Not-a-number Posted July 26, 2020 Author Share Posted July 26, 2020 Outer pattern with runner system. 9 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted July 27, 2020 Author Popular Post Share Posted July 27, 2020 Since I plan to ship these back to NZ I want to make as few sand boxes as possible. So Im making the patterns removable from the boxes. Usually I just glue them down. Threaded insert The removable sections. Still need a bit of cleanup. 12 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted August 2, 2020 Author Popular Post Share Posted August 2, 2020 Putting the sand in the freezer before adding the catalyst has given me a good 15-20minutes work time (instead of 5!) Did the outer mould today with 30kg of sand no issues. 32 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted August 3, 2020 Author Popular Post Share Posted August 3, 2020 Busy weekend. 2nd half worked well. Little removable corner inserts look clean. Next I need to make a new inner core and figure out where to put some risers. Should be close to going to the foundry! 25 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted August 11, 2020 Author Popular Post Share Posted August 11, 2020 New core done, ingate and risers added. Sealed and bolted up ready for the foundry. Made a mistake on the size of the ingate unfortunately and since its glued closed Im sh#t out of luck. So we'll just have to see how it goes. 18 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted August 12, 2020 Author Popular Post Share Posted August 12, 2020 Made a cool paper weight! As I thought, the in gate was too small and it filled too slowly causing some cold shuts/holes. Also the thicker sections in the middle shrunk and caused some tears. Other than that it looks reasonable. So the plan is to increase the ingate area (maybe add another gate on the front) Then to sort the shrinkage I need to learn about adding heat sinks into the sand mould. 26 2 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted August 18, 2020 Author Popular Post Share Posted August 18, 2020 So the plan is to add 4 risers to the thick top areas. Then add chill blocks for the bosses in the middle. Couldnt find info on sizing a chill block so Im going to go with making one set total the mass of the boss and the other set twice the mass. See if they are any different. Also doubled the ingate area (back to what its meant to be in theory) and made it feed from both sides. 20 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted August 23, 2020 Author Popular Post Share Posted August 23, 2020 Got the next one ready. Now have 4 chill blocks, 4 risers, 2 main in-gates and 2 small gates. One of the chill blocks didnt pack very well so we'll see what happens there. The sand around that area is pretty thin so theres a chance itll get super hot and fall apart. Bigger problem is I had an issue with the sand strength for some reason and it cracked when bolting up. Hopefully it doesnt fall apart when filled! 23 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted August 24, 2020 Author Popular Post Share Posted August 24, 2020 Well it worked pretty good! Only real defects are on the face with machine allowance. The volume of the chill block didnt really seem to matter so I think going forward I'll size them to at least 100% of the volume that needs chilling. 46 1 Quote Link to comment Share on other sites More sharing options...
Not-a-number Posted August 25, 2020 Author Share Posted August 25, 2020 So the only issue was the back face. It looks like a crack. But what I think happened is the tapered 'disk' type chill blocks have no where to expand to. They are also in really thin sand. So when the chill block started doing its thing and getting hot it expanded, cracking the sand and pushing it into the face that hadnt solidified. The front did the same looking at the sand mould after the pour but it wasnt on a flat face so it didnt matter. May look at changing it to more of a boss like the others. 1 1 4 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted September 14, 2020 Author Popular Post Share Posted September 14, 2020 Finished up 2 more. Added chill blocks to the bigger top bosses and also a bigger flat one to the middle (instead of the tapered one). Still have the same risers. 21 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted September 17, 2020 Author Popular Post Share Posted September 17, 2020 Another 2 done. Worked well. I think 4 paper weights is enough for now. Time to move on to something big! For reference of where it goes. Houses cam gearing. 43 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted September 29, 2020 Author Popular Post Share Posted September 29, 2020 Chassis mandrel finished! Exciting stuff. Brunton Engineering in Palmy did an awesome job. If you need fab work Id definitely recommend. 34 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted October 11, 2020 Author Popular Post Share Posted October 11, 2020 Did bit of a time laps video of the camtree casting. Not great but its a start. 34 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted November 10, 2020 Author Popular Post Share Posted November 10, 2020 Starting on the sump. Its going to be a pretty big job! 36 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted November 12, 2020 Author Popular Post Share Posted November 12, 2020 Fitting up well. Inserts and removable pieces are looking good. Its going to take a bit of bog before paint and a lot of sanding afterwards. 27 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted November 16, 2020 Author Popular Post Share Posted November 16, 2020 These are 'feet' for the sump. So the engine can stand upright. Good chance ill break them off at some point so I printed a hole up them and bonded in some steel dowels. Started bogging. 21 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted November 17, 2020 Author Popular Post Share Posted November 17, 2020 Runner system printed. 23 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted November 26, 2020 Author Popular Post Share Posted November 26, 2020 High build primer is like sanding chalk! Coming out ok but taking a lot of sanding! 23 Quote Link to comment Share on other sites More sharing options...
Popular Post Not-a-number Posted December 20, 2020 Author Popular Post Share Posted December 20, 2020 Since I can only safely mix 30kg of sand at once Ive made some partitions over the pattern for 30kg sections. Will do some sequence of removing walls and work along the pattern. Probably key the sand together as I go so hopefully it doesnt shift around. The base is an overly complicated 30mm spacer that the inner cores align to. Could have done it out of wood but when you have a big printer why not! Once Ive figured out if the pattern works I will be able to fill it at the foundry in one go without partitions. 33 Quote Link to comment Share on other sites More sharing options...
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