DaytonaTim

That is exactly what I did. I first cut a single saw cut down the centerline of the components for each bearing pair. Put both bearings on the rod. Put the epoxy on the wood surface. Then layed the rod/bearing assembly in the groove. The rod lined up the bearings relative to each other and the grooves kept the two rods parrallel to each other. It worked like a champ! I have been toying with the idea of carving out a 1/18 scale body of an Aston Martin DBR1 I modeled a while back. http://www.turbosquid.com/FullPreview/Index.cfm/ID/331931 I think I can do it with a two sided machining process (ie machine from the top down, flip the part over and machine from the bottom down). I have yet to do any 2 sided machining and I think I am going to hold off on the body until I can experiment on some smaller parts. The estimated time to carve the body is about 20 hours, that is waaaaayyyyy too much time to invest in my first 2 sided part. Ettore, do you do 3D computer modeling?

No, don't figure I will be in Atlanta for the show. My friend, who's web site is hosting my pics, wants to show the allison at a show in October in Ohio. I think he said it was in Cleveland, I could be wrong though. I will just have to see how things shake out. My router went together pretty good with the excetion of the mounting of the oil-lite bushings. The way they describe it in their plans is cr*p and very prone to binding. How far are you on the fab of your router?

Hey everyone. Been doing the family vacation thing for the past couple of weeks, but I have made some progress. Here is a link to the hosting site http://public.fotki.com/gkulchock/allison-v12--18-and/ Now that the machining is complete for most of the large pieces, I think I am going to concentrate on finishing out the parts I have to the primer coat level. This will give me a chance to fabricate a better dust collection system..... and cleanup my garage I am actually using the same Rockcliff plans you have, Ettore. I did take mine up to 19x19x7 so I could do the larger scale models and plan on incorporating a 4th axis as soon as I can find all the parts I need. I am also using the Xylotex stepper motors and controler with the Mach3 software. Stbear, here is a link to some Allison pics that show a lot of detail http://www.missthriftway.com/Photos/Engine.htm

Got some new updates posted for the Allison. Here's the link http://public.fotki.com/gkulchock/allison-v12--18-and/ Been spending my time on the 1/6 scale version. Man... is this thing getting heavy. The block is about 3.5 inches thick by 7 inches long and made in 4 separate section. Everything is glued together with temporary glue that dissolves in water I got my new tooling in and it is helping me up the level of detail. I'm learning something new with every new part. I am done with the very large parts now (block, cylinders and valvecovers) now I will be starting the intricately detailed parts. I will have to experiment with different tooling to try and pick up the finer details. Jairus, I am working on a gear reduction unit, like the one shown for the P-51. I will plan on including it in the 1/8 version I make. I figured I might as well try and keep the airplane modelers happy too.

Yes, that drive configuration appears to be a direct drive unit because it's output shaft is lined up directly with the centerline of the crankshaft. But who knows for certain. Certainly not me. Just and educated guess on mypart.

I have studied a lot of photos of variouse configurations of the Allison. Jairus, the photo you have is for an airplane application. and there is no doubt that the output shaft is much higher. For an automotive application, which is what I was going for, you definately would not want the output that high. It is kind of hard to line up the output shaft with a differential. Also since the max rpm on an Allison was 3000 and the "normal" rpm for automotive applications is about 6000 the rotational speed of the Allison needed to be doubled inorder for it to function with standard performance automotive components. The place on my model that you thought was the location of the output shaft (the upper cylindrical section) is actually the location of the crankshaft of the engine. The output for the engine is located at the lower cylindrical section. This arangement would make the unit not a gear reduction unit, but one that increased the speed and lowers the location of the output relative to the ground, more inline with what is necessary for automotive application. I have plans on working on the unit in your picture in the near future but for now I have way too much on my plate.

Hello, this is my first post here. I have been coming to this site quite often over the past few months and I am amazed at the work that is shown here. I wish I could model like you guys do, but I am afraid I will never have the pateints (sp?) and skills like you have. Instead I model in 3D in the computer but I have decided to try and take it one step further.......and try and get my models actually "in hand" instead of on disk! So to make a long story short, I made a computer model of an Allison V-12 engine, built a CNC 3 axis router, and now I am slowly turning out the parts for it. I want a 1/6 scale model of the engine to go with the other 1/6 scale models I have collected, but I am also going to turn out a 1/8 scale model too. I have not figured out how to post pics on this forum yet, so here is a link to a website where I will be chronicaling the birth of this engine. http://public.fotki.com/gkulchock/allison-v12--18-and/