Author Topic: 30ft 1890's navy steam launch 1/6th scale  (Read 82783 times)

Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #60 on: December 03, 2019, 05:59:26 PM »
the prop casting arrived today,, it was cast using a very old model steam pitch prop as the master,, after some rough clean-up I'll have to get the center drilled..
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #61 on: December 05, 2019, 01:03:52 PM »
worked on cleaning up the prop casting, planning to drill 1/8th for each end and hopefully meet in the middle,, as the final bore will the a taper for a 5/16th shaft should be plenty of room to make any needed corrections,, started working on the frame to block drilling jig,, had to wait for a better drill chuck to arrive,, the one that came with the mill was about worth the "included" price.. also a 4" rotary table with 4 jaw chuck will be arriving today,, it should help with holding the prop to start with..
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Offline Admiral_dk

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #62 on: December 05, 2019, 07:34:33 PM »
While the new rotary table + four jaw are some very nice additions to your toolbox (enjoy  :cheers: ) - I'm not sure how easy it will be to actually "fix" the prop in the four-jaw in a stable fashion that will allow you to mill / drill it without mishaps ...  :thinking:

Will follow your progress and best wishes

Per

Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #63 on: December 05, 2019, 08:01:19 PM »
props are not easy to clamp in any fixture,, I did a little test a few minutes ago and it seems like things fitted well in the 4-jaw on the six inch atlas,, clamping to the prop hub (still thinking some extra hose clamps or the like to make sure the blades stay tight to the chuck face) another option would be to epoxy/bondo the prop into a metal ring as a clamping surface,,not rushing into this, most likely will plan out and make the shaft taper,, do a practice run or too with some brass stock until I feel ready to tackle the prop bore.
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Offline crueby

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #64 on: December 05, 2019, 08:06:15 PM »
props are notoriously hard to chuck up for drilling the hubs, always need some sort of custom fixture. One possibility is to make a set of wedge shapes mounted on a backer ring, to clamp the blades against.

Offline mklotz

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #65 on: December 05, 2019, 09:05:46 PM »
Cast the prop into a cylindrical pit filled with liquid Cerrobend (Wood's metal) or similar and chuck the resulting cylindrical slug cum prop in the 4jaw, center on a previously marked center point and drill for prop shaft.
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #66 on: December 05, 2019, 11:08:10 PM »
I do have some cerrobend, but would need a larger amount.. the nose casting has a well defined ring/center  using a brass tube and a transfer punch I made a precise punch mark,, on the back side the lines of the blade edges were connected and the intersection was punched,, put the prop on center points on the lathe and it looks fairly close,, the back center may need adjustment,, the casting blades are longer and wider so their reduction will help get things correct..
« Last Edit: December 06, 2019, 11:01:48 AM by tghs »
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #67 on: December 06, 2019, 01:41:26 PM »
turning and marking the prop on the centers and then adjusting the rear punch spot,, the prop being a casting of a casting is about dialed in as it will get.. marked the blades for correct diameter and for any high spots on the front and rear edges,, on both sides three blades are about perfect with one blade needing just little file work.. everything should chuck up well after.. all in all I'm really happy with the casting otherwise I would have been doing a thread on making a prop!!!
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #68 on: December 10, 2019, 09:42:11 PM »
chucking the prop was proving problematic,, set a plate with a center hole on the mill and drilled the prop half way from each side with a 1/8" bit,, the leveling in the lathe centers must of paid off because the holes lined up nearly perfect (less than 1/64th off) some work with 5/32nd hand reamers and the bore looks good,, put the prop back in the lathe centers and it very close to where it was with the center punches..
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #69 on: December 11, 2019, 09:28:14 PM »
drilled the block to frame holes today,, drilled the pilot holes in the jig, turned some alignment pins and cylinder bore guides,, set it all together and drilled spot markers, removed the jig plate and finished the holes,, had put the center stud and nut earlier to keep things in place,, mounted the jig plate on the frame jig and drilled those holes,, now its a bunch of tapping, filing and reaming to get the parts together..
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #70 on: December 12, 2019, 01:39:12 PM »
my little semi-homemade tapping tool worked great for tapping the block holes,, reamed the covers and frame,, still have to adjust the HP frame castings a bit, things are tight there.. but it all fits together,, the block will bolt to the frames,, the frames need to have the extra material removed to match the blocks lines,,
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #71 on: December 20, 2019, 01:28:35 PM »
my valve shaft guide/way bar castings proved problematic,, after wasting some time trying to get them workable decided to start from stock,, one soldering  run for the valve shaft boss,, one more will be required for attaching the mounting feet,, the hole for the way bar still need to be drilled,, but it will be more like the prototype as the bar can be removed by the bolts,, lots of small work, but my new glasses are ready to be picked up!!!
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #72 on: December 20, 2019, 10:49:06 PM »
did a little more work,, the  guides are looking the part a bit more
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #73 on: January 02, 2020, 09:20:28 PM »
the rod guides should give enough support to do away with rods exiting the valve chest tops,, except the steam line enters the engine through the top of the high pressure chest,, it has a robust fitting/flange as directly above will regulator.. decided to see if both things could work,, plus I got to use my Xmas to me rotary table,, might have been easier to try something larger but it all worked well,, the HP chest has a rod guide hole and holes for steam..
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Offline tghs

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Re: 30ft 1890's navy steam launch 1/6th scale
« Reply #74 on: January 03, 2020, 07:21:02 PM »
drilled and milled the valve guide bases to fit the steam chest,, gave them a quick blast to clean them up,, a quick positioning test shows the three shaft paths in good alignment,, time to start drilling and tapping (lots of drilling and tapping)
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