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You may want to consider ball bearings for the crankshaft as they will reduce friction greatly which is critical in LTD Stirlings.
Bill & Marv: It's not as bad as it looks. Jan is using a point contact for the bearings:The ends of the axle are pointed (60 deg included). It is then supported in set screws that have been spot drilled (90 deg included). The set screws in each post adjust the load/clearance. So theoretically there is a point contact for rotation. I think this is used in clocks and watches? It should work OK??Mike: Great to hear you are bringing along a young machinist. It'll be a real advantage for his engineering career. Are you doing a build log?Thanks.Hugh
I've been slowed down. I need to make some tool holders for the Sherline Mill. For a CNC mill I need several holders in various sizes. SO, I'm trying to become friends with the Sherline CNC Lathe. I need to bore, groove and thread to fit the Sherline spindle. Then mount on the spindle and ream for specific tooling (1/4" & 1/8"). Might as well learn enough to make them on the Sherline CNC lathe since I need several.
Maybe a tap guide from OMW? I have one at work and one at home, they get used regularly. Little Machine Shop carries them.https://littlemachineshop.com/products/product_view.php?ProductID=2571&category=-561984047Dave
Is your end mill a center-cut style? Some are, and will plunge in fine, others have a small gap in the cutter right at the center, and wont do a plunge cut cleanly.And yes, those of us stuck up north in the snow are envious of your sitting in the sun!!
On ones like that I have used Loctite in conjunction with a cross pin through the joint, never had one fail with that combination (tight fits are a must). I usually just hacksaw through the bar to remove the section, then file it smooth.
Quote from: crueby on January 23, 2018, 07:24:47 PMOn ones like that I have used Loctite in conjunction with a cross pin through the joint, never had one fail with that combination (tight fits are a must). I usually just hacksaw through the bar to remove the section, then file it smooth.Thanks. However I can't cross pin this one. I'm sure some here could but I can't. Trying to drill through and pin a 3/32" shaft is beyond my abilities. Do you think just locktite would be enough?Thanks again.Hugh
You'll notice I've already broken the rules.
I can't imagine ramping at 30 degrees, I typically ramp at 1.5 degrees. Even at 3 degrees I get some rubbing on the back side that I don't like.Dave
...crueby: ... Where were you when I was planning this??...
Hi Hugh, Nice work! Don't say much but have been following along. But this time I have something to add....The old gent I started out playing this game with commented once that the BEST thing ( now you can take this with a large pinch of whatever) to use as a heat sink when silver soldering is a potato!! I would suggest that once you finish your silver soldering you don't eat it & you don't let somebody else grab it & put it in the pot for tea!Cheers Kerrin
It means that the cranks are closer together, but a good way to build a 90* crank is to have two plain cheeks on the outside, and one in the centre in an L shape.My smallest motor has a fabricated crankshaft 3 mm diametre with ball bearing big ends, the webs are 2 mm thick, I can't remember which Loctite grade I used, it may have been 641.Ian S C
Looking very good Hugh. It's too bad you have to fold up operations for so long.I have a question about your use of the Sherline chuck in the collet block. Do you have some kind of straight shank adapter or something?--Tim
Nice looking engine parts Hugh.I am sorry to hear that the road show will have to go on hold until autumn. I thought you had found the answer. But it's those damn chips that cause the problem every time.Mike
I will miss your updates Hugh! The traveling Sherline Show has been fun to follow and you have made some good progress on these three little engines. Bill