Author Topic: My little springer "Sequana" (Ramborator)  (Read 22181 times)

0 Members and 1 Guest are viewing this topic.

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #15 on: May 06, 2014, 16:04:11 »
Log 2014-05-06 : 3D printed wheelhouse

Once the wheelhouse was modeled in SketchUp it was time to fire up the 3D printer.

And uh ... things got a bit wrong.

I first decided to print the wheelhouse on its own (no roof, no door ...).

It was going to be an 18-hour print. I started it before I went to bed and should have been complete when I'd come back from work the next day.

Except that when I woke up in the morning and went to check how things were going I found the printing head hovering approximately 4 centimeters above an obviously incomplete wheelhouse.

Somewhere near half of the print the nozzle got clogged and plastic wouldn't extrude anymore. It looked like the printer decided to stop extruding but keep pretending and moving around.

Well, that half printed wheelhouse pointed out some flaws in my design so back to SketchUp for some quick fixes.

I stuggled unclogging the nozzle (which is 0.40mm). Took the printing head apart and tried to unclog the nozzle with a bronze brush I had laying around. I managed to get the nozzle unclogged and printed for about 20 minutes at high temp to try and get rid of any dirt or gunk.

Wheelhouse has large unsupported areas (windows). With a fine tuned printer you can "bridge": print "in the air" from one pillar to another with no support/scaffolding.

Except that the nozzle was still partially clogged or had some leftover gunk: when extruding plastic would curl and curl to a spaghetti-like mess. Forget about "bridging".

Hence I decided to add support (think scaffolding/falsework) using some other software instead of Cura's building support generator (Cura is the slicer from Ultimaker, my printer's manufacturer).

Autodesk Meshmixer is a 3D "sculpting" software which has an interesting support generator which creates tree-like scaffolding which requires less plastic (which means less printing time).


Meshmixer-generated support


Front view


Working hinges


Rear view


All the parts

Though not visible in the pics above the partial clogging caused problems during the print. Will need to clean up the nozzle good.

I'm very please by Meshmixer's support feature. Saves quite some time when printing and the scaffolding just snaps of very cleanly. Just some sanding is required.

Some more modifications to the wheelhouse: added two more brackets to the side walls to support the bridge.

The plastic windows supplied with the Ramborator kit fit quite well into the recesses I modeled at the back of the windows.

Next: setting up the lights and tweak the wheelhouse (to hide/route LED wiring).

I've ordered various fittings from CAP Maquettes: telegraph/power handles, GPS screen and antenna, Radar and screen, ...

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #16 on: May 19, 2014, 00:45:03 »
Well, the wheelhouse prototype shown above ended up at the bottom of the pond yesterday.  :D

Wheelhouse (unpainted, no windows ...) was just double-sided taped to the main hatch so that the tug would look a bit less odd. And when I picked up the boat at the end of the day it fell right of as water had soaked the tape.

Anyway, not a big deal the plan was always to print it in ABS.

All in all a good afternoon of sailing. Recovered five boats, one tree branch that speed boats had been hitting repeatedly and also recovered a soccer ball.  :D

And if I'm to trust my battery charger I should actually be able to get almost 4 hours of run time. Those brushless motors really are efficient !

mengam

  • Jr. Member
  • **
  • Posts: 98
Re: My little springer "Sequana" (Ramborator)
« Reply #17 on: May 19, 2014, 07:18:45 »
Hello Caliméro

Nice 3D printer job.  This technology is a dream for me and certainely for many modellers, not to built a flat wheel house but for complicated winches or deck accessories it would be so nice !

Mengam   

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #18 on: June 02, 2014, 15:22:02 »
Log 2014-05-31 : Wheelhouse ... aka "I work better under pressure"

As I shifted from PLA to ABS for 3D printing, I learned the hard way ABS is much more tedious to print right.

ABS is printed at a significantly higher temperature: around 260°C vs around 200°C for PLA.

ABS also tends to retract/warp when cooling down. The base of the print must hence really stick to the printer's glass plate if you even remotely hope to prevent warping.

Glass plate was covered with Kapton tape and them covered with ABS slurry: ABS is dissolved in acetone to get a watery substance that has to be brushed on the print plate.

Even that way my first prints in ABS showed significant retraction/warping.

Worse: one of the doorposts broke (ie: two layers of ABS "got loose").

And it only went downhill from there. Nozzle got clogged (I suspect that at 260°C any dirt or even leftover/unextruded plastic will just burn). While trying to get the nozzle off to scrub it good (and burn any residue on the kitchen stove) I only managed to snap the wires off of the temperature sensor.

My printer is essentially useless for the time being until I get replacement parts from Ultimaker - which is going to be a problem as they struggle to meet demand. Yay !

Anyway this was tuesday. And the next weekend was Bateaux en Fêtes in Massy (20km south of Paris) a nice event where I was to sail with other tuggers including mengam.

I decided to reuse one of the "semi-failed" prints to make a temporary wheelhouse, put the lights on and give it a quick coat of paint to have it look somewhat decent.

Primer and paint were of course at 500km away at my parents'. Had to get spray cans here in Paris. There's a home improvement shop a couple paces from my office that usually stocks the same brand and colors as I used on my Odin. I try to stick with the same paint in order to reuse paint across boats.

Of course, they didn't have exactly what I needed (satin-mat RAL9010 pure white). Only had some water-based kid-proof version.

Wheelhouse was printed in "natural" ABS which is whitei-sh and somewhat translucent. All areas around lights were first painted black with Tamiya Acrylic paint (with a brush) to make them somewhat opaque. Took like five coats of black and then three coats of white.

After some quick sanding (3D printing is not good at making smooth "walls") wheelhouse was primed with plastic primer. A couple hour later universal primer was applied.

Again some wet-sanding at #600 grit. Not enough obviously as the "finished" product still shows the typical surface of 3D printed parts. It probably needed two extra rounds of priming+sanding I guess. But at four o'clock Friday morning (with your alarm clock going off three hours and a half later to get to work) you tend to lower your standards drastically.

A new wheelhouse will be printed as soon as I get the printer back up and running. And this time I'll spend the required amount of time to really prep
the parts before painting.

I didn't use the supplied window panes on this interim wheelhouse. I instead cut panes from a 0.40mm clear styrene sheet (from Evergreen). Glued them with CA glue and as expected they got somewhat cloudy. I'll need to get some "canopy glue".

I also had to put a new hatch with a GoPro mount together. Threw a few plywood parts together to make a replacement hatch I would use instead of the "scale wheelhouse". Also added lights to the "filming hatch" so that I'd be able to film at night. A glass of epoxy and a glass of G4 sealer/primer later and it was done. Ugly as hell but it worked and proved watertight. Function over form ...


Interim wheelhouse - From a distance and with some overexposure it doesn't look too bad


Railings - Bending and painting the railings was also some kind of mess ...


Lights on - Very decent brightness

Propeller was changed/upgraded as there was some heavy towing planned at Bateaux en Fête with mengam bringing his "Toy for Tugs". I got a 4-blade #174 45mm Raboesch prop to replace the 4-blade #147 40mm propeller I usually sail with.


Type 147 4-blade prop - 40mm diameter / 41mm pitch


Type 174 4-blade prop - 45mm diameter / 40mm pitch

Type 174 props obviously have much more blade area. Combined with the increased diameter it gave a significant increase in thrust. The minor loss of pitch was negligible (if not a welcome side effect).

It proved a wise move considering the massive tow we got to play with at the meeting ...

Obviously current draw increased but event with some heavy towing (ie: constant full throttle) I was able to get a solid hour and a half out of the 7.2Ah battery. Could probably have gone up to 2 hours. Motor was barely above air temperature and ESC was cool (rated at 60 amps ....).

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #19 on: June 02, 2014, 15:44:04 »
Here's a video of the Sequana towing mengam's Spirit of Archimedes a 4-meter semi-submersible heavy lift ship. Ballast capacity is around 300 liters.

<a href="http://www.youtube.com/watch?v=YsZXOuTRnmw" target="_blank">http://www.youtube.com/watch?v=YsZXOuTRnmw</a>

There's also a Voith tractor tug at the stern helping as the Spirit was somewhat a dead hull after an earlier mishap (either coupling broke or motor shifted ... no propulsion).

Thanks to mengam for his toy for tug. We had three VSP tractor tugs (the Morbihan even had 100% custom machined VSP that were near perfect replica down to the paint job of the real deal). There was also a twin-ASD model of the Fairplayer. Had a looooot of power. There were also more classic tugs including one running on live steam. Damn that bastard was quick ! I couldn't keep up with my Springer with the GoPro.  :D

I'll start a new dedicated topic in the "Events" section and post more pics and footage of the "Bateaux en Fête" event.

Jarvo

  • Jr. Member
  • **
  • Posts: 98
Re: My little springer "Sequana" (Ramborator)
« Reply #20 on: June 03, 2014, 03:05:10 »
 Hi Calimero

Quick reply to your problem of paint creep under your masking tape. The easy answer is spray a dust coat of clear acrylic lacquer over the joint, this will seal the edge.

Like us all you are looking to save money on disposables, cheap masking tape is crap, buy good stuff 3M etc, ask at a local body shop were they get there supplies from. Possibly buy it from them most places are interested enough to help.

Hope this helps

Mark
Etherow Model Boat Club

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #21 on: June 03, 2014, 04:11:17 »
I read somewhere (don't remember where) that there's vinyl masking tape (instead of the paper-based stuff) that supposedly gives a much better seal.

Using lacquer sounds like a good idea too.

Next or maybe next time I'll just spray paint all the way. I'm thinking of another springer with dual korts (maybe even steerable korts).  ;D

Jarvo

  • Jr. Member
  • **
  • Posts: 98
Re: My little springer "Sequana" (Ramborator)
« Reply #22 on: June 04, 2014, 01:33:33 »
You are right, there is vinyl masking tape, and plastic tape, if you are not careful the plastic tape can leave a lot of residue behind, clean up, removal is difficult. This is because when you clean the job ready for paint the thinners or pre paint soften the tape.

Vinyl tape is brilliant for difficult corners like round the stern etc, it can turn to follow the contours, but it can be very expensive, try using PVC insulating tape, or better still use small lengths of paper masking tape and follow your contour lines and trim back with a sharp scalpel type blade.

Mark
Etherow Model Boat Club

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #23 on: September 07, 2014, 11:07:31 »
Hi guys & gals, just a quick update with a lousy video and more importantly some hard data

Here's a quick video of the Sequana at our club's pond in Velizy-Vilacoublay. Not the best footage (sailing and filming at the same time is quite challenging, especially with the lousy grip a cell phone has to offer):

<a href="http://www.youtube.com/watch?v=M7lR9d2SGtc" target="_blank">http://www.youtube.com/watch?v=M7lR9d2SGtc</a>

The main point here is actually some hard data I collected this afternoon. I got this Turnigy 2-in-1 Power meter/Servo meter. I decided to measure the actual power draw of the brushless outrunner in the Sequana.

Current setup is described in the bill of materials. In short: 3542-800KV brushless outrunner from HobbyKing, Trackstar 1/10th 60A car ESC, 6V 7.2Ah SLA battery.

The Sequana was running with the "standard" Type #147 Raboesch 40mm 4-blade propeller (not the "heavy towing" #174 45mm 4-blade prop).

Power on, throttle 0% (ESC powers the receiver and its own cooling fan): 0.50A
Power on, throttle 40% (cruising speed): 2.20A
Power on, throttle 100% (not practical unless towing): 7.10A

While the 2.20A figure (~1.50A for the motor itself) is in line with the battery life I get, I'm a little surprised by the full throttle figure. I assumed it would be a little less.

I'll get the same measurements with the "heavy towing" wide blade #174 prop next time. Power draw should be significantly higher.

des

  • Sr. Member
  • ****
  • Posts: 408
Re: My little springer "Sequana" (Ramborator)
« Reply #24 on: September 07, 2014, 21:12:16 »
Further to the discussion above re masking tapes, for my AZIZ I used Tamiya 25mm width tape around the joint line where I wanted to add a second paint colour.  I then used plain Scotch masking tape (available from most hardware stores) and newspaper to mask off the bulk of the hull.

Where I found that the Scotch tape would lift and peel if left on overnight, the Tamiya tape remained in place until I peeled it off.  It came off cleanly, with no residue to speak of, and without peeling off any paint with it.

Admittedly, the Tamiya tape was expensive compared to the Scotch tape.  But you get the results you pay for.

Des.

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #25 on: November 23, 2014, 17:17:51 »
Quick update Log 2014-11-10 : Dusk sailing and more data

<a href="http://www.youtube.com/watch?v=FFVkuq1UOto" target="_blank">http://www.youtube.com/watch?v=FFVkuq1UOto</a>

And some data with the #174 45mm Raboesch propeller:

Power on, throttle 0% (ESC powers the receiver and its own cooling fan): 0.55A @ 6.35V
Power on, throttle 40% (cruising speed), out of the water: 1.55A
Power on, throttle 40% (cruising speed): 2.60A @ 6.30V
Power on, throttle 100% (towing): 11.2A @ 6.25V

First amp gets lost in the motor and prop shaft. Quite expected.

Amp draw at cruising speed is not bad so I'm going to keep this prop on (I thought amp draw would be significantly higher than the #147 / 40mm prop I usually go with)

Full throttle figure on the other hand is significantly higher: 10.6A vs 6.6A.

I just got a fishing/luggage scale. I'll try and see whether I can get decent/repeatable bollard pull figures !

tbone

  • Sr. Member
  • ****
  • Posts: 383
Re: My little springer "Sequana" (Ramborator)
« Reply #26 on: November 28, 2014, 23:06:26 »
Interesting tests you're doing.  Does the 174 prop have noticeably more towing capability?  I'm guessing either prop is overkill once under way but the bigger one may help get it going quicker.

ChrisE

  • Newbie
  • *
  • Posts: 16
Re: My little springer "Sequana" (Ramborator)
« Reply #27 on: November 29, 2014, 05:59:48 »
What are the comparative thrust numbers?

It has occured to me for some time that the 40mm 3 blade (for purists) 174 might well be a better Springer prop than the more common 147 higher pitched example.
« Last Edit: November 29, 2014, 06:03:03 by ChrisE »

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #28 on: November 29, 2014, 11:24:22 »
I got a fishing/luggage scale which - from basic tests (weighing known weights) - seems relatively accurate.

I won't be able to make an 'apple to apple' comparison as I only have a 40mm #147 and a 45mm #174.

To me it is obvious the #174 prop is the way to go for tugs. Lower pitch, much larger blade area.

I'll post BP figures as soon as I can.

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: My little springer "Sequana" (Ramborator)
« Reply #29 on: December 14, 2014, 11:54:24 »
Back from the pond. No regular club members in sight. Ducks also had deserted. Not unexpected considering the temperature: 1.5°C.

There was just one guy testing his Mono-1 FE. Hull has a flood chamber so that it rights itself. He had tweaked/tested it in his bathtub but once on the pond it just wouldn't get back up even with a few throttle "bursts". As always the Sequana was here to save the day !  :D

As I said earlier I got a cheap luggage/fish scale from eBay. I weighted a few items at home and compared to an electronic kitchen scale. Got the same figures +/-4g. Luggage scale only displays weight in 5g increments (up to 1kg; then 10g increments). Looks like it's going to be good enough for my tests.

Scale lanyard was hooked to a steel pipe that protrudes 30cm from our pontoon. The scale was laying flat on a piece of plywood I held in my hand.
It was tricky "guiding" the scale while steering the tug with one hand as she would rock left to right. Pull would spike up to 900g+ but once I was able to keep the Sequana in line BP stabilized around 780g.

While the #174 moves a lot of water I'm still somewhat surprised by the figure especially compared to BP figures from other model tugs. Higher than I expected.

I'll take the scale with me again so that I can confirm those figures. I'll ask another club member to help me so that we can get 10 samples and average them.