1/6 P&W R-985 Wasp Jr by Bob Roach / Vernal Engineering

[ninefinger]

This thread got dragged up from the depths and I figure as the originator I should say I'm still around and progressing at speeds that make tectonic motion look fast....
That said I did more in the last 4 months than I had done in the previous 8 years (lots of excuses).
I'll need to switch PC's to post some photos, but I've made progress on the major hurdle that had been slowing me down, which was the cylinder fin cutting. That is now done and I'll provide some details in a separate posting on how that was done (rotary table on the mill and cutting 1 fin at a time with a slitting saw..)

With the cylinders done, I moved on to making the valves. I setup my Emco Compact 5 CNC (updated to Linux CNC and new stepper motors and drives). Made about 20 of those. They do need to be better, the tolerance on the stem isn't good enough. I'll run another batch of them using what I've learned by asking around the web.

The cam disks are made and the gears for the cam drive were all fabricated.
And the crankshaft is started.

Lots left to go, but its going!

Mike

 

[peterl95124]

I also have Bob Roaches plans for this engine but too many other projects in the works to get started on it, so in the meantime I'll be interested in seeing your progress.
Pete Lawrence (BAEM)

 

[burns]

Hi, I've been chasing the Radial engine R958 drawings by Bob Roach and castings by Bruce Satra, seems both have passed away and no methods of contact work. I've been in contact with Paul Knapp who took over the castings however he no longer produces them. Does anyone have surplus castings or drawings for purchase? Keen to keep the work of Bob and Bruce alive.

 

[ninefinger]

If you do find a supply of castings I'd be interested in one more cylinder head. One of mine has a casting defect that only showed up when drilling the plug hole. I've patched it up but would rather have a "proper" casting.

Sorry, can't help with drawings - I just have my set.
BTW - this is very far from a novice engine build. Bob drew this up using some advanced manufacturing techniques that aren't available to home machinists - like nitride hardening shafts. I've been picking away at mine for over 10 years now. I almost gave up entirely, but I'll plow on and hopefully have a runner one day that I can then put on a shelf or the front of a nice scale model to hang (not fly).

 

[burns]

Thanks, If I find some drawings I'll CAD up and 3d print at Hi resolution, I can then go for investment casting if there was interest or decide if I have the time to get stuck in. Benefit of 3d printing is test fitting, planning and keeping the enthusiasm going for complex projects like this.

 

[ninefinger]

I did model up quite a bit of this engine, originally in Pro/E Wildfire 4.0 and later imported that into Fusion360, where I continued to model more of it. Its really in bad shape now due to many parts not being drawn natively in Fusion 360, and as an assembly it just misbehaves. I don't have the will to care about fixing the CAD model anymore, and with Fusion 360 de-featuring more and more functions for the hobbiest I'm not inclined to spend time figuring things out. I only model what I need now to make something.

 

[Bentwings]

I’d suggest you either e resin print models first or have them printed for you this way you can maybe foresee issues before you make 28 “ mistakes”.

 

[burns]

I did model up quite a bit of this engine, originally in Pro/E Wildfire 4.0 and later imported that into Fusion360, where I continued to model more of it. Its really in bad shape now due to many parts not being drawn natively in Fusion 360, and as an assembly it just misbehaves. I don't have the will to care about fixing the CAD model anymore, and with Fusion 360 de-featuring more and more functions for the hobbiest I'm not inclined to spend time figuring things out. I only model what I need now to make something.

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I agree, CAD what you need. I use Solidworks, Fusion is OK but gets a little flakey with lots of parts, still it's free so that's a plus and you can import .step files. Nice progress on your engine, good things take time

 

[Bentwings]

I too use SW. but I’ve tased Inventer and several others earlier systems . Good to know that Fusion may have issues.

We are currently planning on a resin printer to actually see” models so another learning thing . But valuable before committing to chip making .

I would be nice to have a desktop model of the finished model especially if it would at least turn over. Like the “ visible engine “

 

[Aerostar55]

I agree, CAD what you need. I use Solidworks, Fusion is OK but gets a little flakey with lots of parts, still it's free so that's a plus and you can import .step files. Nice progress on your engine, good things take time

I tried Fusion 360 but went back to SolidWorks