Help me with my first build: Delta Force Explorer 36 cat.

[RuntheraceAMC]

I just shattered the hull on my BJ24 and now I want to build my first boat. I've narrowed it down to the Delta Force Explorer 36. I'm in love with the sleek look and smooth running I've seen on YouTube. Besides I believe a lot of my electronics are well suited to this hull. From what I've read the DFE 36 is not the best in the corners but great for speed runs. Considering that I am just sport running and I am concerned about blow-overs I think this is a good fit.

the set up I want to start with is a Raider 150a, Leo 4074 1800kv, 642-645 props and 5-6s. I may try 7 or 8s and a 4094 1400-1600kv down the road if it is stable enough. I understand the transom is narrow on this boat so an inline strut/ rudder is almost a must. I would love to run dual leopards but the extra cost and maintenance scars me.

I could use help on the following issues/ questions:

Is my motor/esc/ prop combo on the right track?

Can anyone recommend a YouTube instructional video on how to fiberglass renforce sponsons and the tunnel? I want to strengthen this boat out of the gate.

How do you mount everything? Do you drill the hull and just screw everything down? Or I bought a carbon fiber plate to put down on the tunnel where all the electronics go- should I screw into that?

I like running two cooling lines to the motor and esc. I am use to doing thru hull mounted water pickups. Are there any special tips for dealing with doing this on a fiberglass hull vs ABS?

Thanks in advance for assisting.

[Fluid]

A 4074 motor is too small for a 36" hull. I'd get the TP4050/1700 or the TP4060/1750 if you plan to run 6S. The Explorer can handle larger props like an x447 or x648 for better efficiency. I would use an offset strut/rudder assembly rather than an inline.

I use JB Weld for mounting about everything in my boats directly to the glass (or CF), even my SAW boats. It holds if properly used, which means a clean sanded surface and 24 hours without moving the boat.

You don't need two water lines, just another place to leak. When you drill through the hull, be careful as it can be easy to chip the gel coat. Putting a piece of tape firmly on the hull where you drill can help prevent chips.


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[RuntheraceAMC]

[QUOTE=Fluid;674865]A 4074 motor is too small for a 36" hull. I'd get the TP4050/1700 or the TP4060/1750 if you plan to run 6S. The Explorer can handle larger props like an x447 or x648 for better efficiency. I would use an offset strut/rudder assembly rather than an inline.

I use JB Weld for mounting about everything in my boats directly to the glass (or CF), even my SAW boats. It holds if properly used, which means a clean sanded surface and 24 hours without moving the boat.

You don't need two water lines, just another place to leak. When you drill through the hull, be careful as it can be easy to chip the gel coat. Putting a piece of tape firmly on the hull where you drill can help prevent chips.

I would like to stick with leopard if I can. Can you suggest what might be enough? 4082? 4092? And what kv 1600?

What is a JB weld?

The reason why I did in line vs offset is because of the very narrow transom. No room to mount. What are the pros and cons of the inline mounted rudder?

Thanks for the tip about drilling and the gel coat.

.[/QUOTE

[Fluid]

Either the Leopard 4082 or 4092 would be fine, the Kv is fine. Depends on how fast you want to go and for how long.

JB Weld is a very strong industrial-strength epoxy. It is found in many home and hardware stores. Don't get the fast setting type.

Something like this is what I had in mind for an offset rudder, there are several options if you look around, this one is too small. Inline makes it difficult to remove the shaft and can cause wandering in the straights.

http://forums.offshoreelectrics.com/attachment.php?attachmentid=146870&stc=1

[RuntheraceAMC]

Thanks for the tips fluid

[RuntheraceAMC]

Thanks for the tips fluid
Will a raider 150a esc handle a 4092 on 5 or 6s? Planning on running a 645 prop but I have a 642 and 648

[Peter A]

Will a raider 150a esc handle a 4092 on 5 or 6s? Planning on running a 645 prop but I have a 642 and 648

Nope. Get a T-180 or SF220.

[RuntheraceAMC]

Either the Leopard 4082 or 4092 would be fine, the Kv is fine. Depends on how fast you want to go and for how long.

JB Weld is a very strong industrial-strength epoxy. It is found in many home and hardware stores. Don't get the fast setting type.

Something like this is what I had in mind for an offset rudder, there are several options if you look around, this one is too small. Inline makes it difficult to remove the shaft and can cause wandering in the straights.

http://forums.offshoreelectrics.com/attachment.php?attachmentid=146870&stc=1

Fluid,

Do you know of any YouTube instructional videos that walk you through how to reinforce a fiberglass hull? Or any threads on this forum that provide good instructions?

Should I even be reinforcing it to begin with? I'd like to make this hul last.

[Fluid]

Try a search for carbon fiber or inlay, you should turn up plenty of information. I don't know what the hull construction looks like, but reinforcing the tunnel never hurts. It may or may not help, but at least it looks cool.

.

[RuntheraceAMC]

why do I never hear of anyone using turn fins on a cat? I put trim tabs on my last Cat for more stability but on a hull like this delta force I am building I would think turn fins would help it in the corners.

Am I wrong?

[grsboats]

Turn fins on a cat wlll not help too much,will produce drag i.e. loss of speed.. try to keep the C.G. right and your boat will run good.Gill

[RuntheraceAMC]

146988146990146991

Build progress

[Mxkid261]

Are you running this boat on 6s? What KV is that 4092? You may want to closely watch temps your first outing. Some guy here built a cheetah a few months ago with a 4082 2200kv on 4s and cooked his raider 150 first time having it out. http://forums.offshoreelectrics.com/showthread.php?55293-150-amp-esc-was-not-enough

[RuntheraceAMC]

Starting with 5s. Do plan to go to 6s. 4092 1730kv

When I switch to 6s I will drop from a 645 prop to a 642 to be safe and prop up from there. I do have a psychotic amount of cooling to my esc.
I realize I need to consider something like a swordfish 220.

[RuntheraceAMC]

Ran it for the first time today on 5s. Omg. I think I'm in love. This thing has got some serious legs. Can't wait to get out on a big lake this weekend.

[boredom.is.me]

Speaking of cooling, what's going on in there? Having more entry points doesn't automatically mean more flow in the direction you want. An extra entry can also be an extra exit. Fluids flow to where ever has the least pressure. If all entries aren't submerged, your cooling is literally not reaching anything in the boat.

One in, one out, no t's or y's. You have 6 entry points cooling 3 components (2 on the esc).

[RuntheraceAMC]

I made the mistake of drilling the holes for the larger double pickups before I realized my water cooled engine mount did not fit so two lines I thought I was going to use were no longer needed.

Besides that I have two separate lines to the esc a third to an esc cooling plate and the motor. I hear what you are saying. I just didn't know what to do when the mount didn't fit. Good news is that I can see flow from all four exhaust pipes so all components should be getting some flow.

[grsboats]

Looking to your pics I see a raw prop ...don't forget to have it well balanced and sharpened and get ready for some action on 6S.Good boating.

[RuntheraceAMC]

Just balanced it tonight. Getting ready for tomorrow

[bob horowitz]

Speaking of cooling, what's going on in there? Having more entry points doesn't automatically mean more flow in the direction you want. An extra entry can also be an extra exit. Fluids flow to where ever has the least pressure. If all entries aren't submerged, your cooling is literally not reaching anything in the boat.

One in, one out, no t's or y's. You have 6 entry points cooling 3 components (2 on the esc).

What's the problem with using a "y" in the cooling lines. I'm building a rigger and I was planning on running my inlet from the rudder to a "y" and then having a line each to the motor and the ESC. Then on to two separate outlets. Is that a no no? Should I just run a single through the motor and then through the ESC, or the reverse. I always forget which to cool first. Sorry to hijack the thread.
Bob

[RuntheraceAMC]

Esc first then motor if you are doing a single line.

[boredom.is.me]

What's the problem with using a "y" in the cooling lines. I'm building a rigger and I was planning on running my inlet from the rudder to a "y" and then having a line each to the motor and the ESC. Then on to two separate outlets. Is that a no no? Should I just run a single through the motor and then through the ESC, or the reverse. I always forget which to cool first. Sorry to hijack the thread.
Bob

It's really just basic physics. Electricity, fluids, pretty much anything that can, will ALWAYS take the path of least resistance. Meaning a y connector does not mean a 50/50 split. It could be 75/25 or even 0/100. You're better off with a single line to the esc, then to the motor and out.

[bob horowitz]

Thanks Guys.
Bob

[RuntheraceAMC]

What size shaft should I be running with my set up. I've blown thru three 3/16 shafts in two days

[Fluid]

A 3/16" cable is plenty, I've run 99 mph with a cable that size. If you are blowing up cables then something else is very wrong.

- be sure to leave a 3/16" gap between the strut and the drive dog
- the distance between the motor coupler and the end of the stuffing tube should be no more than 5/8"
- use a good lube on the cable, relube at least once every day
- take the cable out and dry it off after each day of running

Are you running a Teflon liner? If not what is the exact size of the stuffing tube?



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[RuntheraceAMC]

I know what the problem is. I was just to lazy to fix it. I set the motor about 1/4- 3/8 an inch too far forward for the length of my shaft so I was only getting about 1/8-1/4 an inch of flex shaft in the collet. So I was stripping them like crazy. Then I bought a shat too long and had to leave an inch gap between the stuffing tube and the collet to make it work. That ended ugly. Moving he motor and installing a new stuffing tube now

[fweasel]

You break a lot of stuff. Just sayin' :beerchug:

[RuntheraceAMC]

I've cultivated that reputation. The guys at the hobby shop just hang their heads and mutter, "what did you do today?"

[RuntheraceAMC]

So my DFE 36 is starting to get tuned in now that I've been able to run it a few times. Shaft issues are fixed.

Let me just say that this hull is awesome! It seems like it struggles to stay glued to the water all the way to near 3/4 throttle. Then all a sudden it squats and goes. This thing is glued to the water. I keep thinking I am running it wet but my COG is less than 30% from the end of the sponsons. I would guess I am touching 65mph on 6s with a 645 prop. Temps are good esc 95-105. Motor 100-110

I have put he 648 on but just for short runs. Need to check temps on that prop

Installed bilge pumps for each side because my shaft leaks. Could not avoid having the stuffing tube low due to the motor being so tight in this boat. No worries. The bilge pumps are a cool addition for a geek like me

I am having one problem. My setup is swelling my batteries. I am using pulse 4500mah 45c 5s and 6s batteries. Also the revoletrics 5s 5000mah 70c battery from OSE. Battery temps are 130-150 f. If my motor 4092 1730kv) and esc (raider) 150 are running cool am I really pulling too many amps. Those aren't low quality batteries

Any ideas on the issue?

[RuntheraceAMC]

Another question: If I run my servo off of a separate set of batteries will I see performance gains out of my setup?

FYI- my bilges are also on separate batteries

[boredom.is.me]

What are you running the batteries down to? Over discharging might be the problem.

[RuntheraceAMC]

That could be it. Esc is programmed at 3.2. I can change it to 3.4

[fweasel]

What are you running the batteries down to? Over discharging might be the problem.
2nd

Do you have a cell checker? I use one to check voltages on the batteries after every run just to stay on top of things.

[RuntheraceAMC]

My bateries were down to 3.2 per cell

[RuntheraceAMC]

Another question: If I run my servo off of a separate set of batteries will I see performance gains out of my setup?

FYI- my bilges are also on separate batteries
Any thoughts on this?

[Fluid]

Another question: If I run my servo off of a separate set of batteries will I see performance gains out of my setup?
At max draw the servo draws so few amps and then only when turning that you will not notice a difference.

What are the water temperatures? If cold that could be the reason for the packs being so much hotter. As others mentioned you may be running the packs too low. Another contributor could be excessive resistance between the packs and ESC. Long wires, small gauge wires, poor connectors or soldering jobs can increase the stress on the packs without affecting the motor or ESC.


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[RuntheraceAMC]

So one week with this boat and I already want to go faster. However I'm concerned I am already on the edge with my motor and esc. I know the hull can handle more. I'll remind you all of the set up: Leo 4092 1730kv, raider 150 on 5s-6s 45c-70c batteries

I'd like to take it to 7 or 8s ( I already ordered a matching 2s battery for my 5s battery). But when I look at the specs for my motor it says max Volts 20, max amps 140. So at 6s I am already pushing it. If I put a 7s in it will I blow it up?

A 4092 is about the biggest motor I could put in this hull due to height restrictions. Wanting to stay with leopard...if I look at my options for 8s the highest kv that can handle 8s is 1050kv. It says max volts are 33 and max amps are 102. So I could throw this motor in there but I'm struggling with buying a motor with that low of a kv rating. Maybe it's the rookie in me but I feel like that will not really make the boat faster. Would I have to prop up to see speed gains with a change in motors? My prop options seem limited beyond the one I'm currently using, the 648. Also, I would still like to be able to run 6s and have fast speeds. 6s on 1050kv is 24,000 Rpms. Is that enough? It's still just 32,000 Rpms on 8s.

Some expert help would really go along way here and save me money I'm sure...

[boredom.is.me]

Keep following amp ratings and your setup will eventually blow up. Also why are you fixated on rpm? The prop is what does the work. Lower kv can spin a larger prop at the same voltage and current as a higher kv with a smaller prop. The difference is that the larger prop will have a greater efficiency which equates to more speed. Are you sure that you have maxed out the running attitude (cg, angle, height, prop choice)?

[RuntheraceAMC]

Not sure what you meant by, "keep following amp ratings and my your set up will eventually blow up". If I followed the ratings I'll blow it up?

I am not sur I've maxed out my set up. It's still running in 95-110 degree range on my 648 even on 6s. I do have a lot of cooling going to the motor and esc and water temps are in the low 50's in PA this time of year so maybe those numbers are low because of that and I am pushing the set up more than I think. I'll order a 50 and 52 mm CNC prop.

I do need to play a bit more with the strut angle. I think I have the COG right or slightly too far to the stern.

Haven't messed with the height at all. I did on my last cat and really never understood the pros and cons of raising or lowering the prop. I currently have it at the same height as the lowest part of the sponsons.

[boredom.is.me]

A manufacturer might claim 100 amps max, but that doesn't account for spikes that can often times double what the rating says.

Have any video? You must be hauling right now.

[RuntheraceAMC]

A manufacturer might claim 100 amps max, but that doesn't account for spikes that can often times double what the rating says.

Have any video? You must be hauling right now.

Can't seem to get videos to post here

[RuntheraceAMC]

Pm me with an email or number and I'll send a couple vids

[boredom.is.me]

https://youtu.be/T_E846D9WEA

https://youtu.be/dC4vL9pwkQY

Not quite sure why I'm not getting them to embed here but here are the videos.

[RuntheraceAMC]

Thanks for putting them on for me

[fweasel]

Not quite sure why I'm not getting them to embed here but here are the videos.
I can't get mine to embed on this forum either.

[RuntheraceAMC]

Hey guys. Thanks for the help with this boat in the past weeks. Unfortunately after a couple weeks of the boat running well I've run into a few problems. Before I give details let me remind you of my set up. DFE 36 cat with Leo 4092 1730kv, running 648 and Prather 235 (50mm) props with OSE Raider 150. Batteries I've been using are 5s 70c 5000mah and 6s2p pulse 6s 45c 4100mah.

Last week I started experiencing trouble with the boat stalling on 6s. It would in for 30 seconds and then stall. After another 20-40 seconds it would start again full power. It did not matter if I was crushing or doing top speed runs, it would regularly cut out. When it stalled I could hear it Rebinding or I could hear the 6 beeps usually heard after initially connecting power. Then the rudder would work till the power came on within 20 seconds or so. I tried running 5s and even 3s. No change. I also lost reverse. It would never work. This made me think I should reprogram the esc. After reprogramming I had reverse but no change in the stalling.

Next I changed the radio receiver. No change. Then I threw my old SK120 esc in and it ran fine on 5s. No stalling. So I know it was the raider esc causing the issue. Unfortunately right after my 5s run, I blew up my SK120 when I ran 6s2p.

So what esc do I buy to replace this. Something to keep in mind is that I plan to go to a lower kv 4092 next year and run 8s. I was thinking the SF200. Thoughts??? (Besides that I have more money than sense)

[Peter A]

Those props you are running are pretty big for the kv. You may want to try try some others if you are after reliable speed, bigger does not necessarily make faster. Take a look at some of KFX Guy's threads on his testing and results. The 150 esc was never going to handle the current or spikes. You should look at a SF300 or MGM esc's for what you are doing.

[RuntheraceAMC]

Those props you are running are pretty big for the kv. You may want to try try some others if you are after reliable speed, bigger does not necessarily make faster. Take a look at some of KFX Guy's threads on his testing and results. The 150 esc was never going to handle the current or spikes. You should look at a SF300 or MGM esc's for what you are doing.

Fluid was just telling me that the swordfish esc's have been known to be unreliable. I was looking at the ETTi 220a proII. What do you think about that choice?

[Peter A]

Chap, you have posted the same question in three threads. Have you done any research through threads here at OSE? You can keep burning stuff or learn from those who have done it. I agree with the smaller SF esc's being rubbish, I had one die pretty quick and a V2 T-180 is holding up no problem. That is on a TP 4060 1620 kv in a Q hydro. It only runs a M445 for heat races on 6s 1P and pulls out around 4000mah for a 5 lap heat race. I know you are going zoom zoom but you need to get plenty of headroom in your setup. The SF 300 has it's issues but the main one is sorted in the thread below.

http://forums.offshoreelectrics.com/showthread.php?55442-Swordfish-300

Or try some thing from here

http://www.mgm-controllers.com/race-boats

[RuntheraceAMC]

Actually it was two threads: one in the thread I started regarding the my first build and another in the esc section (which seemed appropriate). I have combed through the forum for ideas. I'll look into the info you shared on the sf300

[RuntheraceAMC]

update on my DFE 36 cat:

147402147403147404147405Installed my new ETTI 220a esc. Finished refining the way I set up the electronics and cooling. Added a bec for my receiver and hard wired power to my bilge pumps (one in each side of the hull and installed a fan to blow air on the esc. All powered by a 3s 1600 mah battery in the bow.

I know my water lines are a bit excessive. Two lines merge to feed the motor water jacket. 1 line splits to feed the motor mount cooling foward and aft. Two lines split to feed the four coolant tubes on the esc. A third line slits to feed two esc cooling plates installed under the cooling fan. These six lines merge to flow out the four exhaust pipes in the transom.