Miss Elam 1/12 Brushless Run reports

[barmonkey]

Hello all...just wondering if there are any run reports for this boat....

[AndyKunz]

There will be after tomorrow (weather permitting). Darin was planning on running his race-prepped one during at their event Saturday.

Andy

[JimClark]

And I will be there to take pictures as long as he run's it after 12:00PM

[Ub Hauled]

And I will be there to take pictures as long as he run's it after 12:00PM

Sleepy head!!!

[JimClark]

Well kind of but I have to drop my wife off at a birthday party for a friend that is 10 miles away from the race otherwise I would be there earlier but i do work nights also.

Jim

[Ub Hauled]

Just kidding Jim!
I am sure that you have reason not to do it...

[barmonkey]

Good to hear...I've been following his "Race Prep" thread...unfortunately much of what he has done is beyond my capability and understanding.

I will definitely cover that big hole at the back of the cowl and add some flotation.

[Darin Jordan]

I have the Elam setup with my EagleTree, and I took the time to also setup the airspeed sensor, so I should be able to get some reasonably accurate speeds around the course as well... I'll let you know how it turns out....

[JimClark]

WooHoo looking forward to tomorrow. Now if the rain will just hold off

[Doby]

What, is Darin afraid the boat will get wet??

[AndyKunz]

Actually, he has a real good reason NOT to risk getting sick this weekend.

Andy

[Darin Jordan]

See my Elam prep thread for an explanation as to why I didn't make the race... Basically, my car broke down on the way up there and after having it towed home, I spend the afternoon fixing it... Needless to say... I was a little bummed... Happy to be warm and dry though...

[Darin Jordan]

Ran my first race weekend with the Elam this past Saturday (April 11th)... Won all three heats and the overall for the day.

I also used the ProBoat BJ26 motor and ESC in my P-Spec OPC Tunnel and won that class as well. Ran the ProBoat BJ26 motor with an B125 ESC in my 1/10th scale and won that class too...

According to my data recorder, I hit 50mph in the first heat with an average for the race of around 40mph... similiar data for the second and third heats as well, with slightly lower max speeds in the 47-48mph range. Props used were X645 (uncut), X646 (detounged and cupped), and something that started life as a Y547, but is now only 42mm or so and has severely spoon shaped blades... Handling really improved with this prop.

I had a sponson walk issue all day, but only when the boat is disturbed laterally, as when you encounter another wake... After trying several props and making some adjustments, I'm almost convinced it's the curved turn fin causing lift. I'm going to make a straight turn fin to try next time out and see if that helps... I couldn't stay in the thottle past the 2/3rds lenght of the straight because of this hop. There is definately more speed there to be had. Cornering was AWESOME.

Ran the boat with the wing as well... Maybe there is something to be gained by removing it. I may try next time out.

I had video, but my camcorder has failed and actually had parts falling out of it when I got home, so I'm can't play the tape back to see if it actually recorded anything.

I do, however, have all the data from the Eagle tree, with I'll post as soon as I can get it transfered to postable images.

Average amps for a heat were right at 55 for the first two heats, and dropped to 48 for the final heat. Peaks/Spikes were hitting near 100amps.... RPMs ranged from 17,000 to 24,000 or so (off the top of my head)... with averages around 19,000... Temps were all pretty cool, but I have a temp probe on the motor and batteries, so I'll post the actuals of that as well.

Overall, I'm very please and think this boat has a shot. It's definately competitive, but we'll see how it does when run against a whole mess of UL1s. I think the Elam behaves better, but we'll see if that's enough to overcome the hotter UL1 motor setup.

[Ub Hauled]

That's great news Darin, thanks for the post.
Did she take the higher speeds well or was she loose? How about in the chop nice handling?
Could you tell me a bit about that?

[Darin Jordan]

Jan,

I'm going to hold a complete opinion of that until I try a different turn fin. In the straights, the boat was good until it encountered a wake or ??? It is my opinion at this point, having made the adjustments I've made, that the curved turn-find was causing it to lift and pitch, generating a sponson walk. When the water was just choppy, it seemed rock stable by the third heat, and it all cases, it cornered GREAT... No issues there that I could tell. I just think that the turn fin needs some attention.

I'm very optimistic at this point, but more time and development obviously needs to occur before one can say anything definitively.

There was another UL1 there, and some other fast boats, but Brian Buaas and Larry Kirby weren't there, and Greg Schweers wasn't running that day, and they are the big-dogs in our club for LSH. The real test will come once we have a full complement of competitors. The data, however, looks promising.

[Ub Hauled]

execellent... point made... will wait for full report,

[Darin Jordan]

Here are some Eagle Tree graphs, showing RPMs, Amps, and Airspeed. These should represent the three race heats, plus a test session I did immediately after the third heat... on the same, un-recharged batteries, so it's a little slower... I trimmed out the runup to the start and the drive in, and just focused on the laps themselves.

Can someone tell me how to adjust the colors of the lines? I couldn't seem to figure it out this morning, though I couldn't spend much time trying...

I'm certain that there is MORE there to be had... I never could really run full throttle, and once I get out front, I tend to ease up a bit and follow Dick Crowe's advice... "Only drive as fast as you HAVE to"... Once I get things more dialed, I'll give it an all out 2-lap effort and see what it's really capable of...

[Ub Hauled]

I tend to ease up a bit and follow Dick Crowe's advice... "Only drive as fast as you HAVE to"...

Won't that generate too much heat on the ESC?

I am trying to remember how I changed colors on mine, I'll get back to ya on this (if someone doesn't be me to it) and post the info.

[AndyKunz]

I think it's a reference to not "trying to set a world record," blowing off in the process, more than as a way to preserve electronics. It's very sound advice.

Andy

[barmonkey]

Darin, I was looking at your data and it looks like you are pulling up to 100 Amps. Did you change your connectors...or did you retain the Deans plugs?

[Darin Jordan]

Darin, I was looking at your data and it looks like you are pulling up to 100 Amps. Did you change your connectors...or did you retain the Deans plugs?

I don't do Dean's anymore... All of my batteries use 6mm, and all of my motor connections of the spec boats use 4mm. All of my other motors use 5.5mm on the motor side.

[Darin Jordan]

Another Race, Another perfect day for the Miss Elam!!

I tweaked and adjusted and tweaked some more, and I still couldn't get the sponson walking out of this thing... I could only run about 1/2 throttle most of the race because as the boat approached top speeds... it would try to climb off the water.

So, after confirming that the turn-fin was perfectly aligned (it was not), and moving the strut down about as deep as I dare... and having none of it really make the situation more drivable... I taped 6oz of lead to the forward cannard wing.

BINGO! I was able to run 4-test laps, around a 1/6th mile course, at full throttle without even thinking of lifting...

The CG, it turns out, was over 3" aft of the sponsons... With the lead on the front, the CG moved forward to around 2" or so... I'll get a more accurate measurement when I get the boat on the bench. The end result, however, was that it simply didn't have enough weight on the nose...

I'm going to play with it some more, but it seems like I'm on the right track. Once I get this part settled down, I'll get back to figuring out which props really work well...

Even with all the issues... I was able to get out front and stay there against a variety of other boats in the class. We had two flights of boats... I think 9 or 10 in all... and I was able to secure high-points for the day with three heat wins!

And... the boat sure looks good doing it!

More to come... Sorry, no pictures today. Too busy tweaking and tuning...

[Camman]

Great thread Darin
Thanks for posting

I have a Gen I ProBoat Miss Bud I sure am thinking of converting



Mike

[Jeff Wohlt]

Congrats...3" aft? Sheez....that is way back. Cells can't be moved enough?

Did you not do a finger test of the CG earlier on?

[Darin Jordan]

Congrats...3" aft? Sheez....that is way back. Cells can't be moved enough?

Did you not do a finger test of the CG earlier on?

NO... there is NO WAY the cells are moving ANYWHERE !! Forward OR AFT! As you can see from the picture... there is JUST enough room to even fit two 4500 2S packs in there alongside the motor...

I DID do a CG test... but with no way to change it... I just ran it to see what would happen...

NOW I know!

Now I just need to figure out a clean and nice looking way to add 6 to 8oz of lead to the nose... As much as people are all hung-up on weight... the extra weight is making the boat FASTER!!

[Jeff Wohlt]

Throw some steel BBs in a sealed bag of shrink wrap and slide it up there with some epxoy on the bottom. Maybe 2 ounce on one side and 4 oz on the fin side? Or what ever the weight is a light amount to the right may also help cornering.

Bummer not to be able to move cells but that is an easy fix with weight.

Sounds like you are the one to beat up there!