PIP Bittburger (Re) Build

[Rumdog]

Hmm. That's odd. Could be the servo, or flimsy linkage.

[marko500]

Keith, I've been running the same Bittburger cat hull for about 3 yrs now. My setup is 10XL, 2-2s 5000mh batteries, Castle120 esc, x648 prop. I run my batteries all the way to the rear on the floor of the sponsons. These hulls had a reputation for not cornering well and wanting to roll if turned sharp at full speed. I run a very deep rudder and it helps some in the corners, but makes steering very touchy. I found that my boat does not like props with too much lift. You're right this boat loves to go fast in a straight line. I'm running at right around 50 or a touch under. I love this boat and really enjoy running her. Any questions let me know.

Mark

[keithbradley]

Keith, I've been running the same Bittburger cat hull for about 3 yrs now. My setup is 10XL, 2-2s 5000mh batteries, Castle120 esc, x648 prop. I run my batteries all the way to the rear on the floor of the sponsons. These hulls had a reputation for not cornering well and wanting to roll if turned sharp at full speed. I run a very deep rudder and it helps some in the corners, but makes steering very touchy. I found that my boat does not like props with too much lift. You're right this boat loves to go fast in a straight line. I'm running at right around 50 or a touch under. I love this boat and really enjoy running her. Any questions let me know.

Mark

Thanks Mark. Your comment about rolling in the turns at full throttle has me thinking. My boat does porpoise at low speeds, but flattens out when you get her going. So far I havent had the guts to take a turn at any reasonable speed at all, let alone full tilt. I'm cornering at maybe 10-20mph tops (either speed does the same thing. you cant go slow enough to not hop and stay on plane). Im wondering if I corner faster (not full out, but maybe like 30-35mph) if it will stop bouncing At the lower speeds when I turn it is already porpoising, then turning it just lets the back end start hopping with everything else...I havent had the guts to yet because this is such a nice looking boat, not to mention I have had 2 seperate hatch-losing incidents with other boats this year and there isnt much to the hatch on these.

[marko500]

Same thing here. She hops at low speed and I'm not brave enought to try a tight turn at full speed. Large sweeping turns at mid speeds seem to be ok, but as I said I have not tried it full speed. Not much of a racing course boat, but they make one heck of a dragster! Some of my twitchy steering I have been able to dial out using the steering expo on my radio. It was had finding anyone with experience with this hull, I was told that not many were imported to the US. I was also told this hull was the forerunner to the Jollysport cat which was made wider to correct some of the cornering problems.

Mark

[marko500]

I also run my esc on the left side of the boat to help offset some of the torque. My strut and rudder are an inline setup.

Mark

[keithbradley]

Got some video today. 6s2p (8000mah total) prather s225 prop. I thought it was crazy fast, but was unimpressed when I watched the video. Sometimes it just turns out that way.

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

[marko500]

I'm impressed. Looks pretty fast to me.

Mark

[keithbradley]

Ripped out the old motor mount setup, and the "S" bent stufing tube. I upgraded the flex from .150 to .187 and the stuffing tube is straight except for one soft bend under the boat. I moved the new motor mounts forward a bit to accomplish this. There is plenty of room to play with pack positioning to get the COG anywhere within reason so I had the freedom to do some repositioning.
Motor is a castle 1520-1y (1600kv). It will be ran on 6s2p, and depending on the amp draw, I might try some short runs on 7s2p. The motor mount sides are just bent aluminum I made up on my lunchbreak at work, and the front and rear parts of the mount are for a Leopard 4074 mount. The castle 15 series are the same diameter without the fins, so I just put this motor in the lathe and took off the rear-most two fins and the mount fits on there perfectly. I didnt have the jacket on in this pic because I didnt want to keep removing it during mock up and tear the o-rings, but it does fit perfectly between the front and rear mounts.

[LarrysDrifter]

Keith,where did you find a Leopard 4082 in a 1600kv?I put a 4082 in my Drifter on 6s and went 62mph.Temps were not even warm.Prop was an X445.Id like to find a 4082 Leopard 1700kv if its made.Was seeing if you know who has a 1700kv since I havent seen an 82 in a 1600kv.

[keithbradley]

I don't know of a 1700kv...I got the 1600kv from Kershaw designs but that was only because OSE did not stock them at the time.
If you are willing to go down to 1600kv, the castle 1520-1y would be great, or the 1518-1y is 1800kv. Both run great and are a bit more powerful than the 4082.

[tiqueman]

Looks good Keith. Cant wait to see her run.

[LarrysDrifter]

I don't know of a 1700kv...I got the 1600kv from Kershaw designs but that was only because OSE did not stock them at the time.
If you are willing to go down to 1600kv, the castle 1520-1y would be great, or the 1518-1y is 1800kv. Both run great and are a bit more powerful than the 4082.

Do you have a link for Kershaw?

[keithbradley]

Well, she WAS fast.

7/32" tubing is suggested for use with .187 cable. I was skeptical of this being that it fit so tight, but figured I'd give it a try. Wish I had went with my instict now.

[johnf]

So what was the damage?

[keithbradley]