peoples thoughts...and help

[Krusty 181]

Hi all andrew here,im relatively new to boating(done the plane and car stuff for years)

id like to know what people thing of the Dumas scale kits (the 1/8th circus circus,miller,van lines and smaller stuff)

i myself enjoy building from a kit and these are the only type kits i have been able to get to Australia ,i have noted that some people consider these kits to be of average quality , id just like to know what this forum thinks and what they use(do you built from scratch or are there better kits out there?)

i have been building an old Atlas van lines U-71 kit, (the sports 40 one? 36 " long if that helps )

and as im not using the dumas running gear id like some help if possible with strut depth ,angle and possible prop choice (im planning on using a K&B 45 at present )

any help greatly appreciated

 

[missbudpilot55]

Hi Andrew, welcome to model boating.

Let's see first off the wood in most of the Dumas kits is an exterior grade of luan door skin material,

it will need some sealing to make it water and fuel proof. Luan is a light weight wood and I have built

several Dumas kits over the years and have used some of it and replaced it with aircraft ply where I needed good solid wood. As for the kit you are currently building the Atlas U-71, 36" kit, that was an early kit and has been out there for a long time and is a nice looking model. You didn't say what hardware you are using

but the set up should be the same. Once you have the boat built & sheeted, all except for the upper decking being attached, install the braces that will support the strut at the correct distance from the transom, so that

the rear eadge of the drive dog on the shaft is even with the transom of the boat and not stick out past it.

Set the boat on a table and set the depth of the strut so that the transon of the boat is the same height from the table as the height of the hull at the rear edge of the sponsons. and easy way of doing this is by using a small carpenters level in the hull so that the rear most part of the hull is level with the table. Before you tigthen the bolts on the strut place a 1/16" or 3/32" peiece of plywood or material under the front edge of the strut which will give it a slight down thrust angle at the prop end, tighten and mark the strut with a sharpe magic marker, you'll be able to go right back to it once you re-assemble the boat after it is painted.

I would also suggest that you install the ruder on the left side of the transom, boat turns a lot easier.

You didn't say which K&B 45 you would be using the, side or rear exhaust engine, but I would start with something in the range of an Octura X-445 2 bladed prop and work from there. You also didn't mention if you intended on using a hard shaft or flex shaft.........

The Dumas Circus Circus, Miller American & Atlas Van Lines 1/8th scale kits are ok for a beginner that needs an instruction sheet and some wood boat building experience, once you have some under your belt

check out Roger Newtons plan site, he has a lot of 3 sheet plans available for those that like building their own scale boats and there are guys like Troy McIntire who is a member of this board that can make you cowls for most of Roger's plans.

http://www.newtonmarine.com/index.html

Any other questions just ask........................

 

[Krusty 181]

Hi Bill thanks for your input , sorry for not adding all the info , the hardware im using is from X-CELL products here in Australia , its billet aluminium stuff ,a lot better quality than the Dumas stuff -i am using a flex shaft and the K&B is a rear exhaust with exhaust throttle ,i appreciate the input because this is the first "scale" boat ive built as you said its an old kit and going off the original plans they suggest a strut angle that just seemed too great ,so i will go with your suggestions with the strut setup.

sealing the wood is not a problem as i have gotten onto an epoxy supplier that has resins for all jobs , you name it he has it and its stood the test of time in my rigger

and thanks for your input with the kits and the link to the plans ,i had a quick look and im impressed ,my biggest problems is finding the time to do them!

 

[Dr Hydro]

Hi all andrew here,im relatively new to boating(done the plane and car stuff for years)

id like to know what people thing of the Dumas scale kits (the 1/8th circus circus,miller,van lines and smaller stuff)

i myself enjoy building from a kit and these are the only type kits i have been able to get to Australia ,i have noted that some people consider these kits to be of average quality , id just like to know what this forum thinks and what they use(do you built from scratch or are there better kits out there?)

i have been building an old Atlas van lines U-71 kit, (the sports 40 one? 36 " long if that helps )

and as im not using the dumas running gear id like some help if possible with strut depth ,angle and possible prop choice (im planning on using a K&B 45 at present )

any help greatly appreciated

Hey Andrew.....I built that same kit a while back and the only problem I had with it was delaminartion of the plywood that forms the inside of the sponsons and extends all the way to the transom. I would suggest replacing those two pieces with a better grade plywood. Other than that, have a ball with it!

 

[Krusty 181]

Hi Doc thanks for that , unfortunately its a little too late for that ........ its being painted as we speak

oh well once it explodes apart it will be easier to fix...

 

[missbudpilot55]

Andrew being that you are using the rear exhaust K&B 7.5 & tuned pipe combo, I would have an

Octura X-447 & X-450 handy as well, especially if you are using a high nitro fuel say 50-60%. I would avoid the 14-series props to start off with untill you get the boat running and then try some of the 14-series as they are a lifting prop.

I hope you sealed the inside of the hull with epoxy before you started the paint! ! ! :unsure:

I'll email you some pics of my U-77 in progress, PM me you e-mail.

 

[Dasboatman]

Hey Andrew, That may be a lot of boat for a K&B 7.5. Let us know what the boat weighs ready to go when you get a chance. Normally a Sport 42 with a K&B 7.5 at 8-9 pounds is about the norm. I'd guess that the Dumas hull will weigh in at a considerably larger weight. CHEERS !!! Bob

 

[rmprecision]

Hi Krusty

I see there is a circus circus kit on ebay(aus)

Starting price is $375 which i think is a little high

Might make a good 2nd project

 

[Krusty 181]

Hi Bill ill send you my email addy, and yes the boat is sealed with epoxy inside and out ,the method i use (i was told about from a mate that flys turbine powered model jets) is to coat the surface you want to seal witha runny epoxy the run a roll of toilet paper backwards over it (backwards so it doesnt unroll )to soak off any excess resin, once its dried give it a quick scuff up with 220 paper , next coat it again with a mix of the runny epoxy with micro ballons(q cells) made to the consistency of honey, once this is set it can be rubbed back wet (removing most of that coat) to give you a very smooth flat ,knock proof finish , then just paint as you desire

And Bob ill keep the weight thing in mind and let you know what it ends up tipping the scales at

Oh btw rmprecision , thats not a bad idea (but a bit dear).. did you guys in the states know that the retail price from the AU dumas distributor for a Circus Circus is near $750AU... assuming they have one

thanks again to all that contributed much appreciated

 

[Krusty 181]

Hey Andrew, That may be a lot of boat for a K&B 7.5. Let us know what the boat weighs ready to go when you get a chance. Normally a Sport 42 with a K&B 7.5 at 8-9 pounds is about the norm. I'd guess that the Dumas hull will weigh in at a considerably larger weight. CHEERS !!! Bob

Hi BOB if you get a chance to read this its all done and weights in at 8lbs(almost exactly without fuel)..so hopefully the old K&B wish push it ok

 

[Dasboatman]

"... its all done and weights in at 8lbs(almost exactly without fuel)..so hopefully the old K&B wish push it ok :

Hey Andrew, At 8 pounds that K&B 45 will have no trouble at all pushing your Atlas. You're going to have a BALL !!! Being that it is Summer in your neck of the woods, Drop Bill and I a line after you get it in the water and let us know how it runs. I just saw your post this evening. Run Fast - - Turn RIGHT !!! CHEERS !!! Bob

 

[Krusty 181]

Hi all hopefully Bob and Bill will catch this ,but any help from anyone is appreciated .... had the boat in the water and its a pretty wild ride ,the front of it does not like being near the water..., can anyone tell me where abouts the C of G should be for this type boat??and can i lower the strut a bit so as to lift the rear of the hull, lowering the front? it runs very flighty.. and cannot cope with any choppy water

at the moment the strut is set up so the hull is level when running and 2 degrees deeper at the rear(if that makes sense)

any help appreciated

Thanks

Andrew

 

[missbudpilot55]

Hi all hopefully Bob and Bill will catch this ,but any help from anyone is appreciated .... had the boat in the water and its a pretty wild ride ,the front of it does not like being near the water..., can anyone tell me where abouts the C of G should be for this type boat??and can i lower the strut a bit so as to lift the rear of the hull, lowering the front? it runs very flighty.. and cannot cope with any choppy water

at the moment the strut is set up so the hull is level when running and 2 degrees deeper at the rear(if that makes sense)

any help appreciated

Thanks

Andrew

Andrew, looking at the picture you may have to lower the strut about 1/8th-3/16th of an inch (3 m/m-5 m/m) and I would also decrease the angle of the strut to around -1 degree or half of what it is now. By lowering the strut you are going to lift the transom and force the nose down a tad. Try the CG at around 1/2"-3/4" (12 m/m - 18 m/m) aft of the front sponsons. Glad to help any time, keep me posted.

Cheers

 

[Krusty 181]

Thanks Bill , as i suspected with the strut i will do as you suggested,and check the Cof G and let you know how it goes hopefully next weekend

thanks again

Andrew

 

[Krusty 181]

Hope Bill will catch this !!!

Bill , needed to add a fair amount of weight foward to get the C of G where you suggested , tried the boat like that , much better , no where near as flighty, then changed from the prather 230 prop to an ABC H1914(i think) , which has a lot more lift ,which pushed its nose down , that with the weight added made this boat a tonne of fun, it may not be the fastest 40 hydro on the water , but it looks good and for a 20 year old kit that owes me around $300 AU total its a blast

Thanks again for all your help

Andrew

 

[missbudpilot55]

Hope Bill will catch this !!!

Bill , needed to add a fair amount of weight foward to get the C of G where you suggested , tried the boat like that , much better , no where near as flighty, then changed from the prather 230 prop to an ABC H1914(i think) , which has a lot more lift ,which pushed its nose down , that with the weight added made this boat a tonne of fun, it may not be the fastest 40 hydro on the water , but it looks good and for a 20 year old kit that owes me around $300 AU total its a blast

Thanks again for all your help

Andrew

Hey Andrew, good going on the adjustments, try to take some of the weight that you had to add and see if you can alleaviate it by say moving the battery pack forward. If this can be done you'll also see a diffence in the way the boat runs. I know that on the hull you have it may not be possible to do this as space is a premium.

Glad you got it tamed down enough to enjoy running it.

 

[R.J.West]

Hope Bill will catch this !!!

Bill , needed to add a fair amount of weight foward to get the C of G where you suggested , tried the boat like that , much better , no where near as flighty, then changed from the prather 230 prop to an ABC H1914(i think) , which has a lot more lift ,which pushed its nose down , that with the weight added made this boat a tonne of fun, it may not be the fastest 40 hydro on the water , but it looks good and for a 20 year old kit that owes me around $300 AU total its a blast

Thanks again for all your help

Andrew

Hey Andrew, good going on the adjustments, try to take some of the weight that you had to add and see if you can alleaviate it by say moving the battery pack forward. If this can be done you'll also see a diffence in the way the boat runs. I know that on the hull you have it may not be possible to do this as space is a premium.

Glad you got it tamed down enough to enjoy running it.

Hope Bill will catch this !!!

Bill , needed to add a fair amount of weight foward to get the C of G where you suggested , tried the boat like that , much better , no where near as flighty, then changed from the prather 230 prop to an ABC H1914(i think) , which has a lot more lift ,which pushed its nose down , that with the weight added made this boat a tonne of fun, it may not be the fastest 40 hydro on the water , but it looks good and for a 20 year old kit that owes me around $300 AU total its a blast

Thanks again for all your help

Andrew

Hey Andrew, good going on the adjustments, try to take some of the weight that you had to add and see if you can alleaviate it by say moving the battery pack forward. If this can be done you'll also see a diffence in the way the boat runs. I know that on the hull you have it may not be possible to do this as space is a premium.

Glad you got it tamed down enough to enjoy running it.

I would love to see some photos if possible, The U-71 is one of my favorites.