Zat German wrote:An E-stop is different from a Reset, which is what you are describing. In the case of an emergency stop, you need to reliably kill everything without depending on the CPU to do it(it might not be in any state to process such a command or input), that means it has to be hardwired. An E-stop could also be tied directly to the CPU's reset pin but then you lose state(even if it is a crazy one) which interferes with trying to debug stuff. An emergency stop is an emergency, recovering the build or losing sync is secondary to to getting the machine off and in a safe(ish, since we are dealing with hot things here too) state.
Cool - (me too , but with an RC BLDC motor) - either way the spindle + end mill is the most dangerous part, and that which i'd most urgently want to shut off with the E-stop.Zat German wrote:Well, I plan on adding the ability to cut foam with a spindle(probably a Dremel MiniMite in a custom housing) to my ORD so that is one reason.
I don't disagree with that either, mostly because i admittedly have an irresistible urge to over-engineer everything i touch, as you may have noticed...Zat German wrote: Another is that the ORD bot seems to move pretty fast from what I have seen, compared to RepRaps and other 3D printers. The Ultimaker which is of comparable speed is basically in an enclosure, where the ORD bot is very open. I consider it a safety requirement for any machine I run, even if others may not.
Absolutely! and I'm glad you did, now I'm seriously considering it - as long as there's room and it doesnt significantly increase cost & complexity - I'm just trying to decide what the right way to do it and how much is enough? If i am to add it it has to be decided quickly. Thus a little discussion & friendly debate goes a long way to answer thatZat German wrote:Since this is a prototype, I might as well ask for it now so it can be considered rather than after it goes into production.
bdring wrote:I am concerned about the amount of custom programming that is going to be required to get your board running. Reprappers love to try new firmwares. I asked Jeremy to try out Repetier the other day and he had it going in minutes. You adjust configuration.h and you are ready to go. Having to hack in digital pot settings for motor current, special e-stop routines means hacking a lot of files. New firmwares and revs come out every day. The same configuration.h usually works.
I think you have a lot of coding ahead of you to get all the features running.
That would just be a straight up power cut to the spindle when the e-stop is hit. I have some really nice and quiet 36v spindles but they are pretty heavy and not really needed for the EVA foam I am going to be cutting. I picked the MiniMite because it is extremely light at 4.8 ounces without the battery where my other spindles weigh more than a pound. That means I can do really quick jogs when not cutting and harness the speed of the ORD.frob wrote:Cool - (me too , but with an RC BLDC motor) - either way the spindle + end mill is the most dangerous part, and that which i'd most urgently want to shut off with the E-stop.
How do you envision handling that part of it?
Zat German wrote:That would just be a straight up power cut to the spindle when the e-stop is hit. ... I picked the MiniMite because it is extremely light at 4.8 ounces without the battery where my other spindles weigh more than a pound. ....frob wrote:How do you envision handling that part of it?
All the ones I have seen latch when you press them and you have to pull them out or twist them to reset. The ones I have ordered have separate NC and NO blocks so you can wire it for either or both.frob wrote:Question: is an E-stop usually a latching switch or a momentary one, and just simple spst or more poles? just trying to figure out how that would be wired.
The MiniMite seems like a good idea so out of curiosity i found the user manual and seeing the exploded view of the parts, it is a bit disappointing to find it looks like a cheap toy DC motor (bushings) with a collect chuck adapter pressed on to the 2mm motor shaft.
Zat German wrote: Where did you find an exploded diagram for the MiniMite? I even contacted Dremel after looking on their site but could not find one. They told me they did not have one.
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