CNC Molds N Stuff Posted April 29, 2015 Report Share Posted April 29, 2015 There might be something here some of you guys can use. 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted April 29, 2015 Report Share Posted April 29, 2015 Great video Bob. That blade vent sure did finish off tidy, hope the resin does the same. Interesting that you shape the posts, all makes sense. At first I was thinking 'not possible' with rod inserts, but actually it is, with a little bit of effort with a ball peen hammer. I will give it a go next time. I also pinch behind the post, using long nose pliers. Next time I am tool shopping, I will be looking for round nose, as in the past I have always just made do with what was in my tool box. I finally found the command that allows me to record the screen directly, so next time I do some modelling, I will have to record some. It might be of some interest to those who have a play with CAD. The files get pretty big and fast, but I have bought a 2Tb disk for back-ups that will help. Dave Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted April 29, 2015 Author Report Share Posted April 29, 2015 (edited) I debated posting the video in the wire baits section, but I was afraid somebody might take it more as the an advertisement than an informational video. The idea of blade vents has scared the heck out of me. I've refused to even try them. I tried everything I could think of with this mold and nothing else would work. Graphite blasting the mold helped, but it still wasn't good. Finally I couldn't think of anything else to try, so I threw it back on the machine and blade vented it. Good castings almost every time. It does need the lead to be on the hot side. It helped me with another mold I was struggling with too. I have a specialty jig mold I couldn't get to fill with some "different" additional hardware cast in. I tried it graphite blasted with the heat turned up and I was able to get good castings out it it then too. I think the graphite spray acts as an insulator keeping the lead from freezing off for a fraction of a second longer. I did some research on graphite and it does have some heat insulation properties. Edited April 29, 2015 by Bob La Londe Quote Link to comment Share on other sites More sharing options...
RayburnGuy Posted April 30, 2015 Report Share Posted April 30, 2015 Good video Bob. Even though I don't pour lead I found it very interesting. There were a couple things about making the wire forms that I thought would be useful for making harnesses and such for hard baits. I have one question. What are the "blade vents" that you and Dave are talking about? Just curious. Ben Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted April 30, 2015 Report Share Posted April 30, 2015 A normal shaped vent would be a round or square section of sufficient cross section size to let the air escape on the pour. The disadvantages of a normal vent is that the pouring medium will usually escape into the vent, giving you some trimming and tidying up to do. Also, the vent only covers one tiny spot and if you don't read the flow correctly, you may not solve the problem and still end up with an incomplete pour. A blade vent is a long, thin shaped vent, the depth of the vent is 0.004" or even less. The length of the vent is sufficient to still achieve the necessary cross section area to let the air out, but the viscosity of the pouring medium is too thick to allow it to pass through, so flashing is kept to a minimum or even eliminated altogether. Also, because the vent is long, it covers those difficult areas were the bubble location is difficult to predict. Dave 1 Quote Link to comment Share on other sites More sharing options...
RayburnGuy Posted April 30, 2015 Report Share Posted April 30, 2015 Thanks Dave. There's a lot of stuff I don't have a clue about when ya'll start talking about designing molds, drawing images in CAD and such as that, but my inquisitive nature loves reading the posts about it. I've always loved to see what makes stuff work. I was tearing into things to have a look at the inside a couple years before I entered grammar school. When my mom would stop by to see my dad at work I always headed to the shop behind the office where one of the guys that worked for my dad would automatically hand me a hammer and give me something to tear into. Anyway, thanks to folks like you and Bob I no longer have to tear into things to get an answer. thanks again, Ben Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted April 30, 2015 Report Share Posted April 30, 2015 It is understandable. This is innovation and something that Bob and I have talked about over the last couple of years, but not got around to testing. As far as calling it innovation, I am pretty sure it would have been done before. This could be worth trying by those that make plaster molds, using aluminium foil to mold the vents. I don't think it would work for RTV, too soft. Dave Quote Link to comment Share on other sites More sharing options...
Cannon Posted April 30, 2015 Report Share Posted April 30, 2015 Great video Bob I learned several things there. Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted April 30, 2015 Author Report Share Posted April 30, 2015 In this case I cut a blade vent the ENTIRE perimeter of the mold cavity with spurs off the blade to allow the air to escape from the blade. I think Bass Tackle makes some soft plastic molds with blade vents. Usually I do not get flashing (or very much) with the tiny point vents I use on plastics and lead molds I make, but the vents necessary for things like sand casting are often as large as the sprues and runners requiring just as much cleanup as the runners. There are some great videos on YouTube from some of the guys doing backyard foundry work with aluminum that show that sort of casting, venting, and cleanup. You do have to wade thru a lot of crappy "Look at me! I can melt metal!" videos to find them though. Quote Link to comment Share on other sites More sharing options...
Fatman Posted May 3, 2015 Report Share Posted May 3, 2015 Great video Quote Link to comment Share on other sites More sharing options...
Yo Al Posted May 4, 2015 Report Share Posted May 4, 2015 Thanks for posting. Good video. I have a question you and Dave should be able to clear up for me. I was told to always put a 90 or sharper bend on the tag end of the wire in lead so it won't pull out. Will the straight end hold? I just bend it because I learned that way. Am I just adding an unnecessary step to the process? Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted May 4, 2015 Author Report Share Posted May 4, 2015 (edited) I do not know, but it makes sense. It might also depend on the size fish you are fighting, and the size wire you are using. In the case of the smallest one cast in this mold it would be pretty hard to leave a 90, but I suppose it could be done with some care. Edited May 4, 2015 by Bob La Londe Quote Link to comment Share on other sites More sharing options...
Yo Al Posted May 5, 2015 Report Share Posted May 5, 2015 Thanks Bob. I just looked in the Do-It Molds catalog and their wire forms are straight on the tag ends. I guess the sage advice I was given is a bit overkill. Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted May 5, 2015 Author Report Share Posted May 5, 2015 Well, it might not be overkill if you tie into a 50 lb striper, but probably not a huge deal for a 2lb sea trout. I was actually thinking about painting the test pieces up in a nice pearl color, and trying them on busting stripers in the wee hours of the morning. My favorite lure up until now for that was a KastMaster, but these being much heavier for their size should cast even further allowing me to pick off more fish before they spook from the boat and sound. Our river stripers here tend to run pretty small. 1/2 to 2 lbs with a 4-6 being a toad. Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted May 11, 2015 Author Report Share Posted May 11, 2015 (edited) ... Edited May 11, 2015 by Bob La Londe Quote Link to comment Share on other sites More sharing options...