Bomb Vessel Granado 1742 by gjdale - FINISHED - 1/48 - Cross-Section

[Jack12477]

Grant, fantastic.  Love the color of the wood.

[mtaylor]

Lovely work and wood choices, Grant.

[DocBlake]

Grant:  Gorgeous work!  You continue to set a very high bar.

 

Dave

[gjdale]

Thanks again one and all for all the encouraging comments and the "likes".  Life's been a bit hectic lately, so it's been a little while between updates.  I also needed to do some thinking about the next stage, as well as acquiring a new "secret weapon" (more on that later).  At last, this weekend I got to spend some quality time in the shipyard and am well pleased with the results.  I have completed the making of the Mortar Barrel, and documented my process fairly thoroughly in the hope that it may help others who progress down this path, or who (like me) are still novices in the world of machining. This post will therefore be in two parts.

 

The Mortar Barrel

 

The Mortar Barrel is another challenging but fun mini-project in its own right. 

 

 

I decided to turn the Barrel from Ebony, so the starting point was a 1” square piece of Ebony about 90mm long. I chucked this in a self-centring 4-jaw chuck, drilled a centre hole in one end, and mounted it with a live centre.

 

 

The first job was turn the square to a round, with a diameter equal to the maximum diameter of the Mortar Barrel.  Not having much experience in turning Ebony (or anything else for that matter) I used only very light cuts of about 0.25mm depth – it took a while!

 

 

And here’s what was removed to allow the cylinder to emerge:

 

 

Once that little mess was cleaned up, it was time to cut in the various sections of the barrel and reinforcing bands.  I had spent quite a bit of time with the drawings and a ruler measuring where all of these went, and writing myself a set of step-by-step instructions to make the task easier.  This paid off and all went well.  I had to do quite a bit of swapping out of cutting bit from right to left hand bits, and while this is no big deal, it did illustrate the advantage of having a quick-change tool post. (Something to add to the never-ending “accessories to purchase” list!).

 

 

At this point I decided it was a good time to drill the holes to take the “handles”, so the whole piece was transferred in the chuck to the Milling machine.  I mounted the chuck directly onto the rotary table, which itself was mounted on a right-angle attachment.  A right angle tailstock completed the setup, and we were ready to use the sensitive drill attachment, equipped with a No.67 drill bit.  The rotary table was used to position two sets of holes, 60 degrees apart.

 

 

While still in this configuration, I swapped out the drilling attachment for a 3/32” end mill, rotated the piece so that bottom dead centre was facing up, and drilled a hole near where the bottom of the barrel bore would be (more on that shortly).

 

Then it was time to transfer the workpiece, still in the chuck, back to the lathe, where a 5/16” end mill was used to bore out the bore.  An end mill was used in preference to a drill bit for this as it has cutting edges on the sides as well as the end, and so makes a very neat job. The bore was taken down to the bottom of what would become the mid-section of the barrel. (It was very difficult to get a decent photo of this on the lathe).

 

 

Continued next post........

 

 

[gjdale]

Mortar Barrel continued....

 

Once the barrel had been bored, it was time to part off the workpiece to its final length and shape the base end.  A mandrel was then turned down from some aluminium bar stock, so that it was an easy slide fit in to the barrel, and this was then drilled with a 3/32” end mill, using the same set-up on the Mill as previously.  The mandrel was then placed inside the barrel and a securing pin of 3/32” brass rod was inserted to hold the mandrel securely in place. The pin was a tight push fit, which made the whole assembly quite secure.

 

 

Now it was time to break out the “secret weapon”.  The base of the Mortar Barrel is a hemisphere in shape.  I’d been pondering how to achieve this, when I discovered that Sherline make a “Radius Turning Attachment” for exactly this purpose.  Happy days – a solution to my quandary AND a new accessory!     

 

Here is a picture of the setup, showing the mortar barrel being held in a 3-jaw self-centring chuck by the temporary mandrel.  The radius turning tool is mounted on the cross slide and is quick and easy to set-up and to use.  In this picture, I’ve already started to shape the end, having taken the first couple of passes with the tool.

 

 

A few minutes later and voilà, a perfect hemisphere:

 

 

Prior to commencing to use the radius turning tool, I had used a small centre drill to mark the centre of the end of the base.  Once the radius had been turned, a 3/16” end mill was inserted in the tailstock, and a hole drilled to a depth of 5/16” – the reason will become clear shortly.

 

With this hole drilled, the workpiece was again moved across, with the chuck, onto the rotary table on the Mill, this time mounted in the horizontal position.  The 3/16” end mill was transferred to the Mill and the previously bored hole was used to index the mill table into alignment. The pin in the mandrel was used as a guide to align the barrel such that a slot could now be cut at 90-degrees to the pin. In the following picture, the slot has already been cut to the depth of the previously bored hole (ie 5/16”).

 

 

The base of the mortar barrel is an interesting configuration, and includes the trunnion bar that also blends into the mortar barrel body.  I elected to make this in two pieces, both from 3/16” square stock. The first piece would carry a trapezoid shape to blend into the barrel body, while the second piece would have its end turned into a cylindrical shape to form the trunnions.  Sounds complex, but was really quite easy.  A piece of 1/4" square stock was first re-sized to 3/16” square using the Brynes disc sander. The trapezoid shape was also achieved using the disc sander, while the trunnion bar was simply turned down on each end in the lathe.  Here is a picture of the components prior to assembly:

 

 

The pieces were then assembled and the mandrel and locating pin removed. The hole from the locating pin was filled by a mixture of PVA glue and some of those ebony shavings saved from the first part of the process.  Two handles were made by bending a piece of 1/32” brass wire, chemically blackened and epoxied in place.  Here is the final product prior to receiving a coat of Wipe-On Poly:

 

 

 

And here it is with a “test” fit to the Turntable:

 

 

The completed assembly was given a coat of Wipe-On Poly, and then posed in the firing position for a few final photos (the poly is not yet dry here, hence the slight sheen):

 

 

 

 

 

All in all, I’m well pleased with the way this turned out.  Time spent up front measuring and working out the workflow process was well invested, as was the money spent on the radius turning attachment.  Amazingly, there were no re-dos in the entire process!     Next up – the 4-pounder guns and carriages. 

Edited September 13, 2015 by gjdale

[WackoWolf]

Beautifully done, enjoy the walk through very much. I have the Sherline 4 axes mill and also the 2 axes lathe both are CNC. The add-ons are not cheap but they are well worth the money. it never seems to end with them you always find you need something else and either you make it yourself or you by it. Thank you for sharing this with us it was a thrill to see how you did it and no re-dos is a big plus. Keep the pictures coming.

[CaptainSteve]

Just beautiful, Grant.

If I hadn't seen it myself, I would never guess that barrel was wood !!

Edited September 13, 2015 by CaptainSteve

[cog]

Grant,

 

Sometimes a foreign language is a curse, like now ... it makes you speechless for you do not find the proper words to show exactly the exhilaration on such marvelous feat of 'metal casting' or is it more like 'pulling a gun barrel' ... I'm stunned by awe ...

[shipmodel]

Grant - 

 

Really beautiful work.  Clean, precise, accurate.  I enjoyed your inventive solutions to the challenges of making such a complex part.  Now I just have to get over my 'machine envy.' at your fabulous tools.  I would run out and get a set, but by the time I figured them all out I would probably be past my last sale date.  Either that, or everything will be done by 3-D printing or personal robots.  :-))

 

Looking forward to your cannons.

 

Dan

[GLakie]

Very nice work on the mortar Grant! Thanks for sharing the "how to's". 

 

Cheers

[Rustyj]

Hi Grant,

 

Well done my friend.  That was a great tutorial on how to do the mortar too. And you were worried!

[augie]

Simply amazing.  Where's the form to order one????

[mobbsie]

Now that is very nicely done my friend, in future I shall just take it with a pinch of salt when you say your worried about doing something.

 

I'd take my hat of to you mate if I wore one, although your explanation is excellent it's no good to me as I have a different setup all together, I shall be on my own voyage of discovery when I get to that stage, hopefully within the next couple of weeks.

 

Be Good

 

mobbsie

 

P.S. You forgot to rifle the barrel  

[riverboat]

Very very nice !!!!!work Grant....... you're pretty darn good!!!

 

frank

[GuntherMT]

Beautiful machining work, the mortar turned out fantastic.

[dvm27]

Terrific job , Grant. I've never used the radius turning attachment but it's perfect for this piece. A slight modification to your sequence might help in the future. After mounting the square and inserting the live center, mark the jaws with their concurrent ebony face (1-4). Then remove the blank and shape it to eight square or even sixteen square back to, but not including, the base portion in the head-stock. it's the same principle as making a mast. Now reinsert the ebony blank as before, matching up the numbered jaws with the numbered surfaces of the blank. You can now turn it to a round shape in just a few seconds and the dreaded ebony dust will be reduced considerably.

[mtaylor]

That is one sweet looking mortar.  If I hadn't seen the process, I'd swear you turned it out of metal.

[Dan Vadas]

Beautifully done Grant .

 

  Danny

[rafine]

That is simply an incredible piece of work Grant. I share the awe and envy of all who have commented here.

 

Bob

[Canute]

WOW. Beautiful work! Kudoes, mate.

[mikec]

hi Grant, just popped on for a looksee. Haven't looked at what you are up to for a while. all I can say is wow!

I am going to grab a beer (its my birthday) and have an indepth look at how you have achieved this magnificent build.

[gjdale]

Thanks for all the kind words and the likes folks. And Happy Birthday Mike!

 

Things have been quiet in the shipyard lately as life has been getting in the way a little. A couple of weeks ago, I wrapped up my second stint in the RAN - seven years this time around, and a total just shy of 36 years all up. I have now started my own consulting business as a precursor to total retirement in about five years from now. My cunning plan is that working for myself will give me more time in the shipyard, although I've heard the boss is a bit of a tyrant.

 

Currently enjoying a little beach side chillax with the Admiral for a week at a very pleasant spot called Mooloolaba, on the Sunshine Coast just north of Brisbane, in Queensland. It's just a tad warmer than home right now. Here's a couple of pics of the view from the apartment - directly across the road from the beach. Life's tough sometimes!

 

For some reason, photos taken with the iPad always seem to attach upside down. If anyone knows how to fix this, I'd be most grateful. Then again, maybe for you folks in the Northern Hemisphere they are the right way up.

 

 

[Jack12477]

Grant, at least you didn't fall off the earth hanging upside down :D

[CaptainSteve]

For some reason, photos taken with the iPad always seem to attach upside down. If anyone knows how to fix this, I'd be most grateful. Then again, maybe for you folks in the Northern Hemisphere they are the right way up.

 

As Colin Hay (from Men At Work) sang, "I come from a land Down Under ... "

 

Currently enjoying a little beach side chillax with the Admiral for a week at a very pleasant spot called Mooloolaba, on the Sunshine Coast just north of Brisbane, in Queensland. It's just a tad warmer than home right now. Here's a couple of pics of the view from the apartment - directly across the road from the beach. Life's tough sometimes!

 

 

Ahhh Queensland !!  Beautiful one day ... perfect the next !!

 

Congrats on the new career move, Grant. Here's hoping everything turns out as planned.

[mobbsie]

Don't know how you guys do it down under, I tried looking at the pics standing on me head and all the blood rushed into it and made me feel quite dizzy( and don't even think of going there).

 

It does look a lovely place mate, better than sand and camels.

 

Enjoy the rest of your semi retirement hols mate and we'll speak soon.

 

Be Good

 

mobbsie

[mtaylor]

Lovely pics and congrats on the changes and impending change of employment.

 

As for the pics... seems iPads do that for some reason.   Maybe start taking the pictures upside down?  I'd think there would be a way to rotate the picture within the iPad software before posting... but I'm not a Apple person.

[Blue Ensign]

I seem to have lost track of your beautiful scratch build over the past few months Grant, but glad I found it again, your work on the Mortar is just wonderful.

 

Sorry to read about your assistant Sam, I've rarely been without a canine friend, and know how painful their loss is.

 

B.E.

[gjdale]

Thanks B.E. Nice to see you back here and thanks for your kind thoughts re Sam.

[gjdale]

Thanks again for all the kind comments and the "likes". I can't believe it has been almost six weeks since I last posted some progress!  I finally managed to get some time in the shipyard on Sunday - but only a little, so this will be only a minor update.  As an aside, when I tried to post this update on Sunday, I ran into the "Sucuri" issue that many have experienced previously.  A quick PM to Jim Hatch with my IP address and he fixed it in no time - thanks Jim  

 

Mortar Cap Squares

 

The Mortar Cap Squares were made from strips of 0.01” thick brass sheet. The sheet was attached to a carrier of scrap timber using double sided tape and then cut, with the brass facing down, on the Byrnes saw to the desired width – in this case 3/32”. One end of each strip was then bent around a 1/32” thick brass rod to form the hinge end. The middle was then formed around a 5/32” rod to fit around the trunnion, and then finessed into final shape in situ. A 0.8mm hole was then drilled to take the retaining eyebolt. The retaining eyebolt was shaped by squeezing a regular eyebolt into a sort of triangular shape, and then flattening with a hammer.  Finally, a short section of 1/32” brass tubing was cut to insert into the hinge end, to represent the inner part of the hinge.  Here is a shot of the component parts before blackening and final assembly.

 

 

All parts were then cleaned using a wire brush in a rotary tool, soaked in vinegar and then blackened with Birchwood Casey Brass Black prior to installing.  Here is the completed Mortar assembly:

 

 

 

4lb Gun Carriages

 

The carriages for the 4lb guns are made from Redheart.  Two guns will be displayed on the model, and a further two may be incorporated into the display stand.  Therefore, a total of four gun carriages will be made. The sides of the carriages are made from one piece each and are a fairly straight forward operation.  A set of ten blanks (allowing for two ‘spares’) were spot glued together to enable all sides to be cut in the same operation, to produce identical parts.  Once the gang was glued up, a pattern piece was applied using sticky label paper and the process of shaping was commenced. The ‘stepped’ sides and the dados for the axles were cut first using the Sherline mill.  Then curvature between the axles was incorporated by using the spindle sander. Finally, the groove for the trunnion bars was cut using a ball end cutter in the Proxxon drill press (only because I didn’t have a collet small enough to fit the ball end cutter in the mill.  The ends were then trimmed to length on the Byrnes disc sander and the completed part soaked in isopropyl alcohol to debond the spot-glue and separate the individual pieces.  After some final cleaning up, here’s what they look like:

 

 

That's as far as I managed to get on Sunday. Hopefully, next weekend I'll manage to finish the gun carriages and maybe even have a crack at turning the guns themselves.

[Canute]

Very nice, Grant. I've bookmarked this for my someday Amati/Victory Granado Build.