harmonic drives are not made elliptical
except the cam
Prompted by a design posted here, I have been pondering drive systems. I have an idea for two internal gears stacked, one with 200 teeth, one with 203. They have the same ID and root diameter. Running between them are 3 planetary gears, meshing with both, and in the middle of that a small input pinion. I reckon you would get a huge ratio, and low backlash.
MattyMatt i want something like in the video ^^
andypugh that sounds identical to the one the army used in WW2 for radar turrets
Darn! Another potential fortune falls by the wayside
which iirc is linked on the WP harmonic drive page
Which I logged in too late to see the link to
[00:15:18] <numen> http://www.youtube.com/watch?v=y2vRkXoTWqc
after 10th second
Nothing like what I had in mind, but very cool
yes, this is interesting ^^ i want something like this, but the chinese company dont want to give the dxf
Do you have a link for the radar gear?
Oh, and Matt, I have been thinking more about your CNC crop sowing idea. They already have computerised sowing machines which are GPS controlled. Plant lavendar, poppies and something green (spoilt for choice) in 3 passes, and wait.
I reckon you could get a grant. If you got in touch with (for example) Banksy who probably has contacts it could be a goer. Sponsorship and field rental from the computerised crop sowing company.
andypugh what you want?
Radar turret gears, like what I described, allegedly.
what is a radar turrent gear?
that in the video?
[00:31:44] <andypugh> http://en.wikipedia.org/wiki/Epicyclic_gearing
And yes, the one-tooth-fewer idea of mine is at least 50 years old. Bah!
MarkusBec is now known as MarkusBec_away
Isn't the trajectory thread used anymore ?
it does not show up in halscope so I was wondering how come since it's still defined in the ini files
maybe it's not used by hal?
dunno, just thought I might be able to use it for torch height control related hal stuff
make your own thread
I have a user which doesn't have the computing power to use the servo-thread, I recommended he would try: loadrt threads name1=thcthread period1=1000000
and try assigning to it
do you know if user created threads need to be a multiple of servo/base threads _
thx for your recommendation, at least I know i'm on the right path :)
it has interaction with components running on different threads, that would have to be taken into consideration
yup, i don't know exactly what will happen but it's worth testing, I would assume values are left until next run so it should work
should be ok
where can i find a good explanation of joint-pos-cmd vs motor-pos-cmd?
integrators's manual & linuxcnc,org define motor-pos-cmd "The commanded position for this joint." and joint-pos-cmd as "The joint (as opposed to motor) commanded position"
thats nto an explanation, that a puzzle
My Integrator's Manual says (p.46) "...There may be an offset between the joint and motor positions–for example, the homing process sets this offset. " Does that help?
hope that helps, bbl
no, the definition is unreadable, im not questioning some latter feature, thats not the definition
YAY!!!! Shelf brackets complete!!!!
can emc run on a 64-bit computer?
in stepgen.c there's an entry in the struct for pos_mode (default is position, but can be velocity). i dont grep any other code using it? does any other code use that info?
i'd like to use velocity mode, sometimes, and position mode at other times. if no other code cares, i might be able to adapt a new stepgen and toggle the mode selection.
tom3p: in trivkins joint position is the same as axis position (min lim -> max limit)
motor position is position on phisical device
micges_work i think, you will have to wait till monday...
numen: when you send, simply just let me know
MarkusBec_away is now known as MarkusBec
micges_work: thanks, i will try to make the new stepgen component, i'll try a new toggle_mode pin. or, try to estimate the new position and not use velocity mode.
in edm the velocity & its sign are direct result of process, position is result of velocity, not like in emc.
* MrSunshine just put his finger in the endmill :P
when scraping away aluminium dust :P
(yes i did use a tool but wasnt alert enough to where i had my hand :P )
just a small skin patch gone tho ... realy small :)
some damage to self teaches you to keep out
need to make a flood coolant system i think :)
that washes away that damn dust
shouldnt be to hard =)
should wash away the blood too
almost no blood ... just a drop =)
archivist, but looking at ancient steel quenching recepies blood is good as a coolant :P
hmm, how to calibrate backlash ? .. that is .. mechanicaly ... how do i find out how much backlash i got? :)
some backlash nuts self adjust
well no backlash nuts on this machine =)
i have the means to tighten everything up
but i need to know somehow how much backlash i have
maybe one of those indicator clocks .. just drive it forward, put it on and look how many steps it takes before the table turns around
use a dial indicator
i guess i need to make solid motor mounts before doing that tho :P
milled out the last part of the Z motor mount today .. just two holes to be drilled and i can remount the Z motor on a real aluminium motor mount insted of a wooden one :P
and all milled with my mill ... not 100% straight or anything but as i replace parts it will be better and better i guess =)
strangely cnc have a hard time with backlash, machinist operated not
tom3 is now known as tom3p
the cuts that you expect the machine to successfully make are very different in the two schemes
hmm - with a nice guide I bet I could run 1/2-20 holes into cast with my cordless drill...
only around 480 to do..
if the tap is sharp and spiral.. ;)
if I can run 8 inch long 3/8 lag screws in with it...
I've tapped a lot of holes in thin stuff with a cordless drill
for deep holes I think it'd be too hard to get it aligned
for thin: tap in, carefully try not to move the drill too much while switching it to reverse, back out
also, have extra taps :-)
guide? drill a hole in flat scrap ( 2x dia thick) with a drill press to get it square to the surfaces, clamp to work,drill, then hand tap it anyways ;) , you only need 30 turns for max strength
cast taps easy
holes are already drilled.. http://www.electronicsam.com/images/KandT/pcbmill/table.jpg
if only they had a floating tap holder...
bridgeport? use a dead center and a t-handle. put dead center into the divot on end of t-handle ( or even into divot on end of some taps)
did you break down the setup before tapping? then you loose the advantage
these are just great if you have to hand tap
like tom3p says, the point fits in the back of a (good quality) tap handle
I have never inverted it to use the female point, but I guess you can get it apart to do that
ah, the cylinder end has a hole in it for pointy ended taps, its one tool with a reversable ends, clever
just noticed the machine shop I wanted to order from isn't open on Fridays
they are on a 4x8 hour days too
flash is such a piece of junk
adobe needs to schedule a seminar for their programmers on how to successfully use message boxes
you can't ask a seller a question on ebay any more? WTF?
i asked one question a few days ago
it goes to an automated thing that doesn't seem to include a place where I can ask my question
[18:09:14] <eric_unterhausen> http://cgi.ebay.com/3PC-Boring-Turning-Facing-Holder-For-Tool-Post-BXA_W0QQitemZ170418083783QQcmdZViewItemQQptZBI_Tool_Work_Holding?hash=item27adb597c7
nvm it's off screen at the bottom
yeah keep clicking
hit "Other" and there's a link to "contact the seller"
oh never mind
some sellers don't have that page
never seen it before
I guess it's a test to see if you are really interested
wow, that looks like an incredibly crappy way to hold a boring bar
well a round shank one anyway
I'm not buying it for that though, just for regular tools
for square (homemade) it'd fine
the holders with a round hole are a pain though
you have to get a shim, etc
If you saw how I abuse my boring bar in one of those, that's the least of my problems
machinist at work uses both kinds
last week that seller had the regular toolholders for $9 and boring bar holders for $12
When he says "3 pc set" what does he mean? I see a total of 11 parts...
that was my question, my original thought was it was 3 toolholders
pretty sure that's what it is given that $45 is what he was selling them for last week with shipping
Is there a hal component that can give a short pulse output when a signal changes state?
I want a software reset for my e-stop.
if there isn't it can't be too hard to write
I was hoping to wire to the Axis GUI e-stop, to energise the contactor so that it can then be self-energised through the e-stop chain. I am possibly being a bit too paranoid. I want to make sure that it all stays off even if the e-stop buttons don't latch.
I'm confused about estop
Anyway, probably a question for another day.
but you can do that with a relay
I want either of the e-stop buttons to de-energise the main contactor coil.
that's easy, just run them in series
And yes, I was going to use a relay controlled by emc to perform the equivalent function to a conventional contactor "on" switch.
I want a momentary break in the circuit to disengage the contactor though. Once it trips I want to have to re-energise it, rather than have everything power back up once the e-stop buttons are unlocked
you have a relay in series with itself for that
Yes. I know, but you also have a parallel "on" button, and it is that bit I want to do in HAL
problem is you need a reset button then
or get a safety relay
Ah well, I have plenty of time to sort something out. And safety relays cost more that the motors and drives did, for just one.
And even then, I suspect that the safety relay would need a momentary reset pulse.
I got one cheap on ebay
still confused about the startup sequencing of the whole chain though
Bah, what was the company that has rotary encoders?
I got a lot of Heidenhain encoders cheap on ebay since they were misspelled
does that count?
hp is probably under a different name now
ah, it's magnetic
Are HP now Avago?
I buy encoders from US digital if I need a cheap one at work, at home it's ebay all the way
andypugh, that sounds familiar
Anyway. Off to the airport to collect my girl friend.
Pick a good one
probably too late for that once the flight from russia leaves the tarmac
tarmac, russia ?
[18:51:58] <skunkworks_> http://www.electronicsam.com/images/KandT/pcbmill/tableholes.jpg
some day it should get ground...
"i bet you arm's sore from all that drilling"
heh - thank goodness for cnc.. (but yes - I still have to tap them manually some how)
so it is a good start - everything should be square to itself.
good evening a question about robot kinematics on emc please.with mesa card and analog drive is possible create a robot 6 axis with robot kinematics ? thanks
all the mesa cards can handle 6 joints (motors) no problem, but i dont know if there's a kinematics module that suits your robot
just keep a tap near the mill, and tap them as you need to use them..
seb_kuzminsky, i want build a normal antromoforfe robot type kuka abb comau
motioncontrol: i dont know
seb_kuzminsky, ok thanks
MarkusBec is now known as MarkusBec_away
this will make a nice emc2 pendant: http://www.youtube.com/watch?v=PHRSDWZC_m4
picking up the macing to shake it is not an option :)
GonMD, url fail