Revell Type VII Build advice

[Avera]

Too bad there is not a knuckle (universal joint) type of coupler with a built in dog-bone that can be lengthen or shorten depending on application. I am sure these exist in the RC Boat world, just need to find them.

[He Who Shall Not Be Named]

I know I am getting close, but I have another question regarding the dog-bone couplers. Do you guys attach one end of the couplers to either the shaft or the motor couplers? If so with what?

Trying to install the SD while aligning the two dog-bones into both couplers at the same time is hard. One or the other dog-bones drops; I don't have enough hands. I was thinking that the dog-bones could somehow be already attached or held in place by one of the couplers (the motor coupler preferably) with some sort of light or sticky adhensive as they are loosely held in the couplers and fall out. Then all I would have to do as I slide in the SD is rotate the props by hand to align it.

You are on the money: I glue the dog-bone to the propeller end of the running gear with RTV. It hold the dog bone, but gives enough to accommodate the off-center turning when made up to the SD.

I have employed spring-loaded dog-bone as well.

[Scott T]

Here is something to try: take a rubber band and put it over the shaft and place the dog bone
in it as you spread the shaft from the dogbone twist the rubber band.
You probably will want to remove it before running though. Scissors or a sharp knife.

Or mister D can invent some klik-on style dogbones!


Scott T

[Avera]

I know I am getting close, but I have another question regarding the dog-bone couplers. Do you guys attach one end of the couplers to either the shaft or the motor couplers? If so with what?

Trying to install the SD while aligning the two dog-bones into both couplers at the same time is hard. One or the other dog-bones drops; I don't have enough hands. I was thinking that the dog-bones could somehow be already attached or held in place by one of the couplers (the motor coupler preferably) with some sort of light or sticky adhensive as they are loosely held in the couplers and fall out. Then all I would have to do as I slide in the SD is rotate the props by hand to align it.

[He Who Shall Not Be Named]

Does anyone know what is the minimum voltage to run the motors? I was thinking of adding a series of resistors to reduce the voltage going to the motors to a minimum level maybe as little a 3 volts. Just thinking out loud.

I have the 6 channel WFly transmitter and not sure if I can dial down have a throttle mix.

Easy enough to set the end-points with a dumb-ass transmitter. But, you'll do it at the ESC. During MTronik's ESC set-up, only move the throttle stick up and down a bit when setting up the ESC's responce logic. Go to MTronik's site to get details on the process.

Don't put a series resistor in series between the ESC and the motors -- what a waste of energy!

You people!

David

[Avera]

Does anyone know what is the minimum voltage to run the motors? I was thinking of adding a series of resistors to reduce the voltage going to the motors to a minimum level maybe as little a 3 volts. Just thinking out loud.

I have the 6 channel WFly transmitter and not sure if I can dial down have a throttle mix.

[H2Ohaze]

On my Holland, the motor is also too fast for good operation. I use a Futaba 9C to control it now, so I don't know if the WFLY can be made to mix throttle to throttle, but I have three mixes set this way : master and slave are both throttle. I use one 3 pos and one 2 pos switch.

This gives me six different throttle behaviors:
1) Full speed ahead and reverse as originally set up on the Viper 10 ESC.
2) Full lockout; prop will not spin in either direction no matter what position stick is bumped to. Great for panic cutting power to prop suddenly to locate a lost sub with slight + buoyancy.
3) Very slow RPM forward cruise control constant speed, regardless of stick position.
4) Throttle stick speed goes from zero to moderate forward only, no reverse. Stick pos 0 to 100%
5) Throttle stick speed from moderate reverse to moderate forward, with zero at 50% (middle).
6) A version of #1, with a little less forward power.

I also have a switch that mixes channel 4 to itself. This locks out my ballast pump. On the VIIC, it would prevent accidental vent or blow.

I've only been experimenting with this setup recently, but I think I like it. The switches are on right, so I can adjust throttle with left hand as switch state changes. I use #4 85 % of the time.

[He Who Shall Not Be Named]

Hi David,

The waterline on this sub is just above the saddle tanks below the upper vents along the side. Is that correct? My initial trimming (using the rubber bands) had the bow higher than the stern, almost too high. I have already added some foam to the inside where the ballast tanks are with some more towards the bow and stern. I will check this out and add more foam using the rubber bands to see where I need adjustments.

As for the trim with the ballast air removed, the sub should lie in the water with just the upper part (I guess about where the upper gun is mounted) of the conning tower sticking out?

Andrew

One other thing, those motors are very strong, I accidently tap the throttle while it was in the tub, and the sub nearly popped a wheely, like a speed boat taking off from dead stop. Granted I was not controlling any of the planes and the ADF was not functional at the time, but the two motor throw out a lot of trust.

The black/gray demarcation line at the bow and stern IS the surface trim waterline. Shoot for that.

Submerged trim puts about 1/4 - 1/2" of the top of the fairwater above water. Works for me.

You bet they are. At the transmitter: dial your ch-3 end-points down to 30% ahead and 30% astern.

[Avera]

Hi David,

The waterline on this sub is just above the saddle tanks below the upper vents along the side. Is that correct? My initial trimming (using the rubber bands) had the bow higher than the stern, almost too high. I have already added some foam to the inside where the ballast tanks are with some more towards the bow and stern. I will check this out and add more foam using the rubber bands to see where I need adjustments.

As for the trim with the ballast air removed, the sub should lie in the water with just the upper part (I guess about where the upper gun is mounted) of the conning tower sticking out?

Andrew

One other thing, those motors are very strong, I accidently tap the throttle while it was in the tub, and the sub nearly popped a wheely, like a speed boat taking off from dead stop. Granted I was not controlling any of the planes and the ADF was not functional at the time, but the two motor throw out a lot of trust.

[He Who Shall Not Be Named]

You got it right, Andrew.


Tom, you got it backwards .... get some sleep, pal!

Andrew: Rubber band the foam to the outside of the hull during initial trimming tasks -- shifting form inboard and permanently affixed in place with RTV adhesive once amount and position are determined.

Yes, the object of the game is to put as much weight low in the hull as you can counter with foam placed up high, but no higher than the designed waterline.

And your suggesting to make it clear which planes to put the ADF on is a good one -- I assumed everyone would know it's the stern planes ... and you know what they say about the word, ASSUME!


Use of an angle-keeper places control of the boats pitch in the 'even keel' (Simon Lake) mode of ship control. The angle-keeper cares not a bit what the boats depth is, it's oblivious of it. The angle-keeper only works to keep the moving submarine on or near a zero bubble angle through stern plane deflection.

David

[trout]

It has been a long day, but something seems wrong. If you lift the aft end of the wtc the stern planes should go down ( to counter the upward motion) and conversely if the aft end is lowered the stern planes should take an up attitude. If it doesn't do this then the ADF will not keep the sub level. Are we saying the same thing differently?

[Avera]

Thanks to Trout and David, I finally got the SD working as it should (it would help if the Setup Mode instructions for the ADF specified the planes you want the ADF to control vs the planes you actually control). For one last remark, the way I have setup the ADF, as I pitch the sub into a dive, the rear plane operate to level the sub so that the sub dives in a level fashion; Lake method. The same in surfacing, as I tilt the SD up simulating a a surface command on the bow planes the rear planes points downward rising the stern. If this is correct I should be set to begin trimming in the tub this weekend. I have already added some foam, although probably not enough. Is it better to add more foam to create a greater difference between the CG and the CB or reduce the weight in the keel basically achieving the same difference but with a lighter sub? The lead shot is held in place by the silicone adhesive remove I can easily remove.

Andrew

[Avera]

Life throws us all types of ironies and each episode needs to be taken in its own context (like the expression walk a mile in one's shoe before you judge).

When I was much younger, I had enrolled to enter in OCS to hopefully become a submariner, took all the Navy tests and just had to complete my college. I screwed up with my school grants and did not finish college until years later. Perhaps an opportunity lost. Today I could have been captain of my own boat, but that is not how it worked out. Although I did get my Coast Guard Captain's license (6 pack) and retired as captain from law enforcement

Anyone who fought in earnest for my freedom has my utmost respect and admiration with a special fondness for those from WWII. Men and women from that era have a character that is absent on today's generations (integrity, resolve, honor and humility to name a few). Sorry to get off topic but your dad deserves a thankyou from me.

[Kazzer]

Quite a few years back I was at the Pearl Harbor exhibit in Oahu. . I had the honor and thrill of meeting two WWII submariners (one American and the other German) at the same time while reading over the exhibit. For the few minutes I had, they enlighten me with small war story bits and fear of depth charges. It was an amazing experience to have both sides standing next to each other at peace sharing a common bond and telling their tales.

I know how you felt. I met quite a few of these WWII guys. I lived with one of them. I lived with his submariner friends and comrades.

I heard about the depth charges, I heard how the Jap planes strafed his boat. I saw the fear and I saw the resolve in his eyes. This man hated the Japs until the day he died. He was at the surrender of the Japs to the British at Singapore. He saw the way his countrymen were treated, and he experienced the relief that the hell was - at last - over.

I grew up with this, and it took a toll on us all. This man was my dad!

And you know what really ****es me off! That some (a few) think I know nothing about submarines!

[H2Ohaze]

I'm not a Navy guy, just a mechanical wannabe. But here is a load of stuff on subs, more than you need. Look at figure 7 esp to see bow and stern planes in action:

http://www.heiszwolf.com/subs/tech/tech01.html

Having a Holland sub model, I'm biased toward Mr Holland. Simon Lake put wheels on his submarines, and as time went on, merely made them retractable.Scuba Diving