Ageless 9 and 18 Radial

[rlo1]

I would have used hex socket head cap screws to hold the cylinders to the case so I could use a ball-end hex driver at an angle to screw them in and tighten them !!!

In hindsight, that would have been much easier.

 

[Bentwings]

I would have used hex socket head cap screws to hold the cylinders to the case so I could use a ball-end hex driver at an angle to screw them in and tighten them !!!

I’d guess that would be ok in my opinion I have at least 5 sets of ball drivers of various lengths plus a couple hex extensions. I don’t really like those as they are too bulky I looked for just a piece of hex tube to make a special extension but I was un able to find it short of purchasing a hex broach I be left that one on the table there are relatively compact torque device Ed available cheap 2/4” drive torque wrenches don’t seem consistent enough . Once you have made a round wit one I’d guess you could be as good as all but the very best torque wrench .

 

[Bentwings]

one thing I try to do before resigning model things is to look at the original product snd designer . In thi case mr Hogson and his dad worked on these engines for something on thebirder of 35 years there have been many of these built and operated very successfully . Looking atvtge recommended parts, I thinkbyhrse see studs without getting out my drawing set 4-40 stainless steel I think . So why might this be? There is a huge amount of aluminum in the engine . Quite complicated cylinders. Lots of them. I don’t know just how hot everything gets . A 4-40 stud probably can stretch a little the full size studs stretched and recovered. Not being experienced in the full size I do have quite a lot of automotive experience as well as high peer racing. I’ve seen studs. Reduced diameter shanks to allow for stretching and recovery . And of latvthe single use or one time install then throw away . So I’d guess that attaching cylinders with slightly stretchy studs might be a good ide. Socket head cap stews are usually grade 8 or better which is pretty ridged ive used she’s in smaller model engines to replace slotted he’d screws high nitro engines some times simply pulled the threads vout if you found lose head screws, there was likely a worse problem bent rod cracked or burned piston , broken mounts etc I did try studs but high nitro often killed something else .

So in this complicated engine I YHINK I’d go with the designer . He is a very good model engineer and I’m sure he tried or thought about cylinder attachment . He is a wonderful person to talk to on the phone and knows every part of each of his engines quite well . Designing a special wrench just for these nuts says that he fells this is the optimum way to do this I initially thought the shed a good idea too, but looking closer I’d trade this knowing it’s worked many times . Getting fancy I would think that some small electronic torque reader would be ok . Needing an adaptor
I’d guess that would be ok in my opinion I have at least 5 sets of ball drivers of various lengths plus a couple hex extensions. I don’t really like those as they are too bulky I looked for just a piece of hex tube to make a special extension but I was un able to find it short of purchasing a hex broach I be left that one on the table there are relatively compact torque device Ed available cheap 2/4” drive torque wrenches don’t seem consistent enough . Once you have made a round wit one I’d guess you could be as good as all but the very best torque wrench .

I’d guess that would be ok in my opinion I have at least 5 sets of ball drivers of various lengths plus a couple hex extensions. I don’t really like those as they are too bulky I looked for just a piece of hex tube to make a special extension but I was un able to find it short of purchasing a hex broach I be left that one on the table there are relatively compact torque device Ed available cheap 2/4” drive torque wrenches don’t seem consistent enough . Once you have made a round wit one I’d guess you could be as good as all but the very best torque wrench .

 

[rlo1]

I thought about cap screws in the beginning and just dismissed it after seeing the design. My thought process is that if I have to replace a cylinder, I would rather damage a stud than the tapped hole in the aluminum crankcase. My fear is wear of the threaded hole in the aluminum with repeated removal and installation. The studs with the double nuts are a PITA to install. It looks pretty good though.

 

[Bentwings]

. I know the feeling I’ve used 4-40 taps in my Rc s scale models many times. I think to problem is poor quality taps I’ve used rap magic cutting oil for a long time. I often had to make custom drill and tap guides but there is still a problem . I currently use a lot of 3 mm screws in my steamer I have several taps and s drill and tap guide inen have a quite fancy tap handle . I also use quite a number of 1/4-40ME which is a very special tap and die set I YHINK each were 30$ or better . I had to thread 1/4” brass pipe with the tapered die. By hand it was hunorus as the result was a very fine threaded cork screw as our lathe is down . Careful tweeking I was able to straighten the thing out and made the unique depth gage I needed the 3 mm taps and dies are not the best quality . I initially thought the shcs was a good idea but I really agree with the stud snd ouble nut you are using provide a micro bit of stretching without loosening it’s a lot easier to replace a messed up stud than repair a stripped hole and you now have correct tools to do the checking. Just think of trying to put a heli coil insert in a hole down inside the crank case . Bad dream I don’t really know how you would ever get the little non magnetic tang out. I had the fun of changing 3 mm to 4 mm holes in shaft collars but I at least had through hole to work with and small parts I could hold in fingers . Yes it worked fine and a destructive test showed very good strength . Still a messy job . mr Hogson knows his stuff.
Broke my first 4-40 tap in the 9cyl front cover. Was able to clear and re-tap. I thread milled 95% of the 4-40s on this project (several 100's of holes) and never broke anything in the hole. I tap 12 4-40 threads and break a tap... I did not know how to thread mill before when I made this part at the beginning of the project. I very much dislike hand taps.... Rant over.

 

[rlo1]

I have the 14cyl and the BR2 plans too. I have built the BR2 stand and the crank cover. It will be a long term project. The crank is going to take me months... No CNC on the crank, all manual. All I have now is two chunks of steel. lol

 

[Bentwings]

There is nothing like just starting a very complex project . I’ve built a number of big scale Rc planes . A couple from precut basic parts to sheets on parts that need cutting out of plan sheets each part the selecting a suitable sheet of balsa or ply . Either individual contact gluing the individual parts To the material or tracing them . It took 40 hours of cutting parts for one plane then weeks of building . Probably the very hardest thing was the maiden flight. The flight was fine and much fun then came the landing . No computerized pre programmed thing . Gliding fully flaps gear down slip through the gap in the trees then lining up and set down on the runway . The peanut gallery cheering. They have been waiting for a spectacular crash . Overall next to scoring the winning point in sports. Nothing better . After many hours do machining countless parts flipping the pro and hearing the opening startup is th same .
I have the 14cyl and the BR2 plans too. I have built the BR2 stand and the crank cover. It will be a long term project. The crank is going to take me months... No CNC on the crank, all manual. All I have now is two chunks of steel. lol

 

[Bentwings]

. Is this crankshaft a pressctogether at assembly?

There was an 18 cyl build some time ago Tom maker or something like that.

I YHINK he made a slip together or splined assembly on cnc there is pretty and tape Rc well detailed construction and taper pins but it must be tough to get apart if it needs to be disassembled . The full size went through a number of mods and GSD a massive bolt assembly. There were lots of vibration issues that caused crank failures I recently read an article on how this was solved Gleason gear works came up with a very special splined coupling plus numerous floating balancing systems were created. Remember this was slide rule days no computers . They did make some innovative data logging devices . Vacuum tube days.
I have the 14cyl and the BR2 plans too. I have built the BR2 stand and the crank cover. It will be a long term project. The crank is going to take me months... No CNC on the crank, all manual. All I have now is two chunks of steel. lol

 

[rlo1]

On the BR2 it is a 5deg taper and It is bolted together during assembly with a 10/32 bolt.

 

[Bentwings]

On the BR2 it is a 5deg taper and It is bolted together during assembly with a 10/32 bolt.
View attachment 139645

I haven’t looked at the drawings in a while if I remember there is a square tool bit or bar that holds alignment ? The first builder that I followed machined a square into the counter weight then machined a matching pocket . If I remember he used a a kind of shaper tool to pick the Corners rather than round the square feature corners . Not sure why. The method Hogson used is pretty clever I YHINK ther is a fixture involved too. My initial plan was to 3D cad model the entire set of drawings and have a 3D printed
Model made for desk top display. However a stroke interfered and has left me with double vision and med issues so I’ve temporarily put this on hold I’ve added the larger screen TV to my lap top so I can see cad icons better so I’m gradually relearning the cad program . The TV doesn’t have the resolution so I have to revert to occasionally referring directly to the lap top. It’s a unique experience “ machining 3D on the TV THEN VERIFYING FINE OINTS WITH MAG GLASS ON The LAP TOP.

 

[rlo1]

I haven’t looked at the drawings in a while if I remember there is a square tool bit or bar that holds alignment ? The first builder that I followed machined a square into the counter weight then machined a matching pocket . If I remember he used a a kind of shaper tool to pick the Corners rather than round the square feature corners . Not sure why. The method Hogson used is pretty clever I YHINK ther is a fixture involved too. My initial plan was to 3D cad model the entire set of drawings and have a 3D printed
Model made for desk top display. However a stroke interfered and has left me with double vision and med issues so I’ve temporarily put this on hold I’ve added the larger screen TV to my lap top so I can see cad icons better so I’m gradually relearning the cad program . The TV doesn’t have the resolution so I have to revert to occasionally referring directly to the lap top. It’s a unique experience “ machining 3D on the TV THEN VERIFYING FINE OINTS WITH MAG GLASS ON The LAP TOP.

lol, I have a huge monitor for staring at drawings! I also 3D print parts in advance to see what I am getting into. I have CAD'd almost every part on the 9 & 18 and will probably do the same on the BR2. I have 3D printed several BR2 parts to date and have started building fixtures. The crankcase and front cover is massive. You are right about the crank, I am still studying it before making any cuts.

 

[Bentwings]

Wise choice . If if I remember the counter weights are stainless so not the easiest stuff to machine
lol, I have a huge monitor for staring at drawings! I also 3D print parts in advance to see what I am getting into. I have CAD'd almost every part on the 9 & 18 and will probably do the same on the BR2. I have 3D printed several BR2 parts to date and have started building fixtures. The crankcase and front cover is massive. You are right about the crank, I am still studying it before making any cuts.

 

[Bentwings]

I think it might be advantageous to make the counter weights hollow with ribs to save material in printing . Then make the real ones as designed.

 

[rlo1]

Both engines are back on the break in stand. Mechanically complete. Now to building the ignition system.

 

[Tim1974]

Looks like you did a great job it’s all worth it when you get em running well dun

 

[rlo1]

Progress

 

[Bentwings]

Looks like you did a great job it’s all worth it when you get em running well dun

very nice work!

 

[rlo1]

Running wire and trying to keep it all organized.

 

[Bentwings]

Progress[ATTACH this is such a nice build can’t wait for running video type="full"]140391[/ATTACH]

 

[rsholl]

Looking very good. I do have some concern with the wiring. It all looks very good and neat and I don't feel the metal hoops will be a problem but the zip ties could be. If you bundle wires too tight and you have many of these points it can degrade the KV of the wire. The zip ties are OK just leave the wires loosely bound. Looking forward to seeing them run.

Roy