Here are my rammers, both from wood. I use the skinnier one most often to the point where my original machined big one is missing and I am not alarmed. The idea to carve rammers from lost foam is great!
Need and want are two very different things, lol. Do I need another pattern for a sand rammer? Technically, no... Do I want another one, however, that would be a yes. I'd love to make one off of your pattern, and I'd be happy to either send it back or pass it on to another at some point. Besides casting up a bunch of ingots to start with, I'm planning on making a bunch of different varieties of foundry tools to find what I like working with the most. And I'll be happy to link to the patterns I'm using or to otherwise pass on info and patterns to others. I like your color-coding system. Partly because it's easily registered, and partly because I think it'd be fun to have all those colors in the "shop" (it'll be a shop eventually, lol). Even if I do use cope/drag specific brackets, I think I'll also take from your idea and paint on them a bit for quick, easy registry and assembly. I like your strike tool there. Is that just shaped wood or is that cast? I know rammers and strike tools aren't the topic of this thread, so if we should converse on this elsewhere that's fine. I'm currently planning on using an extra piece of flat stock, but I've been considering shaping one up like yours looks either out of said flat stock or out of a piece of hardwood scrap from the local hardwood supplier. I hadn't thought about trying to make a rammer from lost foam, but you're right that would be a good entry-level idea. Though I think the sand used is different for that? I'll have to read up more on lost foam casting. I've been reading up on traditional green sand and petrobond so far (petrobond is what I got with the lot I bought). Your rammers look pretty nice though! I see a lot of rammers cut/carved from wood. It's traditional, and I like that. I'm not much of a woodworker, but I think I have the basic tools with which to attempt a wooden rammer. I appreciate your pattern & measurements reference. That'll help a lot with trying to make that happen.
I tried molding the patterns from post #17 and failed to draw them out without disturbing the 'land bridges' in the middle. Petrobond at 70F (21C) and I did press down in between there while molding. Since I don't need them per se I might be done with them. Hypothetically, if I did need them, would people suggest as countermeasures? -a nail through the centers -redesign with a core -just do better next time I could add more space and more draft in there too. I could also make it solid and add a machining step. At that rate, maybe they could just be made from billet... I got to 'play in the sand' regardless, not too disappointed ... Edit: Thinking of more things to try: -add a strip of waxed paper in the 'crack' to initiate release -drill a vent hole -paint, or epoxy the patterns then wax before graphite (they were just dusted with graphite) -cut patterns in half so they extract in two pieces The vent hole and wax paper would be easiest/quickest. Coating the patterns would be better practice...
I pushed down in between them, still out of practice from not much molding lately. The 3D prints have tiny ridges that don't help extraction either, normally I would paint or epoxy or at a bare minimum wax but chose to try them dry with graphite. Gagger is the word I was looking for, thanks!
I want to be sure everyone understands the importance of flask pin length so here a short demonstrating the requirements for longer pins https://youtube.com/shorts/kfizkeOqveo?si=wFDY_WZtOd3HYQ7W V/r HT1
FWIW there's a bunch of pictures and some video of my cast pin brackets here: https://forums.thehomefoundry.org/index.php?threads/first-try-at-making-and-using-a-match-plate.850/ I only ever cast a couple sets, usually with at least a little breakout between the fins. As I mentioned above, I soon went back to making the brackets out of wood with decapitated bolts for pins. The wood lets things flex a little instead of binding, I find. Jeff
I cast the ears in my aluminum flasks, but before that I was using wood and made up this pattern and follower. I ram up a couple whenever I pour and instead of pigging off, just cast a couple for future use. I mount them and then match drill for the pins using the molding board that will be used with them.
Thanks Jeff, Thanks ESC From Jeff's: View attachment 9087 Impressively small sprue and runner. It might work for me to gate mine that way too, parts in the cope to make room for fins and basin. The flask I want to use has one shallow side.
I was ready to mount 6 existing printed patterns to a board and go after this again, but decided to work with the design a bit more: -more space between tabs and a solid version -split the patterns and print so 3D printing lines are 'right way' for extraction of patterns -drop down to 4 patterns and have ample room for basin Starting to wonder if the 'chunky' one will need a riser up top (if in a deep cope), or pour it all down in a deep drag and let defects manifest on the backs...?
Started the assembly process, using the drafting whales/ducks cast in another thread to help with the process. Wait- using a casting project to make another casting project that will help make other casting projects ?!? It would have been nice to have designed a way to pin the halves together for gluing, at the end of the day it probably will not matter.
My redesign and printing of the modified flask bracket has proven inferior during installation. After doweling and re-drilling 16 holes to allow the new brackets to take the place of the old...I broke a pin straight away. The originals never really bind so they do not have this issue.
Tops can you tell me how you oriented your Pin for print? and the infill? I've been working on the design for HT1 and even though the pins are a bit tight in the holes straight off the printer I don't see them snaping (I've put some torque on the too.) but I haven't mounted them to a flask yet. I have been printing the pint horizontally so that the layer run the length of the pin. This orientation give the prints the most strength in shear. The bond between the layers on a 3d Print are the weakest points. So for mechanical prints you have to orient the parts on the print bed in a way that is the strongest for the application.
I want to say the tops/bottom/walls are 3 layers thick. PLA+ filament (Elegoo) 230 C printhead and 65 C bed. If the below picture from the Cura slicing program does not come through it is also in post #7. Layer height .16mm, 20% infill, supports printed, brim around part. Maybe a heavier wall and infill would help a for-use plastic part. For a casting pattern it should not matter as much.
A set of flask brackets from YouTube discovered via the 'Cracker post' on the 'Cussed Vagaries' thread. He does them both as wood (see other videos) and as 3D printing.
I just stumbled across Roscoe's channel a couple days ago myself. Looking through his videos this caught my eye. Not flask related but this looks like a fun patternmaking and casting project. Soon as I get a bigger sander...: Jeff
Looking at those neat 'Roscoe' patterns and follow boards, is it just me or are they draft-free except the fillets and the outer edge of the follow board? Thinking of whether to 3D print or make a wooden set.
First: email Roscoe and ask him, he responded to me very quickly second: OK I hate to say this it will bring tons of hate and questions, in the case of his pieces it is very possible, a small part with no detail that has a basic shape can be successfully rapped or vibrated out of good sand with little to no draft if you have the skill, its not a Noob process, it often required 3 hands , getting compressed air under the part to break the vacuum (like popping buckets apart) can help a lot . but basically if you have a simple part like a bracket with a good smooth surface finish, you can ram the sand soft, then rap or vibrate aggressively, basically packing the sand perpendicular to the parting allowing removal of a part with no draft , this will not work very deep into the sand so about 3 inches, if there is detail on the face of your pattern the rapping will knock that detail off , but for simple shapes it will work , an example of this is using wooden dowels for risers and removing them by rapping side to side basically oversizing the hole, obviously this will throw of the measurements of your part keep that in mind, also the soft ram may cause cleanup issues low on the casting as you may get finning or even sand inclusions lighter metals like aluminum are the least effected by this V/r HT1
