

Although these issues are not all that difficult to fix, it is just one of those things that should have been done in the factory. So if you do look at the Chinese machines, just be prepared to finish it to your satisfaction. Of course having said this there is a large difference in cost versus effort to do this oneself rather than spending considerably more on a plug and play machine. A second-hand Multicam of similar specifications would have cost me about 50-60% more.

The overall effort I've put into this would probably be similar to having assemble a machine from parts but such a machine would be no-where as solid as what I have. It worked just fine out-of-the-box but I don't like things that are not quite finished the way I would do them.

Cheers,

HarryE.

Example of work before my tuning:

[Ironman1952]

Thanks for your time I really appreciate it. Where are you from? I have been reading and redesigning now for about 3 years. I have looked at the Shopsabre models but by the time I get what I want on it it comes to 50k
I do have some electronic background from a century ago but It does help in understanding what the controls are doing, However I will continue to read and absorb and then make some decisions.
I had thought about making the Frames in the Y axis and then having just them machined and then bolt the spreaders in the X axis to them with some sort of adjustment and a way to bolt them so they wont move with any vibration.
Trying to figure the servo size in the Y and X axis to account for the pressure based on the speed, size of cutter, depth of cut, possible material density is the part that is really complicated for me.

Anyway Thanks again :-) Joe

[he1957]

Hi Joe,

I'm in Tasmania, Australia. I also was designing and wanting to build my own for the last 10 years but decided to buy one so I could just start using it.

Here is my machine sitting in the factory before shipping. It took almost 4 months from order to delivery. Moving 1000 kg in a box 3 metres by about 1.5 metres square is not all that easy!

1224 wood cnc router machine - Jinan Remax Machinery Technology Co.,Ltd

Over the last couple of weeks, I have mounted the 4th axis from the opposite end of the table as seen in the above photos and also recessed it downwards such the top rails of the table slides are below the aluminium table surface - that way I can surface off the rubber to the table top and replace the rubber if I need to. A spoilboard goes over the top to cover the 4th axis if not in use and cover the gap. The gap at the end of the rotary table allows me to mount material vertically for end milling as needed. I'm thinking of mounting the spindle to a manual rotary table (I have one not in use yet) so I can also do easy slant milling but haven't decided how I'll do this yet. If I did that I could also add another motor to make it a 5 (or even 6) axis machine but then the spindle would overhang the end of the table and I'd lose some of my 2400 travel. Being such a solid machine, I could just bolt on an extension come to think of it and max Y travel is actually 2465mm.

As mentioned, I have spent time and effort making it "just right" for me. I've squared up the bits that weren't and some other stuff and it's now almost ready to put to serious work. They built it more of less to order but I added the 4th axis after they started and as a result they stuffed up on the controls and supplied a controller for 3 axes - that's since been sorted out. Originally, I was going to have it made with servo motors but decided to save a few $ and maintain compatibility with a CNC milling machine I built about 10 years ago (stepper based), so I could interchange an older controller if I ever needed to.

Just now I'm surfacing the table top at 4500mm/minute (fastest I've used yet) over the table (rubber) and it takes about 40 minutes at 0.015mm DOC. The finish is excellent.

(max X/Y travel speed was set at 8000mm/min but that speed scared the bejeepers out of me so I dropped it to 5000 max)

If you would like more detail, feel free to PM me.


Cheers,

HarryE.
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