I may finally go with a CNC

[JWD]

I have several products I make part time and sell on the side.  The last several years I've been horribly far behind on production.

The most popular one, I've figured out how to make it via CNC, and I have a friend who will scan it for me and demonstrate how to turn the stp file into a gcode model (I'm assuming this is the tool path step, but not sure yet).

 

So I'm looking for a CNC machine that is nice and rigid, and can be set up with minimal effort by a noob.  I was pretty good with computers 20 years ago but through lack of interest I am pretty much stuck in that time frame.

 

In addition to several that I have seen mentioned in posts here and on router forums (probotix, xcarve, shopbot), this one came up in a "best of 2024" review:

https://www.eagletec-cnc.com/cnc-wood-router/4x4-cnc-router.html

Obviously, made overseas.  But one thing I like is an integral vacuum - I plan to use vacuum to hole parts in place.  The other thing is it appears to be pretty heavy duty for the price, more so than a lot of the domestic machines I've seen that just have aluminum plates supporting the gantry beam.

 

My part will be made as two halves, with a vacuum pallet holding as many pairs as I can fit in the machine.  The 25x25 probotix model would make me 16 pairs at a time.  A 48x48 machine could make 64 pairs.

 

The part that makes me lean much more towards a machine like a probotix is future flexibility.  I won't always be making these parts, it's a tiny market that I've been expecting to saturate for years now.  I will be happy enough if I pay off the machine cost in a year's worth of parts sales and then demand drops.  I think that would be pretty realistic as a worst case if I can keep the machine upgrade cost under $10k.  And for what it's worth, pay off is really pay myself back, so there is no financing involved in this, I just treat it as if it's been loaned in the hope that it helps me make good decisions.

 

Which brings me to the ultimate question - what does anyone with more experience think of all this?  Spend more on the domestic machine or go for an easier pay off target with an imported machine?  I know that is an impossible question, but maybe just some reflections on that import machine?  I couldn't find many reviews of it or discussion of problems in a page or two of search results, just the company selling their stuff.

[4DThinker]

A CNC with a vacuum table is something Probotix doesn't normally offer.  Their open frame design though with slotted aluminum extrusion frame would be easy to mount one into/onto but that would be up to you to come up with.   They have sold many machines for small companies and done unique configurations for them which implies it'll be worth contacting them about your needs.  I've even seen a multi-spindle version they've made for a client so a row of parts could be made at the same time.  Their normal $5k-7k prices also is low enough that getting more than one might be possible and  both could be running at the same time cutting the same parts or unique parts each. 

4D 

[Grandpadave52]

@difalkner, @honesttjohn...ideas, thoughts on JWD questions.

[JWD]

1 hour ago, 4DThinker said:

A CNC with a vacuum table is something Probotix doesn't normally offer.  Their open frame design though with slotted aluminum extrusion frame would be easy to mount one into/onto but that would be up to you to come up with.   They have sold many machines for small companies and done unique configurations for them which implies it'll be worth contacting them about your needs.  I've even seen a multi-spindle version they've made for a client so a row of parts could be made at the same time.  Their normal $5k-7k prices also is low enough that getting more than one might be possible and  both could be running at the same time cutting the same parts or unique parts each. 

4D 

 

Yeah, it's pretty much assumed that I would have to come up with the vacuum for most machines.  That is not a huge deal, but adds to the cost somewhat.  I used to use a Welch 1397 to degas casting resins - there was one at work that no one used, so no one cared if I used it.  Seems like a lot of surplus dealers around here have those and they aren't bothered by a few little leaks since they pull down so fast.  But this is also part of the allure of that import - one less problem to solve before making product.

 

Unfortunately, only one of my products lends itself to CNC production.  The others would all require rotation-axis setups, which limits the appeal.  Doesn't kill it though, since my day job is on thin ice in a couple years when the current survey funding comes to an end.  A four spindle machine with 2-3 rows of parts could be very useful if I'm on hand to change the parts once an hour or so.  I could copy the ganged rotation design from my Terrco machine, with a big enough motor it would drive multiple rows.

 

Thanks for your thoughts, your post alone got me thinking a bit longer term also.

[honesttjohn]

Too bad you weren't closer to Michigan.  I still have my Probotix Nebula just sitting idle.  I really could use the room to build the second Avid.

[4DThinker]

2 hours ago, JWD said:

 The others would all require rotation-axis setups, which limits the appeal.  Doesn't kill it though, since my day job is on thin ice in a couple years when the current survey funding comes to an end.  A four spindle machine with 2-3 rows of parts could be very useful if I'm on hand to change the parts once an hour or so.  I could copy the ganged rotation design from my Terrco machine, with a big enough motor it would drive multiple rows.

 

Thanks for your thoughts, your post alone got me thinking a bit longer term also.

One of the machines Probotix showed on their facebook page was a multi-head rotary axis setup.  I don't remember what their customer was making but they even modified the frame so larger diameter parts could be cut.   I've got a rotary axis on my Probotix Meteor (25x50) and it is limited to 4" diameter parts due to the way the tailstock is supported.  Their current machines have taller side supports (more Z-axis travel above the bed) for the gantry now.  I suspect up to 6" diameter parts could be cut with perhaps some re-configuring of the tailstock rail.  

4D

[difalkner]

I don't have any experience with Probotix or any of the others mentioned.  The Eagle Tec mentioned is a Chinese machine so getting support might be tough and you'll have to take that into consideration.  If 4D likes the Probotix then that's a good reference.  I built my own CNC (26x50 cutting capacity) but it's pretty stout and weighs in at a hefty 600 lbs.  I've seen the OneFinity, Shark, Laguna (rebranded Chinese), another rebranded Chinese machine simply called Professional CNC, and a few others but that's about all I've seen.

[JWD]

On 11/10/2024 at 5:39 PM, honesttjohn said:

Too bad you weren't closer to Michigan.  I still have my Probotix Nebula just sitting idle.  I really could use the room to build the second Avid.

I might be interested if you want to sell it, that is the size I was considering. 

 

Shipping freight is not too complex, I've done it several times with various machines.  I've always done warehouse to warehouse freight shipping since that's cheapest.  The warehouse guys always comment on the high quality of crating that woodworkers seem to do  

[4DThinker]

Not to quell a sale, but that generation of machines Probotix made only have 3" of Z axis travel above the bed.  Stick a 1.5" exposed end mill in the router and that depth is reduced to 1.5" .   Fine if most of what you'll be cutting is no thicker than 1.5" and usually 18mm plywood or .75" thick hardwood. The nebula I used at work, due to the longer gantry beam, also has some flex in it. The vibration from cuts through hardwood often set of the Z axis limit switch. Until they upgraded the control software to ignore limit switch hits after the machine was homed our Nebula was almost unusable.   

 

The new machines Probotix makes have a larger/thicker/stiffer gantry beam, 5" of Z axis clearance, and a few other improvements mostly in response to complaints/suggestions from previous owners such as myself.  

4D

[honesttjohn]

4D - -  there's also the difference between $2500 and, what, $7K or more?  The bed can also be lowered to give more cutting depth if you remember back then when you helped me decide what machine to start out with.  It's a good simple machine to help understand the workings of the CNC world.  It gave me an understanding for the next step up, as well as making a few bucks along the way.

Edited November 13, 2024 by honesttjohn

[honesttjohn]

30 minutes ago, JWD said:

I might be interested if you want to sell it, that is the size I was considering. 

 

Shipping freight is not too complex, I've done it several times with various machines.  I've always done warehouse to warehouse freight shipping since that's cheapest.  The warehouse guys always comment on the high quality of crating that woodworkers seem to do  

PM me if you want to talk about it.  

[JWD]

Good points on both sides of that question.  Going to have to think about it. 

 

The Z limitation is less of a problem for my current project than it would be for future ones that would require a rotation axis.  For what I'm making the max relief is about 3/4" because I'm setting them up as two halves of what I currently make as one piece on the Terrco duplicator.  For this part I don't intend to keep making them as one piece because doing it that way is a pain for a bunch of reasons.  There are similar products I make that I would keep doing that way, but sales of those are so slow that I never even made the jigging to hold them in the duplicator, just carving by eye on a coarse belt sander is less trouble.

 

Flex in the gantry could be a problem, but more from the limit switch bug than anything else.  A little cleanup is likely anyway since the parts are going to have to be glued together following shaping.  Since I started doing this work carving everything by eye, I have plenty of sanding setups to do rough shaping through cleanup.  It would be ideal to have the least cleanup possible however.

 

[JWD]

23 hours ago, 4DThinker said:

Not to quell a sale, but that generation of machines Probotix made only have 3" of Z axis travel above the bed.  Stick a 1.5" exposed end mill in the router and that depth is reduced to 1.5" .   Fine if most of what you'll be cutting is no thicker than 1.5" and usually 18mm plywood or .75" thick hardwood. The nebula I used at work, due to the longer gantry beam, also has some flex in it. The vibration from cuts through hardwood often set of the Z axis limit switch. Until they upgraded the control software to ignore limit switch hits after the machine was homed our Nebula was almost unusable.   

 

The new machines Probotix makes have a larger/thicker/stiffer gantry beam, 5" of Z axis clearance, and a few other improvements mostly in response to complaints/suggestions from previous owners such as myself.  

4D

 

Some thoughts on that vibration - looking at their page for this unit there's a picture of the old vs. new.  The old looks like a 1530 ultra-light gauge extrusion - I'm thinking just upping that to a light or standard gauge extrusion would take care of the problem (which I'm thinking of because I have a source of that stuff, if there's a long enough piece).  Alternatively, cost to change it out looks like $100 or so, which isn't bad in this context.

[honesttjohn]

I've never had a problem with flex in the gantry.  But I just did Vcarve signs and 3d carvings.  I've cut 2" stock with no problems.  Not everybody does vertical compound joints, or whatever 4d did.  Besides, he was the main reason I bought the Nebula to begin with, after he touted how good they were.

[4DThinker]

Swapping out the gantry beam is more trouble than just unbolting it from the vertical sides.  Cables run through it to the gantry stepper and likely a limit switch or two.  When Probotix came out with the taller/stiffer gantry many asked if they would provide that as an upgrade to their older models.  "No" was their answer as they knew how complicated routing all the cables through it was.  The steppers don't unplug from the router cable.  So  you would have to unsolder the plug of both X and Z, feed them back though the cable chains.  That and the power cable that feeds the router.  My meteor has 6 data cables and one power cable that run through the initial cable chain up to the gantry. One for the Z axis limit switch.  One for the Z stepper, two for the X axis limit switches, another for the X axis stepper, and dual limit switches that ride with the gantry on both sides for Y axis limits. 

Not entirely impossible, but considerable work which may end up with some bug hunting if you aren't careful at resoldering the cable ends to the right pins on the right plugs.

 

4D   

[JWD]

Not really a problem, I do stuff like that fairly often in the day job.  Difficulty largely depends on what kind of connectors were used, with a lot of them the pins can be removed and reinstalled.  I can borrow the crimping tools at work if a pin needs to be replaced.  The key thing is to take lots and lots of pictures first  These days that's easy to do.

 

If the cable chain is a type that doesn't open, I would likely swap it for an easier to service type if I was doing all this anyway.  Might never need it but the one time you do it's worth it.

 

But from what honesttjohn says it likely won't be a problem, just thinking of solutions ahead of time.