Thanks for the feedback. My thinking on the riser position for the cross slide was that since I was basically casting a chunk of iron a strategy of directional solidification was pretty much out the window. I figured that it would freeze towards the center, which I believe it did . So by placing a massive blind riser between the runner and ingate I hoped the riser would freeze last and feed the center. I believe this is what Denis was saying above. And yes indeed, the large internal voids were right in the geographic center of the casting. I was hoping the all of the heat concentrated in that area would have kept the ingate from freezing off, but I guess it wasn't enough. Perhaps having the riser in direct contact with the casting would have been better. I don't have a picture of it, but there was no sign of piping in that riser at all. Pete
Yup, have to wheel it off later. But, I would plunk a riser in direct contact right where the voids formed. That is what worked with the blocky prism I pictured above. [I do have a pretty good Makita 7001L 7" diameter angle grinder that does the job quite well. I hesitated to plunk out the money. But the difference in performance and wheel life between that and my decent quality Milwaukee 4" is huge. Nowadays I rarely fire up the Milwaukee but use the Makita all the time. ] Denis
Sometimes smaller multiple ones are better than one big one. They dont feed for a very long distance. Location is the most important factor followed by shape. A properly shaped one will feed around half of its mass. There are many ways to calculate them...size and location. Using the modulus of a casting is how they teach you in industry. If I find one of the better books I have on it I will try and get a pic of the worksheets. Its usually about where you would think it would be the hottest...tight corners..small radius...thick parts. If used improperly you can pull metal from your casting with a riser. I used to deal with them all the time and am lucky that in the last 20 years we have not used one! I usually didnt have time for the worksheets, but the calculations are pretty accurate.
These stanchions are fighting me. 6 done, I want to do at least 11. High fail rate, unfortunately. Need at least 10, I'll try again tomorrow. Unfortunately I'm running out of reasonable temperatures, it's supposed to cool down this week, closer to normal January in Maine temps. I will get this done, dang it...
