Dumas atlas first time out

Well I finally made it to the lake with this boat and thanks to the iw members for all the help it went well. Do have a question thoe... The boat seems to ride too high in the back... It does not turn sharp to the right and will not turn left at all to make a correction under power. Is this just a normal hydro deal? At around half throttle it seems to be better. I don't have anything to compare it to other than videos on The net. The turn fin seems to be doing its job(it is not pushing the nose) The rudder has plenty of travel and range of motion, it has a x457 prop, the strut is set at 13/16" to C/L of shaft from bottom of hull with around 5 degrees of what I'm going to call "trim" (the front of the strut being higher than the rear) the rudder is a speedmaster that is 3" long and 1/2" wide. The CG is at 2 1/2" behind the sponsons. It may sound dumb but it does not produce much of a rooster tail compared to what I'm seeing in the videos. We gps'd it at 48mph. Is my strut set right? Any help would be greatly appreciated.

Pictures would help , what scale? if it's 1/8 scale, you don't have enough rudder as most of it is out of the water. What motor? too many unknowns to give agood answer.

Michael

My bad sorry, it is 1/8 scale with a old ops 80 engine... And yes that is the size of the rudder. I bought this boat off ebay and the hardware was already on it. I called the prior owner of the boat to talk to him about what needed to be done to the boat to get it ready to run. He was a very nice fellow that Claimes he raced the boat that way and it was ok... Thinkin he wasen't too truthful. Can't get this dang computer to load a pic... Thank you all for getting me going in the right direction! Just to help a newbie out what is the proper term for strut angle? Ha ha ha... I got a lot to learn!

Hey Ben,

Can you post some pictures of the bottom of your boat so we can see what you are working with?? If the rear appears to be riding too high - raise the strut but retain the angle.

If you place your boat on a flat table - hang the turn fin off the side and the rudder over the end - that will give you an idea of what your ride angle will be. Her's a pic of one of mine on a set up table,m which is actually a slab of glass sitting atop a table. CHEERS !!! Bob

This is the rudder I'm running on my '72 Bud. LOA 6 1/4" blade width is 1 3/16 Got it from www.mtc-powerboat.de Water pickup on both sides of the blade, and it is a kick-up design.



Michael

Hey Ben,

That's a Speedmaster rudder on my Houston. It measured 4" below the hull bottom, is 1 7/16" high and tapers to 1 1/16" at the bottom of the blade. It was shortened some from the stock Speedmaster 60 hydro rudder assembly.

The rudder on my Sport 40 is 3 7/16" below the hull bottom

What do you have in your boat for a rudder servo?? CHEERS !!! Bob

Mr. Bob, that looks and is suppose to be the rudder I was told was on my boat. Although mine looks to have been butchered along the way. I so wish this thing would let me post some pictures so you guys could see what I am dealing with, I know the folks here could get me going the right direction. The servo is suppose to be a high torque futaba. Will check when I get to the shop on the numbers on it. Looking like I will be ordering a new rudder and trying to get the epoxy or whatever this goofball used to slobber the strut in off and getting it set right. Thanks again for everyone's comments and help!

Hey Ben,

In the case of these boats, a couple pics are indeed worth a few thousand words. This also eliminates the need to know the key words and tricky phrases used by those that have been doing this for a while. There are many boaters on here that would be more than glad to give you a hand.

Try saving your pictures to a My Pictures type file so you can choose them when select "More Reply Options" when you make entry to the "Reply to this topic" block. There is a size limit to each attached picture - 2 megabytes I believe. I generally snap a pic with digital camera, and immediately reduce the size of that pic to 800 X 600 pixels using Photo Impact software that allows me to do this. Check on your camera that you are taking the smallest - less resolution pic you can. My digital camera in high resolution take an 8.1 Mega pixel pic - way too much data to be able to post on this forum. I'm sure there is a help topic on this forum to assist with pictures. What I do works for me, so I stick with it. Good luck.

I generally cut a hole in the hull bottom to clear the strut blade after painted so I can adjust the strut depth and angle. I seal around the strut with DAP clear Aquarium sealant that I get at Home Depot to seal the tub area from water coming in around the strut. This will allow you a very small amount of adjustment once cured.

You will find that you will get many opinions on which servos to use . I personally prefer Futaba, and I also run some Airtronics rudder servos. A servo greater than 100 oz./in. should be fine. The more the torque, the more expensive. Digital servos are more expensive than Analog. Most of mine are Analog - tried and true. CHEERS !!! Bob

I have one of these boats, and even using Aeromarine hardware (strut/rudder) it's been impossible for me to settle down. the most apparent problem with mine seems to be that the angle-of-attack is way too high; it "wallows" in turns and once you go a tiny bit too fast it decides it wants to try to be an airplane and fails at that. I know people have raced these, I just haven't been arsed to take the time to try to get it running smooth. maybe after racing is done this year I'll pull it off the shelf, play with the strut and see if I can make it behave.

You can also use Microsoft Paint to resize the pictures. It comes free on Windows PC's.

it sounds the CG may be back a bit far too

if the Atlas kit is stock, then that means there is a cut out in the back part of the boat leading to the transom. Need a pic of the bottom of the boat. This cut out makes this boat loose. It will also have very little rooster tail and the turn fin wont set in the turn. It may not have a big enough turn fin as it is if the hardware is the stock dumas hardware. .Anthony is right as everyone else is that is trying to help. I would call the size of dasboatman's turn fin near ideal. (not to mention the fact that i like the front sponson angle with the step) Most people haven't dealt with that cut out in the back but I have helped a couple boaters over the years with this same boat built stock. If that cut out area was redone to match the rest of the bottom. The boat would run flatter and would need a hardware upgrade to make it turn like the ones you have seen in the videos. Hope that helps some.

Hey Ken,

I have never seen a Dumas Atlas. The only Dumas hull I ever worked with was one of their Miller hulls. A recessed transom brings a whole new dimension of issues. We really need to see pics of what Ben has so we can tailor suggestions.

Ben,

Do you have any boaters near you in MO that can give you a hand with your boat?

Ken,

Thanks for the kind words. You'll be seeing my Houston in Evansville on the 20th. Rick and I will probably be there late afternoon. I'm looking forward to this race. Best numbers I've seen in a while. I met some of the Evansville guys in Atlanta. Looking forward to shootin' the bull with them and some others that will be at the race. CHEERS !!! Bob

It will be a blast,

We will have to go to the steakhouse and make Phil another year older!! I think he is like 165 now! haha!! I will be bringing the Valcon.com, I think my son Is going to run the Oberto. My other son is not ready for scale yet but my Thirty year old 82 Atlas is waitng on the shelf for him. I am looking foward to meeting you. Ken

Hey Ben,

WHere do you have to run in columbia? I am in Florrissant, Mo. I know its 100mile ride but I could make it worth your trip with what you would learn in hands on work.

Ken

I run at a private lake just north of columbia. My boat is a stock dumas build with the recess in the rear. Not really any other boaters around me that I know of other than my dad and brother. We are all kind of learning this thing together and having a blast so far! I make trips to saint Louis about once a month for work. Would love to meet and chat face to face with a fellow boater. I have a lot to learn about these things!

Your welcome to chat with me anytime. I love talking boats! Pm'd you my number.