With the pattern coated and dried I did the final prep. ……and cut the legs off, added the sprue and a little bob, and a little touch up of the coating. This one is ready for the sand. Unfortunately the weather forecast isn’t cooperating. Might be a couple days. Best, Kelly
That’s what we are getting 70° then 55° and rain. I am looking forward to your successful results good luck.
Finally had a good weather day and took advantage of it to pour the lid. It came out well. Here’s the raw casting. Took it directly to the mill for degating. Here’s the degated casting Happy with the results. Here's a video of the events. Best, Kelly
Looks fantastic! I bet locating those holes to mount that is going to be a good time! I have trouble with 3 holes, can't imagine a dozen. I did the tubalcain method recently where you sharpen a handful of screws to a point, thread them in to the hole, set your piece on top and give it a tap. Worked a treat! Someone needs to patent that idea.
I was thinking I'd just clamp the existing aluminum plate lid to the casting and use it as a drill template Best, Kelly
Impressive work as always. One comment about the production quality of the video, the wind noise is pretty annoying, you need a dead cat for your microphone. In case anyone doesn't know what that is, https://www.amazon.com/s?k=dead+cat
I have one of these. It's a good mic. Too bad the gopro is too stupid to remember to use it. https://www.amazon.com/Rode-VideoMi...ne&qid=1618288791&sprefix=rode,aps,252&sr=8-3
It's just the built in iPhone Mic.......tougher to install a dead cat on that one. The wind was much worse than normal. Don't know if you noticed (during the pour I think) the camera/phone started wobbling around on the tripod. I need to do something as far as the mic though because you can tell when I turn and look at the camera the volume and clarity briefly returns but is otherwise muffled. None of my vids are great but that one was a bit of a hack job even for me. My Bluetooth camera remote doesn't work reliably either and I had several clips that never shut off where I thought I stopped it and required additional editing. I guess I've been more focused on making good castings then good video and the video bit can be a bit distracting. That looks like a pretty good one and I'm sure would make a world of difference on my indoor clips. I was thinking maybe a wireless mic and loop might be better for me because then I wouldn't need to be a slave to the camera location to speak for the outdoor stuff. Maybe something like this one to do double duty? https://www.amazon.com/NASUM-Microp...6768&sprefix=remote+microphone,aps,185&sr=8-6 Bonus! The gating was bit over the top and required some additional effort to remove......but it was my take-no-prisoners approach to increase probability of first pass success. I did break my favorite slitting saw. I didn't want to temper the casting because I needed to do some straightening so it was in full annealed state and rather gummy. It loaded the slitting saw blade and that was the end of it. In the future, I'm going to use cheap carbide tipped fleet store saw blades. They actually work better because the teeth are quite a bit wider than the blade and tend to clear chips and thus not load a quickly. I have a 3.5" one mounted on my die grinder......got to be careful with that bugger but it works great cutting awkwardly placed gates and runners. Best, Kelly
Oh I have them, but even when using center drill and then drilling to diameter I get better accuracy with a drill guide. Even with TiN coated drills and cutting fluid, an untempered casting will still adhere to the bit after a couple holes. Best, Kelly
We used to have a big straight edge ruler that was cast iron shrinkage on one side and aluminum on the other. It had the shrinkage built into the measurements and made building things for casting much easier, it was also pretty easy to forget it was a shrinkage ruler and could cause something to be all jacked up if you forgot.LOL
They make sets of them. The nose of the screw has a tiny hex and a point, so you can screw them in and out. They come in a tube that has the wrench socket for the tip in the end. I have two thread sizes and I think McMaster sells them. When I was about 10 dad bought an old Atlas lathe and a new chuck and asked a swiss machinist at his work to mount the chuck on the unmachined face plate. The guy softened up a set of setscrews and machined points on them, and then hardened them again. Used them to locate the 3 bolt holes in the new chuck. Beautiful work this guy did on mounting the chuck.
Kelly, Beautiful job as always. I find your work really inspiring. I used to model parts in Rhino from photos and got pretty good results. I'd shoot a picture and import it into Rhino then trace the curves by simply placing points along all the lines. Rhino has a smooth function and you can move points after smoothing to get a really good match. With CNC I would do the bolt hole protrusions just the way you did, and cut them from the scrap. You can rescale a model in any Cad program, I wonder how that would handle shrinkage? Some CNC controllers can do automated probing using a touch probe to walk itself around a path automatically generating a cad file of points. That would likely handle most of this part pretty well.
That's what I was alluding to back in my earlier comment. In past lives I've hired such things (even 3D scan), but as with everything, reading about it and actually doing it can be two different experiences. Besides buying the software there is always learning curve to actually use it. A flat scan is better than a photo because photo will have error. For photo reproduction, best to position the camera at the geometric center and at height 5-10x the max dimension of the piece......then scale from that. However, I will say that if you were proficient in the process, this would probably have significantly reduced the first eleven hours of invested time to get to a completed pattern as most of that was layout. Most of the time, I'm dreaming up my own parts instead of reverse engineering so not sure it'd be worth it to me.....maybe for lettering and artwork but I think most of the 2D cnc and sign software already handle that pretty well. I'll get there eventually. Just like casting, keep learning and adding tools and gaining experience. I think increasing the part size to 101.3% would be a very good aluminum shrink approximation. Somewhere I saw a non-touch optical probe that you hung on your gantry and did the same, but again, software intensive because you need to select resolution of the scan, which has to be interpreted into a solid after the fact. For this go, it's looking like 20hrs total start to a finish machined part.......A second would be much quicker. Best, Kelly
At my job we are getting ready to pull the trigger on a flatbed optical scanner that can completely measure up a part in about 1 minute. About 8” x 8” and is $25K! We do extrusion and my expectation is this is going to save us a boatload of money because we make so much scrap and downstream processes fail and make even more. We looked at a Starrett that looked down from above with a camera on a gantry so could easily do parts like this cover, for about $50K!