Beavers Prize 1777 by Mike Y - 1:48 - POF - Hahn style

[Kurt Johnson]

Mike, It looks beautiful! Is the case vented in any way? If this was mentioned before, I’ve forgotten.

 

Kurt

[alde]

Wonderful workmanship Mike.

[cog]

My offer still stands

 

Lovely display case, Mike. Very handsome, something your build deserves!

[druxey]

Very nice, Mike. A Forstner drill bit will do a non-tearout job nicely, but you did well with the hole-saw bit.

[BANYAN]

Nice work with the case Mike; especially in your recovery of the break.

 

cheers

 

Pat

[Mike Y]

Thanks everybody!

 

Kurt, it is not explicitly vented, but the wall is not ideally flat and the wallpaper is textured, so there are enough gaps on the back side of the case for air to flow in and out. Not planning any extra air holes (gaps), they will let too much dust inside.

 

druxey, yes, a good forstner bit would make it easier and safer, but it is too expensive for a one-time operation. Also, could not find a bit of a right diameter (36mm), they are sold with pretty big diameter increments in that size range. Hole saw of this type could be squeezed with a ziptie to adjust the diameter +/- few mm.

[Mike Y]

Phew, it's done!

The film removed, no scratches underneath it. 

 

 

 

No more display case photos, I promise! This log will finally get some model updates.

 

To summarise the experience from this case build:

1) Designing your own construction is fun and adds a lot of experience. It is difficult to estimate the proportions in SketchUp, I should have done some 1:1 mock-up with cardboard and sticks. If I do it again - I would make it flatter and lower.

2) Same for LEDs - test how the light hits the model. Both top and bottom strips are angled incorrectly (top one is hitting the wall, while bottom one is highlighting all the dust on the floor). Not a super big deal, but not as nice as I planned. 

3) Epoxy is a blessing, holding together tiny crossgrain-to-crossgrain joints well enough.

4) Be super pedantic about square angles, even a tiny misalignment sums up to a big skew on a long distance.

5) Pear wood is nice.

6) Sanding is magic!

7) The Admiral is a keeper for tolerating that "hamster hut" in our living room  Though I secured my daughter's support by promising her that her model would also be in that case. 

 

 

[md1400cs]

Mike,

 

Very nice--great noted comments. I will be using pear wood for the first time. Lovely color - much to like with this wood.

 

PS: I was in your neighborhood a few weeks ago - ride back many hours of just white. Wonderful indeed.

 

Regards,

 

 

 

 

[Kurt Johnson]

Yeah, back to Cromwell.  The case looks professionally done, Mike. Nice job.

 

Kurt

[Mike Y]

Michael, nice photos! Looks like you was there at a right time, when the sun is out  

Note that the pear wood colour changes a bit depending on a finish you use. I am now experimenting with some sanding sealers, to keep the wood in its original colour instead of a darker shade that different kinds of oil lead to. Will post the test results once it's done.

[ChrisLBren]

Hey Mike,

On a piece of furniture that gorgeous you may want to consider this finish - classic French Polish using thin coats of shellac.  

 

https://en.wikipedia.org/wiki/French_polish

 

Or even a simple wax finish would work well.  

 

http://www.thefurnitureconnoisseur.com/c/furniture-wax/

 

I know many use sanding sealers on their models - but on furniture its not really considered a final finish its more of a sealer before applying a finish from my research.  

Edited May 5, 2018 by ChrisLBren

[Gaetan Bordeleau]

Hi Mike

 

Very nice case.

Very nice color.

 

Knowing the story, I like to see both models in the case.

 

Is it difficult to remove the model from the case?

[Mike Y]

Thanks everybody!

 

Chris, it is a Danish oil - pretty popular furniture finish. I tried tung oil, danish oil and osmo polyx - for this particular wood and application danish oil looked a bit better. Thanks for the advice, but french polish is a bit above my skill level at the moment, it requires quite a lot of time and effort to apply...

Sorry that I confused you, the sanding sealer experiments are for the model scale only, not for the furniture. 

 

Gaetan, the case is designed to open easily - the front glass panel is just pulled out by hand, it is held in place with magnets. There are some detailed photos showing it in this comment: https://modelshipworld.com/index.php?/topic/7297-oliver-cromwell-by-mike-y-148-1777-pof-hahn-style/&do=findComment&comment=540399 

Just need to be careful when pulling the panel to avoid leaving fingerprints on the glass  Apart from that - that part of the case design works as intended, opening / closing the case is easy. I start to love magnet mounts more and more, they are easy to make and are fully invisible. The only nuance is picking up the right magnet size/strength for the job. With this case, I started with magnets that were a tiny bit too weak, but it was easy to solve - I just added a pair of stronger magnets into each top corner, and now it is quite strong. At the same time, you do not need to use a lot of force when removing the front panel.

 

 

 

[Niklas]

Hi Mike! Been following your display case build and I am very impressed! Now looking forward for some Cromwell! 

Niklas

[kees de mol]

very nice display

[Mike Y]

Kees, Lawrence, thanks!

 

There is no stain, it is a natural colour of pear once it is oiled.

19 hours ago, canoe21 said:

I have been milling over my set of plans for the Oliver Cromwell and have decided to follow in your footsteps of gluing the framing segments to cardboard templates and cutting them by hand.

Hmm, not sure what you mean, there is no gluing involved. Just cut one set of framing segments, fine tweak them to make sure they match the drawing, and then use these as templates to transfer sizes and rough angles to the framing stock. No gluing required.

Then same templates are used to set a correct angle on the disk sander. Then you do not need to worry about precision when cutting the pieces on a bandsaw or a table saw. Just leave a margin of a millimiter or two, and finish it on a disk sander.

Sorry for the brief explanation, hope it makes sense. Please PM me otherwise.

[ChrisLBren]

Thanks for the clarification Mike.    If you can build a display case as perfect as yours - applying a French Polish finish would not be above your talent !  Well done - the Danish Oil looks great.  

[Mike Y]

Finally back to the model building. To prepare, I need to make a set of Jorgensen-style clamps (also locally known as Tosti clamps on MSW for Ed, who popularised them in his Naiad build  ). I bought a pair in Lee Valley, but they are way too big for the modelling purposes. But I loved the way they work, and I quickly got used to them.

 

It is also my first time using tap & die (since that clamps require a mix of left-hand and right-hand threads) - I know the basic theory, but never had a need for cutting my own threads. So it was definitely a learning curve! More experienced man will chuckle reading that, so enjoy  Bought a high quality tap&die tools from Völkel, famous Swiss manufacturer. So at least I am sure that my troubles are not because I was using a cheap chinesium tools. 

 

First drilling the holes in the round bushing. It went surprisingly ok with just a mill and a Proxxon metal cutting drill bit. I thought it would slip and bend, and was ready to pre-mill the flat surface first, but it was ok even without it:

 

Second is tapping:

 

And threading:

 

Threading was harder than expected, the force required is quite high, so it was not easy to find a way to clamp the brass rod without damaging the thread that is already cut on its other end. I followed the rule of rotating it back every now and then to break the chips. 

It also took forever! 

 

To my surprise, the result was not good, especially on the left hand side - the bushing was rotating properly on some part of the rod, but getting tight or even jammed on the other part of the rod. I could not find a problem with a bare eye, no particles and the thread was looking quite even. Few extra runs of the die back and forth improved the situation, but just a bit.

 

The next test rod I cut with a lubrication. That was easier, but lead to the same quality of the thread, and much more mess (also brass chips not falling out but getting stuck because of the oil).

 

It helped to clamp the rod into a screwdriver and make a few passes with the bushing instead of a die. That way the rod and the bushing kind of adapted to each other, I guess..

Few more passes - and I ended up with a thread that is too loose. Whoops!

 

Then I tried to use the screwdriver to cut the threads instead of manual cut. That was much better! 

 

So the next test rod was cut much faster and had a good fit from the start. Maybe a bit on a loose side, but I suspect it is because I was cutting too fast, and die and rod became too hot -> hence they expanded a bit -> and the thread ended up too loose because too much material was cut. But at least it worked!

 

Few more cuts on a mill - and the test version of the clamp is done:

 

It works, but needs some tweaking of proportions to look good. Once I am satisfied with its proportions - will start cutting the real clamps out of pear, lined with a super soft basswood on the inner surface, to avoid damaging the model parts.

[gjdale]

Mike,

 

I’m no expert on this and I’m sure there are others who can provide more/better advice, but my experience to date in cutting threads with a die led me to learn that the die (at least good quality dies) have an adjustment screw that sets the “depth” of cut. Basically, it forces the cutting jaws apart. If you start with the cutting jaws as open as possible, and take a light threading cut first, it will be much easier/faster. Then adjust the “depth” of cut and go over it again. Repeat until you have a thread running “just right”.

 

Hope this helps.

[Mike Y]

Grant, thanks for the info! Google says that it is a special die design, the ones that have a split and an adjustment screw. Like this:

 

And here is my die, no split:

 

So it is probably more related to the feeding speed (and, hence, temperature). Will try to feed slower and see how it goes.

[druxey]

Is the rod diameter that you are attempting to thread the correctly specified diameter, Mike?

[Mike Y]

The rod diameter is 3mm, bushing has a 2.5mm hole. 

Both tap and die are the M3 size, DIN 223 standard. 

The rods are from the same batch, but I will doublecheck their diameters carefully. Everything is possible!  

[mtaylor]

I've found that brass rod isn't always as round as it should be, so I touch rod up in a lathe.   If it's out of round that causes problems also.

[Mike Y]

7 hours ago, canoe21 said:

Those are very nice scarf Joints that you just cut. Could you please tell me just how you came up with the sizes and angles

Hi Lawrence,

 

I do not remember to be honest - some books and a photos from some other build logs, plus experiments to see what angle and depth looks better. Once I found the scarf that looks the best from my point of view - I just made a template to keep that angle and use the same depth every time.  

[AON]

This might help with laying out your scarph joints.

The Elements of Wood Ship Construction - Scarph Joints - W.H. Curtis (1919).pdf

[Mike Y]

This summer I had a perfect plan - send off the family to their parent/grandparents in July, and enjoy the hobby in the evenings. "Ha ha oh come on" said my work life, and I ended up with a series of business trips instead  Some of them were good though, can't complain.

 

I am still making the "Tosti-style" clamps. 

Drilling the holes on a mill:

To prevent the drill bit from slipping to the side of the rod - I flatten it with a file first:

That method is simple and works well enough.

Thread is tapped manually, no problems with that approach:

 

Then slicing this rod with a Knupfer slitting blade. It is really great, cuts brass like butter, I am impressed!

 

Cutting the thread in a thin (3mm) rod is trickier though. Frequently the thread is being cut off-center, resulting in a wobble closer to the center of the rod. Googled a bit, most common reasons are incorrect angle, uneven feed, etc.

 

I found a method that works well in the end. Die is placed on top of the benchdog hole, vaccuum is placed below it, and everything is held in place purely with a vaccuum.

In action:

Being on a flat surface, it is easy to control the angle and is easy to apply a steady pressure. As a bonus, air flow immediately cools both die and rod, and all chips are sucked into the vac.

The end result is a clean and straight rod (on top), versus wobbly alternative (the same die was used for both rods):

 

I am nearly done with metalwork, but now my left-handed die died (no pun intended), it cuts a larger radius and gets a lot of resistance - I broke two rods when trying to cut that thread  Ordered a new die, will cut the clamp jaws in a meanwhile. 

 

P.S.: machining is, actually, quite hard! You can't sand away the excess or cover gaps with sawdust and glue mixture. There is only one chance to do things right.

Edited September 8, 2018 by Mike Y

[Mike Y]

Experimenting with clamp shapes (on scap pieces, real clamps would be made out of pear).

The shorter version looks better (needs a bit more meat on the back side though):

 

But it should more practical if I taper the jaws:

 That would allow to grip in narrow places (between frames, carlings/ledges, etc). I was worried about them flexing too much, but it is not an issue even on a soft pine that I use for this prototype. The clamping force on the very end is more than enough for all modelling applications. I could not clamp it hard enough to get any flex. 

The only downside - it looks kind of ugly. On the upside, I can make a lot of dad jokes about a clamp that looks like a duck, walks like a duck and quacks like a duck  

 

Any opinions? What clamp shape is more practical based on your experience?

 

[tlevine]

I think the second alternative is more practical.  

[Gaetan Bordeleau]

Hi Mike, 

 

I guess yo could say that the standard shape looks like the second one.

I have metal ones exactly the same, I think it was from Lee Valley.

Also I have boxwood ones similar and I broke 1 in 20 years.

 

[Gaetan Bordeleau]

I looked others and actually it is the opposite for the metal ones...  It is easier to mill a straight angle than a curved one.

 

With the parallel clamps that I broke, it was never at the tip but on the side walls where the screw is passing.

 

In wood, probably that the first one is stronger. I would begin by trying a stronger angle and if a thinner angle is needed, I would sand the tip as needed.

 

The difference for both in strength is not so big, so at the end it can also be simply a preference visually.