The 'real' Roscoe design is 3+1/8" wide at the top and front tapering to 3" in the bottom/back. One of the right angle legs is 1+3/4" and the other is 2+1/4". Mine is based on a 2+1/2" cube, which I started making before I emailed Roscoe and decided it would work as-is as a proof of concept. This drag is extra deep for no good reason other than I had a half-used piece of 1X6 piece wood at the ready. Seems like I always need a flask 'one bigger' but I took it too far and agree it would be too heavy once loaded. I could remake one side shallower or convert the works into a planter or toolbox.
I had to throw a flask together to cast the bowl. The 1x6 was an old concrete mould, the 1x3 was an old furring strip that had a hole in the side. They were so wobbly I could have used them for a rocking chair. Stole the hardware off another flask and had to hammer the pins to get them lined up. As bad as they were, they still worked to get the bowl done. Never enough flasks.
Bruce, AKA Crazybillybob hooked me up with these amazing 3D printed Flask hardware i told him to sell the files online . I'm curious how long they will last in normal HT1 use. I may set up my drill press get a jig and the Double D broach and a reamer, and sell sets of them... Everyone will tell me they are overpriced "SHRUG" V/r HT1 P.S ill try and keep track of their use and let you all know
@HT1 @crazybillybob Nice collaboration! Are both sets (both sides of flask) of pin receivers D-broached or just the one side with the other being a plain round? PS/Edit: I am still working on the more true-to-size Roscoe patterns, just made the follow board and gating.
If anyone wants to try the pins out here's a link to the STL files. https://www.printables.com/model/829591-casting-flask-alignment-pins If someone needs a couple sets let me know we'll work out a price. There's a lot more plastic in the useable sets than the "pattern" sets.
My gating piece was not quite ala Roscoe so I redid it so it hooks over the follow board per the video.
OK I love What Bruce did for me, but I want to "pro " it up so I priced up tools and parts: first off I could find nothing off the Shelf In SAE so I switched to metric 20MM for Pins I apologize for the long links One Ill need the Double d Broach: $197 https://www.aliexpress.us/item/3256...2850af&afSmartRedirect=y&gatewayAdapt=glo2usa two Shoulder Bolts to convert to pins : $20 Each https://www.aliexpress.us/item/3256...5tV5I9x8&utparam-url=scene:search|query_from: drill bits and reamers will add another $60 then casting the parts , metal etc.. cost to me is probably about $75 once I make them I can put them on any wooden or cast aluminum flask ... Im questioning if there is even enough value to me... 10 years ago I would have been all over it . any chance I could sell them at $100 a set??? Thanks In advance V/r HT1 P.S I have to ask myself people that might find these useful could make their own, and people that might be too hobbiest to consider proper flask hardware essential... I mean I still level flasks to get perfect mating surfaces my rubbing them on my concrete drive way
Hard to say. I could see getting a set just to say that I have something designed and made by Burt and Henry, but I would not see myself (hobby guy, non-profit, cheap by nature) converting more than one flask over until I was gaining throughput that mapped to income from them...even if they worked a treat. My guess is that most of crowd here is likely to DIY before buying out. I could be wrong too, others should feel free to comment.
Throwing my hat in the ring after making another one of my own cast aluminum flasks. This design doesn't exactly solve all of the issues mentioned in the thread, but it works well for me, and is better than any wood or 3D printed alignment solution I've tried so far. These are the raw castings after removing the sprues and drilling the assembly holes in the short sections. I designed the patterns in Fusion360 and 3D printed them in PLA. Nothing special about the molding, rammed all of them in the drag as shown and then flipped over and dug out the sand from the undercuts before ramming the cope. Cut a sprue and riser directly over each pattern. On the long pieces you can see the drill centers I added to the patterns which saves a few minutes of marking and center punching. Clamped them in position and used the pre-drilled holes as guides for a hand drill. The 45 degree mating surfaces aren't perfect, but the machine screws do a good job of squeezing everything together. Also, it's hard to see in the photo, but I purposely printed the patterns at a very low quality setting which leaves a rough textured surface on the interior faces. This does an excellent job of grabbing on to the sand. After screwing everything together I drilled the pin holes of the cope on the drill press. I eyeball the center of the ears and start by rotating the bit in the drill press by hand until I'm about halfway through the top ear, which prevents any walking on the drafted surface. Two large clamps and some flat plywood scraps align the two halves for drilling the drag pin holes. Drilled the drag pin holes using the cope as a guide. Referencing the drag off of the cope does prevent this from being a modular system, but these are designated for smaller patterns in my case. I use regular SS 3/8th bolts for the pins. Maybe not the most elegant solution, but the play is almost negligible. I use wing nuts to clamp the two halves during molding and pouring. The pressure from this sort of forces the cope and drag into their natural "best fit" position, and I've never experienced a misaligned casting. Having the bolts floating like this also gives me a guide for lifting either half straight up off of a pattern. Typically I will ram the drag, then insert the bolts into their holes and lift the drag up while pressing down on the bolts with my thumbs. The cope can then slide on and off the protruding ends. My 4 flasks after an aluminum bronze casting. If you were wondering about the cutouts in the flask, I designed them to work for both vertical and horizontal molds, and they do both well. For smaller parts that don't require risers, I prefer the vertical pouring arrangement. In this case, there is a runner that connects the two openings, in which the metal travels below the part and is gated up into it. I seem to get a better surface finish this way, and the molding is greatly simplified by not having sprue and riser patterns sticking up out of the sand during ramming. I plan on trying some larger flasks soon, but I do wonder if play in the pins will become an issue as the molds get heavier. The nuts to a good job of seating the two halves together in a repeatable manner, but I think it would be smart to try for some additional hardware, or possibly some mating geometry along the parting lines of the flasks so they aren't trying to slide across each other.
