I’m a recently retired Design & Technology teacher and I first started making these with 14 year old students 40 years ago. It was a great way of them developing a “tool kit” of skills that would serve them well when designing and making their own coursework projects. I started with brass, but transitioned to casting the barrel and wheels in aluminium to bring in, even more processes and techniques. Sadly, this level of work is no longer evident. However, some of the work that the students were doing at the point where I retired using CAD/CAM, Systems and Control and Electronics is equally challenging.
Very good and detailed video. I spent ten years correcting engineer's in NPI and DFM reviews as they often get the ISO tolerances wrong. They'll accidentally define a slip fit when they want a press fit, or the opposite. Sometimes I felt like my title should have been "FIT reviewer".... I don't know about including the tolerances and double-dimensioning the print, I might consider putting H6 for example and then in reference the tolerances in a digital format example "xmm H6 (+xxx,-xxx)" One thing engineers often don't see though is that the ISO metric sized reamers are sometimes a little harder to come by within the tolerances. Additionally, the ISO fits are often require metric gage pins, and this increases cost. They are also tighter tolerances than is needed in some circumstances, and this requires more expensive metric gage pins that are more accurate. So be sure to check that the tolerances of the fits are practical to your application. Engineers would ask me, why does it cost X amount of dollars? Well, I have $2500 in gage pins to buy to guarantee your specific fits. If I could use a standard inch pin on file, I could use the pins I have in stock and the reamers that are easy to find. Generally, in this case the machinist ignores the tolerances, measures the pins, and uses an inch reamer and press fits (or slip fits) according to either a general rule of thumb or inch tables in the machinery's handbook. One thing machinist's know is, especially on a press fit, you can't measure the hole after the press fit is made. The other thing to consider on pressfits is the impact of thermal expansion on your part. If the press fit is too loose and your parent material is something like aluminum, the pin can fall out. This is important to pay attention to the press fit in heat applications. Depending on the material, the pin often has a lower CTE (Coefficient of Thermal Expansion) than the part material. So when your part heats up and grows, the pin stays the same and falls out. But CTE is a different topic.
Basically all modern machining is referenced to in either "inches per minute" or "inches per revolution" or the metric equivalent "mm per minute", or "mm per rev" Something to keep in mind for your final revision
Hello everything is fine? My name is Everton, I'm from Brazil, Campinas - Sp, I would like to know if you can send me the CAD for this project, so I can execute it here.
I refuse to heed you're results. As soon as I can get ahold of several 45 lb plates. They will asap be attached to a homemade kinetic wood splitter that's been on pause for a while because I don't plan ahead or think things through when i get a idea..
I hear ya. There are some good off the shelf options that you can get without having to go into the level of detail I have. I'm hoping I can get this refined and bulletproof enough to be able to offer it for sale some day!
Right. I think I'm going to proceed with an RS 485 chip on the physical layer and just use I2C over it. I've cut my GPIO requirements down even more (dare I say.. tripling down on I2C), but I think this will make it much more reliable.
I have successfully used I2C over Cat5e by making it differential. There are some chips specifically designed to allow this. The PCA9615 is a good example. Great video, keep up the great work Greg
They are kind of small. I guess it comes down to personal preference, but for an application like this you can sort of take as much time as you need looking closely at the screen and switching the switches, and then all you really use is the feed/reverse switch
It may very well come to that, I was mostly just trying to avoid using a second microcontroller. I was thinking "half the microcontrollers means half the coding" :P
The connector is called DE-9, not DB-9 - A DB-9 would not make any sense as only having 9 pins in the shell size B that can house 25 pins is silly and pointless.
Interesting, I didn't know that! I guess my first exposure to the D series of connectors was DB25, which does in fact use a B-sized shell. Just poking around online a bit more, it looks like people like me misusing the term has also made "DB9" fairly mainstream too.
I realize it's a WERID question, but IIRC creators can see if someone has commented before/what those comments are. Have I commented on any of your videos before this? I am subscribed, but i have NO memory of ever seeing any of your vids... Was wondering if maybe YT just black holed you for a couple years, or What? LOL
I don't know that I can look up if you've commented before, but it's possible. As much as I'd like to say YT black holed me for a couple years, I sort of black holed myself :(. Life got pretty crazy, but hopefully that period has passed.
@@TabletopMachineShop Oh? Odd, maybe that's a third party tool they were using then? Last time I commented on a Tuber's video who I hadn't seen in a long time, they asked me if i was still living in a foreign country, and when I said that was an impressive memory, they replied that it wasn't the case, they could just see my prior comment to that effect. So, I was under the impression that is was some YT backend stuff to help creators see who they were interacting with.
