boy did i machine myself into a corner today
how are you gents.
Good toast, you?
Guest871 is now known as skunkworks_
03jepler 07TRUNK * 10emc2/lib/python/rs274/ (glcanon.py interpret.py): (log message trimmed)
a better fix for the "360 degree arc turns tiny" problem
The original problem was that the start and end points of certain 360
degree arcs would be different by a tiny amount (for example,
1.0433070866141736 vs 1.0433070866141734) when offsets were in effect.
Originally, the case for this wasn't found. Instead, a small FUZZ
factor was introduced; circles that were smaller than FUZZ radians
cradek_ is now known as cradek
I posted this earlier but in the wrong channel. It's a general overview of "why hexapods are cool" and why someone should give me money to git 'r done: http://fenn.dyndns.org/pub/emc/bfi/bfi-draft.txt
are you asking for input?
if you have something to say about it, sure
are you looking for investors or grants?
its a contest entry, but the idea is probably more important
i would rather get grants because i think investors would screw it up
you say "All of my work so far has been done with free and open source software tools so it can be distributed and used widely for no charge" and that causes two issues for me: the "so it can part" does not follow, since you can use free tools to make a non-free product. also, you don't say how you intend to license any future work or final product.
the "so it can" part
yeah if you want it to be Free, most investors will want to screw it up.
if you use non-free tools it's a huge pain in the ass for someone to come along and make a minor contribution
oh I think I see what you meant now
if it's not Free people will think it's a gimmick
I did not understand the whole sentence I guess
that's one of the hardest things to explain, for me, since it's not a technical issue
I read: "as an (accidental?) consequence of my use of free tools, my work can be distributed/improved"
very neat. I have a growing hexapod 'itch'.. Great - another project.
when you meant "I used only free tools to make it most easily distributed/improved because that's my goal"
I agree it's hard to explain, especially succinctly
if you meant the second thing I said, the "so far" makes it really wishy-washy
ok, i reversed the wording
also I see some unnecessary negativity in "usually a pointless endeavor" and "to pursue a real career" - you should reword or just drop things that secretly let us know how you think you might fail
the rewording of "So that it can be" is much clearer
but the "so far" still leaves me wondering a bit
minor grammar problem in "They could be used for:... by rescue workers"
cradek: what where you an editor for in your former life?
skunkworks_: I'm not an editor but I play one on TV
also "used for:... in physical therapy"
how do you explain what rescue workers do
does just 'rescue work' sound right?
yes either of those I think
(I'm not sure what kind of rescue work you mean)
pulling cars and fallen buildings off of people
i guess i could just say that
yeah those companies change names every few years..
cool a hexapod waterjet - i had that idea too
the rotory one is pretty cool.
fenn: you should post info on your simulation here. http://www.cnczone.com/forums/showthread.php?t=753&highlight=hexapod
bring it back to life. They had some odd ideas about how hexapods worked.
not that I am an expert.
how much harder is it to calculate the kins for a hexapode using universal type joints for the strut ends?
if you use coplanar swivels in the joint it should be the same calculation
really? compared to a ball joint?
i think so
one problem is that rotation around the screw axis causes the joint to extend and retract
a U-joint should have some point where the two centerlines intersetc. that's the point you'd use as the joint origin
SWPadnos_: there are designs that have u-joints with skewed u-joint axles
those would be harder ;)
ok - I was just thinking in a car drive shaft you need to make sure that you have both 'in phase' or it will pump.
if you put it together wrong, then all bets are off
i would like to be able to correct for all possible errors in the machine, even if it sounds insane
iut would be nice, but I think it may be a hard problem
I am just trying to visualise. If I where to make one at the moment - I would have preloaded universal joints (timkin) on each end of the strut with the linear whatever device (ball screw) between. maybe have the universal joint hollow so that the screw could go thru it. and have the spinning ball nut at that point. \
actually, that should be "a Hard Problem"
you think it's that bad?
I think it might be
when yuo consider that every bearing or joint could be irregular / eccentric
there's only 32 centerlines in the machine
there are probably places where you get multiple or no solution
The forward kinematics problem, a system of equations which given the leg lengths, yields the position and orientation of the platform, has up to 40 solutions. However, the inverse kinematics problem (i.e. given the position and orientation of the platform, find the required leg lengths) has a unique and very simple solution.
dunno. I have a cold, and I haven't had much coffee, so I don't think my visualization engine is at 100%
that is interesting.
[16:52:30] <skunkworks_> http://en.wikipedia.org/wiki/Stewart_platform
very stupid question... Is there a calculater out there that you can enter strut sizes, movement, and centers to get it maximim work envelope?
besides my own calculator?
nothing convenient i'm sure
[17:21:14] <fenn> http://hexapod.zemris.fer.hr/engleski/calc/
ooh - that looks interesting. thanks
the cross section thing is cool
fenn: very cool. I love the 'cloud' work area it shows in vrml. Gives me a good idea of what envelope you have.
what are you using to look at the vrml?
I just did a quick search and found this one http://www.parallelgraphics.com/products/cortona
its really lame how quickly vrml has sunk into obscurity
Hexapod by Leonardo :)
yah - that site is going into my favorites.
Thanks again fenn
although it seems to be down now..
I think I broke it
SWPadnos_ is now known as SWPadnos
I'm making some .2 pitch pulleys, getting there...
skinnypuppy34: hobbing them?
Just turned a blank, going to single point cut them with the dividing head
i get outbid on every damn lathe i bid on...
Looking at the xl belt tooth profile in machinerys handbook looks like a single point could be ground in a few minutes.
Keep on chr0n1c my 17" swing clausing + 3 and 4 jaw and burnerd quick release collet and chuck set for only $1000 on ebay and a $250 flat bed tow
i have been looking at 9", 10", 12" machines...
something small, but able to do most things still
Where ya at?
*that i would need to do
i have only been looking on ebay
You should see something regularly I would think. Been a few months since I've hunted
today i found 387 brake rotor lathes when i searched
I've seen two or three in driving distance in the last few months...
there must have been some big advance in brake rotor lathes recently
i'm going to keep looking....
it's not something i need need need right now... so i have some time
Yeah I understand. I've been hunting a toolroom quality lathe. without paying an arm and leg
machinery auctions are often advertised in the sunday paper
you live in ohio so it should be easy
we get notices at the shop... if i can get to them before the boss tosses them...
he throws away all the good bathroom reading material
WIsh this machine had been a little closer.
[23:47:38] <skinnypuppy34> http://cgi.ebay.com/Hardinge-Lathe_W0QQitemZ120173350285QQihZ002QQcategoryZ104241QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
[23:49:48] <dmess> http://www.fa22raptor.com/
if you have a good connection grab the video frol the Langley Va air show.... AWESOME bird... but looks like a flying wood duck to me...
that looks like a nice lathe to have around
is it still available??
It didn't sell, email the seller
I'd probably pester him if it were a bit closer
where are you??
its in alabama?? right??
I could be mistaken
shite for 500 bucks i could have it droped anywhere in georgia
if ts in alabama
dmess I'll keep this in mind for the future
small machine.. fits in pick-up...
some good friends would bring it home to me for free... ;\)
Oh reallllyyyy ... didn't realize it was quite that small
Does anyone know a good source for used/surplus Ice Maker parts?
commercial ice maker
but works ANYTHING to aprox. 12 inches with the right tooling...
call the local ice maker.. ask him where he finds part.. unless thats YOU
If you're interested get it by all means, my wallet needs to recover from motors/geckos/powersupply/wires/belts in the last month
dmess: That's the problem the comany is no longer in business and they want premium price for the parts.