forsakenrider

Looks great! I cant wait to hear what this engine does, I really want one.

Maybe a fall visit will be in order? Christian got his car finally so all we need is a few planes and some planning!

... and a tank or two

MJD

My Feedback: (1)

I need to bench run it a few times to get a feel for it. The hottest 1/2A I've run to date is a VA MkI. Anything you can say on the subject of first runs on these little guys that differs from what I'd do by habit? I figure I'll run an APC 4.2x4 for starters (I have some Eliminator 1/2A speed props to check out later, 4.25x4.5, 4.25x5.5), and run it rich for a few seconds, then into a rich two cycle for a handful of short runs with cooling time between. Fuel, 25% with 22-23% total oil. Y/N?

Rarely do I think that I have any need for 2.4gHz yet, but in this case I wish I didn't have an antenna to contend with.

FSRider - I'm getting back in the game, so am working to finish some of these straggling, stale projects that have been in mothballs all summer. Meaning: I should have a few toys ready if you two characters make it to ON.

combatpigg

My Feedback: (3)

Hmm...I think you'll find that the 4.2x4 is "IT"....just a guess.

Start it with a fast drip rate, almost breaking into a stream. Always rehearse your hand movements around the engine and never be in a hurry to do anything.

If the Profi is set to run faster than a Cyclon, they must be doing it with the kind of tricks that will make it less able to handle "bigger" props...but I don't know..

It's handy to have the bladder in your hand so you can set the needle for a scream, but squeeze the bladder to periodically cool off the engine...instead of dinking with the needle.

MJD

My Feedback: (1)

It may well be the best prop, but I was ordering some props for my .65's and could not resist some little CF 1/2A speed props. They are pretty conventional design & look like little MA props. This thing with the engine hanging out like that may not be clean enough to use any more pitch. But it will be interesting to find out! Maybe the next generation (due to be started in 2012 or so..?) will have a cowl.

As I recall the Profi is set up for max hp at 36k. What prop it will spin there remains to be seen. I have a few of Larry Driskill's 1/2A combat props but they are all pretty low pitch for this type of application. Might be perfect for test flights to keep the speed down, the vertical should be killer at least.

I'll try to get it on the bench this week. Now where did I put my ear plugs?

smoknrv4

My Feedback: (11)

Lookin' good, perhaps another nerd session is in order for this thing.[sm=49_49.gif]

MJD

My Feedback: (1)

Okay - progess. Finally. Unbelievably. It's been a busy summer and fall.. and diddly progress on toys. Big phase of dormancy in the workshop. Blah.

But.. in the last few days I've got the servos in, ailerons are fitted and pinned, tank assembly done and figured out how to secure it, and discovered I need 3/4" 2-56 mounting bolts (nice thick firewall) and don't have any. Or T-nuts. "L"HS time.. can't get that in town.

But the main thing is I bench ran the Profi .061 tonight! Since I have virtually no exposure to current 1/2A competition activity, this was an eye opener. Holy #@%&! This thing is powerful.. [:-]

To date the VA .049 is the hottest 1/2A small engine I have ever run. I had just finished up the bladder tube assembly and pressure tested it (used a small plastic screw top parts container from Lee Valley Tools with the lid silicone taped on to seal, very light). So it seemed there was no reason not to bolt it down and run it. I used one of Larry Driskill's combat props, this is the one with the two carbon rovings in the glass/epoxy, something like 4.8 x 2.75 or somewhere around there.. I should know but I forget. Anyhow, on Sig Champion 25%, I ran it a bit rough and rich for 30 seconds, with a few little pinches. On the second run I saw 33,700 while still on the rich side. Snotty little devil indeed.

I'm cycling the flight battery now, a 300mAh NiMH, and it that works out I'm pretty much there. Just gotta paint the hatches and make attachements, then fit the Rx and battery.. so this thing might fly any day now.

combatpigg

My Feedback: (3)

I never use machine screws and blind nuts to mount engines any more. Not even with the .40 size Nelson engines.
For 1/2A I use those #2 socket head sheetmetal screws and send them into 1/4" total of aircraft ply if working with a Cyclon. A #50 or 51 drill is used for pilot holes. Fiddling with screws and blind nuts has proven to be more trouble, so I switched. For really big stuff, then blind nuts are a necessary evil.

MJD

My Feedback: (1)

I might be able to rotate the engine to fresh wood and do that. Yeah, you've had engine mounting issues haven't you?

The engine was really easy to start. Release the line for a sec then clip it off, pull it through a few times, hook up the clip, flip flip, run on prime, off with the clip and wheee..

combatpigg

My Feedback: (3)

That's good to hear that your's is easy to run. When you think about it, they have to be fairly easy or they won't get used for World class combat.