dagabu Posted July 24, 2012 Posted July 24, 2012 Cool! Thanks for the very in-depth description. Unfortunately, my school's lathe only has a 3-jaw chuck, (That is what the live center is for, ask your teacher for one, he probably has it in his desk drawer) and so if you cut a part, take it out, then re-chuck it, it is no longer the same center as before. I'll see what I can do to workaround that though. I'm getting my brass in a few days, I'll give it a whirl and let you guys know how it goes. Also, quick question about the rammers. When the rammers are fully inserted up to the "no-pass lines", should there be a bit of clearance between the spindle and the rammer hole? Or should they exactly match? Just wondering what "typical" sets do. I know that SLD and I jam the rammer on the spindle at the No-Pass line, no comp gets past when fully pressed.
btdk34 Posted July 24, 2012 Author Posted July 24, 2012 Ah, I do apologize. It just goes to show my lack of lathe experience. So if I am understanding you right, after you drill/tap the hole for your 1/4" x 20 bolt and turn down the spindle base end, do you stick the spindle base end back in the chuck, or do you turn between centers at this point? It sounds more like the first one, with the support of the live center. And I wasn't very clear last time I asked about the spindle/rammer holes, so I drew a picture. I'm not sure if I should be designing my set like the picture on the left, or the picture on the right.
dagabu Posted July 24, 2012 Posted July 24, 2012 (edited) Ah, I do apologize. It just goes to show my lack of lathe experience. So if I am understanding you right, after you drill/tap the hole for your 1/4" x 20 bolt and turn down the spindle base end, do you stick the spindle base end back in the chuck, or do you turn between centers at this point? It sounds more like the first one, with the support of the live center. And I wasn't very clear last time I asked about the spindle/rammer holes, so I drew a picture. I'm not sure if I should be designing my set like the picture on the left, or the picture on the right. METALLURGY LESSON: No matter how well a rod is formed and how pure the materials are, when you turn any material, when you take it out of the chuck and turn it around, it will not be true. Cryogenically treated steel has the least amount of warp but even a great material like brass will not stay straight after turning. Yes, after making the base end, drilling and tapping, turn it around and chuck it up on the spindle base and make your indent for the live center. The material will indeed be off center, that is the warp, don't worry about this warp. It is indeed the first one. Yes, you want it to jam on the spindle at the no-pass line if you make them like mine. It is completely up to you to decide though. Leaving a gap is safer but your pressing will be inferior. Good luck! -dag Edited July 24, 2012 by dagabu
btdk34 Posted July 24, 2012 Author Posted July 24, 2012 Thanks for the quick lesson. I understand the answers to both questions now, thanks! I'm hoping to do a test spindle run tomorrow on 6061 before I attempt the brass.
dagabu Posted July 25, 2012 Posted July 25, 2012 Thanks for the quick lesson. I understand the answers to both questions now, thanks! I'm hoping to do a test spindle run tomorrow on 6061 before I attempt the brass. Yes, please do. Having extras sure is nice. -dag
btdk34 Posted July 25, 2012 Author Posted July 25, 2012 (edited) Today, I finished my first 3/8" "Hybrid-Universal" spindle, machined out of 6061 aluminum! It took me a while, but I am proud of it. The pictures show the spindle in a base I designed and machined last week. The best picture is shown below. (The rest are in my gallery!) Dag, the method you told me to use works wonders. I thought I might run into alignment problems with the base of the spindle due to the re-chucking, but it was nearly exactly centered. Now I just need to work on taking smaller cuts and leaving myself a little cutting leeway before the final cut... I'm sure it will come with more patience and experience. Edited July 26, 2012 by btdk34
dagabu Posted July 26, 2012 Posted July 26, 2012 Today, I finished my first 3/8" "Hybrid-Universal" spindle, machined out of 6061 aluminum! It took me a while, but I am proud of it. The pictures show the spindle in a base I designed and machined last week. They are in my gallery. Dag, the method you told me to use works wonders. I thought I might run into alignment problems with the base of the spindle due to the re-chucking, but it was nearly exactly centered. Now I just need to work on taking smaller cuts and leaving myself a little cutting leeway before the final cut... I'm sure it will come with more patience and experience. CONGRATULATIONS!!! They look wonderful, great job! You can post pictures in the post too if you wish, just go to the gallery and open your picture, right click and select "Copy Image URL" then click on the little icon at the top of your post that looks like a picture frame with a green tree in it and paste the link to the window and post it here. -dag
btdk34 Posted July 26, 2012 Author Posted July 26, 2012 (edited) Thanks dag! Your input has made it possible. I'm getting my brass tomorrow, but I'm planning on making rammers to my specifications first to see how accurate my plan's current spindle is. If it and the rammers are close enough to perfection, I will attempt to make a complete set all over again to see if I can repeat myself. Edited July 26, 2012 by btdk34
btdk34 Posted July 26, 2012 Author Posted July 26, 2012 Thanks cali! It will look even better when the spindle is brass and I actually have rammers to go with it.
btdk34 Posted July 27, 2012 Author Posted July 27, 2012 Thanks mikeee! I made a set of four rammers for the spindle yesterday (low quality as I was under a time constraint), and made a few rockets this morning. One was nozzle-less, using 75:15:10 as fuel. It took off quite quickly! My other one was a nozzled 65:25:10 core-burner. It took off like a bullet, I was surprised it didn't explode on the stand! I was quite pleased, until I bent one of the tubes while ramming off center, thus bending the spindle too I ordered some aluminum square stock for a tube support, which should be finished next week sometime. I think this will help with the bending issue. Time to machine another spindle...
dagabu Posted July 27, 2012 Posted July 27, 2012 Thanks mikeee! I made a set of four rammers for the spindle yesterday (low quality as I was under a time constraint), and made a few rockets this morning. One was nozzle-less, using 75:15:10 as fuel. It took off quite quickly! My other one was a nozzled 65:25:10 core-burner. It took off like a bullet, I was surprised it didn't explode on the stand! I was quite pleased, until I bent one of the tubes while ramming off center, thus bending the spindle too I ordered some aluminum square stock for a tube support, which should be finished next week sometime. I think this will help with the bending issue. Time to machine another spindle... Are you going to split the square stock and hold it together with bolts? If so, split it first then drill and bore it out, if you dont, you will have oval rockets. Better is to get some DOM aluminum in heavy wall and bore it out to hold the tube. Press the finished rocket out if you have a press split the tube first and use hose clamp to hold it shut and bore it out if not. -dag
btdk34 Posted July 27, 2012 Author Posted July 27, 2012 Oops, I actually meant 'bar stock'! I got 0.625" x 1.25" stock, so when put together, it makes a square. I actually considered buying some aluminum tubing, but I didn't really want to have to deal with the rocket becoming stuck in it's support sleeve. Eventually, I plan on investing in a small arbor press, but for now, all I have is a rawhide mallet.
btdk34 Posted July 31, 2012 Author Posted July 31, 2012 (edited) One quick question, are the dimensions for generic UH-Tooling posted somewhere? Or, would someone mind sharing theirs? That might be a long shot, but I would like to make mine as close as possible so I can make many different types of rockets. It looks like most UH-Tooling sets nozzle width is about 2/3 of the ID of the rocket tube. Or perhaps my eyes are deceiving me... Edited July 31, 2012 by btdk34
dagabu Posted July 31, 2012 Posted July 31, 2012 One quick question, are the dimensions for generic UH-Tooling posted somewhere? Or, would someone mind sharing theirs? That might be a long shot, but I would like to make mine as close as possible so I can make many different types of rockets. It looks like most UH-Tooling sets nozzle width is about 2/3 of the ID of the rocket tube. Or perhaps my eyes are deceiving me... No, sorry. The UH is owned by Steve LaDuke, I suggest that you contact him for the specs. I will also ask that others here don't share that information here but contact Steve for permission as well. I worked out an agreement with him, I am sure he will do so with you. -dag
btdk34 Posted July 31, 2012 Author Posted July 31, 2012 Oh! Didn't mean to undermine Steve LaDuke. Thanks for the info dag.
btdk34 Posted August 1, 2012 Author Posted August 1, 2012 So, today was my major "rocket clean-up day", and when I was cleaning out my rammers for my 3/8" tooling, I noticed TONS of black powder was jammed up into them. Is there a good way to avoid this? I think this was mostly why my spindle was bent after the second rocket I made...
dagabu Posted August 1, 2012 Posted August 1, 2012 So, today was my major "rocket clean-up day", and when I was cleaning out my rammers for my 3/8" tooling, I noticed TONS of black powder was jammed up into them. Is there a good way to avoid this? I think this was mostly why my spindle was bent after the second rocket I made... No, there is not, you must clean the rammers after every rocket. Make it a habit to clean them BEFORE using them as well as after you are done, you will likely remember that way. Bore cleaning brushes (Nylon and brass) work well. -dag
WonderBoy Posted August 1, 2012 Posted August 1, 2012 (edited) Don't feel held back because your spindle is not the exact Hybrid-Universal spindle. Yours may not perform exactly the same as the H-U spindle, so it will take some experimentation, but it will more than likely work with many of the compositions used on the H-U spindle. For instance I have made, I think, 11 types of motors using my spindle and it is closer to a "Standard BP" spindle than anything else. Dag, I am having trouble thinking of all 11 motors that have been made with the H-U spindle. I can only think of 9; Benny whistle, color tailed, hybrid #1 and #2, BP, LWS, strobe, whistle assisted BP, and nozzleless. What are the other two? Stinger and chuffers? WB Edited August 1, 2012 by WonderBoy
btdk34 Posted August 1, 2012 Author Posted August 1, 2012 Dag, I should've known better than to think the black powder would simply fall out of the hole when I was done ramming it... Thanks for the tip. Looks like I'll have to invest in a few bore cleaning brushes. And WonderBoy, you're right, I should just experiment with my "UH replica" instead of trying to copy it exactly... This way, I can make slight variations on my design and test them out!
dagabu Posted August 2, 2012 Posted August 2, 2012 Don't feel held back because your spindle is not the exact Hybrid-Universal spindle. Yours may not perform exactly the same as the H-U spindle, so it will take some experimentation, but it will more than likely work with many of the compositions used on the H-U spindle. For instance I have made, I think, 11 types of motors using my spindle and it is closer to a "Standard BP" spindle than anything else. Dag, I am having trouble thinking of all 11 motors that have been made with the H-U spindle. I can only think of 9; Benny whistle, color tailed, hybrid #1 and #2, BP, LWS, strobe, whistle assisted BP, and nozzleless. What are the other two? Stinger and chuffers? WB DING, DING! Plus Sali whistle, Super Whistle and MUTH (AP/PP) fueled. Dag, I should've known better than to think the black powder would simply fall out of the hole when I was done ramming it... Thanks for the tip. Looks like I'll have to invest in a few bore cleaning brushes. And WonderBoy, you're right, I should just experiment with my "UH replica" instead of trying to copy it exactly... This way, I can make slight variations on my design and test them out! I think your spindle is fine like WB says, go make something and post the video. -dag
Col Posted August 2, 2012 Posted August 2, 2012 A quick twist with pointed wooden kebab skewer helps bp fall out of a rammer. I make a point of keeping my rammers clear while i`m using them.. just to be on the safe side.
WonderBoy Posted August 2, 2012 Posted August 2, 2012 Ahh forgot about those. That brings my list to 15ish for my spindle then; Benny whistle, color tailed, BP, LWS, strobe, whistle assisted BP, whistle assisted nozzled BP, whistle assisted stinger, stinger, nozzleless, howler (sorta counts), chuffers, Super Whistle, Muth #2, and MnO2. I think that in some ways "Universal" is only limited by the imagination What do you mean by Sali whistle? Just toned down Sali whistle pressed all the way up? WB
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