FINALLY, got to run my Spartan

[dag-nabit]

So, I finally got to run my Spartan a few times this past weekend. Overall things went very well, with only a few technical difficulties.

No amazing revelations, most of what I experienced has been documented already.

I was running by myself, so sorry, no videos and only a few boring pics confirming temps etc.

Most of you know my setup from following my threads the past few months, but here is a quick recap of the key modifications for those who are new here.

-Tacon 3674 1700kv motor with upgraded aluminum cooling jacket.
-T180 ESC set at 15* timing advance
-Prather S215 prop, sharpened polished and balanced
-Additional water pick up mounted on Trim Tab Adjuster
- Jeff Wohlt .150 flex cable and upgraded collet.
- MaxAmps 6500mah 3S 150C and Turnigy Nano tech 5000mah 3S 45C batteries






First run:
Water was very smooth and calm, and I started out with batteries full forward, the boat ran extremely stable but top speed according to Eagle Tree GPS was only 47kph (29 mph). I wasn't timing the runs but I'm guessing about 5-6 minutes on Maxamps 6500mah 3S batts before hitting lvc.

I had excellent water streams coming out of both outlets, so the modified rudder,and trim tab adjuster water pick up, work well.

The boat had a lot of torque roll to the right.

On subsequent runs I worked the batteries toward the stern, and also made minor adjustments to the right trim tab to try and correct for the torque roll. I also found the strut had a wee bit of negative trim, even though I thought I had it set neutral. I adjusted it slightly positive.

As I worked the batteries toward the back, the dreaded death wobble reared it's ugly head. My best recorded speed was 64.5kph (40 mph) with the batteries all the way back, but the chine walk was severe enough I wasn't able to run WOT.

I found the best running was with the batteries at the mid point. Only minimal chine walk, and still hitting 62 - 63 kph (38-39mph) at WOT with a good stable ride.

I know I can squeeze more speed out of this configuration, just need to settle down the chine walk first.

The last couple runs I pulled the liner out of the stuffing tube to see if that would help the torque roll, it didn't eliminate it, but seemed to help a bit. Hard to say for certain though, the water conditions were a bit rough on Tuesday and the boat was hopping around a fair bit.

I headed to the lake Friday and spent part of the day running the Spartans and my other boats, then headed back to town for the night. When I left for the lake again Saturday to spend the remainder of the long weekend at the cabin, I somehow managed to leave the eagle tree sitting on the table, therefore I don't have a lot of eagle tree data to evaluate yet. However temps were consistently in the mid 30 *C range (95*F) on the motor, esc and batteries, with the water temp at 10*C (50*F). Amp draw was spiking 120-140, but seemed to average around 50-60 amps.







Quirky LVC
I found the lvc on the T180 a bit quirky.

Originally had lvc set at 3.2v cut off. First two sets of batts came off showing just over 3.7v residual, but only 10-15% charge capacity remaining.

Changed the lvc setting to 3.4v for the next two runs and it was just about perfect, high side of 3.7 volts residual, and about 22-24% charge capacity remaining.

Then the next few runs the lvc (still set at 3.4v) was kicking in after only a minute or two of run time, with 75-80% charge remaining in the batts. I checked everything over thoroughly, but could find nothing that may have been causing the issue, so set the lvc back down to 3.2 volts.

The next few runs were better, but still short. Residual voltage over 3.8v with 50 -55% charge capacity left.

The last couple runs I lowered the lvc to 3.0v. The run times were OK, residual voltage was over 3.7v, and 35-40% charge remaining in the batts.

I plan on leaving the lvc at 3.0v for several runs before lowering it any further to ensure it is stabilized. (unless it starts drawing the batts too low again, in which case I will increase the lvc set point).

I was running all brand new batteries, so that may have had something to do with the erratic lvc behavior until they had a few charge cycles on them??

Next time out
I will be sure to have the Eagle Tree with me.

I will start experimenting more with tweaking the set up and will run a couple different props to see what the results are for amp draw, etc.

Overall it was fun to finally get back on the water after a long winter. The top speeds were a bit disappointing, but with a bit of tweaking and finding the right prop for this setup, I think the Spartan's will provide a lot fun for us this summer.

Kevin

PS my daughter was away on a school trip and not with me at the lake, so we didn't run her boats, but her Spartan is setup identical to mine so i suspect results will be similar.

[dag-nabit]

Here is a couple Eagle Tree graphs from the second and third run of my Spartan

3rd Run
Tacon 3674 1700kv w/ Prather S215
Batteries full rear point in tray
T180 - Timing set 15*
Water Temp 10*C (50*F)
Max Amps 122
AVG Amps 57.5
Max GPS 64.46 kph (40 mph)



2nd Run
Tacon 3674 1700kv w/ Prather S215
Batteries mid point in tray
T180 - Timing set 15*
Water Temp 10*C (50*F)
Max Amps 121
AVG Amps 58
Max GPS 62.78 kph (39 mph)



Kevin

[millzee]

Hi, maybe I should put this in the "whats the dumbest question" thread but, how do you save those eagle tree snap shot's? I was playing around with mine the other night and just didn't know how to save the graphs as pic's?

[dag-nabit]

Took me awhile to figure it out as well.

Click on "chart settings" in the lower left corner, then click on the export tab.

You can also change the pen colors and a bunch of other stuff in chart settings.

Kevin

[millzee]

thanks mate, I'll have a play around tonight

[scoota]

This might be the 2nd dumbest question , but how do you guys post those big a$$ pictures ???

[millzee]

I only just learnt this one the other night, you'll need to set up a Photobucket account, just the free one is fine. Then load the pic's you want to share and I've been opening (double left mouse click) them large in photobucket, then right mouse click on the large picture, go into properties and copy the Address (url), some sites will need the http:// and other (like ose) will already have it. Then when your typing a post you just click on the insert image icon above the message box and then paste the url.
I hope this helps.

Thank god for this spartan thread, a few of us are learning a thing or two, sorry dude, keep up the good work on your boat!!!

[scoota]

Cheers Millzee Kevin, sorry for asking these dumb questions in the middle of your thread ....

[dag-nabit]

Based on the the the thoughts/theory discussed about the drive line augering grease out of the stuffing tube, I have completed the following mod on my driveline, based in part on recommendations by George (GeoVW72).

I drilled out the back strut bushing to 1/4" diameter and approx. 4mm depth using a 1/4" drill bit and drill press.

I then made a new stuffing tube out of 1/4" K&S tubing approx. 8mm longer than the stock stuffing tube. (ballpark length, take your own measurements to be certain)

I lined it with Octura teflon liner.

The stuffing tube now fits into the rear bushing on the strut, Because drilling the bushing out with a 1/4" drill bit and drill press is hardly "precision" milling, the fit is a bit loose. (not an interference fit)

I adjusted the length of the stuffing tube a wee bit by sanding off the end until I got the correct length so the stuffing tube is "bottomed" out on the lip inside the strut bushing. This provides forward support for the strut to help hold it in place and maintain the correct negative/neutral/positive trim.

I have mine set at approx. 1mm positive trim. Minor adjustments can be made either by sliding the component tray forward or backward a mm or so, or by loosing off the stuffing tube clamp at the front of the tray and moving the stuffing tube forward or back a mm or so. (Be sure to leave clearance for the collet.

I also plugged the vent hole in the strut with silicone.

I'm hoping this might help retain grease on the flex shaft.

Hopefully can run it sometime this weekend to see if it works.





Kevin

[dag-nabit]

GLORY BE AND HALLELUIAH

Grease Left on the drive line!!

The mod I did above has helped retain grease on the drive line. It is still pushing out around the back of the strut where I did the modification, but some grease is now left on the flex shaft after 2 back to back runs.

Not sure how well it shows in the photo, but there is a decent layer of grease left on both the flex and stub shaft.



You can see the grease is still squeezing out around the end of the strut where I mated the stuffing tube into the shaft.


I may try a bit of silicone around the end of the stuffing tube before inserting it into the strut to see if a bit more of a seal will retain more grease. I'm going to wait to be certain I have the strut angle where I want it before I try this. That way there will be less chance I will be pulling things apart very often.

I gained a new respect for the Spartan today. Ran it in some very rough water and it handled admirably. Batteries mid point, strut approx 1mm positive angle and it ran very stable. It was in the air almost as much as it was in the water.

To rough to hit WOT but had a couple decent runs on an S220 prop.

Kevin

[GeoVW72]

Excellent

I see plenty of grease on that shaft, the stock ends up dry, even with the larger brass tube.
Should run great once you get some water calm enough to hit WOT, more speed, very little chine walking.

[dag-nabit]

Excellent

I see plenty of grease on that shaft, the stock ends up dry, even with the larger brass tube.
Should run great once you get some water calm enough to hit WOT, more speed, very little chine walking.

I noticed the torque roll seemed to be gone when I was running this time, and on a larger prop as well. Can't say for certain because the boat was hopping around so much, and I wasn't torquing it hard on the throttle, but it definitely seemed better.

I'm guessing the little bit of positive pitch on the strut has helped.

Hopefully will find out this weekend, heading for the cabin right chicken Louie. weather not looking great right now, but hopefully it will co-operate to get in a few runs.

Should get some video this time as well, and will be running my daughters Spartan for first time too.

Kevin

[roadrashracing]

I am trying a new idea for the grease issue, I had ordered some parts from the hobbyshop and they ordered me a stuffing tube seal even though I did not need it. WHat I did is I cut the current seal at the hull so part of the stuffing tube was showing, then I just compressed the seal as I tighted the stinger.

[dag-nabit]

I am trying a new idea for the grease issue, I had ordered some parts from the hobbyshop and they ordered me a stuffing tube seal even though I did not need it. WHat I did is I cut the current seal at the hull so part of the stuffing tube was showing, then I just compressed the seal as I tighted the stinger.

That looks like it might work.

Let us know the results. You may need to plug the vent hole in the strut if you find the flex cable is still looking dry after a run or two. I found a lot of grease stuck to the strut behind the vent hole.

[dag-nabit]

Here are a few "on the water pics" from the weekend.

We were having too much fun running to take time to do much for videos, although I did get a short one I will maybe post up later.







Kevin

[Snafujg]

Kevin, in one of your other posts, you mention the death wobble at WOT. I would suggest the double trim tab setup. It helped my boat tremendously. The only time I get the wobble now is if the water is choppy. If it's smooth, my boat sits on top of the water and glides nicely.

I think the death wobble comes from the trim tabs being so high. At high speed, the boat really gets out of the water so I think the original placement is too high. When you lower them down to the holes closer to the bottom, they seem to sit right on top of the water.

[dag-nabit]

Kevin, in one of your other posts, you mention the death wobble at WOT. I would suggest the double trim tab setup. It helped my boat tremendously. The only time I get the wobble now is if the water is choppy. If it's smooth, my boat sits on top of the water and glides nicely.

I think the death wobble comes from the trim tabs being so high. At high speed, the boat really gets out of the water so I think the original placement is too high. When you lower them down to the holes closer to the bottom, they seem to sit right on top of the water.

I have been reading the posts about moving/adding trim tabs and it is something I am considering trying.

Just trying one thing at a time, and also trying to just have some fun running our boats.

I will probably order up a couple sets of tabs to give it a try.

Kevin

[dag-nabit]

A very short video of my Spartan running. Nothing new or spectacular here, just proof it runs.

http://www.youtube.com/watch?v=WU4suaGaYE0

Kevin

[chadrob30]

Is the "vent hole" actually an oil hole? I always put a couple drops of oil in there before and after running lol....hope it's ok by doing that. Oops...

[dag-nabit]

Is the "vent hole" actually an oil hole? I always put a couple drops of oil in there before and after running lol....hope it's ok by doing that. Oops...

Perfectly fine to add a few drops of oil. Some boaters recommend adding a few drops of lightweight oil to the stuffing tube in addition to greasing the flex shaft.

I should clarify, I'm not recommending sealing off the vent hole, just suggesting it as something to try. My mod above, which includes sealing the vent hole, has resulted in having residual grease on the flex drive after a couple consecutive runs.

Kevin

[roadrashracing]

I ran my spartan today witht the new setup and it worked really well.

[dag-nabit]

I ran my spartan today witht the new setup and it worked really well.

Did you have grease residue on the drive line after a couple runs?

Kevin

[roadrashracing]

yep

[dag-nabit]

UPDATE:

So here is a bit of an update from a couple weekends ago. I have commented on some of this in other posts already but here it is....

On my last weekend off my Daughter and I had the opportunity to get in several runs with the Spartans, and our other boats. We had a blast, but it was an eventful weekend of running.

This was the first time my daughter ran her Spartan, and she was pretty excited, not more than a minute into her first run the drive cable snapped. We are running aftermarket .150 cables from Jeff, and the liners are changed out to Octura. I also modified the stuffing tubes as described above.

The cable snapped just .5 inch away from the stub shaft. not sure what caused it to fail, but fortunately the cable splayed enough to get tight in the liner and we didn't lose the prop. There was no sign of overheating and the liner was not damaged.

Slipped in the Traxxas OEM cable and we were off and running.

A few minutes later my Spartan died mid run. (of course about as far away from me as possible. I waded out to retrieve it while my daughter took great joy in trying to spray me with her rooster tail.

Turned out the negative wire on my Eagle Tree let loose. Bad solder from the factory. I thought the Eagle Tree was fried because the plastic wrap was melted and it was all black underneath. I soldered it back together a couple days ago and fortunately it seems to be still working. But we were without it for the weekend, so no data graphs for you this round.

A few runs later we had a little side swipe collision, We were coming toward each other with good room to pass by, I was at pretty much WOT and the boat took a pretty good sideways hop and I couldn't correct in time. It didn't appear to be much of a hit (sorry no video) but my turn fin caught her hull and sliced it open like a razor blade. (I had sharpened the edges on the turn fins)

The hull is cut clean through between the red marks, just as clean as if done with a razor.


I didn't have the correct glue with me for a repair, so she ran the Fightercat for a few runs.

After several more good runs I broke the drive cable in my Spartan. Running the same setup as in my daughters boat, but my cable snapped right near the collet end.

There was evidence of overheating on both the stuffing tube and flex cable with both showing discoloration. The liner was destroyed at the point the cable failed. The stuffing tube did not get hot enough to melt the plastic on the component tray.

Again I was fortunate not to lose the prop. Although the stub shaft came out far enough for the prop to contact the rudder and gouge it a bit.

This of course raises the whole chicken or egg question; which came first, did the cable start to fail, bind, over heat, and then completely fail, or; was the drive line dragging causing enough friction to overheat and cause the cable to fail?? There was no prior evidence of drive line heating, and it failed in the straight part of the stuffing tube, not at the bend.

You can see the discoloration on the stuffing in this photo


Failed cable is also discolored


Damage to liner, the pile of "stuff" is failed liner material, it would pretty much turn to powder if rolled between your fingers.


Damage to Rudder


Despite the set backs we had a ton of fun, we both like our Spartans (when they run they are a blast) and if they can hang in reliably for a couple seasons I will be OK with the coin I had to drop into them to make them work.

All the other mods are working great, good water flow from the trim tab pick up, grease residual on the flex drive after running with the longer stuffing tube, Tacon motor seems good so far, lvc on T180 seems a bit quirky but watching it to see what is happening.

Everything is repaired and ready to run this coming weekend if the weather co-operates.

Kevin

[dag-nabit]

TURN FINS STRICTLY COSMETIC??

After the collision with my daughters boat, one of the screws on my turn fin was pulled out and the threads stripped.

I took the turn fins off and took the boat for a short run. It seems to handle and turn fine without the turn fins.

I haven't run it enough to form a definitive opinion on the handling characteristics without the turn fins (especially high speed turns) but the initial indication I'm seeing is that the turn fins are ineffective on this hull and pretty much cosmetic only.

I hope to get in some good runs this weekend and will update after I have a chance to further evaluate the handling sans fins.

Kevin

[bdp1174]

Hey Kevin what type of glue do you recommend on abs plastic for hull repairs and for gluing the seam between the top and bottom hull pieces?

[dag-nabit]

Hey Kevin what type of glue do you recommend on abs plastic for hull repairs and for gluing the seam between the top and bottom hull pieces?

Most glues that work well on ABS actually fuse the parts together by chemically "dissolving" the plastic together. Most glues that work well on ABS will contain toluene or acetone, although there are a couple other chemicals used that also work.

This works well if the parts mate together well, as was the case with my repair. I just used good old Testors plastic model cement and let it dry overnight. If possible clamp the parts firmly together until the glue sets. The shape of the hull doesn't always facilitate easy clamping, On this particular repair I used a piece of lightweight mechanics wire wrapped around the hull and then just twisted the ends with pliers to tighten it enough to cinch the halves of the split tightly together.

I have seen a couple other products recommended here (I think there is a thread on it) but availability of "designer" adhesives isn't great where I live. So I went with what was readily available.

If you have a gap between the parts that require repair, then you need to source a product that has gap filling ability.

Kevin

EDIT: Here is the thread on adhesives: https://forums.offshoreelectrics.com/...ad.php?t=25560

[roadrashracing]

Have you solved your grease exit problem yet? I blocked the whole in my strut with some jb weld, I ran two packs today with that setup, no grease mess and a nice coating on the flexshaft yet.

[dag-nabit]

Have you solved your grease exit problem yet? I blocked the whole in my strut with some jb weld, I ran two packs today with that setup, no grease mess and a nice coating on the flexshaft yet.

Yes, with the extended stuffing tube, and the hole plugged in the strut, I have a decent coating of grease left on the flex shaft after two, back to back, runs.

The silicone plug came out of the hole on my daughters strut and the flex shaft on her boat was pretty much completely dry after one run.

Going to have to find a more permanent way to plug the hole.

Kevin

[dag-nabit]

Crappy weekend at the lake for running RC. Cold, wet and windy all weekend.

Only got one run in with the Spartans.

Mine was handling well with the turn fins removed, and got a quick video of my daughter running hers in rough water.

http://www.youtube.com/watch?v=jfZRhlHR2fk

Kevin