#linuxcnc Logs
Oct 15 2020
#linuxcnc Calendar
12:31 AM snakedGT is now known as snaked
12:54 AM CaptHindsight: https://www.surpluscenter.com/Power-Transmission/ACME-Thread-Lead-Screw-Nuts/ACME-Thread-Lead-Screws/ stil cheap
12:55 AM XXCoder: wow
12:55 AM XXCoder: might want to link to reprap too maybe
12:55 AM XXCoder: but then chinese still is cheaper
12:55 AM XXCoder: wait not really those is much longer
12:57 AM Deejay: moin
01:32 AM Loetmichel: mornin'
01:42 AM * Loetmichel just found out why the convertible is so loud... http://www.cyrom.org/palbum/main.php?g2_itemId=17958&g2_imageViewsIndex=1
01:45 AM XXCoder: lol
01:45 AM XXCoder: reminded me of story i read about guy who had car that purred like kitten all time
01:45 AM XXCoder: one day he come in for muffler replacement and sound is gone. he missed it lol
04:57 AM JT-Cave: morning
04:57 AM XXCoder: hey
05:05 AM JT-Cave: just as my wife was about to go to bed last night she heard a dog yelping and running away from the house toward the gate :) I love it when a plan comes together
05:06 AM Loetmichel: JT-Cave: wired a bug zapper to the doormat?
05:07 AM JT-Cave: 25 mile fence charger on 100' of fence around the chicken yard
05:08 AM JT-Cave: it's real hot, I know
05:08 AM JT-Cave: I touched it once with wet leather gloves and it made my finger go numb for a while
05:25 AM Loetmichel: hehe. i remember touching a chrged fence accidentally while petting the horse in it.
05:25 AM Loetmichel: horse wasnt amused
05:26 AM Loetmichel: who could have thought that a horse can jump up THAT high from a standstill?
05:26 AM Loetmichel: <- didnt feel much though
05:29 AM rs[m]: don't know about horses, but at least cows are very sensitive to electricity
05:29 AM rs[m]: easy to electrocute with voltages that are mostly harmless to humans when touched
05:30 AM Loetmichel: same for horses
05:30 AM rs[m]: that in combination with their large distance between front and hind legs (and that the heart is in between) makes them very susceptible to lightning strike
05:30 AM Loetmichel: and i am not that sensitive either, working as an electronics repair tech for a few decades
05:31 AM Loetmichel: so the jopt barely registered to me... unlike the horse that i touched ;)
07:51 AM Loetmichel: hmm, anybody got a recommodation for a cheap colour laser printer with scanner? (aka. multifunction device)
09:02 AM TekniQue: I need a recommendation on what hardware card to get to control my stepper motor equipped CNC mill
09:03 AM TekniQue: the 14 year old Dell Optiplex I am using is dying
09:03 AM TekniQue: it's starting to take a few attempts to power it up
09:03 AM TekniQue: won't boot every time
09:03 AM TekniQue: so I need to replace it before it stops booting altogether
09:07 AM TekniQue: so I guess I need a parallel port card for pci express?
09:07 AM TekniQue: if I am to replace this PC with something that isn't 10 years old
09:13 AM JT-Shop: Loetmichel, dunno if you can get the same printers we have over here or not but I have two Brother laser printers and it's easy to find cheap cartridges for them
09:14 AM JT-Shop: TekniQue, I'd use a 7i96 and pick either a motherboard with dual NIC's or add a NIC for the LAN
09:15 AM TekniQue: well I have wifi in my shop
09:15 AM JT-Shop: of course I recommend you getting the card from me :) https://mesaus.com/product/7i96/
09:15 AM TekniQue: looks good
09:16 AM JT-Shop: wifi works too, I've just never tried to use filezilla over wifi to copy files to my machines
09:16 AM TekniQue: yeah I mean using wifi for network connectivity the on board LAN will be free for this interface
09:17 AM JT-Shop: 7i96 configuration tool https://github.com/jethornton/7i96
09:18 AM TekniQue: and there's a driver in LinuxCNC for this?
09:20 AM TekniQue: What about the 7i92?
09:20 AM TekniQue: since my machine is already set up for parallel port as it has been for the past decade
09:21 AM JT-Shop: 7i92 is good too
09:23 AM JT-Shop: IIRC 7i92_G540x2D.bit is the correct firmware to use as a parallel port pinout
09:23 AM JT-Shop: pcw_home, would know for sure
09:24 AM TekniQue: it does not give me any shipping options to Iceland when I try to order
09:24 AM * JT-Shop wanders out to the other shop to weld up a cover for the third time... maybe I have it the right size this time
09:24 AM JT-Shop: standby
09:35 AM TekniQue: I had 5 of the same model Dell Optiplex with Core2 duo processors from 2006-2007, and they all died the same way
09:36 AM JT-Shop: ok, Iceland added
09:36 AM TekniQue: sweet
09:40 AM TekniQue: ordered
09:45 AM JT-Cave: wow first day the pullets only laid 1 small egg rest were medium, with a large and an extra large
09:59 AM Nic is now known as Guest90488
10:02 AM JT-Shop: TekniQue, do you want me to flash the firmware?
10:03 AM TekniQue: sure
10:21 AM JT-Shop: 7i92_G540x2D.bit has 4 stepgens, encoder and a PWM
10:22 AM jymmmm: Blackout.. Day 2
10:41 AM roycroft: if you're lucky the blackout will continue until 4 november
10:43 AM jymmmm: ?
10:44 AM roycroft: the end of silly season (hopefully)
10:44 AM jymmmm: ah
11:15 AM TekniQue: JT-Shop: perfect, I am using 3 steppers and the software just turns the spindle on or off
11:39 AM * JT-Shop can see it's not going to be a productive day making the same part over and over and over and over
11:40 AM roycroft: i'm still trying to decide what bandsaw to get
11:40 AM roycroft: i had almost settled on a laguna, and laguna are on sale this month but i think i'd rather get the jet
11:40 AM TekniQue: the way my workload has been I'm only managing to ship stuff one day per week
11:40 AM roycroft: the jet is just a wee bit too tall to fit through my garage door upright, though
11:41 AM roycroft: but i think i can adjust the door to gain the clearance i need
11:41 AM roycroft: i have to do that before the end of the month, though
11:41 AM roycroft: in case it doesn't work
11:41 AM roycroft: i don't want to lose the sale price of the laguna
11:44 AM JT-Shop: which laguna are you looking at?
11:45 AM roycroft: the 14x14 suv
11:46 AM roycroft: vs, the jet jwbs-15-3
11:46 AM roycroft: i've heard of a lot of issues with laguna
11:46 AM roycroft: inconsistent quality
11:47 AM JT-Shop: I have this one https://www.woodcraft.com/products/rikon-14-deluxe-bandsaw-model-10-326
11:47 AM roycroft: and very mixed customer service reports
11:47 AM JT-Shop: https://www.woodcraft.com/products/laguna-14bx-bandsaw-110v-1-75-hp
11:47 AM JT-Shop: is that the laguna your looking at?
11:47 AM roycroft: i want something a bit beefier than the 10-326
11:47 AM roycroft: no
11:49 AM JT-Shop: the tool less adjustment for the guide rollers is a bit of a pain to try and make small adjustments
11:50 AM roycroft: https://www.rockler.com/laguna-lt14-x-14-suv-bandsaw
11:50 AM roycroft: that one
11:50 AM JT-Shop: https://www.woodcraft.com/products/powermatic-15-bandsaw-model-pm1500 that one looks nice
11:50 AM roycroft: i'm not sold on laguna's ceramic guides
11:50 AM roycroft: https://www.woodcraft.com/products/jet-15-bandsaw-3hp-model-jwbs-15-3
11:50 AM roycroft: that's the one i really want
11:51 AM roycroft: 3hp, 14" resaw capability, and a nice fence
11:51 AM roycroft: but it's 77" tall
11:52 AM roycroft: and i don't have quite that amount of clearance through my garage door at the moment
11:52 AM roycroft: i'd like to be able to move it outside easily
11:52 AM roycroft: the laguna is 70" tall
11:52 AM JT-Shop: that's a big boy for sure
11:52 AM roycroft: i want the resaw capability
11:54 AM * JT-Shop wanders out to the other shop to bend the same part again...
12:05 PM roycroft: i like the trunion design on the laguna much more than the jet, and i like the foot brake with microswitch on the laguna, but i have concerns about quality control and customer service
12:06 PM roycroft: plus, laguna comes with a 1 year warranty, while jet offer a 5 year warranty
01:01 PM Tom_L: JT-Shop, filezilla works fine over wifi
01:01 PM Tom_L: i've used it on the rpi4
01:06 PM JT-Shop: cool, just never needed to try it before
01:06 PM JT-Shop: not as bad as I thought... this is only the fifth time I'm making this cover :(
01:07 PM Tom_L: heh
01:07 PM JT-Shop: first on perfect except a smidgen narrow to fit over the tom hinge
01:26 PM JT-Shop: and my truck has a slow leak it seems in the left front tire... must be time for a beer or a nap not sure
01:50 PM JT-Shop: on the plus side my TIG skills are returning back to normal...
01:55 PM beachbumpete1: I really enjoy tig welding
01:59 PM JT-Shop: if I can get braced correctly I do ok
01:59 PM beachbumpete1: hell yeah man gotta get comfy
02:00 PM beachbumpete1: I use a pair of those Tig fingers I bought from Welding tips and tricks doubled up behing my bracing hand and its great because it never gets hot
02:03 PM JT-Shop: https://www.amazon.com/Welding-Tips-Tricks-Finger-Shield/dp/B08KQGMTGC?th=1
02:10 PM beachbumpete1: JT-Shop: yeah that is them, they actually have two sizes, I think I used the larger ones to double up and the smaller ones on my other hand if necessary
02:13 PM JT-Shop: cool, I don't do enough tig welding to need them I just make short welds from some support
03:29 PM Deejay: gn8
04:32 PM TekniQue: hrmph
04:32 PM TekniQue: my hot air station shat itself
05:57 PM HighInBC: TekniQue: oh my, and such a useful tool
05:59 PM TekniQue: yes
06:00 PM TekniQue: going by the sound it makes I think the blower impeller scattered
06:00 PM TekniQue: makes a crunching sound and not a blowing air sound when I turn it on
06:00 PM TekniQue: didn't last long
06:01 PM TekniQue: 2 years I think
06:04 PM veegee: What is the "dash number" for hydraulic fittings?
06:04 PM veegee: Is it just to line up the actual sizes between NPT, JIC, ORB?
06:05 PM Tom_L: ID
06:05 PM Tom_L: Simply put, a dash size refers to an I.D. of a hydraulic hose or fitting in 1/16" increments. For example, -6 hose would indicate a hose with I.D. of 6/16" - or 3/8". Hoses are measured by inside diameter, unlike tubes which are measured by outside diameter.
06:06 PM veegee: I'm sitting at the office and drawing out all the fittings I need but I don't remember the actual size for the ports on the forklift valve, but I do remember that the ORB ports had the same thread size as a 1/2" JIC fitting
06:06 PM veegee: Tom_L perfect thanks
06:06 PM veegee: I was so confucius before, you know?
06:07 PM veegee: What I mean was, this is the fitting that matches the ORB ports: https://www.princessauto.com/en/detail/1-2-in-jic-plug/A-p8413288e
06:08 PM veegee: I'm guessing that's 1/2" inside diameter of the hole
06:10 PM veegee: So perhaps a -08
06:11 PM veegee: Whoops I mean 1/2" thread OD
06:11 PM Tom_L: https://www.hoseandfittings.com/wp-content/uploads/2015/10/Hydraulic-Hose-Size-593x725.jpg
06:14 PM JT-Cave: I need 4 -022 o rings...
06:14 PM Tom_L: there's an o ring shop here
06:16 PM JT-Cave: really, that specialized to just sell o rings?
06:16 PM Tom_L: yes
06:16 PM Tom_L: www.crownproductsinc.com
06:16 PM JT-Cave: I'll look at the box stores they have quite a few in stock
06:16 PM Tom_L: they have all sorts there
06:17 PM JT-Cave: not critical but I'd like to change them when I rebuild the last two cylinders
06:17 PM Tom_L: yeah
06:17 PM Tom_L: i forget how they measure them. it's been a long time since i got any
06:17 PM Tom_L: cross section and either ID or OD?
06:18 PM JT-Cave: ID and cross section
06:19 PM JT-Cave: not sure how the dash numbers work but 022 is 1" ID 1/16" cross section
06:23 PM Tom_L: they've got various materials too
06:25 PM Tom_L: http://www.crownproductsinc.com/docs/ORingChart.pdf
06:26 PM Tom_L: you're right
06:26 PM Tom_L: i didn't doubt... just didn't know
06:52 PM veegee: JT-Cave I wrote a program to forward my IRC connections to all my "logged" in locations at once
06:52 PM veegee: so I don't need multiple different users
06:53 PM veegee: The server acts as a proxy and handles the actual connection to the IRC server. The clients connect to my special proxy
06:54 PM Tom_L: fairly common
07:04 PM _unreal: hello
07:06 PM _unreal: ok so at this point I guess I need to work on getting the linuccnc setup its self with the ini control file for the 7i96
07:07 PM _unreal: ?
07:07 PM _unreal: ok linuxcnc crashed
07:07 PM _unreal: trying to load with the ini file created from last night
07:10 PM Tom_L: the screen will give you clues
07:12 PM _unreal: https://paste.centos.org/view/882093e3
07:13 PM _unreal: thats the print out error
07:14 PM Tom_L: what os are you running?
07:15 PM _unreal: Linux lcnc 4.9.0-12-rt-amd64 #1 SMP PREEMPT RT Debian 4.9.210-1 (2020-01-20) x86_64 GNU/Linux
07:15 PM _unreal: the paste bin is from THE ini created last night
07:15 PM Tom_L: i figured
07:16 PM Tom_L: how did you install it all?
07:16 PM _unreal: it just apeared in the list
07:16 PM _unreal: when starting LCnc
07:16 PM Tom_L: the os and linuxcnc
07:16 PM _unreal: My configurations
07:16 PM Tom_L: from an iso?
07:16 PM _unreal: lcnc from ISO
07:16 PM _unreal: lcnc iso
07:16 PM Tom_L: 2.8?
07:17 PM _unreal: ahh not sure how do I look that up
07:17 PM Tom_L: http://linuxcnc.org/iso/
07:17 PM _unreal: look up whats installed
07:19 PM Tom_L: wait... where is coordinates=xyz defined?
07:19 PM Tom_L: in the ini?
07:20 PM Tom_L: line 32
07:21 PM _unreal: I dont know
07:22 PM _unreal: all of this is the first time I've ever looked at anything
07:22 PM _unreal: So I'm leraning
07:22 PM Tom_L: find it and comment it out for now
07:24 PM Tom_L: oh that's in [TRAJ] section
07:24 PM Tom_L: it should be ok there
07:24 PM Tom_L: post your configs somewhere
07:26 PM Tom_L: pcw_home, does the 7i96 use a config= line in the ini?
07:26 PM Tom_L: like the rest of em
07:26 PM veegee: https://www.reddit.com/r/nier/comments/jbz62g/nier_automata_cover_laser_burned_on_a_painted/
07:26 PM veegee: Yes I'm the idiot asking how he did it
07:27 PM veegee: My first guess would be with a CNC router, but is there some other obvious way I'm totally missing?
07:27 PM Tom_L: magic laser dust
07:27 PM _unreal: arg...
07:27 PM veegee: You can't turn laser into toner and do toner transfer with that dust can you?
07:28 PM veegee: Because the shapes look like smooth vector drawing operations as opposed to rasterized dots
07:29 PM _unreal: fuck it I give up for tonight
07:29 PM _unreal: I cant think fam is blairing the @!#$@#$ biden town hall...
07:29 PM _unreal: bs
07:29 PM Tom_L: post your configs
07:29 PM _unreal: goodnight
07:29 PM veegee: LOL I just watched your debate from 2 weeks ago, it was pure gold
07:30 PM veegee: Trump's "you're a number 2"
07:31 PM * Tom_L snickers
07:31 PM _unreal_: omg. he's driving me nuts keeps laughing loudly and yelling thats truth.... at the TV wtf
07:31 PM Tom_L: cut the cable line
07:32 PM _unreal_: he's clearly reading a propter. you can see HIS eyes
07:32 PM _unreal_: prompter
07:32 PM _unreal_: I've already heard several faulse statements
07:32 PM _unreal_: I cant take it
07:32 PM _unreal_: backin my room
07:33 PM _unreal_: had that fucking manager at work NOT fucked up my breaks with the sole intent of fucking up my stocks. I'd have had the money to buy a house right now. and gotten out of this night mare
07:34 PM _unreal_: its just insane, my father is doing everything he can to keep me from moving out of this house. on top of stocks issue
07:34 PM _unreal_: god ALLLLL I want to do is leave
07:34 PM veegee: How old are you?
07:34 PM _unreal_: to old
07:35 PM veegee: I'm 29
07:35 PM veegee: ^ In that format
07:35 PM _unreal_: my father is recovering from stage4 cancer
07:35 PM _unreal_: been taking care of his house etc....
07:35 PM veegee: Same here
07:35 PM veegee: (really)
07:36 PM veegee: But I do live elsewhere
07:36 PM veegee: (it's called the office and when not there, the workshop)
07:36 PM _unreal_: I was suposed to move out 2 years ago but my step mother left him out of the blue. come to find out she was super pro move me in because she was planning on leaving him. and sticking me to watch the house when he was world traveling with work
07:37 PM _unreal_: dog died finally and less then a month later he got the cancer diagnosis
07:37 PM veegee: So I'm guessing 20s
07:37 PM * Tom_L gives up on lcnc support for today
07:37 PM _unreal_: I already said I give up
07:37 PM _unreal_: the puter is in the other room
07:37 PM veegee: Ok that sounds like you /wanted/ the dog to die, and then for him to get the diagnosis
07:37 PM _unreal_: but I cant take his BS
07:37 PM Tom_L: but you came back
07:38 PM _unreal_: DIFFERENT computer
07:38 PM _unreal_: I miss the dog but 17yo ridge back. thats an old pup
07:38 PM Tom_L: i'm gettin tired of waiting for my junk
07:38 PM _unreal_: ?
07:39 PM veegee: Would you rather him to die and the dog to get the diagnosis?
07:39 PM veegee: kidding, just kidding
07:40 PM veegee: On the bright side, stepmom left
07:40 PM veegee: Can't take anything from you
07:41 PM Tom_L: veegee, what was wrong with your cylinders?
07:42 PM veegee: Good call changing the topic. It was going to get dark really fast
07:47 PM veegee: Narrowed the issue down to the cylinders. They seem to get stuck at random positions
07:47 PM veegee: Also can't rotate the rod (I didn't try very hard for fear of breaking something)
07:47 PM veegee: So it's definitely seized up/seizing up randomly
07:47 PM veegee: To the point where pressure exceeds the pressure relief valve pressure
07:47 PM veegee: And it seems like both cylinders are affected
08:03 PM Eric__: are they pneumatic or hydraulic cylinders?
08:04 PM Eric__: my fatigue machine came with replacement seals and there is no way they are ever going to be used
08:06 PM veegee: Eric__ hydraulic cylinders, specifically two double-acting cylinders used on the fork positioners on my forklift
08:07 PM veegee: Next step is to disassemble the cylinders
08:07 PM veegee: I already confirmed that the forks slide smoothly in their linear slide ways by decoupling them from the ram and manually sliding them with my own muscle force
08:08 PM Eric__: can you get parts for them? I imagine they are a mess inside
08:08 PM veegee: The forklift came with a 2,000 lb pallet of spare parts I haven't even opened yet
08:08 PM veegee: I bought it used, it's an old Allis Chalmers F60-24
08:08 PM Eric__: wow
08:08 PM veegee: Got for like $2,500 CAD
08:09 PM veegee: everything including engine runs super smooth. One and only problem is these fork positioner cylinders
08:09 PM veegee: Hydraulic cylinders should all be standard, so worst case I can drop in replacements
08:09 PM veegee: But since this is purely a hobby, I'd like to invest my own time learning than throw money at the problem
08:10 PM veegee: Well paint is peeling off, but aside from very shallow surface rust, no other problems at all
08:10 PM veegee: So yeah next step is detaching the cylinders and disassembling them
08:10 PM veegee: All other cylinders/valves are in perfect working condition
08:11 PM Eric__: I hate oil
08:12 PM veegee: lol yeah I spilled about 20L of clean hydraulic oil while replacing all the hoses
08:13 PM veegee: all it takes is one burst hose on the gigantic main mast cylinder to drain that entire cylinder volume worth of fluid
08:13 PM Eric__: for how benign hydraulic oil is, it sure feels funny on my hands
08:15 PM veegee: feels just like any other non detergent oil to me
08:15 PM veegee: I always wear nitrile gloves as much as possible
08:15 PM veegee: but I get a feel for the oil between my fingers to check for tackifiers
08:15 PM veegee: Hydraulic oil has no reason to have it, but in general I mean
08:16 PM veegee: I love tackifiers in my machine slideway oil
08:16 PM veegee: Motorcycle chain lube has lots of it, it's great
08:16 PM veegee: It helps it stay in place and not drip out. Great for general purpose use where I'd otherwise use grease but want something thinner in a non-sealed environment
08:17 PM veegee: Also motorcycle chain wax is another one of my favourites
08:18 PM veegee: it forms a very very very thick grease almost like "wax" and is an excellent barrier against rust
08:25 PM roycroft: well bugger
08:25 PM roycroft: i had 70" of clearance with my garage door open
08:26 PM roycroft: i needed more for the new bandsaw i want, and i knew i could open the door a bit more
08:26 PM roycroft: i just spent some time tweaking it
08:26 PM roycroft: and it opens to 76-1/2" now
08:26 PM roycroft: which is great
08:26 PM roycroft: except i need 77"
08:26 PM roycroft: and i'm not sure if i can get that extra 1/2"
08:26 PM roycroft: i'm pretty much at the limit now
08:31 PM Tom_L: have you looked at any grizzly bandsaws?
08:32 PM Tom_L: my friend got one after he sold is business along with his commercial bandsaw
08:32 PM Tom_L: he likes it better than the commercial one
08:32 PM roycroft: yes, but they don't have any with the specs i want
08:32 PM roycroft: my current one is a grizzly
08:33 PM Tom_L: his has a foot brake
08:33 PM Tom_L: don't know much about it as i've not used that one
08:35 PM roycroft: and my table saw, jointer, thickness planer, 6x80: edge sande, and mill-drill are from grizzly
08:36 PM roycroft: i lived in bellingham when they first went into business in the early '80s
08:36 PM roycroft: and when they built their new warehouse/showroom i lived only a few blocks away
08:36 PM roycroft: i'm not at all afraid to buy and use their gear
08:39 PM roycroft: but they don't have the right band saw for me
08:41 PM roycroft: the mini-lathe i just sold was from grizzly, too
09:33 PM Eric__: my bandsaw tipped over all by itself. None the worse for the experience
09:34 PM Eric__: roycroft, what bandsaw?
09:34 PM Eric__: I always wanted one of the giant Hitachi resaw bandsaws
09:36 PM CaptHindsight: Eric__: http://tom-itx.no-ip.biz:81/~tom-itx/irc/logs/%23linuxcnc/2020-10-15.html discussed in detail earlier today
09:37 PM Eric__: thanks
09:37 PM Eric__: don't get the laguna, they are a horrible company
09:38 PM Eric__: OTOH, my Laguna bandsaw has been just fine
09:39 PM CaptHindsight: anything made pre 1070, just plan on swapping bearings and motor
09:39 PM CaptHindsight: 1970, 1070 power tools tend to be very woodsey
09:41 PM Eric__: I need new guides for it though
09:48 PM Eric__: I didn't know you could get a manual torque multiplier wrench.
09:48 PM Eric__: seems potentially useful
09:52 PM CaptHindsight: manual impacts as well
10:09 PM veegee: roycroft just tip it over when you move it in
10:09 PM veegee: I tipped mine over when transporting it so it was laying flat on its side
10:10 PM roycroft: i want to be able to move it in and out at will
10:11 PM roycroft: without tipping it
10:11 PM roycroft: i sometimes move machines outside when i'm working on large parts, since my shop is so crowded
10:12 PM roycroft: and it's nice to be able to roll all the machines outside when it's time to do deep cleaning
10:12 PM roycroft: i'm at a point where i'm thinking about building a new bandsaw
10:13 PM roycroft: it would probably be cheaper than buying one, and i could make it to my exact specifications
10:22 PM veegee: Cheaper than buying used? I don't know, and it would take a lot of time
10:22 PM veegee: But hey if it's a hobby, always worth it
10:22 PM roycroft: i'd repurpose many of the parts from my current one
10:22 PM roycroft: that would save much time and money
10:22 PM veegee: ah true
10:22 PM roycroft: i'd basically build a new frame for the current one
10:23 PM roycroft: upgrade the motor, and add a vfd