Actually thinking about it you are probably right. The input of the op amp and its output need to be referenced to each other some how. So adding the ground there at the moment does make sense. Attached is an updated schematic.
Greg2835
Mechanical...
Great question, and I don't know haha.
The thought was the left side source and op amp would be independent. The left side just gives a step input, and the motor gets power from the 9V batteries. I could connect the bottom of the capacitor to the ground between the batteries, but with my...
Hi All,
I am using a low power geared (hobby) motor that has a time constant of about 0.002 sec. I would like to slow this down closer to 0.2 seconds. My first thought was to add a LP filter and a buffer (see attached) before the motor. The buffer has ±18V (2 9V batteries) at the rails. The...
Thanks for the input CWB1. When I said release I meant prototype release (release to outside manufacturing to begin prototype parts). Final release meaning the prototype has been production approved (you are correct in your definition for "release," this is just the vernacular I am used to from...
Aha, yes IR stuff you are correct - I have been misusing "free rein" for quite some time now :) I have been walking through best methods for electronics part numbering, and that task seems MUCH more cumbersome (and I have never worked at a place that has done it well). Luckily, we do not have a...
Thanks truckandbus, that is the heart of the manner that I am trying to research, how much "tempering" I will need in my situation. The resource you suggested looks great! I will certainly consider its methodologies.
In my experience, I have seen instances where parts are revised for every...
Thank you for the recommendation cowski, I will certainly give it a look!
To CWB1, we might have different working environments - so I'll provide a bit more detail. My company does all the design work and outsources manufacturing. Small changes come up time to time after drawings/models have...
I see, ECO is placed and new part dwg may list something like "REV A - REPLACEMENT FOR P/N 12345" in the rev block, I assume.
Thanks IR, I actually was going to expand on things a bit but after thinking it through I at least have a decent starting point. I'll be joining a start-up company in a...
Thanks IR, I have not considered that approach but I do like that these cosmetic changes have a place in your CM. Let me go a bit further then, and ask if you do anything special with a previous part number that required a FFF change? For example, part 12345 did not fit, so part 12406 was...
In my experience all employers have employed the "every change gets a revision." Meaning if I have Part1 at Rev A, get it manufactured and sent back to me, then find out it doesn't fit, I then revise Part1 to Rev B (no new part number).
I am aware of the "parts get no revisions" rule and it...
I'm trying to find a legitimate way for calling out a bend on a part that has a flat on the end. Essentially, I want to say "the flat must remain perpendicular to the plane of the bend (which is my "A") by this much." Since the part is cylindrical I don't really have a good reference to relate...
Emo01,
You are on the right track that the class of fit will dictate the maximum movement of a screw shaft relative to a hole. It all has to do with pitch diameter and how much that is allowed to vary (which is defined by fit class i.e. 2A/2B).
For example, from ASME B1.1 a 4-40 2A screw has a...
Couldn't agree more, mkcski. Right now I'm just coming up with brain teasers to get my head around this stuff. My thought was if I wanted this part to fit in an assembly where feature B is mated to another surface and the remaining edges must fit within a given tolerance window.
pylfrm,
that's exactly what I was afraid of. Wasn't sure if there was something I didn't know in the standard that "shifted" the window for cases like this but I guess that could get rather confusing in other circumstances.
mkcski,
perfect, that makes sense. I guess the way I look at it is...
Well now your just making all sorts of sense :)
Ok I see the point for the using the base number as the drawing number. I guess the way my company issues dash numbers isn't what is done by most of the people on this forum. The reason we create dash numbers goes something like this. "Hey, Greg...
I want you to know Mike, that your post put a big smile on my face (especially the part about the cranky old lady).
Yeah I kind of figured at times there would have to be no real correlation between drawing number and part number. Every place I have worked uses equivalent numbers for both and I...
Can someone please explain the following. I am looking at what exactly drawing numbers are and why they differ from part numbers. Most things that I have seen say something along the lines of "part number is 12345-01 and drawing number is 12345." I understand the dash number in the part number...
Right and I understand that Datum B clocking is not needed. But let's say I want the part to be inspected such that feature B is clocked (see the attached). In my previous attachment if I were to clock B horizontal the edge would have fallen just outside the profile window and I would want that...
mkcski
You're right, basic dimensions cannot be used for parallelism and perpendicularity (smacks forehead). That answers that question then. You're statement about the profile example leads me to another question. Let's say I want the profile "window" of .030 around the part, but I want the...
