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View Full Version : TFL P1 Outdrive Scale build Part Two...



virnoche
07-29-2015, 07:48 PM
Lets begin with some general information on how the build looked with this thread....
http://forums.offshoreelectrics.com/showthread.php?52244-The-TFL-Scale-Build-has-begun

As you can see the boat itself went together very easy and actually looks quite nice! I'de say its a near perfect scale 30' Fountain with a Mercury NXT drive hanging off the back! No paint yet as of yet and my son is going to end up finishing this one. I'm guessing it will be colorful!

Lets go over the details of the P1 drive first and cover the first impressions from un-packaging. This drive is built very nice. The machining and the finish work on the parts is outstanding! After measuring this and comparing it to the real thing It is real close to 1/10 scale.
The engineering on how it is built is also quite notable. I have had the Graupner Z-Drive and quite frankly those aren't even in the same category as these TFL's. The way it mounts to the hull, and the easy ability to disassemble in the field is a big PLUS for this drive. In a matter of minutes you can have the drive apart with the mounts still in place. All of the important grub screws for the dog bone couplers are easily accessible for tightening should they loosen up.

Out of the box the unit was greased and probably ready to run, but I am stickler for blue Loctite on all threads on things that move. I took the entire drive apart and loctited with 242 all the grubs and the bolts that hold it all together. This was literally just a 5 minute job.

After this process I noted a few things that I had concerns about.
1) Gasket between the upper and lower halves is THIN
2) The seal between the drive and motor is not the proper length for this drive.
3) The screws that mount the drive to the gimbal ring are awful short
4) The Bolt to tighten the drive angle isn't possible to get a socket on the nut unless you adjust the drive all the way up

Ok...so on to the water! The firs time out I had real problems with the grub screws not staying put. After 4 trips home/water I ended up stopping at the local hardware store and picking up some new ones. I don't know if the factory aren't cut right or what, but the new grub screws seemed to hold ok....more on that after water part two. Over all the first time other than the grub screws was awesome! I GPS's it right at 25-26 m/p/h. this was a little faster than my target but that can be adjusted in the controller.
The next day was the durability test day. I had three sets of batteries charged and ready. I am using 3S 6400 mah in parallel for run #1, then 3S 5000 mah for run #2, then 2S 5400 mah for run #3. My target was to get an hour for #1, 45 minutes for #2 and 3. As it turned out I was about 45 minutes for #1, then 35 minutes for #2 and 40 minutes for #3. This is a LONG time to run any RC craft! I was actually getting bored! LOL!
After 10-15 minutes I was stopping and checking temperatures of the electronics and pumping a little grease into the very convenient ports for lubrication. After almost two hours of pretty much non-stop running the boat was put away until the following night when I planned on taking it apart to check things over.

Video of one of the runs....
https://youtu.be/XODREQu8BIA


The first thing I noticed is that somewhere along the line in the third run I lost the bottom mounting screw that holds the drive to the gimbal ring. I had already replaced the top screw with a longer one because after the first run I noticed that it was stripped due to being too short. I left the bottom one alone for this reason....to see if it would last. It didn't.
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Opening up the drive I noticed that the middle bevel gears were pretty shiny and the grub screw on the middle gear had loosened AGAIN! This gear being captive by its design allowed it to run because the grub stayed on the flat spot and the gear was able to just jump up and down.
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At this point I noticed that the gasket was very wet and fragile and no matter how careful I was It ripped.
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Accessing the bottom half of the lower unit turned out to be QUITE a challenge. The grub screw that holds the barrel in place that holds the final drive shaft was STUCK! and I mean STUCK! I thought I had it free when I started to try removing the barrel...as it turned out it wasn't free and I goobered up the flats.
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after a few hours of trying heat.....then acetone I finally got the grub screw out!!! what a pain in the arse! I don't know what held that in there so tight but the next issue might have something to do with it.

Here is what is left of the outer flanged bearing on the lower unit! The water was 75 degrees and very clear spring fed lake. I can't contribute the failure to dirty water or heat because I was checking that. I'm going to just say it was fluke bad bearing. The inside one was actually ok. I have these in stock from other RC projects so its replacement was easy and painless.

I ran out of picture space so watch for TFL build Part 3! more pictures and explanations.
http://forums.offshoreelectrics.com/showthread.php?52382-TFL-P1-Outdrive-Scale-build-Part-Three