Intruder s testing !!!!!!!!!

[Brushless55]

This is odd, a club member runs one of the "salvaged" MeanMachines with a UL-1 setup and has GPS'd at 40+ mph - although I think that high 30s are more common for him. IIRC he runs an m445 with the strut bottom about 3/16" above the sponson bottoms and slightly up at the prop end, CG at around 8.5". Where is your prop depth now - use a flat table to measure. Cats usually pick up speed as you raise the strut, not lower it.

What cells, ESC and prop are you running? The SV motor has a lower Kv than the UL-1 but more torque, so a different prop may be called for.



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I am using 5250mah 30c batteries, was using the stock esc now my own creation modded water cooled 200A esc..
I don't have much for different props. I was using a 40mm (brand ?), and tried a S220..
CG was at 9", now 8.5"
Strut was at 3/16", when I lowered it I gained speed.. now set to 0"
I'm thinking I need a much bigger prop? I do have a CF48 that I ran in my SV and it worked awesome! I will try a pass with this next..

[Fluid]

Yes, not enough prop is at least part of the problem. The 40mm prop explains the speed gains by lowering the prop - not enough blade area. Try at least a 45mm diameter prop, the K48 may work better but check temps carefully.



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[Brushless55]

The S220 is just under 44mm.. I may order a few more CF props because there so cheap..
I think the smaller props is giving me the issues with the lower KV motor..
I will keep a check on temps when I toss my MM with the CF 48..
maybe I could try my UL-1 motor?

[Fluid]

Personally I believe that the UL-1 motor has a higher Kv than optimum for this hull. I think the SV or BJ motors will be better, with good speeds and lower temps swinging larger props for this 'big' hull.

Part of your speed issue may be trimming. This cat needs to run on the back 4"-6" of the sponsons to run fast with a low amp draw.


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[Brushless55]

Personally I believe that the UL-1 motor has a higher Kv than optimum for this hull. I think the SV or BJ motors will be better, with good speeds and lower temps swinging larger props for this 'big' hull.

Part of your speed issue may be trimming. This cat needs to run on the back 4"-6" of the sponsons to run fast with a low amp draw.


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That's where she runs...
just like what you posted earlier..

[ozzie-crawl]

"qoute" What cells, ESC and prop are you running? The SV motor has a lower Kv than the UL-1 but more torque, so a different prop may be called for. "fluid
ul-1 motor is a 6 pole motor so even tho its a higher kv motor should have more torque than the sv motor ?

[Brushless55]

I am using 5250mah 30c batteries, was using the stock esc now my own creation modded water cooled 200A esc..
I don't have much for different props. I was using a 40mm (brand ?), and tried a S220..
CG was at 9", now 8.5"
Strut was at 3/16", when I lowered it I gained speed.. now set to 0"
I'm thinking I need a much bigger prop? I do have a CF48 that I ran in my SV and it worked awesome! I will try a pass with this next..

from earlier

[Fluid]

ul-1 motor is a 6 pole motor so even tho its a higher kv motor should have more torque than the sv motor ?

Both are 6-pole motors. The UL-1 was designed and is made at a different plant to be able to meet the demands of higher production. The SV (and the BJ too) motor has significantly more torque than the UL-1 motor, but less rpm. Both deliver about the same amount of "power" but have to be proped differently. Don't believe me? Then buy both and see for yourself.




.

[ozzie-crawl]

if you read it my post was a question, i was under the impression the sv motor was a 4 pole and the ul-1 motor is made by ammo not aquacraft

[sailr]

Impressive running boat! Gives me some ideas for a "spec" cat I'm going to put together soon.

Thanks!

[bigpapa]

kinda suprised me too i expected low 50's now it's tweaking time that was first pass cog was too far back gonna add 1oz to each sponson in front...... move batteries 1" foreward a see

[sailr]

Yep, you get her flattened out and the speed will be awesome! But if she keeps 'flyin' you may have to install an 'airspeed indicator'. Haha.

[bigpapa]

i here u my friend tks

[Darin Jordan]

Both deliver about the same amount of "power" but have to be proped differently. Don't believe me? Then buy both and see for yourself.

I believe you, Jay! And I have test bench data to prove what you are saying!

[bigpapa]

well darin you thoughts ???????