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Skipjack by michael mott - 1/8th scale - SMALL - 19 foot open launch


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thanks for all the likes and encouragements.

 

 

.but have you given any thought to a closed system?

Denis it is one of the things I have thought about. the issue would be the size of the tank and the volumes. a good filtering system and small pump might still be the best option, there is lots of time for experimenting.

 

Michael

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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I'm not going to suggest a thing.  I'm having too much fun just watching. 

 

Bob

Every build is a learning experience.

 

Current build:  SS_ Mariefred

 

Completed builds:  US Coast Guard Pequot   Friendship-sloop,  Schooner Lettie-G.-Howard,   Spray,   Grand-Banks-dory

                                                a gaff rigged yawl,  HOGA (YT-146),  Int'l Dragon Class II,   Two Edwardian Launches 

 

In the Gallery:   Catboat,   International-Dragon-Class,   Spray

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I'm with Carl and Bob.. except my jaw is still on the floor.   My mind is duly boggled.

Mark
"The shipwright is slow, but the wood is patient." - me

Current Build:                                                                                             
Past Builds:
 La Belle Poule 1765 - French Frigate from ANCRE plans - ON HOLD           Triton Cross-Section   

 NRG Hallf Hull Planking Kit                                                                            HMS Sphinx 1775 - Vanguard Models - 1:64               

 

Non-Ship Model:                                                                                         On hold, maybe forever:           

CH-53 Sikorsky - 1:48 - Revell - Completed                                                   Licorne - 1755 from Hahn Plans (Scratch) Version 2.0 (Abandoned)         

         

                                                                                                                                                                                                                                                                                                

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Michael,

 

Very clever idea, sliding the blank progressively out of the collet chuck to keep the cutting close to the chuck. So obvious once you mention it, but not obvious enough that I ever thought of it. We continue to learn from the master!

 

Mark

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Michael,

 

Still absolutely amazed!

 

Re: Closed or open system cooling, I can see no reason why either system shouldn't work - with an open system (raw water cooling) the main issue is generally with over cooling so perhaps some method of adjusting the flow rate needs to be gone into with a bit of the engineers favourite (not!!) trial & error...

With the closed system I wondered if you'd given any thought to keel cooling? It's an incredibly simple set up and almost certainly 'age appropriate'.

 

Decisions, decisions . . .

 

Regards,

 

Row

1:28 Scale J class yacht 'Enterprise' (R/C)

Build log currently at: http://www.rcsailing.net/forum1/showthread.php?6264-1-28-J-Class-Enterprise-build-log

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I like that collet method as well, Micheal.  Tthanks.

 

I can only echo what others are saying - beautiful work.

 

Ed

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The testing of various ways of dealing with the small fittings is now completed for the most part,

 

post-202-0-46947100-1421965729_thumb.jpg

 

and the final model parts in scale are coming together well. That said I am contemplating the false union at the junction with the cylinder and wondering if I can actually make one that works as a real union. Cutting a thread on some 1/8th diameter is not a problem usually the standard thread in imperial being a 5x40 the only problem is that at this scale that is an extremely coarse thread.

 

The elements are now in scale and the tubing is 3/32.

 

post-202-0-34493400-1421965731_thumb.jpg

 

post-202-0-52741100-1421965732_thumb.jpg

 

post-202-0-81487700-1421965733_thumb.jpg

 

I am thinking that if I can make a thread cutter that will cut say 5x80 then that would be a much better size for the union, the concern that I have is if the whole lot were soldered together then separating the cylinder from the crankcase would be problematic, because there would be too much piping hanging off the cylinder and therefore easy to damage. In making the union actually work like a union it eliminates that problem.

 

The saga continues.

 

Thanks to all who are following along and commenting, providing useful tips, and for the likes.

 

I am happy that some of the methods I am using are useful to some of you. it is the least I can do for all the knowledge I have gained from you all who share your methods and tips.

 

Michael

 

 

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Bob I did not know that such a die existed, I shall have to look now for instrument taps and dies, but it makes sense it just had not occured to me. so thanks again for another great tip..

 

Michael

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Bob This site has a number of specialty taps and dies, pricey but good quality I suspect, I am always concerned about ensuring that my taps and dies are of the best quality, I have found sometimes that the cheaper ones are not ground threads and have a tendency to tear the material a bit even with good cutting fluids. since I am only cutting one or two and in brass i might just thread-cut some 1/8th inch drill rod and make a small tap and thread up some brass rod at the same time. then they will match.

 

Michael

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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This evening I had to give the union a run.

First order was to set up the change gears on the Myford lathe to cut 80 threads per inch, then did some test cuts with a freshly ground cutter on some brass.

 

then turned down some 1/4 inch drill rod to .138" which is the size of the major diameter of a #6 machine screw then turning everything by hand(I unplugged the lathe) and taking .001" cuts threaded the shaft, polished it up with a leather strop. Hardened and tempered it then ground three flats with the diamond stone.

 

post-202-0-77544400-1421989421_thumb.jpg

 

next I turned up the brass nut, and threaded it after the threading was done the clearance hole wad drilled through and then it was parted off.

 

post-202-0-84451200-1421989420_thumb.jpg

 

Next the male part was threaded and tested with the tapped nut and  .0005" reduction threading cuts until the nut wound on to the thread easily.

 

post-202-0-80919200-1421989419_thumb.jpg

 

The male part was then parted off and slipped onto the end of some 3/32 tube.

 

post-202-0-86355100-1421989418_thumb.jpg

 

A couple of tiny refinements and it will work just fine.

 

michael

 

 

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Lovely work on the union, Micheal.  When I look at the photos I keep wondering how the open crankcase and timing gear will be enclosed.

 

Ed

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I've been a mechanic most of my life...figure I've seen quite a bit.  but I look at what your doing...and I'm totally amazed!  nice!

I yam wot I yam!

finished builds:
Billings Nordkap 476 / Billings Cux 87 / Billings Mary Ann / Billings AmericA - reissue
Billings Regina - bashed into the Susan A / Andrea Gail 1:20 - semi scratch w/ Billing instructions
M&M Fun Ship - semi scratch build / Gundalow - scratch build / Jeanne D'Arc - Heller
Phylly C & Denny-Zen - the Lobsie twins - bashed & semi scratch dual build

Billing T78 Norden

 

in dry dock:
Billing's Gothenborg 1:100 / Billing's Boulogne Etaples 1:20
Billing's Half Moon 1:40 - some scratch required
Revell U.S.S. United States 1:96 - plastic/ wood modified / Academy Titanic 1:400
Trawler Syborn - semi scratch / Holiday Harbor dual build - semi scratch

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When I look at the photos I keep wondering how the open crankcase and timing gear will be enclosed.

 

Ed this link on the old marine site shows the cover on the gears and the plates covering the openings on the crankcase. They are different engines but the same model, there seem to have been quite a few innovations and modifications to these engines, sort of reminds me of some of the dressing up that the hod rod cars seem to have.

 

Druxey, thanks I followed the same design as the miniature 00x90  taps that I purchased from Walthers the  model railroad suppliers. the same tap that was in the pin chuck. I used the hockey puck tap holder when I cut the thread. by making the tap first it was not difficult to then by trial and error get the mating part to fit nicely.

 

Steve the taps are the easy part the dies are a different story. having a screw cutting lathe is the key, I just wish i had the quick change gearbox for the Myford instead of having to change the set up by hand following one of the three different plans that are in the set up diagrams.

 

thanks for all the likes

 

Michael

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Thanks for the weblink. (for those of us that don't have your skill and patience. )

 

As far as pro tips, it would not have occurred to me to crank the lathe while unplugged for cutting tool steel. It makes perfect sense now that you have explained it.  Thanks! (I may try that at some point, but 80tpi won't be my 1st experiment! :))

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Michael,

 

Do you need to make a threaded coupling? Will the pressure be that high, or could you do it by pressing a conical end in the other tube ...?

Carl

"Desperate affairs require desperate measures." Lord Nelson
Search and you might find a log ...

 

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Do you need to make a threaded coupling? Will the pressure be that high,

Carl no I already have one now :D

Sorry Carl  I couldn't resist

 

I prefer a solid connection because of vibrations and the possibility of water spraying all over the inside of the boat, should the connection come undone.

Having spent many years fixing exhibits built by people who didn't think that their exhibits would ever need fixing, I am rather shy of things that cannot be dis-assembled.

 

Bob, glad the link was useful.

 

Thank you to all who have posted likes over the last entry.

 

Michael

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Michael, I have a thread cutting lathe with a whole bunch of gears that can be swapped around to set the pitch, the thought of it is a bit overwhelming at present and the fact that the instructions aren't great doesn't help.

 

It doesn't change the fact that I never would have thought of making a tap though, another lesson filed away.

 

I would have thought the die would be the easy part, drill, tap, drill three adjacent holes for the swarf and then harden. But then I have absolutely no experience.

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This is just getting ridiculous! :huh:  :)

John I know I'm completely bonkers.

 

 

I have a thread cutting lathe with a whole bunch of gears that can be swapped around to set the pitch, the thought of it is a bit overwhelming at present and the fact that the instructions aren't great doesn't help.

Steve what kind of lathe do you have?

 

Screw cutting is easy if you unplug the machine and are using brass or free machining steel.

 

here is a bit of SBS of union building. I used the dremel with a small stone to add some relief to the tap. By locking the rotation of the quill and clamping the dremel in the vice I was able to take very small cuts by indexing in the grinding stone and raising and lowering the tap in the quill because the depth of the amount of threads in the union I did not need to make the relief very long. this really helped to make the threading more smooth.

 

post-202-0-89624200-1422067266_thumb.jpg

 

threading the blank nut

 

post-202-0-73455800-1422067267_thumb.jpg

 

threaded 3/32 deep"

 

post-202-0-83668700-1422067268_thumb.jpg

 

filing the flats

 

post-202-0-00665200-1422067270_thumb.jpg

 

polished ready to part off

 

post-202-0-22432900-1422067271_thumb.jpg

 

male part threaded and bored 3/32"

 

post-202-0-15216300-1422067272_thumb.jpg

 

parted off onto the shank end of the #42 drill(.093) I used the drill as a support because the wall thickness is around .010"

 

post-202-0-13186500-1422067273_thumb.jpg

 

the two halves are sweated to their respective pipes. and threaded together

 

post-202-0-45323300-1422067274_thumb.jpg

 

uncoupled

 

post-202-0-71437200-1422067275_thumb.jpg

 

thank you for all the likes, I lost count so thank you for that.

 

Michael

 

 

 

 

 

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Michael, it's a cheap Chinese job, Sieg C6 with the mill attachment.

It will be good enough for most of what I do but I think I need to learn a lot about it, like I have a feeling the head isn't exactly square to the bed as I always seem to end up with a slight taper on longitudinal cuts, maybe I am just thinking the stock material is more rigid than it really is though.

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Steve i had a look at your type of lathe. To check if the head is out of alignment I suggest you put an 8 inch length of 1 inch ground bar stock in the chuck. Put a dial indicator in the tool post and set it up as close to the chuck as possible zero it and wind the carriage away from the chuck and watch the dial if the head is parallel to the bed then the dial should stay at 0.

If the dial changes then there will need to be some adjustment.

 

A common problem with turning a slight taper is that the material springs away from the cutter very slightly if it is longer than 3 diameters in length unsupported.

 

Use a live centre to support the end if it is longer than 3 diameters or use a collet and feed it out. Self Centering chucks are not good at re-centering a piece once it is removed from the chuck.

 

Collets on the other hand are very good at keeping the material concentric.

 

I notice that the ways on your lathe have a v on the front part of the bed this is a good thing, I wish Myford had done that the V is good for keeping the carriage in line.

 

I looked at the manual and the headstock is set with the V groove as well, so it does not look like you can change anything on it (you really don't want to anyway. I think that with a bit of research and some tweaking your lathe will be more than adequate for your hobby work.

 

Michael

Edited by michael mott

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Thanks so much Michael.

 

I know 3 jaw chucks are rubbish for re-centering so I always work out how to do the turning in one go. I do have a 4 jaw independent chuck as well but have only used it once or twice as I have not had any job that was that involved I needed to mount and re-mount.

 

The tip about 3 diameters is gold and probably explains the problem. I see much more live end use in my future.

 

Next I guess I need to buy a ground bar, is that an item designed for this purpose?

 

I have been thinking about collets for a while, I know they are much better and watching what you are doing with them really confirms that.

 

I won't be doing anything about it for a while though, I head for Sydney on Tuesday morning in readiness to sail out for Hobart on the Endeavour on Wednesday. Really looking forward to that!

 

Steve

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Next I guess I need to buy a ground bar, is that an item designed for this purpose?

 

Steve this is drill rod.

here it is sold in 36 inch lengths and comes in all the fractional sizes from 1/16 to 1 inch, anything that is ground and rigid between 1" and say 3/4 would work, I noticed that the headstock bore is 20mm that is just over 3/4 so some 3/4 rod would work even if it longer just let 6 inch hang out of the chuck.

 

 

Maybe you should start some "HowTo's" for the less educated amongst us

Carl I'm not so sure about that, there is a lot of talented builders here who I have learned from.

 

 

Michael

Current builds  Bristol Pilot Cutter 1:8;      Skipjack 19 foot Launch 1:8;       Herreshoff Buzzards Bay 14 1:8

Other projects  Pilot Cutter 1:500 ;   Maria, 1:2  Now just a memory    

Future model Gill Smith Catboat Pauline 1:8

Finished projects  A Bassett Lowke steamship Albertic 1:100  

 

Anything you can imagine is possible, when you put your mind to it.

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Hi Michael,

 

From your post:-

 

... To check if the head is out of alignment I suggest you put an 8 inch length of 1 inch ground bar stock in the chuck. Put a dial indicator in the tool post and set it up as close to the chuck as possible zero it and wind the carriage away from the chuck and watch the dial if the head is parallel to the bed then the dial should stay at 0.

If the dial changes then there l

Would that also measure the 'runout' of the chuck which is likely to impart far more inaccuracies than the headstock? I only ask as the company that my lathe (Warco WM240) came from supply test bars with a taper to match that which is also machined into the headstock spindle. Although I've not bought a test bar I have turned a 12" bar (between centres) and my cheap digital calipers indicate a fairly consistent diameter, certainly within half a thou which I reckon is pretty good for a mass produced Chinese machine. IIRC, mine, the Sieg's and the many other iterations available are basically copies of a much earlier Russian built lathe. More for Steve's benefit (& anyone else considering the purchase of a small lathe), the Sieg's are generally regarded as amongst the better built machines - some have even claimed, with appropriate 'fettling' and/or 'tinkering', that their accuracy can match the Myfords. Mind you, I guess that's a part of the problem; where the Myford will produce accurate repeatable results 'out of the box', the Chinese lathes generally don't...

 

Anyway, back to the main subject, your skills, as always, continue to amaze, astound, etc etc. The 'pump' really does look superb & I particularly like your threaded union, it was definitely worth the effort producing it to the correct scale size for the engine. I'm most definitely looking forward to the next chapter of this truly phenomenal engineering marvel!!

 

Regards,

 

Row

1:28 Scale J class yacht 'Enterprise' (R/C)

Build log currently at: http://www.rcsailing.net/forum1/showthread.php?6264-1-28-J-Class-Enterprise-build-log

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Row,

 

Definitely check the runout.  What was suggested to me was to put a coin at the "bottom" of the jaws and tighten the jaws.  The coin should be small enough to allow the jaw "teeth" to be inside the circular opening. Then using the inside cutter, set the lathe spinning and just let the cutter kiss the jaw teeth. Move the cutter a very very small amount and cut a tiny bit off.  The runout should be gone.  You have to do the "kiss" with the cutter, slowly and carefully because if you try to move it too much at a time, you'll destroy the cutter and possible receive and injury from flying shrapnel.

Mark
"The shipwright is slow, but the wood is patient." - me

Current Build:                                                                                             
Past Builds:
 La Belle Poule 1765 - French Frigate from ANCRE plans - ON HOLD           Triton Cross-Section   

 NRG Hallf Hull Planking Kit                                                                            HMS Sphinx 1775 - Vanguard Models - 1:64               

 

Non-Ship Model:                                                                                         On hold, maybe forever:           

CH-53 Sikorsky - 1:48 - Revell - Completed                                                   Licorne - 1755 from Hahn Plans (Scratch) Version 2.0 (Abandoned)         

         

                                                                                                                                                                                                                                                                                                

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 I have a feeling the head isn't exactly square to the bed as I always seem to end up with a slight taper on longitudinal cuts, maybe I am just thinking the stock material is more rigid than it really is though.

You may have already done this, but but it helps immensely to very carefully level the bed, using a couple of high-quality machinist's bubble levels.  My office is in an old mill building, and I was surprised at the amount of shimming and tweaking I had to do to get it right, even though the bed is less than 32" overall.

Edited by hexnut
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