Roundnose attributes

[WikiWiki1]

Before I start working on this comming winters round nose project, I thought I would ask

around for the best attributes of a successful 1/8 scale shovel. I'm interested in ride pad design

tunnel design and weight distribution or anything to help it stay on the water and perform well.

Thanks, Brent

 

[WikiWiki1]

So nobody wants to play? How about I get more specific. Is a wide tunnel better than a narrow one? Should I build to the maximun tunnel width or the narrowest? Should I use the standard 3 degrees angle of attack on the sponsons or make it around 1? How much prop weight should I shoot for? Some one must have some experience I can draw from.

Brent

 

[Hydro Junkie]

As a general rule, a wider tunnel is better than a narrow one. Since you mentioned 3 degree sponson runners, I'm assuming you are working from Newton plans(please correct me if I'm wrong), and if this is the case, build your boat pretty much as drawn. I have a set of plans for the 1971 Miss Madison/Nitrogen 2 and was concerned about some of the same things. I would guess that you would want less than 16 ounces of prop weight as the round nosed boats have very little bottom area in the back to have air pressure help support the rear while running at speed. One thing you have to remember on prop weight is that every boat is different, so plan on doing some experimenting with balance and props

 

[Gale54]

Here is some names of people I know that had great running round nose hulls in my area. Marty Davis, Brain Blazer,and Steve Ball. Try pm the guys and see if they will help. Wish I could help but, I run modern hulls. Don McKay

 

[SayMikey]

Here is some names of people I know that had great running round nose hulls in my area. Marty Davis, Brain Blazer,and Steve Ball. Try pm the guys and see if they will help. Wish I could help but, I run modern hulls. Don McKay

The sponsons on my Fritz 73RedMan have no steps,boat runs great! A project boat im almost ready to release has steps,this boat was a mto with a couple changes, and alum turn fin and transom doublers. As we know MTO is gone i took this project on because it was a great boat. I tried in vain to buy the molds or even just a hull Mark declined so i had molds made using one as the base. By Jan 1 2008 i will be ready to produce them in 3 versions. GAS,NITRO and ELLECTRIC with or without engine rails.Keep a look out for Classic R/C Scale Hydros....Mike

 

[Hurricane]

Closer to home you could try Gene Gager, Burien, Gary Jenson, Hallmark Homes or Marc Connelly, Notre Dame. Gene is very fast and runs UNW while Gary& Marc RCU.

 

[joefroooo]

Here is some names of people I know that had great running round nose hulls in my area. Marty Davis, Brain Blazer,and Steve Ball. Try pm the guys and see if they will help. Wish I could help but, I run modern hulls. Don McKay

The sponsons on my Fritz 73RedMan have no steps,boat runs great! A project boat im almost ready to release has steps,this boat was a mto with a couple changes, and alum turn fin and transom doublers. As we know MTO is gone i took this project on because it was a great boat. I tried in vain to buy the molds or even just a hull Mark declined so i had molds made using one as the base. By Jan 1 2008 i will be ready to produce them in 3 versions. GAS,NITRO and ELLECTRIC with or without engine rails.Keep a look out for Classic R/C Scale Hydros....Mike

Mike, I am looking foward to see the round nose hull assembled and running. Is there a link to show the different boats this hull will make.

Joe

 

[SayMikey]

Here is some names of people I know that had great running round nose hulls in my area. Marty Davis, Brain Blazer,and Steve Ball. Try pm the guys and see if they will help. Wish I could help but, I run modern hulls. Don McKay

The sponsons on my Fritz 73RedMan have no steps,boat runs great! A project boat im almost ready to release has steps,this boat was a mto with a couple changes, and alum turn fin and transom doublers. As we know MTO is gone i took this project on because it was a great boat. I tried in vain to buy the molds or even just a hull Mark declined so i had molds made using one as the base. By Jan 1 2008 i will be ready to produce them in 3 versions. GAS,NITRO and ELLECTRIC with or without engine rails.Keep a look out for Classic R/C Scale Hydros....Mike

Mike, I am looking foward to see the round nose hull assembled and running. Is there a link to show the different boats this hull will make.

Joe

www.rcunlimiteds.org go to information then find Master Hull Roster it builds #5303,5513 and 5722 with no mods.With a few small changes it builds more #5722 has 24 boats so this will make a bunch of neat boats

 

[WikiWiki1]

Here is some names of people I know that had great running round nose hulls in my area. Marty Davis, Brain Blazer,and Steve Ball. Try pm the guys and see if they will help. Wish I could help but, I run modern hulls. Don McKay

The sponsons on my Fritz 73RedMan have no steps,boat runs great! A project boat im almost ready to release has steps,this boat was a mto with a couple changes, and alum turn fin and transom doublers. As we know MTO is gone i took this project on because it was a great boat. I tried in vain to buy the molds or even just a hull Mark declined so i had molds made using one as the base. By Jan 1 2008 i will be ready to produce them in 3 versions. GAS,NITRO and ELLECTRIC with or without engine rails.Keep a look out for Classic R/C Scale Hydros....Mike

Mike, I am looking foward to see the round nose hull assembled and running. Is there a link to show the different boats this hull will make.

Joe

www.rcunlimiteds.org go to information then find Master Hull Roster it builds #5303,5513 and 5722 with no mods.With a few small changes it builds more #5722 has 24 boats so this will make a bunch of neat boats

Mike can you provide the dimensions of your upcoming roundnose hydro's? That way I can see if it will fit into the dimensions of other hulls with minimal modifications.

Thanks, Brent

 

[SayMikey]

Here is some names of people I know that had great running round nose hulls in my area. Marty Davis, Brain Blazer,and Steve Ball. Try pm the guys and see if they will help. Wish I could help but, I run modern hulls. Don McKay

The sponsons on my Fritz 73RedMan have no steps,boat runs great! A project boat im almost ready to release has steps,this boat was a mto with a couple changes, and alum turn fin and transom doublers. As we know MTO is gone i took this project on because it was a great boat. I tried in vain to buy the molds or even just a hull Mark declined so i had molds made using one as the base. By Jan 1 2008 i will be ready to produce them in 3 versions. GAS,NITRO and ELLECTRIC with or without engine rails.Keep a look out for Classic R/C Scale Hydros....Mike

Mike, I am looking foward to see the round nose hull assembled and running. Is there a link to show the different boats this hull will make.

Joe

www.rcunlimiteds.org go to information then find Master Hull Roster it builds #5303,5513 and 5722 with no mods.With a few small changes it builds more #5722 has 24 boats so this will make a bunch of neat boats

Mike can you provide the dimensions of your upcoming roundnose hydro's? That way I can see if it will fit into the dimensions of other hulls with minimal modifications.

Thanks, Brent

I will get them tonite.............

 

[Hurricane]

The master hull roster has the dimensions listed for the hulls listed. Who do you race with or going to race with?

 

[WikiWiki1]

The master hull roster has the dimensions listed for the hulls listed. Who do you race with or going to race with?

The master hull roster give a range for each dimension, without knowing exactly what the hull measures you can't figure out all the potential

hulls it can make. I run with RCU and UNW.

Brent

 

[SayMikey]

The master hull roster has the dimensions listed for the hulls listed. Who do you race with or going to race with?

I race IMPBA but guys have run this hull in NAMBA and RCU

 

[Hurricane]

David Newton's Kia is a MTO. The dimension listed are the limits for each hull. Looking forward to seeing you at the races. Just remember that there are some hulls that are raced around the country that are not legal in RCU. Phil's 8255 hull is one that isn't because of the belly pan. I tried to get it approved but the board said no. Be sure a get a copy of the RCU rules to be sure.

 

[SayMikey]

David Newton's Kia is a MTO. The dimension listed are the limits for each hull. Looking forward to seeing you at the races. Just remember that there are some hulls that are raced around the country that are not legal in RCU. Phil's 8255 hull is one that isn't because of the belly pan. I tried to get it approved but the board said no. Be sure a get a copy of the RCU rules to be sure.

Here are what I have bear in mind this is off the plug and may change slightly Length 44.25 width 19.25 tunnel 10.25 sponson depth 4.00 After Plane 22.75 this is right on for MHR#5722,5513 and width a slight change will do 5303. It may do more with other small changes like the Kia with a pointy nose it depends on what you want it to do. My scedule is full for the next 8 weeks then i will start making boats,there will be a learning curve but a short one. The only wood in the hull will be engine rails i hate rotten transoms so it will be Alum, drill tap and add jam nuts life is better. The first boat is out of the mold my mold maker pulled the first one for quality control and its a beauty. After i recoup my investment a drop sponson will follow. My goal is to keep alive the Classic boats ALIVE Olly Douglas proved they can still win big races.......Mike

 

[Ralph Kemp]

The master hull roster has the dimensions listed for the hulls listed. Who do you race with or going to race with?

The master hull roster give a range for each dimension, without knowing exactly what the hull measures you can't figure out all the potential

hulls it can make. I run with RCU and UNW.

Brent

Brent

I have the master hull roster for UNW, it gives the actaul dimensions and the plus-minius dimensions. give me a jingle.

Ralph

 

[DON MAHER]

At the present time I am running a drop sponson MTO hull in the sport-60 class in NAMBA

When set up is correct, this is a very fast and stable hull.

It is the current sport-60 2-lap record holder

Mike,

You will surely have a winner with the MTO style hull.

Don

 

[’69 Dame]

Closer to home you could try Gene Gager, Burien, Gary Jenson, Hallmark Homes or Marc Connelly, Notre Dame. Gene is very fast and runs UNW while Gary& Marc RCU.

Boy howdy, Genes Miss Burien is a fast one. But there are several excellent roundnose designs, seems to me. It is wise to remember a couple of key points where, arguably, the roundnose boats have an edge. The aerodynammic drag accounts for approximately 60% of the overall drag on a hydroplane. Secondd, anny 90 degree intersection of shapes createdd a drag vortex that is approximately six times that of a (more or less) flat surface. Now look at thhe cannards, verticals, wings and 90 intersections of the shape of a hydroplane- picklefork or roundnose. The roundnose hulls have a lot lower induced drag coefficient. I am not sayiing this makes them better, it is just one small opportunnity for advantage. Of couurse the pickles have a nice wide footprint to compensate, offering their own advantage. This is whhy you (sometimes) see an old roundnose pulling the pickles iin a straight line, givinngg back some grouunnd in the turns.

The other, more obvious advantage is that they are just plain cooler looking!

guitarmarc

 

[Marty Davis]

So nobody wants to play? How about I get more specific. Is a wide tunnel better than a narrow one? Should I build to the maximun tunnel width or the narrowest? Should I use the standard 3 degrees angle of attack on the sponsons or make it around 1? How much prop weight should I shoot for? Some one must have some experience I can draw from.
Brent

Brent:

You have asked some really good questions.

I should assume from your questions that you have the ability to change the Newton Plans.

I ran a fairly successful Roundnose Miss Vernors for several years and the boat that I had ran about 2 degrees of attack angle and was at the limit on width. As for strut weight, I would suggest that you use as little strut weight as possible. My boat actually balanced only very slightly behind the front sponson ride pad. I ran X Style props so they would hook up well. If I tried to run 1400 series props it would blow the back end of the boat out of the water because of the lack of strut weight.

No need to get carried away trying to save a ton of weight as the round nose boats have a tenancy to blow off and a little extra weight is not bad. I did try to save weight and the boat would sometimes instantly blow off if I was pushing it.

Be sure to put the rudder on the left and make the strut as wide as possible within the rules. You should run a couple of degrees of shaft angle to help the boat lift the transom coming out of the turns.

Hope this is what you are looking for....

Marty Davis

 

[’69 Dame]

Before I start working on this comming winters round nose project, I thought I would askaround for the best attributes of a successful 1/8 scale shovel. I'm interested in ride pad design

tunnel design and weight distribution or anything to help it stay on the water and perform well.

Thanks, Brent

The beach debate will rage through tthe ages, but in my view the best attribute of a roundnose hydro is substanbtially reduced induced drag. That is pretty much the only advantage a roundnose is ever going to have over a pickle. You just punch a smaller and cleaner hole through the air. That’s why you see the occcasional roundnose bullet up the backstretch. The prop is simply pushing less stufff throughh the air. Aerodynamic drag counts for about 60% of the overall induced drag.

Oh yeah, and they look cooler too. That counts for something, right?

marc