Albacore continued

[Slats]

I have been able to locate some super motors that I want to try. They are 550 ,12 volt motors that are supposed to have 70 inch pounds stall torque. WOW! They have a 1/8" shaft , but its only .3 inches long. Out of the question for the older 3.5" motor bulkhead, with external gerboxes. But I think it will work for Daves newer style 3.5" motor bulkhead with internal Gearboxes. Some green sleeve retainer will hold the small drive gears on those short shafts, Im sure. Ill order them tomorrow and when they get here Ill test them. If I like them, Ill order more.

Just wondering why you'd want the extra grunt? Torque I find is everything with subs and the geared motors we run I find are not lacking in operating speed or efficiency (run time). Also are you considering a 3.5" SD for your Albacore? I am thinking if you up diameter beyond the 3" SD you might find that the SD is above the WL which means ballast issues and stability issues. The 3" and 2.5" SD are a better bet in MHO.

J

[greenman407]

John, thanks for the feedback. As you can probably tell, with my many Hobbies, Im always trying to push the envelope. The duo prop Albacore has two huge propellers, that are being driven by two Anemic Speed 400 motors. By going to 550 motors, they will spin up higher for sure. With the counter-rotation of those very same props, its just begging for this Mod.
As far as the 3.5" cyl., Im going to do the same thing that I did with the Seaview, Increase the size of the Subdriver to 3.5" in the motor compartment only, leaving the rest at 3". If theres an increase in buoyancy it will be in the area of the motor compartment and a little bit of weight at that point will take care of that.
In my book, its better to have too much power, you can regulate that. But if you dont have enough...................then , well then .......you dont have enough.
The motors that we all get from Mike and Dave are just fine for your Average............Sane.........Submarine Drivers out there. I just want to see how much more I can get out of her. Shes Scary fast to be sure now, but after a while......your not scared anymore.

[Subculture]

The 550's will no doubt do their work easy, but are the 400's working hard?

To illustrate my point, a while aback I was donated a pair of 6 volt engel tanks. These have 540 size motors, which tend to be a little on the thirsty side. I took some readings, 12 watts free running, ramping up to about 24 watts when pushing against about 1 atmosphere, not too shabby, but probably not as efficient as they could be.

I replaced the motors with some 12 volt 385's. These gave the same speed as the 500's, yet ran at about 6 watts unloaded- so half the power used, but same level of performance. they also weigh considerably less, and take up less space.

Sometimes more isn't better.

[greenman407]

Good point in your specific application. My work with the Seaview and the Albacore over the last 8 years as a history base and the recent improvement in the performance output of the Seaviews mods. convinces me that in these cases, there is room for more Torque(twisting power). The increase netted by swapping over from Speed 400s to 540s is on the order of increase x 5. When the motors arrive I will test there output and post it here. For these two submarines, power is the most important consideration, power usage is secondary.

[greenman407]

Andy, In your situation, if I understand you correctly, is that the 540s were running on 6 volts and your 385s were running on 12 volts. It seems to me that the switch from 6 volts to 12 volts is what netted your increase. Correct me If I am jumping to conclusions.

[Subculture]

Not really the case. It's difficult to find good quality low RPM motors wound for lower voltages.

Going to higher voltage tends to mean thinner cables, as you're pulling less current for equivalent power and it's easier on the batteries (barely an issue with lipo's though).

[greenman407]

As good as my word. Just got these yesterday. Using my volt/ohm meter, set on DC amps, I got .25 amps no load on the 12 volt Caswell motors, so we will use that as a bench mark. The new motors pull .45 amps no load. To test torque output I used a very precise and ingenious method. I put on a leather work glove and tryed to stop the spinning motor shaft. On the Caswell motor, I was surprised at how strong it was. But I was able to stop its rotation by squeezing between gloved thumb and forefinger, running at full RPM on a 3 cell Lipo. The new motor, however there was no stopping it. I was able to slow it down somewhat, but I could not stop it.
So, there you have it Folks.....a very precise and reliable way to test your motors. Did I mention that I charge for this service???
At any rate , I plan on putting two of these motors in the Duo-prop, X tail Albacore when I redo the WTC. Also Im going to stick one in the 1/72 Revell/Caswell/Merriman Skipjack. Yep, I plan on adding more ballast weight and upper end foam to try to help keep it from becoming a High Speed Drill Bit. Bonapetit. Oh, did I mention that the new motors are fan cooled. I dont know if thats good or bad inside a confined space like a Subdriver. In the pictures , the New motor is on the left.

[He Who Shall Not Be Named]

The fan in a closed space won't change the net pressure within. Local pressure changes yes; but the differential within will be zero. You're good.

However, Charles Law says not to raise the temperature in there too much or you will pop a bulkhead off.

YOU NUT!!!!!

What are you ... some kind of dynamometer?

M

[greenman407]

Yep, thats what makes a hot air balloon rise, Hot Air. But, so far, apparently the small quantity of air in the Subdriver motor compartment hasnt been enough to do that. That coupled with the motors reaching a relatively low temperature of 140 degrees. Ive melted down two Speed 400s in there before and no blowing off of the endcap. So hopefully that wont happen.

[greenman407]

IT IS DONE! Installed. Dave, what do you use to affix the brass gears to the motor shaft? OMG!!! I heated them for 45 seconds with a propane torch and still couldnt getem to come loose. I had to cut the motor shaft and drive the shaft out of the gear with a pin punch. Green Sleeve retainer was used to re install the gear on the new motors. Now Ill have to get some 3&1/2" lexan tube on the way. Oh yes, I had to remove the field sleeves off the outside of the new motors to get enough clearance to get them to fit inside the Lexan without hitting.

[He Who Shall Not Be Named]

Mark, you are one determined SOB, aren't you!? You just keep punching till you get where you're going. I like that.

I trill the pinion bores to be a very tight interference fit to the motor drive shaft and hammer them down onto the shafts.

M

[Subculture]

I use a puller to remove press-fit pinions. They usually come off without much fuss, although steel hardened gears can be a swine, and I sometimes have to file them down a bit to get them loose (in an instance where it's the motor I'm trying to salvage).

[greenman407]

LOOKY, LOOKY!!! LOOK WHAT JUST ARRIVED FROM "THE CAVE"!! Once again Dave Merriman has come through with a work of art! We all saw how Dave posted about his new Albacore hull and sail with the built in rudder. I dropped a few well timed "hints" about wanting to retrofit one on my Phase IV X-tail. Well it seems to have worked because I am now the proud owner of one of those sails. Im sorry about the photography as these pictures do not do it justice. Its beautiful!
Im going to start work right away on it as the top has to be CAed on and the seam filled. Ive decided not to put a periscope on this sail or to open up the cockpit area to eliminate the resulting drag. And now..........BEHOLD!

[He Who Shall Not Be Named]

LOOKY, LOOKY!!! LOOK WHAT JUST ARRIVED FROM "THE CAVE"!! Once again Dave Merriman has come through with a work of art! We all saw how Dave posted about his new Albacore hull and sail with the built in rudder. I dropped a few well timed "hints" about wanting to retrofit one on my Phase IV X-tail. Well it seems to have worked because I am now the proud owner of one of those sails. Im sorry about the photography as these pictures do not do it justice. Its beautiful!
Im going to start work right away on it as the top has to be CAed on and the seam filled. Ive decided not to put a periscope on this sail or to open up the cockpit area to eliminate the resulting drag. And now..........BEHOLD!
[ATTACH=CONFIG]29534[/ATTACH][ATTACH=CONFIG]29535[/ATTACH][ATTACH=CONFIG]29536[/ATTACH]

The end-game (have not yet painted the 'clear' parts)

[greenman407]

I LIKE IT! However.....it would look better if it were on my sub.