Official FMS 1500mm P-47D Razorback Thread

[OV10]

The motor is 70mm from prop face to motor mount, the stock one is 58mm.

Gotcha.......definitely a motor body(can) to fake radial interference. I looked at the motor board and it is the same as used on the P-40B, F4U, v4 T-28 so the motor mount doesn't fit also.......definitely a no-go!! No HK motors also so the only viable direct bolt in is the FMS 4258-550kV(I mentioned earlier) which is a 6S 80A rated motor. It increases your RPM range from 10212 to 12210(20% increase). Could be a workable solution which means you could swing the 16" prop at 50-75% throttle usage knowing that 100% to the firewall would be limited to the occasional 5-10 sec burst. OK Delta, let us know how this works ;)

[Grossman56]

Now its starting to sound like the real thing, even a WEP setting!
Few birds come along that simply beg for a paint job/weathering treatment like a razorback P47, I'd love one just to paint it. This looks like a terrific airplane. The size is great and soem of the features that Rich was showing on Force R/C make it look like a pretty outstanding bird. I'm particularly impressed with the idea of ball bearings between the wheel hub and the axle. Keep us posted guys!!

Grossman56

[TiredIronGRB]

Gotcha.......definitely a motor body(can) to fake radial interference. I looked at the motor board and it is the same as used on the P-40B, F4U, v4 T-28 so the motor mount doesn't fit also.......definitely a no-go!! No HK motors also so the only viable direct bolt in is the FMS 4258-550kV(I mentioned earlier) which is a 6S 80A rated motor. It increases your RPM range from 10212 to 12210(20% increase). Could be a workable solution which means you could swing the 16" prop at 50-75% throttle usage knowing that 100% to the firewall would be limited to the occasional 5-10 sec burst. OK Delta, let us know how this works ;)

I have one of those motors...what about limiting the throttle travel? Can you tell I really want to use this prop?

[OV10]

I have one of those motors...what about limiting the throttle travel? Can you tell I really want to use this prop?

Can you tell I want to too. Throttle travel can be limited very easily with these new fangled computer radio's ;)

[Grossman56]

Hey CB, could you limit your throttle and assign a boost to a switch for that little 'goes to eleven' power?


Grossman56

[TiredIronGRB]

Can you tell I want to too. Throttle travel can be limited very easily with these new fangled computer radio's ;)

That's what I was doing earlier tonight and got the motor pretty hot.

[F106DeltaDart]

Hmm.. If the fit will be problematic, there are a couple of solutions that might work. First off, the prop is pretty low pitch at 6", and lower pitched props generally unload in the air by as much as 30-40% especially with multi-blade setups. So despite cutting out on the ground, it might be fine in the air. As a test, you could take it out with the scale prop and takeoff, keeping the throttle below 75%. Then, try full throttle in straight and level flight and climbing. If it cuts out, you should be able to reinitialize the esc by bringing the throttle back to zero and advancing it again. I had a friend who had this same issue running a 15.5" 4 blade on their Sea Fury. Cut out on the ground, but full; throttle was never an issue in the air. Try at your own risk though, like everything else.

Option 2 is run on a 4S setup with the stock motor. This will keep the Amps well in check, and should still give great climb performance. Speed might be a little low though. I run the 4250 580kv with this prop on the Bearcat, so we know that is a viable option as well.. We'll find some way to make this beautiful prop viable ;).

[OV10]

That's what I was doing earlier tonight and got the motor pretty hot.

Throttle travel wasn't really the culprit on your near melt down. A 2 inch larger prop is exponential in power versus rpm unlike your linear inputs on the stick. You were most likely hitting the 60A rating of both devices way before you realized even though your stick might have been only halfway thus the need to use meters when banging these voltage/amp hogs.

[OV10]

Hey CB, could you limit your throttle and assign a boost to a switch for that little 'goes to eleven' power?


Grossman56

I don't believe so.........motors are not readily tricked into a "boost" like engines are with nitrous and ram air

[TiredIronGRB]

Option 2 is run on a 4S setup with the stock motor. This will keep the Amps well in check, and should still give great climb performance. Speed might be a little low though. I run the 4250 580kv with this prop on the Bearcat, so we know that is a viable option as well.. We'll find some way to make this beautiful prop viable ;).

This sounds like the way to go, what ESC are you running?

[F106DeltaDart]

This sounds like the way to go, what ESC are you running?

I am using an 85A ESC.

[TiredIronGRB]

I am using an 85A ESC.

I've got some 4S 5500s that should balance out good.

[F106DeltaDart]

Great, I'll be eagerly awaiting your flight report! Rain forecasted for all weekend here, so plenty of down time for me to play around with setups for the P-47. In fact, that means next weekend will be 3 maiden flights for me if everything gets finished up.

[TiredIronGRB]

Great, I'll be eagerly awaiting your flight report! Rain forecasted for all weekend here, so plenty of down time for me to play around with setups for the P-47. In fact, that means next weekend will be 3 maiden flights for me if everything gets finished up.

Wouldn't the stock motor and ESC work with the 16X6 prop on 4S power or would you need the extra KV?

[OV10]

So am I............Looking forward to some good news on that 580. Got one of those and a 540 if it needs to drop some turns to haul the extra weight that it has over the Bearcat. No reason for holding out on measurements now TI cause I'll bet your 4S are set with EC3 or Deans.;)

[OV10]

Wouldn't the stock motor and ESC work with the 16X6 prop on 4S power or would you need the extra KV?

Need the kV..........

[F106DeltaDart]

Yes, the 460kv stock motor should be fine 4S and that prop. It will be a bit slow, but vertical should be impressive. Ecalc is showing 78A at full throttle :).

[F106DeltaDart]

Other option is this motor: https://hobbyking.com/en_us/turnigy-...ner-motor.html, size and KV both look spot on for 6S. Might be a nice option if it still needs a bit more punch than the stock motor or the 580kv.

[Aros]

..........

[TiredIronGRB]

Need the kV..........

That's what I thought, you know looking at this prop compared to others I have it looks more like a 16X8 than a 16X6.