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BattleMaster
Aug 14, 2000

Aurium posted:

SSRs fail closed way too often for me to trust them in a safety application.

I also don't really like them as a sole power switch as they have a high enough leakage current that they can leave things unexpectedly live even when off. It's usually not a problem, and you really should be unplugging things before sticking your hands inside them anyway.

Many estop switches are rated for decent currents as a matter of course, but the way to deal with large currents is just to use a contactor (a fancy name for a beefy relay).

Thanks, when I buy some proper components I'll swap out the SSRs.

So if I replaced the SSR with a normally-open relay, it be sufficient for the estop switch to interrupt the relay coil current? It would be a DPDT switch too, so it would send a signal to the PC that poo poo happened so the fault needs to be cleared in hardware and software to resume.

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Commodore_64
Feb 16, 2011

love thy likpa




1) Buy a good brand relay
2) Make sure the BREAK rating on the relay exceeds your maximum current draw by a good amount. They will generally be rated for how much current can be flowing through them when they open. If they are NOT, see 1)

Edit) If you don't mind running 24V for contactor coils, or mains 120V AC, ebay can help. Search contactor or IEC contactor. Look out and make sure the coils are 24V DC and not AC, that gets annoying. Transformer vs power supply. Note the 5kA rating on this.
https://www.ebay.com/itm/ABB-AL9-30...7Cclp%3A2334524

Commodore_64 fucked around with this message at 15:15 on Mar 25, 2021

horse_ebookmarklet
Oct 6, 2003

can I play too?
I've been doing the 3d printing thing, looking to make more robust parts. Pondering acrylic stackups from a laser cutter, or perhaps some aluminum on a desktop "mill". Budget is flexible but 1k to 2k, "dipping toes in" territory.

With my budget and hobby approach the obvious options to me right now are. in no particular order.
  • Buy a $400 sainsmart 3018prover cnc router on amazon + upgraded spindle ($200?).
  • Buy a 5 month membership to makerspace ($220/mo!) PLUS tool time. Learn me some haas mini mill.
  • Upgrade 3d printer, do polycarbonate. Major downside no hot metal chips.
  • China 40w laser, acrylic stackups. No hot metal chips, potentially hot retinas.

What are some other options?
Are these desktop "mills" going to be able to take a 1 inch aluminum plate and cut real material away?

Sagebrush
Feb 26, 2012

What are you trying to make? What kind of robustness? Do you need the parts to be more tough or more stiff? What kind of loads will they see?

An inch of aluminum plate is a completely different ball game from a stack of acrylic sheets. 3D printed parts can be incredibly strong or incredibly weak depending on your design choices.

In theory one of the benchtop routers can cut an inch of aluminum, yes. You'll have to do extremely light passes and it will take forever and probably burn up several tools. I wouldn't do it. If you need to cut that much metal, I'd go with the makerspace option.

But see if you actually need metal for it. 3D printed ABS can be surprisingly strong...

Sagebrush fucked around with this message at 02:12 on Mar 30, 2021

Aurium
Oct 10, 2010
A cnc converted import minimill. Grizzly, Harbor freight, etc.

Massively more time and work, but far more capable.

Acrylic is kind of meh mechanically. It can be brittle and is prone to cracking. Delrin also lasers well, and is generally quite good.

horse_ebookmarklet
Oct 6, 2003

can I play too?
I think I need it to be tougher, stiffness isn't a problem. If it temporary deforms it doesn't matter, the permanent deformation and cracking is the problem. I'm a bit out of my wheelhouse with all this.

This particular part is an overhead garage door lock. I've got a latch that I can actuate into my garage door track, with the intention of locking/blocking the door opening. I'm printing PLA 100% infill, layer lines perpendicular to load. Cracks after a couple hits from the opener. The spring open part "sees" momentum of the door in one direction, and when resisting load it sees the "1.5 horsepower" opener in the other. Here is an older revision; the top hole now has a bearing and is the pivot, the right hole is the actuator. The garage door when closing contacts the sloped surface and pushes the latch out of the way. When opening the door hits the flat surface.

My thought was, if am gonna drop some cash either way, can add metal capabilities to my home setup? Upgrades for PC or ABS on the 3d printer makes a LOT of sense and seems reasonable, just exploring alternatives.

Sounds like these desktop mills aren't really all that capable?
Time I don't care about, I'm not making any money on this. Burning up tools seems impractical tho.

horse_ebookmarklet
Oct 6, 2003

can I play too?
I had not heard of these mini mills before, these look way more legit than these routers you can buy on amazon.
Are these more suited to removing real material? I suppose I should do some research..

poll plane variant
Jan 12, 2021

by sebmojo

horse_ebookmarklet posted:

Here is an older revision; the top hole now has a bearing and is the pivot, the right hole is the actuator. The garage door when closing contacts the sloped surface and pushes the latch out of the way. When opening the door hits the flat surface.

This seems like the kind of project I'd approach with some steel stock, flux core and an angle grinder honestly.

Sagebrush
Feb 26, 2012

That part is simple enough that I would probably just cut it by hand, with a saw and drill, out of a chunk of UHMW polyethylene and call it a day.

But if the project is more about adding milling equipment to your shop then yeah by all means there are good options for that. I second getting one of the manual mills and adding a CNC kit to it.

insta
Jan 28, 2009

horse_ebookmarklet posted:

I've been doing the 3d printing thing, looking to make more robust parts. Pondering acrylic stackups from a laser cutter, or perhaps some aluminum on a desktop "mill". Budget is flexible but 1k to 2k, "dipping toes in" territory.

With my budget and hobby approach the obvious options to me right now are. in no particular order.
  • Buy a $400 sainsmart 3018prover cnc router on amazon + upgraded spindle ($200?).
  • Buy a 5 month membership to makerspace ($220/mo!) PLUS tool time. Learn me some haas mini mill.
  • Upgrade 3d printer, do polycarbonate. Major downside no hot metal chips.
  • China 40w laser, acrylic stackups. No hot metal chips, potentially hot retinas.

What are some other options?
Are these desktop "mills" going to be able to take a 1 inch aluminum plate and cut real material away?

Jesus gently caress the pricing on that makerspace is insane

Aurium
Oct 10, 2010

horse_ebookmarklet posted:

I had not heard of these mini mills before, these look way more legit than these routers you can buy on amazon.
Are these more suited to removing real material? I suppose I should do some research..

Extremely so, they aren't even in the same ball park. They are baby machines for machinists, but they are proper machine tools. They're stiff enough to cut steel (slowly) and ~4-8x the power. (60w for a typical, 150w for some of the "pro" 3018 variants vs 600w) They are much bigger, you can pick up a desktop router in one hand, and the mini mill is going to be like ~140lb

They're also manual machines. Making them CNC, even with a kit, is not a small undertaking. To be honest, I don't recommend it unless you want to do a conversion as a project, not just what you can do with it. You will also need to learn all sorts of things about work holding, tool selection etc. This is something that 3dprinting (and laser cutting) spoils us on. Also, be prepared to spend even more on tooling. A usual rule of thumb is to take what you spent on a machine, and then spend it again on accessories.

For ready to run, there is taig's cnc offering. Taig is a pretty long established small US mill brand. It looks a little odd (light switch on off) because it's a long standing design. It's slightly outside your price range. It's a bit smaller than the import minimills, at a svelte 100lb

On the 3d printer side, abs isn't too hard to get right, and can be as simple as a cardboard box. PC is an adventure.

Describing your part, I wouldn't do it out of acrylic, delrin would probably be fine.

insta posted:

Jesus gently caress the pricing on that makerspace is insane
This jumped out at me too.

Rutibex
Sep 9, 2001

by Fluffdaddy
I wouldn't pay $200 per month for a maker space unless they had a star trek replicator

Sedgr
Sep 16, 2007

Neat!

Shapeoko or Onefinity can do some aluminum work from what Ive seen. My Onefinity is scheduled to be here in May and I am looking forward to playing around with it. Looks doable depending on what you need to do.

https://youtu.be/qTB3L-Dqv84

BattleMaster
Aug 14, 2000

I absolutely would not trust a 3018 or similar cheapo machine to handle aluminum even with the spindle upgrade. Even if the spindle was powerful enough for the job I don't trust the rigidity and strength of the X and Y axes, and the Z axis is a few levels of crap beyond that.

I got one to gently caress around with and I feel it performs far better than I hoped with MDF, but I wouldn't expect it to work well with anything significantly harder.

NewFatMike
Jun 11, 2015

I've seen some 3018 videos doing aluminum, and the chatter marks are visible from the wide shots encompassing the entire machine. I wouldn't be comfortable recommending it for that purpose.

I had been looking up the plans from Crank Organ, but it turns out that dude has closed up shop, which is unfortunate because he had had some plans for benchtop aluminum milling machines. No idea how good those were, though, and the machine is probably the hobby more than the output, much like a CNC conversion.

sharkytm
Oct 9, 2003

Ba

By

Sharkytm doot doo do doot do doo


Fallen Rib

Rutibex posted:

I wouldn't pay $200 per month for a maker space unless they had a star trek replicator

They're usually less Makerspace, and more TechShop. Fully staffed, high-end machines, and big money.

babyeatingpsychopath
Oct 28, 2000
Forum Veteran

I have a 3018. It'll engrave aluminum just fine. Won't cut it at all. Tools just explode because there's so much flex.

I also have a shapeoko. That'll cut 6mm aluminum plate with a 1/4" endmill using a couple passes. I have a feed/speed calculator that I let it run the math on and the cuts came out just fine. I don't think I'd trust it to do bas relief or anything that would be considered "machining" beyond cutouts, holes, and slots.

NewFatMike
Jun 11, 2015

What calculator are you using for the ShapeOko? I've got some use for that for some SOLIDWORKS CAM TechDB setup for my makerspace.

babyeatingpsychopath
Oct 28, 2000
Forum Veteran

NewFatMike posted:

What calculator are you using for the ShapeOko? I've got some use for that for some SOLIDWORKS CAM TechDB setup for my makerspace.

I bought G-wizard from CNC Cookbook. The ability to import a Fusion toolcrib and just plug in a material, tool, and operation, hit go, and plug that stuff back into fusion was worth it. The large material library was absolutely a good selling point; I was doing a bunch of sorta-weird plastics and the calculator had them all and produced good ballpark numbers.

NewFatMike
Jun 11, 2015

Hell yeah! CNC Cookbook is great. We've got the license over at the space, so I can run with that. Thanks!

meowmeowmeowmeow
Jan 4, 2017
Cnc cookbook is great, there's a ton of great articles on machining theory and considerations for programming etc beyond just the g-wizard software

Karia
Mar 27, 2013

Self-portrait, Snake on a Plane
Oil painting, c. 1482-1484
Leonardo DaVinci (1452-1591)

sharkytm posted:

They're usually less Makerspace, and more TechShop. Fully staffed, high-end machines, and big money.

Yeah, and even with that TechShop still went bankrupt (RIP, you are missed.) That high monthly fee gets eaten up much faster than you'd expect: the machines can be very expensive to maintain, and letting non-professionals play around with heavy machinery shoots your insurance costs through the roof. Seriously, insurance costs were one of the top reasons TechShop folded.

The other main cause was massive embezzlement.

horse_ebookmarklet
Oct 6, 2003

can I play too?
For the specific part a twist drill and a sparkle wrench could surely lop it out, but yes I want to build capability for homeshop.

Been watching a bunch of those grizzly conversion videos, looks downright reasonable, if not time consuming. Seems everyone makes a kit to do a conversion. The Taig-cnc looks perfect as I don't currently own a machine. All these options are gonna require me to save the pennies a bit longer, which is fine.

Not gonna waste money on those 3018 desktop machines, that much is decided.


I have a tour of the $220/mo Makerspace next week, will report on if O'Brien has fixed the bloody replicator or if the coffee still comes out wrong.

honda whisperer
Mar 29, 2009

horse_ebookmarklet posted:

For the specific part a twist drill and a sparkle wrench could surely lop it out, but yes I want to build capability for homeshop.

Been watching a bunch of those grizzly conversion videos, looks downright reasonable, if not time consuming. Seems everyone makes a kit to do a conversion. The Taig-cnc looks perfect as I don't currently own a machine. All these options are gonna require me to save the pennies a bit longer, which is fine.

Not gonna waste money on those 3018 desktop machines, that much is decided.


I have a tour of the $220/mo Makerspace next week, will report on if O'Brien has fixed the bloody replicator or if the coffee still comes out wrong.

I'm curious about this and their price, please post about what you get access to for that kind of money.

poll plane variant
Jan 12, 2021

by sebmojo
What do these desktops offer that a good used bridgeport doesn't at the same price anyway

honda whisperer
Mar 29, 2009

Can be loaded on a truck, unloaded with friends, doesn't require 3 phase power etc.

babyeatingpsychopath
Oct 28, 2000
Forum Veteran

honda whisperer posted:

doesn't require 3 phase power etc.

This is the biggy for home gamers. Even if you get a VFD to generate your 3-phase, these machines are power hungry. A 220V single-phase circuit with the same VA requirements as the 3-phase is an impressive capital outlay in itself.

Aurium
Oct 10, 2010
They take up much less space. I can put one on a workbench in my garage instead of clearing multiple feet of floorspace. I could even put one in the spare room of an apartment on the second floor.

They exist. In many places a $1000 Bridgeport may as well be a unicorn. I can go to grizzly's or hf's or nt's page and have one in a week or so.

They're new. That $1000 Bridgeport might exist, but what state is it in? Are its ways wallowed out? The leadscrews? Am I, the entry level hobby machinist l, really the right person to inspect and tell what kind of wear is ok? There is a conversation here about the QC and finishing of some of the importers, and why some are <800 and others are hundreds more, but anything beyond the absolute cheapest noname will be functional, or obviously broken and returnable.

Feel. Sure this is more where the Sherlines and Taigs of the world are, but on small pieces done with small bits it's nice to have a very smooth machine with light responsive wheels can be helpful. If you've ever watched a clickspring video he switches between his Sherlines and his (still not large) import lathe all the time depending on the part. Basically jeweler's and watchmaker's machines are a thing.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
"Good used bridgeport" in 2021 is definitely a matter of getting lucky too; if you do get lucky and have a place to put it they're great bang per buck, but I've seen them trading more in the $5k range lately and personally, at that price, I'd be looking at CNC stuff; Tree CNC knee mills for example.

sharkytm
Oct 9, 2003

Ba

By

Sharkytm doot doo do doot do doo


Fallen Rib

mekilljoydammit posted:

"Good used bridgeport" in 2021 is definitely a matter of getting lucky too; if you do get lucky and have a place to put it they're great bang per buck, but I've seen them trading more in the $5k range lately and personally, at that price, I'd be looking at CNC stuff; Tree CNC knee mills for example.

Prices have gone up dramatically, and the quality overall is down. They're getting worn out and replaced, and there isn't the glut of small shops dying off like there were in ~'08. I'd be looking at something else if I was in the market. Mine is decent, but it was $2300 with a ton of tooling and fixtures, 2+ years ago.

NewFatMike
Jun 11, 2015

I bought a Sainsmart 3018 PROVer, which is very exciting. I'm really excited to work on a GRBL post processor for SOLIDWORKS CAM, unfortunately I accidentally bought the version that runs on Mach3, which is rad as hell because there's a built in post processor for it, but that's not the main goal of buying one right now :v:

I'm psyched to check this little thing out. I've got a whole mess of things to do in wood that fit right into this thing's envelope. I'm also really excited to work on some composite paper stock making, almost homemade MDF, to replace a lot of what I would otherwise use 3D printing for.

Already thinking about what I could make on the Tormach to improve this little thing.

NewFatMike
Jun 11, 2015



I'm pretty excited to see how this stupid little thing does. I have some wood projects I'd like to get done, and I need to learn to write a GRBL post processor anyway.

Snagged an 1/8" ball end router bit from McMaster, looking forward to running something this weekend!

The assembly process was pretty much entirely painless, about on par with my Prusa Mini, maybe a little easier.

NewFatMike
Jun 11, 2015

Anyone have any good recs on Mach 3 tutorials? It feels like I'm doing things in an order the software doesn't like.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
Been going through low-cost cam software today - meshcam seems most "correct" so far, cambam awkward and estlcam annoyed me too... anything else worth trying? I don't want to mess with Fusion I want stuff that runs on my darn computer.

ante
Apr 9, 2005

SUNSHINE AND RAINBOWS
Very boomer energy

Ambrose Burnside
Aug 30, 2007

pensive

SchnorkIes posted:

What do these desktops offer that a good used bridgeport doesn't at the same price anyway

throw an enclosure over it and i can run my taig cnc mill in my apartment living room. the bridgeport would tear through the floor and end up in the basement before i could even google “which household electrical outlets are three-phase” and realize id made a very expensive mistake

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull

ante posted:

Very boomer energy

I mean, I'm at the point of "all of these things will theoretically do what I want them to, I'd prefer something that works like how I expect". Fusion's stuff has changed enough that I don't want to rely on it if I have any alternative.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
OK new frontrunner is Deskproto; even the free version seems to do what I want, and it seems like its toolpath generation is a couple orders of magnitude faster.

ZincBoy
May 7, 2006

Think again Jimmy!

mekilljoydammit posted:

OK new frontrunner is Deskproto; even the free version seems to do what I want, and it seems like its toolpath generation is a couple orders of magnitude faster.

I started out with Deskproto on my Taig and it is pretty good. Another one to check out is Vectric Vcarve. It is great for 2.5D stuff and I used it with my cnc router. Might be a bit more than you want to spend though. I am on BobCad now for the trochoirdal tool path generation that allow you to get full use out of smaller machines. And also for 4 axis work on my machining center.

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NewFatMike
Jun 11, 2015

Mach 3 just kinda fuckin sucks, huh?

Seems like there are some endemic signal issues regardless of configuration. I almost got 10% into a job before the software poo poo the bed and continues to poo poo it.

I've had a lot less trouble with GRBL, somehow also ShopBot control, and I'd consider trading a finger or toe even for PathPilot.

What are y'all using to control your home machines?

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