The Bottom of a Scale

[dr gary turner]

Can someone clarify the rules as to what is allowed on the bottom, running surfaces of a scale hydro? Trule is not clear. It basically says that the bottom is not considered,but should be scale like. What can be done and not done to the running surfaces? Gary

 

[Wesleys Custom RC]

Can someone clarify the rules as to what is allowed on the bottom, running surfaces of a scale hydro? Trule is not clear. It basically says that the bottom is not considered,but should be scale like. What can be done and not done to the running surfaces? Gary

I'm not the pro here but In IMPBA you can do just about anything as long as it looks scale from the side or top. At least as far as stuff like sponson depth, strakes etc. I'm sure if you added a 3rd sponson somebody would kinda frown if you know what I mean. Sometimes you have to make mods to get a boat to handle better. You just have to keep it within the "spirit" of the class and that is open to interpetation by the CD....oh ya, keep that drive dog under the boat.

 

[SayMikey]

Can someone clarify the rules as to what is allowed on the bottom, running surfaces of a scale hydro? Trule is not clear. It basically says that the bottom is not considered,but should be scale like. What can be done and not done to the running surfaces? Gary

I'm not the pro here but In IMPBA you can do just about anything as long as it looks scale from the side or top. At least as far as stuff like sponson depth, strakes etc. I'm sure if you added a 3rd sponson somebody would kinda frown if you know what I mean. Sometimes you have to make mods to get a boat to handle better. You just have to keep it within the "spirit" of the class and that is open to interpetation by the CD....oh ya, keep that drive dog under the boat.

As scale rules go better ask before you do something. Most boats do have a number to go by for sponson depth. Mike

 

[P THOMAS]

Can someone clarify the rules as to what is allowed on the bottom, running surfaces of a scale hydro? Trule is not clear. It basically says that the bottom is not considered,but should be scale like. What can be done and not done to the running surfaces? Gary

I'm not the pro here but In IMPBA you can do just about anything as long as it looks scale from the side or top. At least as far as stuff like sponson depth, strakes etc. I'm sure if you added a 3rd sponson somebody would kinda frown if you know what I mean. Sometimes you have to make mods to get a boat to handle better. You just have to keep it within the "spirit" of the class and that is open to interpetation by the CD....oh ya, keep that drive dog under the boat.

As scale rules go better ask before you do something. Most boats do have a number to go by for sponson depth. Mike

Like Wes says just looking scale and having the hull the correct size is IMPBA ok. The more scale it is the more chance you have for a concours trophy but we have a standoff type of scale judging, read the rules and get proper pictures of a boat you want to build.

Mike what are these numbers you speak of for sponson depth?

 

[Brian Schymik]

Doc.

One thing you cannot do, is add rear shoes if the real boat didn't have them, or remove them if the real boat had them.

You can change anhedral/dihedral change pad shape to any design add or remove engine tubs

change angle of attack change sponson depth change length of bottom before the break add air dams etc

Many options here

Good luck....great class to race

Brian

 

[Darin Jordan]

... add or remove engine tubs

Is this true for both organizations??? I was told by Roger (Newton) that the 82U55 Phil Thomas hull was deemed illegal for their 1/8th scale RCU races because of the size of the motor tub... Is this just an RCU thing, or does it apply to NAMBA/IMPBA as well???

Thanks,

 

[SayMikey]

... add or remove engine tubs

Is this true for both organizations??? I was told by Roger (Newton) that the 82U55 Phil Thomas hull was deemed illegal for their 1/8th scale RCU races because of the size of the motor tub... Is this just an RCU thing, or does it apply to NAMBA/IMPBA as well???

Thanks,

tHE BOAT IS LEGAL Except in RCU Sponson depth is in the MHR I adhere to it maybe some dont but its there and i make sure mine passes that number as well

 

[dr gary turner]

Doc. One thing you cannot do, is add rear shoes if the real boat didn't have them, or remove them if the real boat had them.

You can change anhedral/dihedral change pad shape to any design add or remove engine tubs

change angle of attack change sponson depth change length of bottom before the break add air dams etc

Many options here

Good luck....great class to race

Brian

Thanks Brian, Gary

 

[dr gary turner]

... add or remove engine tubs

Is this true for both organizations??? I was told by Roger (Newton) that the 82U55 Phil Thomas hull was deemed illegal for their 1/8th scale RCU races because of the size of the motor tub... Is this just an RCU thing, or does it apply to NAMBA/IMPBA as well???

Thanks,

tHE BOAT IS LEGAL Except in RCU Sponson depth is in the MHR I adhere to it maybe some dont but its there and i make sure mine passes that number as well

Who is RCU? Gary

 

[P THOMAS]

... add or remove engine tubs

Is this true for both organizations??? I was told by Roger (Newton) that the 82U55 Phil Thomas hull was deemed illegal for their 1/8th scale RCU races because of the size of the motor tub... Is this just an RCU thing, or does it apply to NAMBA/IMPBA as well???

Thanks,

Yes it is a R C Unlimited club rule they have a rule for size of belly pan like 3x6 or something. My 82u55 has a 5 inch wide belly pan, it is designed like the SuperSport45 bottom.

I do plan on putting a newer bottom on that 82U55 hull that will not have the belly pan. No big deal I think there are only 4 82u55 in RCU and they are scratch built hulls more scale than my boat Im sure.

PHIL

 

[Darin Jordan]

Yes it is a R C Unlimited club rule they have a rule for size of belly pan like 3x6 or something. My 82u55 has a 5 inch wide belly pan, it is designed like the SuperSport45 bottom.
I do plan on putting a newer bottom on that 82U55 hull that will not have the belly pan. No big deal I think there are only 4 82u55 in RCU and they are scratch built hulls more scale than my boat Im sure.

PHIL

Thanks Phil... I'm going to be doing mine up for FE anyhow... I was just curious... I think it should fit the NAMBA guidelines for 1/8th hulls from what I've read/seen...

 

[Hurricane]

I had the 82u55 PT hull that the RCU board used for there ruling. I also ask John Logan if he thought it would be legal in UNW and he thought it would need to modified for there club also. So as far as the original question about bottom modifications, I would say you need to check with the group you race with.

 

[Hydro Junkie]

okay, to make things VERY CLEAR on belly pans, per the R/C Unlimiteds rulebook Section 3 Subsection A rule 8, the rule reads as follows:

A boat bottom shall have the same general appearance and number of propellers of that of the unlimited which the hull represents.

Exceptions include:

a. Sponson riding surfaces, which may be modified

b. Propeller shafts, which may be articulated

c. Rudders and skid fins, which may be configured and located as desired

d. Motor belly pan: for motor and flywheel only. If applicable, dimensions will not exceed 3 1/2" width, 7" in length and 3/4" in depth. Under no circumstances will said belly pan be allowed to exceed the depth of any riding surface or recovery surface. If the real boat had a full length belly pan, the model must conform

The rule says clearly what the legal size in R/C Unlimiteds is for a belly pan, though I don't know the dimensions of Phils hull's belly pan. One thing to note is that excerpt is from the 2000 season rule book, though I don't think anything has changed since in that regard

 

[SayMikey]

okay, to make things VERY CLEAR on belly pans, per the R/C Unlimiteds rulebook Section 3 Subsection A rule 8, the rule reads as follows:A boat bottom shall have the same general appearance and number of propellers of that of the unlimited which the hull represents.

Exceptions include:

a. Sponson riding surfaces, which may be modified

b. Propeller shafts, which may be articulated

c. Rudders and skid fins, which may be configured and located as desired

d. Motor belly pan: for motor and flywheel only. If applicable, dimensions will not exceed 3 1/2" width, 7" in length and 3/4" in depth. Under no circumstances will said belly pan be allowed to exceed the depth of any riding surface or recovery surface. If the real boat had a full length belly pan, the model must conform

The rule says clearly what the legal size in R/C Unlimiteds is for a belly pan, though I don't know the dimensions of Phils hull's belly pan. One thing to note is that excerpt is from the 2000 season rule book, though I don't think anything has changed since in that regard

R/C Unlimiteds are a group of Scale guys in the Seattle area that only race Scale boats. For a Scale guy its the ULTIMATE RACE. www.rcunlimiteds.org Mike

 

[Dasboatman]

Who is RCU? Gary

Doc,

R/C Unlimited is the long time Scale Group in the Pacific NW. Their site is:www.rcunlimiteds.org

You can view their 35 (or so) page rule book and their Master Hull Roster in the Information area - left column of their site. They have been insured through APBA for years, but are considering NAMBA presently. If I can help you with any scale questions, just drop me a line. CHEERS !!! Bob Johnson

 

[Hurricane]

I only brought up the RCU, UNW ruling to show that not all bottom modifications are legal every where. As the original question was about what can be and can not be done to the bottom of a scale hydro. When I got the PT hull I petitioned the RCU board and they looked at the hull and made there ruling on the hull. Roger was on the board and can fell in all the info if needed. But the answer to the original question remains it depends on where and what orginzation you race in.