| Gallery, Projects and General > Project Logs |
| Building a New Lathe |
| << < (156/171) > >> |
| awemawson:
Steve good to see you back casting again :thumbup: You may have seen I now have my big induction furnace back in commission but can’t yet use it in earnest as I’m plagued by roof leaks where it is. (So far 5 roofers have attempted repairs plus myself. Waiting the next rain to see the latest results. Trouble is it’s the join between the roofs of three buildings). I have taken delivery of 18 meters of 6 mm x 100 mm steel to weld up some copes and drags as I seem to have given away all the commercial ones that I had! Good luck with you next go at the brass handle. |
| vtsteam:
Hi Tom, I have used pour extensions in the past, but have to admit I don't like them too much. They put a lot of hydraulic pressure on the cope when using heavier metals and can float it or blow out, unless the flask is heavily weighted or clamped. They need bigger melts, etc. Okay for aluminum on lost foam, though. My problem was just not thinking the casting through, and lack of recent practice :hammer: Hi Andrew, sorry I missed the induction furnace -- I'll look for it. Just starting to catch up reading here. Water/moisture/condensation and mouse damage are the bane of my existence here, so I feel your pain! Thanks for the good wishes! :beer: |
| vtsteam:
Okay, second try, fingers crossed. This time I eliminated the riser, I bulked out the spokes by simply scooping away a little sand under them on the cope side. And I remembered to vent both the cope and drag, right through the pattern impressions. My guess about last time was that there was gas entrapment at the opposite end to the sprue, and brass just flowed up the stem and riser without filling the far side of the ring. And the spokes were too thin to let the brass flow through them-- especially on the gassy side of that casting. Hoping that by eliminating the riser, and venting everything, the metal flow will now be toward the vented far side of the ring first, and the bigger spokes will then allow easier flow up to the hub. So far it looks better -- a neater pour, and also the shrink cavity at the top of the sprue is a good sign that a bigger (fuller) casting is drawing metal, and hot enough to remain fluid while doing so. |
| vtsteam:
Breaking out, my hopes are up. It's a full ring! But you never know until it's completely free. ....... |
| vtsteam:
Yessssssss! :ddb: Sometimes less is more. No riser, better casting. It's possible to overthink stuff like this. Just sprue as normal, and remember to vent the darn thing! |
| Navigation |
| Message Index |
| Next page |
| Previous page |