Model Boat Mayhem

Mess Deck: General Section => Tugs and Towing => Topic started by: oldflyer2 on August 01, 2015, 06:57:59 pm

Title: Dumas Mr Darby - My build
Post by: oldflyer2 on August 01, 2015, 06:57:59 pm
Hello All

I have just received an untouched Dumas Mr Darby hull that has never been started.

I have the plans, and a multitude of reference pics found on the net. I do not intend to do an actual Mr D, but something of my own design.

I am wondering if anyone has a set of running gear they don't want, either the Dumas one or the Harbour Models one. I could be interested if the price is right.

Also, I would like to do the Kort knozzle version so if anyone has a pair of them for Mr D laying around, I could be interested in that as well.

I am planning on doing the water ballast treatment as I couldn't lift the fully ballasted one anymore.

Cheers

Tom
Title: Re: New To Me Mr Darby Hull
Post by: oldflyer2 on August 08, 2015, 11:28:38 am
All sorted. I am going with the open wheels so don't need korts, and the props are on their way from the usa.

Tom
Title: Re: New To Me Mr Darby Hull
Post by: Martin [Admin] on August 08, 2015, 12:43:41 pm
 
What motors will you be using Tom?      :-) 

Some inspiration photos...



(http://u.cubeupload.com/Mayhem1/HJOIff.jpg)

(http://u.cubeupload.com/Mayhem1/iiaS3M.jpg)

(http://u.cubeupload.com/Mayhem1/3vxS9b.jpg)

(http://u.cubeupload.com/Mayhem1/5mqrZ1.jpg)
 (http://cubeupload.com)
Title: Re: New To Me Mr Darby Hull
Post by: Mark T on August 08, 2015, 06:18:53 pm
Now that's a nice looking tug - good luck with the build Tom
Title: Re: New To Me Mr Darby Hull
Post by: oldflyer2 on August 09, 2015, 11:58:32 am
Martin, I haven't decided on the motors just yet. I would like a pair of Pittman 3700's but they are scarce these days. Harbor does a pair of 850's with belt drive as a set of direct drive one's.

I am trying to figure out some timing belt and pulley sizes and then I also might make my own belt drive. There are a couple of robotics suppliers near me where I can get what I need.

Do you have any idea where one can get the knitted brow in the pic or the pattern for tying one up? I really like them.

Mark, I have lusted over one of these tugs for 20 years and I am going to enjoy building her.

Cheers

Tom
Title: Re: New To Me Mr Darby Hull
Post by: oldflyer2 on August 09, 2015, 07:30:43 pm
I am putting in a stern roller similar to the current day Atlantic Salvor (ex Mr Darby).

This is what will be cut out of the stern at this point ...

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/SternCutOut.jpg)

That may change as I am making the bits for the roller before I cut the hull away. There does come a time when that needs to be cut though. <:(

I also reinforced the bottom of the hull to make it a bit stronger. It will get more when the battery box goes in.

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Hull10.jpg)
Tom
Title: Re: New To Me Mr Darby Hull
Post by: Capt Podge on August 09, 2015, 07:38:19 pm
Keep the photos coming as you progress Tom - she looks like a mighty beast - good luck with your build :-))
 
Regards,
 
Ray.
 
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 09, 2015, 08:49:59 pm
Ray, she will be around 65lbs when up to the water line. I am going to try water ballasting as I can't lift that much. I am aiming at a 20 to 25 lb finished hull. Err, that doesn't include the celebratory bottle of amber liquid when done.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: nemesis on August 09, 2015, 10:17:03 pm
Hi, With water weighing 10lb a gallon plus the size of a gallon can, you will not have the space to get all your ballast in. You will have to use Lead, more weight less volume plus you will still have your boyancy. A fellow club member has this model and it takes quite a lot of weight to take it down to the marks. water ballast,in my opinion, is not the way to go. nemesis
Title: Re: Dumas Mr Darby - My build
Post by: Stavros on August 09, 2015, 11:36:44 pm
Personally I wouldn't bother with a MFA850...ok everyone knows I hate them with a vengence for the simple reason of how much amps they can draw...All you need on this one is a Brushless motor with a KVA of 700 ish and that will give you around 8500 which in fact should be right for it flat out with plenty of reserve power....oh and go direct drive nad don't bother with a gearbox you wont need it

Dave
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 10, 2015, 12:48:28 am
I didn't mention that the 35ah battery weighs in at around 26lbs according to the specs, so I should only be needing another 10 or 15lbs or so. Anyway, it is all speculation at this point and I won't worry much about it until much later in the build.

In my earlier post, I meant to say mfa800 motors. They are being used direct drive in another Darby with good results. This decision will come a bit later as well. I am visiting a friend next week that may have the answer to the motor question.

Version one of the roll didn't wuite work as advertised so I will have another go at that in the morning.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 10, 2015, 12:32:22 pm
Dave, is this the sort of thing you are talking about?    http://www.hobbyking.com/hobbyking/store/__9449__Turnigy_540L_V_Spec_Inrunner_w_Impeller_810kv.html

I know absolutely nothing about this new technology. Will these run on a car battery? I refuse to have lipos in the house.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: Stavros on August 10, 2015, 12:47:30 pm
http://www.hobbyking.com/hobbyking/store/__12922__Turnigy_D2836_11_750KV_Brushless_Outrunner_Motor.html

That's what I would personally use yes you will need some suitable esc's for them and YES they CAN be used with a car batt....I am exactly the same as yourself with Lipo batts cant stand them......


Dave
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 10, 2015, 01:32:43 pm
Thanks for that link Dave. The one thing I am going to splurge on is a P94 from action. That includes two 20a esc's that I think the motors you linked to would work well with.

The only thing I see is they call for 7.4 to 11.1 v input. Would they take 6 or 12v?

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 10, 2015, 06:29:35 pm
I have ordered 2 of those motors to check out.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: Stavros on August 10, 2015, 08:18:40 pm
Hang on a mo the motors that I linked you are Brushless motors and the P94 will NOT work with them, it is only for brushed motors.
You will need a pair of these esc's to run those motors and get a programming card to set the esc up and YES you can run them off a lead acid batt


Dave
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 10, 2015, 10:48:49 pm
Hi Dave

You didn't include a link to the esc's.

Not to worry, the motors will work in two other boats I have and are cheap as chips compared to what is available here.

What BRUSHED would you or anyone else recommend with the Action controller?

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 10, 2015, 10:59:06 pm
OK ... just a question ... does a tug boat, going at scale speed, have enough speed through the water to make a scoop cooling system work? The esc's and the motors may need to be coioled under heavy load. Just thinking ahead as now is the time to put the scoops in.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: Stavros on August 10, 2015, 11:07:08 pm
I wouldn't have thought they would get warm enough to need water cooling......if they will need cooling all you do is to put a scoop in and use  12v pump to work it.. easy to rig up....Y lead to an esc off the main motor lead to the receiver


Dave
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 11, 2015, 12:24:42 pm
I have been looking for esc's for the brushless motors above. I found these ...  http://www.hobbyking.com/hobbyking/store/__11616__Turnigy_AE_25A_Brushless_ESC.html   They seem to have the right specs except for the input battery type. They call for lipo's or nimh ... will they work with lead acid gel type battery?

Can someone point me to a tutorial that explains all this new battery/brushless/esc technology or a chart that tells me what goes with what? I am getting a very serious headache with this stuff.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 11, 2015, 01:42:45 pm
Another silly question ... will esc provide reverse?
Title: Re: Dumas Mr Darby - My build
Post by: Martin [Admin] on August 11, 2015, 02:03:39 pm
 
You could always try the Action P82 micro MOTOR MIXER - which should work with any ESC motor combination

Connects to the Throttle and Steering outputs from the Rx and automatically slows down the motor on the inside of a turn when a rudder command is given. P82 feeds the power for the motors directly through to the ESCs from the receiver connections i.e. the whole model requires only one battery pack to power everything. Suits P68A and P52 ESCs. It has an ABS case - 34mm x 24.5mm x 16mm, with onboard plug-in connectors for two outer motors and the steering servo.

http://www.action-electronics.co.uk/mixers.php
Title: Re: Dumas Mr Darby - My build
Post by: Martin [Admin] on August 11, 2015, 02:09:21 pm
 
It doesn't mention Reverse in the specs for those controllers!
Also, look at Car ESC as there do reverse better than boat ESC's.

Brushless Motors:   http://www.modelboatmayhem.co.uk/forum/index.php/topic,13538.msg130068.html#msg130068

I have been looking for esc's for the brushless motors above. I found these ...  http://www.hobbyking.com/hobbyking/store/__11616__Turnigy_AE_25A_Brushless_ESC.html   They seem to have the right specs except for the input battery type. They call for lipo's or nimh ... will they work with lead acid gel type battery?

Can someone point me to a tutorial that explains all this new battery/brushless/esc technology or a chart that tells me what goes with what? I am getting a very serious headache with this stuff.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: inertia on August 11, 2015, 02:12:21 pm
Tom
Harbor Models offer two alternative hardware sets; both having belt-driven MFA 800 motors. The ACTion P94 will be fine with either of these but NOT with the 850 motors which, as Stavros says, are prone to draw much higher currents than claimed - although with belt-drives the current will be less than with direct drive.

The brushless speed controller you have linked to doesn't have reverse - not many do. There are marine ESCs with reverse; these guys do a couple and there are loads more on the Internet if you include the word "marine" in your search criteria. http://www.componentshop.co.uk/brushless/speed-controllers-esc/boats (http://www.componentshop.co.uk/brushless/speed-controllers-esc/boats) If the technical blub doesn't specifically mention the word "reverse" then you can assume that it doesn't have it. A number of folk use car speed controllers and program out the brake function. These are generally fan-cooled. As regards water-cooling, tugs will use large slow-revving motors so are unlikely to need any cooling.

SLA batteries are not capable of supplying large currents unless they're the heavy-duty and expensive "leisure" type. LiPos are popular because they're what the aeromodellers use and can supply very large currents. NiMH packs are a happy half-way alternative for those who believe all of the scary nonsense put around about LiPo batteries. Treat them properly and they're perfectly safe; act carelessly with them and they can bite - but so can a Stanley knife...............  O0

Just seen Martin's post - the P40E is a better unit because it has four different modes of operation whereas P82 has only one.

Dave M
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 11, 2015, 04:38:13 pm
I do have a Viper marine esc on the way for another boat. They are supposed to have excellent low speed control. I will see how it works out and then, I may get a pair of them along with a pair of torpedo 800's and a P40.

Thank You for all the information ... the fog is clearing a bit more now and I have a better idea of what to look for.

And now, I best get back to work as all this is errelivent if I don't get the boat built. It is almost time to cut that large bit of the stern out.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: inertia on August 11, 2015, 05:14:47 pm
Tom
A P94 is better than two separate ESCs and a mixer for a number of reasons, not the least of which is the ease of connection and setting up.
Dave M
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 11, 2015, 06:03:55 pm
Thanks Dave. In thinking about it, you are right as it would be much simpler. In reality, the simpler, the better and it does cut down the number of places to look if it all goes pear shaped.

Thanks

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 11, 2015, 09:22:29 pm
OK, so I put all thoughts of electronics aside for a bit and I have the stern roller made ... I think ...

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Roller1.jpg)

It is made of a piece of acrylic towel rail someone gave me "just in case". I picked this instead of metal as there should be no corrosion of any kind, it paints well and fiberglass resin sticks to it.

Now I need to cut the hole, then slot the tapered ends of the end bits so they fit over the hull sides. Some filling and sanding should see it soon done. As I read in another thread, I am treating each bit as a sererate project and when all the little projects are done, the big one should be as well.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 12, 2015, 11:56:30 am
This is where the roller will go ...

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/P1050149.jpg)

Quite a bit of clean up and fiddling to do but it should look ok in the end.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 12, 2015, 12:52:00 pm
First rough fit ...

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/FirstFit.jpg)

A bit of fiddling to do and some filling and then on to the next bit.
Title: Re: Dumas Mr Darby - My build
Post by: Martin [Admin] on August 12, 2015, 01:26:16 pm
 
You've 'bit the bullet' now Tom!
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 12, 2015, 01:31:30 pm
Martin, I now have no choice ... gettr done or gettr very wet!



(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Roller2.jpg)

Fitting better now.

The roller is centered both horizontally and vertically at this point.

Time for another think of the watertight box I need to do before I glue anything in.

Tom

Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 12, 2015, 01:57:16 pm
The black line on each side is about where the deck will be ...

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Roller4.jpg)

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 12, 2015, 04:58:56 pm
The final bit for today ... the solid block of wood that will help fill the gap, and there will be two long screws from the outside, through the bulwark and into this piece. The whole works will be fiberglassed in and it should be rock solid.

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Roller5.jpg)


Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 12, 2015, 08:50:34 pm
After a bit of fiddling around ...

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Roller6.jpg)

Pretty darn straight.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 13, 2015, 10:03:01 pm
Props have arrived, so once the roller is done I can start on the drive line.

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Props.jpg)

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 14, 2015, 04:48:26 pm
Sanding and filling to do, which I will do a bit at a time,  but the roller is in place, warts and all.

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Roller7.jpg)


I think it will look fine once it is all filled and sanded and painted.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on August 17, 2015, 01:13:33 pm
This will do for now ...

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Roller8.jpg)

I will clean it up and finish it when I finish the hull.

Time for some main deck supports and under frame, as well as the drive line.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on September 02, 2015, 07:52:37 pm
I have been delayed do to an illness, but will be back at it in a week or so. I am still busy "thinking" about everything that needs to be done.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on September 20, 2015, 12:35:42 pm
I have managed to make a rope walk and do a bit of experimenting.

Thanks Brian for the info.

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Rope1.jpg)

A couple of the ropes I have made so far.

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Rope.jpg)

Now I need to learn to splice ... Youtube will be my friend on that one.
Title: Re: Dumas Mr Darby - My build
Post by: Tug Hercules Fireman on September 20, 2015, 05:08:20 pm
Here is a great WEB Site for Rope Work, including splices.

All illustrations are animated.

http://www.animatedknots.com/indexsplicing.php (http://www.animatedknots.com/indexsplicing.php)


Title: Re: Dumas Mr Darby - My build
Post by: Brian60 on September 20, 2015, 06:19:00 pm
Coming along nicely. And if it will load I have included a PDF on how to splice ropes :-))
Title: Re: Dumas Mr Darby - My build
Post by: Capt Podge on September 20, 2015, 06:26:24 pm
Downloaded straightaway on my system - I'm still on XP  :embarrassed:
 
Thanks for sharing Brian  :-))
 
Regards,
 
Ray.
 
Title: Re: Dumas Mr Darby - My build
Post by: Brian60 on September 20, 2015, 07:58:30 pm
Downloaded straightaway on my system - I'm still on XP  :embarrassed:
 
Thanks for sharing Brian  :-))
 
Regards,
 
Ray.

Always happy to help where I can. O0
Title: Re: Dumas Mr Darby - My build
Post by: rhavrane on September 20, 2015, 09:10:28 pm
Bonjour,


My friend Didier, great modelist, has also built his rope machine and offered me a few meters for one of my boats :


https://www.youtube.com/watch?v=3h7LHmlnRzY


https://www.youtube.com/watch?v=avVTMzQOKl8
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on September 21, 2015, 12:26:09 pm
Thanks for that link Brian. It downloaded here just fine.

Those animated pages are very easy to follow as well.

I need to go and get some supplies but will have a go at the splicing during the week.

That was interesting seeing the video of the other style of rope machine. I assume that it is the second motor with the single hook that actually twists the rope when the tension is right.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: Brian60 on September 22, 2015, 08:57:06 am
https://www.youtube.com/watch?v=2M5mo2I2c0Q

https://www.youtube.com/watch?v=IaHQUvG8jzA

A couple of videos on how full size rope is made, the first is the longest rope walk in the world, existing since the late 1600's, Chatham Dockyard.
Title: Re: Dumas Mr Darby - My build
Post by: Brian60 on September 22, 2015, 10:09:58 am
Forgot to add this...how to splice an eye into a rope.....

https://www.youtube.com/watch?v=QeYBkMCQ8WY
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on September 22, 2015, 10:51:07 am
Thanks for the videos Brian ... they went well with my morning coffee.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on October 02, 2015, 04:45:47 pm
I have finally got something done but no pics just yet. Both prop shafts and stuffing boxes are made and assembled so now I need to make the rudders, locate them, and then I can do a final location of the prop shafts and epoxy them in place. It should be ready to go in the water in about ... oh ... a year or so.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on October 03, 2015, 01:05:38 pm
I have one prop/shaft sort of in place.

(http://i994.photobucket.com/albums/af64/oldflyer_2/Mr%20D/Prop1.jpg)

A question ... should the shaft alignment be parallel with the bottom of the hull? This one is not quite there at the moment and needs just a tad more filed out of the slot.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: rhavrane on October 03, 2015, 03:07:48 pm
Bonjour Tom,

I am not a specialist but I was always told that the propeller shaft should be parallel with the water (horizontal), not with the botton of the hull.

If the bottom of your hull is horizontal...  ok2

I hope other modelists will confirm my opinion


Title: Re: Dumas Mr Darby - My build
Post by: Mad Scientist on October 03, 2015, 10:27:37 pm
Yes, for a typical working vessel, the shaft is horizontal - or close to horizontal.

In the case of high-speed boats (such as pilot boats or fast patrol craft), the shaft points downward, to help with the vessel's trim at speed.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on October 03, 2015, 10:30:47 pm
Thank You for the replies. As far as I can tell I can have the shafts level and still have lot's of leeway inside for motor mounting. I will know in a day or two.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: Capt Podge on October 03, 2015, 11:31:47 pm
It's difficult to tell from the photo Tom, but just make sure the blades of the prop don't foul against the hull as you near the horizontal.
 
Regards,
 
Ray.
 
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on October 04, 2015, 11:22:13 am
Thanks for the reminder Ray. As it sits at the moment there is about 1 1/2" clearance, but one I take the slight angle out, there will be around 1".

I now need to make the rudders so I can fit them and then get the final length of the stuffing tubes.

Thanks

Tom
Title: Re: Dumas Mr Darby - My build
Post by: Brian60 on October 04, 2015, 12:09:28 pm
an inch clearance seems quite a lot? Bigger prop {-) or I would try and re-angle the shaft to reduce the gap. Usually there would some type of skeg at the rear to support the shaft like this image or a 'A' frame of some sort.
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on October 04, 2015, 04:12:30 pm
Brian, I have a pair of 3 1/2" props at the moment and it would cost me $100.00 the pair for a set of 4" ones (at current exchange rate for the USA). It is far easier and cheaper to  just cut the slot deeper.

Yes, there is either a skeg type support for each shaft, or a pair of "A" arms to support the shafts. None of that is done as I haven't made the rudders which will determine where the props go.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 13, 2016, 12:34:05 pm
I am happy to say that I am finally able to get back to this build. I have tested some motors and they should have all the required power. I am building the battery tray and machining the motor mounts at the moment.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: rhavrane on February 13, 2016, 01:23:12 pm
Bonjour Tom,
If you have not definetely fixed the propeller shaft yet, another possibility is to use wheel gears to allow the shaft to be in the bottom of the hull, example (https://www.youtube.com/watch?v=UOjylZzQyeA) at 3'50". Plastic ones are less noisy than metallic ones.



Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 13, 2016, 05:00:17 pm
Hello RaphaŽl.

The shafts are now permanently in the hull. I have a huge amount of room in the hull and the 24 volt motors will have more than enough room.

I looked at some of your videos ... very nice indeed. I love the tug pulling you in the dingy and that is wahat I am hoping to be able to do with my tug.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: rhavrane on February 13, 2016, 07:54:00 pm
Bonjour Tom,
Of course, electric engines are easier to manage than steam plants ! Sorry, I had forgotten this "detail"  :o

And I am sure you will be able to pull heavy launches or dinghies, I know my Moulay-Idris powerful by ITSELF (https://www.youtube.com/watch?v=_8BZAgnvt6E), but please have a glance HERE (https://www.youtube.com/watch?v=HF0bGRDXGjA) and THERE (https://www.youtube.com/watch?v=0fm5igfZIok) when it fights against electric tugs... And thank you for the compliment  :-))
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 14, 2016, 10:35:27 am
Hello  RaphaŽl

Thank You for the video links. It is interesting to watch how different tugs can pull. It is also nice to see so many model boats out for a day in the sunshine.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 14, 2016, 11:31:08 am
We have propulsion ... well ... propellers anyway. Some filling and sanding to do yet but at least something done.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: ballastanksian on February 14, 2016, 02:43:29 pm
She looks good Tom.
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 16, 2016, 05:59:12 pm
Thanks ... I only hope I have them in straight! One minute they look fine and then the next time I look the seem to be crooked. I am going to get another model boater to look at them.

I just ordered my P94 controller from Action and it should be here in a week or two.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 18, 2016, 03:56:33 pm
A question for the brain trust here ... What sort of thing would be used for sealing and waterproofing bare wood these days. The stuff I used to use is no longer acceptable to elf and safety in this country. I am looking for something thin, that soaks in easily. I need to do the skeg and prop shaft supports on the outside, and eventually, all of the wood bit of the house works.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: JimG on February 18, 2016, 09:21:32 pm
I like to use brushing epoxy, used by aeromodellers for wing skinning with glass cloth. It is thin and will soak into the wood, even better if it is thinned further with alcohol. As well  as waterproofing it gives a harder surface to the wood. I often add some microballoons to the epoxy which gives a surface finish which will sand smooth with only one coat.

Jim
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 19, 2016, 11:14:33 am
Thanks for the info Jim.  I will have a look 'round and see if any of the local shops have anything like that.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 22, 2016, 11:55:00 am
Another question for the brain trust ... I am looking for couplers for my prop shafts. In looking around the net I came accross something called a "safety coupling". They appear to be two bits of turned brass with a bit of plastic tube in between them and held from spinning on the shafts with a bit of brass wire. Does / has anyone use these couplers and would they work on something as big and powerful as a Darby type tug? I see that Mobile Marine sell them as well.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 22, 2016, 10:50:06 pm
My P94 arrived today so I need to read up on it, do the cuts on the case and give everything a test run.
Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 27, 2016, 10:44:07 am
Well. this week has been the old two steps back trick. I spent many hours looking at my installation of the prop shafts/tubes and in the end I realized there was nothing for it but to yank them out and redo them. It was a bunch of work, but I think they are correct now.

In the course of the redo, I also decreased the clearance between the prop tips and the hull. It is just a bit less than 1/2" now. Also, Ontario suffers from heavy weed growth in most of the small lakes and it makes it easy for a boat to get caught up on them. To that end, I have installed solid supports for the prop shaft instead of the "a" arms. This should also give some extra protection from submerged stumps etc.

I have the case for the P94 mostly cut out to suit and I am going to work on a test board next week.

For them moment I shall start making the rudders and getting them put in.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 27, 2016, 02:30:26 pm
I just acquired this winch for a large tug boat. Apparently it came in kit form at one time and it used the parts from a Penn fishing reel to make it all work.

Does anyone out there know anything about these? What # of Penn reel it needed to get the proper parts?

It looks to be of good quality and I will use it whether I can get the spooler working or not.

Also a quick pic of the newly installed prop tubes. Quite a bit of sanding and filling to do on them when I get the rudders and skeg in.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on March 07, 2016, 10:39:43 pm
Just a quick update ... the parts for the winch are on their way from Texas.

I have the parts of the rudders glued up and they will dry overnight and the profiling can begin.

I have cut the 1/8" ply for the rear deck frame and now I can start to trim and sand and trim and sand and trim and sand .... untl I get it all to fit just right.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on November 28, 2016, 10:56:33 pm
Well, after several delays, health issues and just plain didn't want to do it, I am back on Darby. I was going to make the belt drives, but it just wasn't worth it so I ordered a couple.

Once they are here, I can get on with some stuff.

The deck crane is ordered.

Bow thruster ... this boat is 45" long and will weigh 65lbs or so ... what size will I need? Pipe diameter and motor size? Roebesh seems good but some reports say they break a lot and are under powered. I always fancied making one but I have no idea of size.

I will be doing a winch as well ... double drum I think.

Mare in a bit.
Title: Re: Dumas Mr Darby - My build
Post by: Butts on November 29, 2016, 03:28:27 pm
I guess it depends what you want to do with your tug as to what bow thruster you will need.
I have a 49" tug with the biggest of the Raboesch thrusters fitted (the one with two brass props).  At best it turns gently.  It is also very noisy  Maybe you could argue it runs a scale speed.
My working tugs have home made thrusters with brushless motors and racing propellors.  They are based on 42mm plumbing pipe with a 3" prop shaft running through the tube.  There have been a number of threads on here showing that design.  It works really well for competition use, but you could argue it is far quicker than any real vessel would achieve.
Title: Re: Dumas Mr Darby - My build
Post by: mike_victoriabc on November 29, 2016, 04:07:02 pm
Hi Tom
Looking at your winch - think this might have been made by someone on the island here - looks similar to one I acquired a few years ago. Will see if I have photos of it on a tug. Where did you find this one? Mike
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on November 29, 2016, 04:55:12 pm
Thanks Guys

Butts, I will look for a build thread. I don't want to be able to turn on a dime. I just want it to look realistic and throw out some water. This won't be a competition puller as there are no competitions anywhere near here that I know of. I have heard several comments about the Roebesh thrusters not living up to expectations.

Mike, the winch is a Ron Burchet one. I am working up a design for a two drum one.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: mike_victoriabc on November 29, 2016, 05:41:22 pm
Mine came from him as well. Will look for a photo of the motor setup.
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on December 03, 2016, 10:27:48 pm
OK, so I have done some work on the skeg. It is a framework covered with a ply skin. Once the one side is skinned and the cover sheet is on, I will cut out most of the inner frames and fill the interior with led shot to add some stern weight. Once the deck is on, there is not that much room left to add weight if needed.

I have attached some pics of what I have done.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on December 04, 2016, 03:05:23 pm
Some of the frames are now out and I have done a rough "fill em up and weigh" test. Disappointing at only 1.5 lbs, but I guess that is better than an empty air space that would want to lift the hull up.

That might help a wee bit with stability

Tom.
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on December 05, 2016, 07:46:21 pm
Done and taped in place until I decide if I want to make a heavier one or not.

Anyone have an idea if it is worth the trouble to do a heavier one or not? Do any of the competition type tug drivers out there have an opinion or used a weighted bottom like this?

Filling and sanding to do yet.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on December 09, 2016, 01:29:31 pm
The skeg is glued into place and I am working on my rudders now. I have the blades just about done and the parts that glue into the hull and are roughed out, the tube inserted, and glued and the epoxy is curing as we speak. I will sand them to profile, and then cut the holes in the hull for them.

Once the rudders are in, I will start some of the clean up work on the bottom and get that bit all ready for a good coat of primer.

You can see that I extended the centering marks beyond where the larger holes will be. That way, when I expand the holes, I will still have reference points. Don't ask how I know this.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on December 10, 2016, 02:09:34 pm
While I was out yesterday, my drive systems from Harbor Model showed up but needed a signature. I will go to the post office on Monday and retrieve them. Once I am done with the rudders, I will start on making a mount and installing the drive assemblies. Once that is done, she will be waterproof for now and water testing (friend has an indoor pool) can begin.

The rudder stubs that go through the hull are glued up and dry so I can start to profile them tomorrow.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on January 25, 2017, 11:25:39 am
It's been a while. I haven't been doing much in the shop but I have been trying to learn to use the 123D drawing program.

I managed to draw and print a rudder support and rudder for this build. I will have a go in the next week to install them in the hull.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on January 25, 2017, 06:49:23 pm
Forgot to post the pic, but at this point it appears it is all immaterial as I just did an experiment and fiberglass resin or bondo won't stick to the pla.

Oh well, more recycle scrap.
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 06, 2017, 04:15:01 pm
This build has come to an end. Unfortunately, I had some sort of "episode" in the shop, and fell down, landing on the hull that I had knocked off of the bench. The hull is toast, but other than a couple of cuts and bruises, I will be OK.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: Brian60 on February 06, 2017, 06:48:09 pm
Somethings are not meant to be Tom, its karma. I know my current build has thrown up so many problems of late that I feel like intentionally damaging it beyond repair - a different scenario but same result.

Hope you recover from your fall without any pain except the damage to the tug.
Title: Re: Dumas Mr Darby - My build
Post by: Umi_Ryuzuki on February 06, 2017, 07:17:59 pm
Good to hear you are okay after such an incident.
Perhaps a query around the web might turn up a hull somewhere.

Title: Re: Dumas Mr Darby - My build
Post by: Tug-Kenny on February 06, 2017, 08:04:24 pm

 So sorry to hear that Tom.  I'm glad you're alright though.  I can imagine how you feel.

Box up all the parts and pieces and you might come back to it with fresh eyes. 

All the best

ken


Title: Re: Dumas Mr Darby - My build
Post by: ballastanksian on February 06, 2017, 08:32:02 pm
I am so sorry to hear that, but like everyone else, I am pleased that you were not badly hurt. Definitly box it up and stow it away for a year. have a practice on the old 3D business, try out a few Resin friendly Reprap filaments and then get back to it with fresh heart.

Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 06, 2017, 10:54:47 pm
Thanks Everyone. The bits are in a box and under the bench for now, but I have my doubts.

I won't be in the shop for a while so I might feel different when I return.

Tom
Title: Re: Dumas Mr Darby - My build
Post by: oldflyer2 on February 07, 2017, 07:06:56 pm
The bits have been picked up by a friend that does fiberglass repairs to full size boats. He said he will have a go as he likes a challenge.

Cheers

Tom
Title: Re: Dumas Mr Darby - My build
Post by: ballastanksian on February 07, 2017, 08:16:39 pm
Well that is a great bonus! I hope he manages to sort it out and get you back on track with your enthuiasm undiminished Tom.