#garfield Logs

Jun 14 2025

09:24 AM rue_mohr: no, just aluminum
09:39 AM rue_mohr: I made a vac chamber, but for casting was postiives
09:53 AM rue_mohr: so, do I know what I need to know to become a robot yet?
10:04 AM Tom_L: no
10:06 AM rue_mohr: oooooh
05:39 PM rifraf: anyone use makerworld.com ?
05:41 PM rue_shop2: not i
05:41 PM rifraf: cannot work out how to download basic stl model, and the amf file opens all weird, https://makerworld.com/en/models/1513626-infinite-diamond-glitch-zoetrope-top#profileId-1585259
05:42 PM rifraf: rue_shop2 what did you vacuum cast in metal?
05:42 PM rue_shop2: I didn't
05:42 PM rue_shop2: I made the setup and was going to use it to do lost wax casting
05:42 PM rifraf: rue_mohr: I made a vac chamber, but for casting was postiives
05:42 PM rifraf: ok i am as well, lost castable resins though that I can print
05:44 PM rifraf: how well did diy vac chamber work, the things like this do not seem to be rocket science to make. https://www.aliexpress.com/item/1005006314259004.html
05:45 PM rifraf: did you get a vacuum pump? how far did you get?
05:46 PM rue_shop2: its all built, ready to use
05:46 PM rue_shop2: but I dont know what to do with it :]
05:47 PM rifraf: start by showing me what you made if you can
05:47 PM rue_shop2: too bad you dont have a big bad air compressor, you could use it with a venturii
05:47 PM rue_shop2: http://ruemohr.org/%7Eircjunk/projects/vacuumplate/slide.htm
05:47 PM rifraf: have used various venturi with phneumatics, fine for tiny suckers, but not for making a real vacuum
05:52 PM rue_shop2: so, thats what I built
05:52 PM rifraf: cool, still looking at all the images
05:53 PM rifraf: so you can vaccuum the investment with that, is vacuum from a fridge?
05:53 PM rifraf: or something
05:54 PM rifraf: glass bell jar seems pretty brave , borosilicate or plain glass?
05:57 PM rifraf: cannot see a vacuum though, lots of work in your plate, could you not just use like a 10mm steel/ss plate
06:01 PM rifraf: is your vacuum pump single or dual stage?
06:02 PM Tom_L: use a tank and suck it down for more volume
06:04 PM rue_shop2: I dont know where the one I used it from
06:04 PM rue_shop2: it should be fine, the bottom is thick, and the sides have ~no stress
06:04 PM rue_shop2: single stage
06:05 PM rifraf: ok, i like the benefits of dual
06:05 PM rifraf: why no pressure on the sides of your jar?
06:05 PM rifraf: because there is no seal on the base? lol
06:13 PM rifraf: rue_shop2 is this as far as you went? http://ruemohr.org/%7Eircjunk/projects/vacuumplate/p1130325.jpg i want to see some bubbles
06:15 PM rue_shop2: no a cylinder doesn't experience the majority of the forces on its sides, they are on the ends
06:15 PM rue_shop2: sylinder physics
06:15 PM rifraf: the more i look at these units the stupider it seems to spent $1K + on them, they don't even have dual stages pumps, i think investing in the pump and guage and then make the rest, for both investment and casting
06:15 PM rue_shop2: I have not used it
06:15 PM rifraf: you are as bad as me
06:15 PM rue_shop2: I dont have anyone to show me a process
06:16 PM rue_shop2: and its not been on my guessing list
06:16 PM rifraf: i can show you, been researching a bit
06:16 PM rue_shop2: right now I'm trying to make a power converter and its not going well
06:16 PM rifraf: the new castable resins are where its at
06:16 PM rue_shop2: but I want to be working on the mini loader
06:18 PM rifraf: power convertor? like transformer?
06:20 PM rifraf: is so cold here, we had coldest day in 16 years 2 days ago
06:21 PM rifraf: down to 4°C
06:22 PM rifraf: not used to it at all anymore, days still around 20 so ok if you are in the sun, too cold in shed
06:23 PM * rifraf better attend to finish resin print, has been hanging in printer for 12 hours now
06:23 PM rifraf: and i want to print one of those tops, but cannot get a bloody file\
06:24 PM rifraf: will have to cnc one in brass, lots of 1mm holes to drill though
06:45 PM rifraf: Tom_L if you had to drill 200 holes 1/32" x 3/8" in brass using rotary axis would you use drill bits or endmill?
06:50 PM rifraf: on angled surface, so may need to start with centre drill before drilling, an endmill should start the holes and finish them
06:57 PM rifraf: rue_shop2 would you like to try casting something?
07:00 PM rifraf: will fit in your setup perfectly i think https://desire3d.com/images/public/tree1.jpg https://desire3d.com/images/public/tree2.jpg
07:00 PM Tom_L: short endmill might work better
07:01 PM rifraf: yeah, am thinking same way
07:01 PM Tom_L: or start with that to get a flat surface then go back in with the spot, drill
07:01 PM Tom_L: make sure it's center cutting
07:01 PM rifraf: did you see that zoetrope top?
07:01 PM Tom_L: nope
07:02 PM Tom_L: yup
07:02 PM rifraf: https://makerworld.com/en/models/1513626-infinite-diamond-glitch-zoetrope-top#profileId-1585259
07:02 PM rifraf: see you you can find an stl or model that works
07:02 PM rifraf: i am missing something
07:05 PM rifraf: looks like many holes also intersect each other
07:06 PM rifraf: a good challenge but perfect for my machine to have a go at, you have rotart axis as well don't you?
07:52 PM Tom_L: yes
07:54 PM Tom_L: can you get them after clicking 'designer'
07:57 PM Tom_L: i'm not signed in but there's a place for downloads it won't let me see
07:57 PM Tom_L: https://makerworld.com/en/models/1513626-infinite-diamond-glitch-zoetrope-top#profileId-1585259
07:57 PM Tom_L: v 120
07:59 PM Tom_L: You can always print this model for yourself or to gift, for free. Selling prints requires a tier 1 or higher membership. The allowed sales quantity is specified within each tier's terms.
07:59 PM Tom_L: for a price
08:01 PM rifraf: i am logged in, but they seem to be presliced for specific printers
08:02 PM rifraf: and stl download is just some cap, not the top itseld
08:10 PM rifraf: this seems as good as a bell jar or better, thoughts? https://www.ebay.com.au/itm/355062689017
08:11 PM rifraf: with this pump, https://www.ebay.com.au/itm/405955619776
08:15 PM rifraf: then just need to weld up some big stainless tube, have some 6" tube here that a bottom could be welded on, make a few flask fittings for the top , add some fittings and would have a vacuum casting chamfer
08:30 PM rifraf: rue_shop2 would this have any negatives from the way you did it? for $135AU seems perfect for air removal from investment, and 5 gallon seems huge, 0.75" tempered glass lid
08:30 PM rifraf: https://www.ebay.com.au/itm/355062689017
08:32 PM rifraf: would be way more than $135 or time to make just the plate you cast and machined
08:33 PM Tom_L: just saw a chunk off the end of one of these http://tom-itx.no-ip.biz:443/~webpage/cnc/local_stock/9.jpg
08:36 PM rifraf: or pay local laser guy $20 to cut some 10mm plate with holes
08:37 PM rifraf: i just wanna know why a bell jar setup is better then that unit i linked to, want to buy it now
08:39 PM rifraf: you can still only see the top of your investment bubbling with a clear dome, a 5 gallon unit seems it could have many more uses, like degassing a 4 litre tin at once
08:40 PM rifraf: beats me how they claim 5 gallons in an area 11" wide x 12" high
08:40 PM rifraf: gallons or air or what
08:42 PM Tom_L: 4.94 gallons
08:42 PM rifraf: yep, seems they are correct
08:43 PM rifraf: but a 4L / 1 gallon paint tin is nearly that size
08:43 PM Tom_L: but not quite
08:43 PM rifraf: yeah
08:43 PM rifraf: amazing how it adds up when you go a bit wider
08:44 PM rifraf: Tom_L would you buy the chamber?, rue is off with the fairies as usual
08:45 PM Tom_L: no
08:45 PM Tom_L: i don't need one
08:45 PM rifraf: lol
08:45 PM Tom_L: seems you got ants crawling in your pants to get it
08:45 PM rifraf: i can see exactly the same listing for $280 as well, 135 seems like a good deal
08:45 PM Tom_L: time to wait and ask rue
08:45 PM rifraf: well the electric melting unit will be here tuesday
08:46 PM rifraf: true is sunday, nothing gonna ship till tomottor
08:46 PM Tom_L: nothin but my rp5
08:47 PM rifraf: rapi ?
08:48 PM Tom_L: rpi5
08:48 PM rifraf: whats that?
08:48 PM Tom_L: https://www.raspberrypi.com/products/raspberry-pi-5/
08:48 PM rifraf: oh yeah
08:49 PM Tom_L: you can run a mill with it
08:49 PM rifraf: so overpriced, i still have several rpi3 sitting unused
08:49 PM rifraf: whats the new project?
08:50 PM Tom_L: testing linuxcnc on it
08:50 PM Tom_L: i've run linuxcnc on the rpi4
08:50 PM rifraf: or get a used small format pc for 1/2 the price with 4 times the power
08:50 PM rifraf: ok cool
08:50 PM Tom_L: that's not the point though
08:50 PM rifraf: what is the point
08:50 PM Tom_L: i have probably 4 i could run it on
08:51 PM Tom_L: to test the install & hardware
08:51 PM Tom_L: spi & ethernet
08:51 PM Tom_L: i have a pile of mesa cards too
08:51 PM Tom_L: for testing
08:51 PM Tom_L: mostly
08:52 PM rifraf: do you have rotary axis on any of your mnachines?
08:54 PM rifraf: hrm, wonder if I could cast inside a vacuum chamber, what happens to boiling metal in a vacuum?
08:55 PM Tom_L: http://tom-itx.no-ip.biz:443/~webpage/cnc/rotary/Rotary2.jpg
08:55 PM Tom_L: it's got a stepper on it now
08:55 PM rifraf: make an external handle to pour the flask inside the chamber, but seems the idea is more to pull the metal through the porous investment
08:56 PM rifraf: thought you had one, just for show or you use it?
08:56 PM Tom_L: testing mostly
08:56 PM Tom_L: i've used it a bit
08:58 PM rifraf: i'd like to be able to angle mine but really have no use, rotary positioning and use as extra spindle though is used all the time
08:58 PM Tom_L: takes alot of room
08:58 PM rifraf: 4" chuck?
08:59 PM Tom_L: http://tom-itx.no-ip.biz:443/~webpage/cnc/rotary/mount/Rotary_mount11.jpg
08:59 PM Tom_L: i think so
09:00 PM rifraf: ok, so the indexing sheel is to hold it in position because stepper too weak?
09:00 PM rifraf: wheel*
09:00 PM rifraf: ot how that work
09:00 PM Tom_L: it's just for manual if you want to index
09:01 PM Tom_L: i don't use that with the stepper
09:01 PM Tom_L: it comes with a few different index plates
09:01 PM Tom_L: for manual indexing
09:01 PM rifraf: oh
09:02 PM rifraf: you replaced the index wheel with a stepper?
09:02 PM Tom_L: basically yes
09:02 PM Tom_L: http://tom-itx.no-ip.biz:443/~webpage/cnc/rotary/mount/Rotary_mount7.jpg
09:03 PM rifraf: tool or toy?
09:03 PM Tom_L: you can see an index wheel at the bottom there
09:03 PM Tom_L: tooly
09:04 PM Tom_L: nobody uses rotary alot
09:04 PM rifraf: i do
09:04 PM Tom_L: not even when i was helping my friend in his shop
09:04 PM rifraf: primarily even
09:05 PM Tom_L: https://www.youtube.com/watch?v=YUAqIt_YRQQ
09:06 PM Tom_L: i was still tuning the rotary
09:06 PM rifraf: all this made on rotary https://desire3d.com/images/public/Drillrig1.jpg
09:06 PM rifraf: the handle swirls were just a quick things to have a continuous line all the way around
09:07 PM Tom_L: i was fixing my cad post while building it so basically 2 projects at once
09:07 PM rifraf: how nice are those drill bits, hard to see points, 50 years old
09:08 PM rifraf: pretty easy to make it miss steps?
09:08 PM Tom_L: no
09:08 PM Tom_L: https://www.youtube.com/watch?v=pvDBfJQT2Ec
09:08 PM Tom_L: my feeds were still way off in that one
09:08 PM Tom_L: had to adjust for angular instead of linear
09:09 PM rifraf: whats all the noise? so glad to not have steppers
09:09 PM Tom_L: skip to ~2 min
09:09 PM Tom_L: turn the volume down :)
09:09 PM rifraf: i watched the whole lot
09:09 PM rifraf: is nice
09:11 PM Tom_L: http://tom-itx.no-ip.biz:443/~webpage/cnc/rotary/mount/Rotary_unwrapped_2.jpg
09:11 PM Tom_L: my cad only does wrapped rotary
09:11 PM Tom_L: that's what it looks like when you draw it
09:11 PM Tom_L: unwrapped
09:11 PM rifraf: i need to get stronger holding power on my servo, rotary not held rigid enough but still works, is just a setting to tune, currently i can move it a few degrees with some force
09:11 PM Tom_L: my cad is pretty old
09:12 PM rifraf: yep i wrap mine as well, so work on the design unwrapped
09:12 PM Tom_L: 40:1 isn't really goin anywhere
09:13 PM rifraf: did you make a decent spinning top yet?
09:13 PM Tom_L: the bump in the line was just to see if it would reverse
09:13 PM Tom_L: no not really
09:17 PM rifraf: 3cfm vacuum or 9cfm vacuum pump? its just a speed thing right? how fast the air can evacuate? the vacuum would still be same pressure
09:18 PM rifraf: and for casting i want fast evacuation for the casking flask, so would be silly to get 3 cfm like all the cheap units have
09:18 PM rifraf: they are same refrigeration though, not boiling how metal fumes :/
09:18 PM rifraf: hot*
09:19 PM rifraf: rue_shop2
09:20 PM rifraf: am pretty sure fridges are all hot on the other side of condensor
09:30 PM rifraf: https://www.youtube.com/watch?v=p2FIzLQNJFM
09:30 PM rifraf: i can make this for way less, uses 8cfm as opposed to 3.
09:32 PM rifraf: bought the pump and chamber
09:34 PM Tom_L: is that purely for degassing?
09:34 PM rue_shop2: hi
09:34 PM rifraf: yes
09:34 PM rue_shop2: was distracted
09:34 PM rue_shop2: now building oscillator
09:34 PM rifraf: but the pump will be used for casting as well
09:35 PM rifraf: just need to make a casting chamber, have the SS tube and iso wool already to insulate
09:36 PM rifraf: rue_shop2 when are you not distracted?
09:37 PM rifraf: rue_shop2 what you think? https://www.ebay.com.au/itm/355062689017 and https://www.ebay.com.au/itm/405955619776
09:37 PM rifraf: got the pair for $330 delivered
09:40 PM rifraf: 290 CAD, wow our dollar pretty close to yours now, what happened?
09:46 PM rifraf: Tom_L there are many units available where you need to add your own vacuum pump, so having a decent pump increases option, but a vacuum casting chamber just seems to have a vaccum on the outside or the porous investment flask, so cannot be hard to make something up, and then the last big ticket item is a burn out kiln
09:46 PM rifraf: i miss melting metal, gave away all my nice setup that could melt 15 kg at a time
09:47 PM rifraf: but will be able to make some cool stuff
09:48 PM rifraf: rue_shop2 are you going to be undistracted in the next few hours?
09:48 PM rifraf: i wish you could remember communication with people is a good thingful, even if you just want to be a robot
09:49 PM rifraf: i get more sense from chatgpt these days which is pretty sad
10:33 PM rue_shop2: hah, but its always wrong