First boat build - Delta Force 45 - Help much appreciated

[MikeP323]

I have always had RTR boats and then upgraded them for racing but find this process of more or less starting from scratch brings questions
I never had to think about before.

Basically I have the Delta Force DF-45 hull and am planning to use a TP4070 1650KV 5D motor with a Swordfish 240A HV ESC. I plan on running
6S at first and perhaps step up later. All the stern hardware is hung - the stuffing tube is in and lined up and I am about to glue in the motor/servo mount.
I will be using a .187 shaft.

Questions - What prop would make sense to start with on this - perhaps a 447 or a 450? - I usually use Octura props.
What is the difference between a tapered rudder and a straight one other than looks ? I have the speedmaster dual
pickup ros-spdr-011a with a five inch setback - the T block is mounted. (this is a tapered rudder)
This ESC requires a battery pack or a UBEC to run the receiver another first for me. What seems better for
this job? I have a unit that holds 4 AA batts and could put a switch on it. Or I can buy a UBEC which is hooked directly to
the ESC input leads? - or I believe some guys are using small lipo batteries???

I would welcome any help with the above questions and /or with the basic setup that I have outlined above although
changing that may be difficult as the money has already been spent. Thanks for any ideas/suggestions you may have.

[Fluid]

I am afraid you will be greatly disappointed in your boat's performance with the parts you plan to use. We have had several big DF monos in our club, they all use large format motors like Lehner 3060s, Neu 2230s or Castle 2028s. I doubt that 6S will supply enough power for this large hull, most use a minimum of 8S, most use 10S. A 47 mm prop is far too small to efficiently move this hull, most use a minimum of 60 mm to 65 mm. For those you need a 1/4" flex cable.

Your other questions are less important than the basics above.


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[MikeP323]

I am afraid you will be greatly disappointed in your boat's performance with the parts you plan to use. We have had several big DF monos in our club, they all use large format motors like Lehner 3060s, Neu 2230s or Castle 2028s. I doubt that 6S will supply enough power for this large hull, most use a minimum of 8S, most use 10S. A 47 mm prop is far too small to efficiently move this hull, most use a minimum of 60 mm to 65 mm. For those you need a 1/4" flex cable.

Your other questions are less important than the basics above.


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Fluid - thanks for your reply. I was wondering regarding the size of the motor etc that you stated - would a boat set up like that be used for 1/8th mile club racing like I am doing or would that be for
SAW use? Would my ESC run a Castle 2028 or a Neu 2230? Again I appreciate your reply - you have helped me in the past also. (Hope I have put this reply in the right place?)

[zooma]

If it is this DF 45, then it is only 38.5 inches long, and the proposed power system is a good match.

http://www.offshoreelectrics.com/pro...=df-DF45-MK-ll

OP, how long is your hull?

[Fluid]

Depends on the hull. I assumed (perhaps wrongly) the one below, which is the hull my club members use. Never seen a 38" DF-45.

http://www.offshoreelectrics.com/pro...prod=df-sniper

But for the little 45 hull the OP's original power system will work - although I'd strongly recommend a lower Kv motor (~1200-1300). He won't be able to "step up" to 8s safely with the 1650 Kv motor. Too many folks seem to get hung up on high rpm, which in most cases just isn't needed unless all you want to do is make zip-zip passes. High Kv motors make it much easier to accidently burn down your motor/ESC with a minor prop change, particularly if you have limited experience with high power systems.



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[MikeP323]

If it is this DF 45, then it is only 38.5 inches long, and the proposed power system is a good match.

http://www.offshoreelectrics.com/pro...=df-DF45-MK-ll

OP, how long is your hull?

I did not know their were large and small DF-45 MK-II hulls - anyway this one is 38.5 inches long as Zooma pointed out. I should have been more specific.

[zooma]

I did not know their were large and small DF-45 MK-II hulls - anyway this one is 38.5 inches long as Zooma pointed out. I should have been more specific.

Hey, Mike, I did not realize it was you. I guess you are referring to one like Chuck's red one and Gary's old yellow one. Just a little bit bigger than our Ariane 2 hulls. Your KV choice would put you around Chuck's speed, but no growth to 8 cells. Ask him what prop he is using. Gary had a low KV Neu motor, but I think it was under propped a little. I think Rich bought it.

I hope someone on the forum can answer your rudder question. I put the tapered Speedmaster rudder on the Ariane 2 because that's what Gary had for sale and I wanted the longer setback. How about it, guys, tapered or square rudder for oval racing?

[srislash]

I did not know their were large and small DF-45 MK-II hulls - anyway this one is 38.5 inches long as Zooma pointed out. I should have been more specific.

I think they get mixed up with their old 'nitro' classification. I'm sure with time it'll get standardized but till then...

I too am curious about the tapered/square rudder comparison. I have both here and am going to try on my R-42 cat(hopefully this next year), and i have been noticing the big hydro guys seem to use tapered, but have no idea the effect on a mono. But am curious.

Shawn

[RaceMechaniX]

If you have the shorter 39" version the motor combo will be OK, but know that is the upper limit. The 4070-1650kv motor is pretty hot for a mono and will require 6S2P. Several of us run that motor for Q hydro and it pulls pretty healthy amps in the 200A range. Start small with a 447, run 3 laps and check temps. Work you way up to larger props. A X646/3, 447/3 or X450/3 will probably be as large as you want to go.

Some layout ideas. This is my MkII DF39". I run a Lehner 2280-1233kv on 6S2P 10,000mAh minimum. I find the key to the DF hulls is keep the CG fairly far in the back to keep the nose from bow steering in the turns. I would set yours up to allow some CG adjustment by means of shifting the batteries. I have tested the higher kv options with small props, but found the lower KV motors in the 1200kv range swinging larger props run better particularly in race water.

DSC_4271.jpgDSC_4274.jpgDSC_4287.jpgDSC_4290.jpg

Here is what you can expect:

Tyler

[MikeP323]

Tyler - thank you for the reply. I will follow your suggestion re working my up with the prop size. See what works with sustainable temps....I assume those are 3 blade props you list in
your reply. I have no expierience with those but would be willing to try a couple. Build is going well and I am learning as I go. I would be willing to change motors if this does not work
in this boat - it would be an interesting swap into my Ariane 2 that now has a Leopard 4092 in place. Again Thank You !

[RaceMechaniX]

Mike,
The motor size is correct, but in the end you will likely find the lower kv with larger props runs better and cooler. The 1220kv would be an excellent choice for the second round.

http://www.tppowerusa.com/motors/in-stock/tp-4070-1220-kv

I would start with 2 blade props for your build. I run three blade props on mine with the 1233kv motor. I believe the prop in the video is a X460/3.
Typically if someone does not add a slash and prop blade number you can assume it is a 2 blade.

Tyler

[MikeP323]

Tyler -

I appreciate your info and will be aware in the future. I write all this stuff down because at my age if I don't its gone in a week (or less)

Thanks again. Mike

[MikeP323]

If you have the shorter 39" version the motor combo will be OK, but know that is the upper limit. The 4070-1650kv motor is pretty hot for a mono and will require 6S2P. Several of us run that motor for Q hydro and it pulls pretty healthy amps in the 200A range. Start small with a 447, run 3 laps and check temps. Work you way up to larger props. A X646/3, 447/3 or X450/3 will probably be as large as you want to go.

Some layout ideas. This is my MkII DF39". I run a Lehner 2280-1233kv on 6S2P 10,000mAh minimum. I find the key to the DF hulls is keep the CG fairly far in the back to keep the nose from bow steering in the turns. I would set yours up to allow some CG adjustment by means of shifting the batteries. I have tested the higher kv options with small props, but found the lower KV motors in the 1200kv range swinging larger props run better particularly in race water.

[ATTACH=CONFIG]148832[/ATTACH][ATTACH=CONFIG]148833[/ATTACH][ATTACH=CONFIG]148834[/ATTACH][ATTACH=CONFIG]148835[/ATTACH]

Here is what you can expect:

Tyler

Tyler - I know this is an old item but thought I might get your thoughts again. I am running the 38.5 inch version of the Delta Force 45 and will be changing to a 220 amp Swordfish esc as I have swapped out the TP 4070 that was in the boat
and installed a Neu 1527 - I have an Ariane 2 that I want to install the TP4070 in and the 240 amp Hi volt Swordfish will go with it. My question is what prop(s) would you now think a good fit for the Delta Force in view of the changes and
do you have any thoughts on props and the combo on the Ariane 2 (36.5 inch boat) I run both of these on a 1/8th mile oval track in club racing. Our races are generally only four or five laps.

Thanks Mike

[RaceMechaniX]

If you are running the 1Y-1250kv motor I would start with an X452/3 or similar. A X455/3, x457/3 or X460/3 are all options with increasing levels of current.

[MikeP323]

Df45 prop help

If you are running the 1Y-1250kv motor I would start with an X452/3 or similar. A X455/3, x457/3 or X460/3 are all options with increasing levels of current.

Thanks again for your help with this. I have never run a 3 bladed prop before but I believe I will try a 452/3 and see what happens and then go from there. Mike