fubar57
General
Great work
1/48 Classic Airframes Boeing P-12E
- Thread starter Grant Barr
- Start date
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- 1/48 boeing p-12e yellow wings
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Crimea_River
Marshal
Impressive use of a home made template to get it right. Plenty of patience too.
Good work so far!
- Thread starter
- #44
Grant Barr
Senior Airman
Happy New Year to everyone! Thought it was time to get back to this kit and am keen to get it prepared enough for paint as soon as possible. Work is progressing slowly, however.
I've managed to assemble the engine cowl (Townend ring) and have also inserted a ring made from 0.50mm styrene rod that on the real thing would be running around the outside of the cylinder heads. Given the engine is yet to be assembled and needs the cowl and ring to set the correct dimensions it was easier to install the ring inside the cowl. The tops of the cylinder heads will be fixed to this ring once they have been assembled with the gear housing/crankcase.
I've spent quite some time on cleaning up the cylinders and heads before removing them from their casting blocks. The details are great; however, it appears that some of the mold seams were a bit worn and have left some flash or resin blobs in places. I've also drilled out a hole for the spark plug in the cylinder front and the two inlet/exhaust ports to the rear.
The process of fitting the cylinders to the crankcase is all by trial and error. As the casting of the crankcase where the holes for the cylinders fit is quite rough and inconsistent, each cylinder needs to be cut to its proper length and test fit inside the engine cowl/ring. Really quite tedious work, but necessary to ensure the best outcome.
The other issue I have noted relates to the "length" of the engine. I've tested the length of the resin crankcase block against the cowl. More of the front gear casing is visible than is indicated in both plans and from photos I have at hand.
I do have a little bit of play with the engine inlet manifold ring (indicated by yellow arrow) and I can thin this a bit more. It is also apparent that the rear surface, where it was removed from the casting block, is not quite perfectly flat and square to the centre line. I'll try to correct this as I reduce the length of the block.
I am continuing to clean up parts as I go and one of the next steps will be to fix the cabane struts in place on the fuselage. I've already broken on of them as I clean up edges so I will need to be careful with both their installation and final alignment. They are becoming too brittle to "flex" to much into place, so reasonably accurate alignment will be essential.
I've managed to assemble the engine cowl (Townend ring) and have also inserted a ring made from 0.50mm styrene rod that on the real thing would be running around the outside of the cylinder heads. Given the engine is yet to be assembled and needs the cowl and ring to set the correct dimensions it was easier to install the ring inside the cowl. The tops of the cylinder heads will be fixed to this ring once they have been assembled with the gear housing/crankcase.
I've spent quite some time on cleaning up the cylinders and heads before removing them from their casting blocks. The details are great; however, it appears that some of the mold seams were a bit worn and have left some flash or resin blobs in places. I've also drilled out a hole for the spark plug in the cylinder front and the two inlet/exhaust ports to the rear.
The process of fitting the cylinders to the crankcase is all by trial and error. As the casting of the crankcase where the holes for the cylinders fit is quite rough and inconsistent, each cylinder needs to be cut to its proper length and test fit inside the engine cowl/ring. Really quite tedious work, but necessary to ensure the best outcome.
The other issue I have noted relates to the "length" of the engine. I've tested the length of the resin crankcase block against the cowl. More of the front gear casing is visible than is indicated in both plans and from photos I have at hand.
I do have a little bit of play with the engine inlet manifold ring (indicated by yellow arrow) and I can thin this a bit more. It is also apparent that the rear surface, where it was removed from the casting block, is not quite perfectly flat and square to the centre line. I'll try to correct this as I reduce the length of the block.
I am continuing to clean up parts as I go and one of the next steps will be to fix the cabane struts in place on the fuselage. I've already broken on of them as I clean up edges so I will need to be careful with both their installation and final alignment. They are becoming too brittle to "flex" to much into place, so reasonably accurate alignment will be essential.
Vic Balshaw
Major General
Plating with resin parts is always a pain, you're lucky if you ever get a part that fits snugly. But we soldier on. 
Last edited:
Lucky13
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fubar57
General
Nice work
Crimea_River
Marshal
Good stuff Grant.
Lovely work so far!
- Thread starter
- #51
Grant Barr
Senior Airman
Thanks gents - have been soldiering on with this one. As I suspected there is a considerable amount of work required to make this kit look right!
Continuing with the work on the engine and cowl.
I have managed to clean up all the cylinders now and size them to allow for an accurate fit within the cowl/ring. You may notice that each one now has a brass pin to help with locating the cylinder into the crankcase. I'm starting to think that this kit is now more brass than plastic!!
So, time for the acid test. I have dry fit all the cylinders with the crankcase and squeezed them into the engine cowl. Good news, it fits reasonably accurately with a bit of wriggle room if needed.
The next task was to clean up the resin engine components. The crankcase has a couple of minor air bubble holes that I have filled, and the inlet manifold tubes have been removed from the casting block and cleaned up as required. Unfortunately, one of the tubes has broken and I seem to be missing the broken piece. My thinking at this point is that it will be easier just to make a new tube from styrene rod rather than trying to fix the broken end. That is a job for some time next week.
The other task now complete was to cut 18 identical length styrene rods that will serve as the push rod tubes. I finally got to use my new cutting clamp with its adjustable stop end. Makes cutting identical length rods a breeze.
One last job completed today was to fix the cabane struts into place. They are not quite perfectly aligned with the top wing holes, but there should be enough flex in the struts to allow for a <0.5mm error.
Because the struts are just a butt joint to the fuselage, they will require a lot of work to fair them into the fuselage as seen on the real aircraft. Not 100% sure how I'll do this just yet; it will probably just end up being some filler shaped appropriately around the bottoms of the strut legs.
That's about all I have at this time. Thanks for looking in.
Continuing with the work on the engine and cowl.
I have managed to clean up all the cylinders now and size them to allow for an accurate fit within the cowl/ring. You may notice that each one now has a brass pin to help with locating the cylinder into the crankcase. I'm starting to think that this kit is now more brass than plastic!!
So, time for the acid test. I have dry fit all the cylinders with the crankcase and squeezed them into the engine cowl. Good news, it fits reasonably accurately with a bit of wriggle room if needed.
The next task was to clean up the resin engine components. The crankcase has a couple of minor air bubble holes that I have filled, and the inlet manifold tubes have been removed from the casting block and cleaned up as required. Unfortunately, one of the tubes has broken and I seem to be missing the broken piece. My thinking at this point is that it will be easier just to make a new tube from styrene rod rather than trying to fix the broken end. That is a job for some time next week.
The other task now complete was to cut 18 identical length styrene rods that will serve as the push rod tubes. I finally got to use my new cutting clamp with its adjustable stop end. Makes cutting identical length rods a breeze.
One last job completed today was to fix the cabane struts into place. They are not quite perfectly aligned with the top wing holes, but there should be enough flex in the struts to allow for a <0.5mm error.
Because the struts are just a butt joint to the fuselage, they will require a lot of work to fair them into the fuselage as seen on the real aircraft. Not 100% sure how I'll do this just yet; it will probably just end up being some filler shaped appropriately around the bottoms of the strut legs.
That's about all I have at this time. Thanks for looking in.
fubar57
General
Lots of good, albeit fiddly work Grant
Vic Balshaw
Major General
Very fiddly work but my goodness your doing a sterling job.
Crimea_River
Marshal
Vic said it
- Thread starter
- #56
Grant Barr
Senior Airman
Back to the bench for some minor bits and pieces, mostly revolving around the engine.
As you can see from the first photo, I have now managed to get some paint onto the engine crankcase and cylinders as well as the inside of the Townend ring. You might also notice the 2 x 9 sets of plug wires cut for the front and rear plugs. These wires will be routed together with the help of some tiny pieces of aluminium foil wrapped around them once installed. The second shot shows the back of the engine. You can see I ended up not going forward with the resin pieces for the inlet manifolds, they were just too fragile and inconsistent in terms of shape and diameter. I used some 1mm ø styrene rod and carefully bent it in a jig after heating it in boiling water. The process was a bit hit and miss, but I made enough to ensure all 9 inlet manifolds were replaced.
The next couple of shots are close ups of the mostly completed engine showing the plug wires installed with their wraps to keep them routed together.
There is not a huge amount of contrast with the engine, being painted with a dirty mix of black with a bit of yellow and blue/grey to tone down it's starkness. The leads were done in a red/brown.
I am yet to install the exhaust stubs; they are quite small and will be prone to being knocked off and lost to the carpet monster. Once the engine has been fitted to the fuselage, I think it will be the best time to install them.
Meanwhile I have removed them from the casting block and cleaned them up. Because they are shaped such that the outlets are just a narrow slit, I ran a marker along the outlet edge to highlight it and proceeded to gouge out a narrow channel along the length. My hope is that, once painted, this will give it a bit of depth and make it look more like a real exhaust outlet – albeit a very narrow one.
I ended up sticking them to a piece of masking tape just to be sure they don't disappear into the ether.
Next steps will be assembly of the engine into the Townend ring and some test fitting to place the engine in the correct location at the front of the fuselage. I might also be creating a couple of fuselage extension panels which reach up in between the cylinder heads as is seen on the real thing. I did something like this on an earlier build of a P-26A and was happy with how it turned out – if time permits I could do the same with the P-12E.
As you can see from the first photo, I have now managed to get some paint onto the engine crankcase and cylinders as well as the inside of the Townend ring. You might also notice the 2 x 9 sets of plug wires cut for the front and rear plugs. These wires will be routed together with the help of some tiny pieces of aluminium foil wrapped around them once installed. The second shot shows the back of the engine. You can see I ended up not going forward with the resin pieces for the inlet manifolds, they were just too fragile and inconsistent in terms of shape and diameter. I used some 1mm ø styrene rod and carefully bent it in a jig after heating it in boiling water. The process was a bit hit and miss, but I made enough to ensure all 9 inlet manifolds were replaced.
The next couple of shots are close ups of the mostly completed engine showing the plug wires installed with their wraps to keep them routed together.
There is not a huge amount of contrast with the engine, being painted with a dirty mix of black with a bit of yellow and blue/grey to tone down it's starkness. The leads were done in a red/brown.
I am yet to install the exhaust stubs; they are quite small and will be prone to being knocked off and lost to the carpet monster. Once the engine has been fitted to the fuselage, I think it will be the best time to install them.
Meanwhile I have removed them from the casting block and cleaned them up. Because they are shaped such that the outlets are just a narrow slit, I ran a marker along the outlet edge to highlight it and proceeded to gouge out a narrow channel along the length. My hope is that, once painted, this will give it a bit of depth and make it look more like a real exhaust outlet – albeit a very narrow one.
I ended up sticking them to a piece of masking tape just to be sure they don't disappear into the ether.
Next steps will be assembly of the engine into the Townend ring and some test fitting to place the engine in the correct location at the front of the fuselage. I might also be creating a couple of fuselage extension panels which reach up in between the cylinder heads as is seen on the real thing. I did something like this on an earlier build of a P-26A and was happy with how it turned out – if time permits I could do the same with the P-12E.
Crimea_River
Marshal
You're doing a cracker of a job there Grant.
Good work so far!
