Member postings for Andy C

A lot of work maybe, but you could list the plans here or another site. There is also a Facebook page for roc boat plans. They need to be electronic copies though. So even more work.  In case anyone fancies a particular one. 

Edited By Andy C on 28/07/2018 10:55:42

My plans are stored in a file. I pull the relevant pages out of the mag an recycle it. Keep the pages with the plans. Just in case I ever get round to finishing one and starting another.

Found this on the Rolls-Royce marine website

Promas integrates the propeller and the rudder into a single system to optimise hydrodynamic efficiency. A special hubcap is fitted to the propeller which streamlines the flow onto a bulb that is added to the rudder, effectively reducing flow separation immediately after the propeller. The result is an increase in propeller thrust as previously wasted energy is recovered from the flow. The addition of the bulb on the rudder also streamlines the flow aft of the rudder, further reducing drag. A twisted rudder provides further improvements in efficiency and manoeuvrability. In general the efficiency gain is between 3-8% for single screw vessels and 2-6% for twin screw vessels. Virtually any vessel will benefit. The position of the rudder in the slipstream and the skeg design can deliver further improvements.

Erm. Isn’t there something missing

Hi Martin

I have had a squint around the net and most photos I have seen do not show crash tenders with flags flying. However I did find the following

**LINK**

Cheers

Andy

Hi Martin

Quick search of Youtube found a couple of videos. One where the bloke did not actually speak. Just twiddled a few buttons and hey presto. This one however did actually talk. See if it helps.

https://www.youtube.com/watch?v=Er0GeSj0cNw

There are some "most abundant" cars on the road, but not seen a boat powered by it. Interesting concept though.

andy

Edited By Andy C on 10/06/2018 20:53:40

Edited By Andy C on 10/06/2018 20:53:55

Thanks guys. I had a look at other pumps. Even the graupner item is not self priming and it is sold for this particular purpose. I have made a modification that I hope will work. Will have to make another trip to the pond tobtr6bit out. Oh well. Not all bad, as long as the sun is shining.

Andy

Thanks Ashley, I will investigate the motor and props.

There was a man steering, but he got called away to man the pumps. Only to find they were not actually working. May have to employ the services of a couple more people. He needs a hat too, seems he left his behind in the boat shed.

Okay so on the back of today’s boating, which was a great morning, I have tried some other things. Without the hoses connected it will fire both sides using forwards and backwards on the viper marine esc. However when I take it of the bucket of water to connect the hoses it stops working again. It will not squirt at all once you do this.

I still think it needs some water in it to work properly. So just means I will have to prime it pond side beforehand.

Unless anyone has any ideas.

Andy.

Was indeed a wonderful morning. The diver being chased b6bth3 shark was a cool sight on the pond caused quite a stir.

Tom had fun wi5h the fire boat until it blew a fuse. Gotta love the smell of blown fuse wafting on the breeze. We think the little speed 300 is the wrong motor for the job. So going to look at a 385 as recommended b6 Ashley. Pump still causing trouble but not a topic for this thread. Will post in the right place.

Thank you Ashley for letting Tom loose on your spare landin* craft. H3 had @ great morning.

Thanks Paul

Stuck with the balsa in the end. Just need to make sure I seal it well. Glynn's method of sealing seams quite sound and he does it that way all the time so not going change things now. I know there a lots of ways to do it, and as I have never done it before I think I will stick with what is printed.

Should be a fun model to whizz around the lake. some funky Colour choices going on but should be doable with Car paint.

Andy

So a little photo update. Jet drive installed. Did not see Glynn's little note about leaving out until later un the build but hey ho. It is in and looks good. A bit on the heavy side but will see how it goes.

Shot of it in the drive bay.

Started the side skins. From the stern forwards as per instructions.

More to follow.

Cheers

Andy

Edited By Andy C on 20/02/2018 18:41:33

Hi Dave

No offence is ever taken, especially from more experienced builders, when I ask for help or opinions. This is only my third ever boat build so I am still learning. I will stick to the build instructions as they are written. As you say I can always add a bit of ballast once it is finished.

Cheers

Andy

Hi all

Made a little bit of progress on the Vivace. No pics just yet, but will put some up later. I have a question though. The plan calls for the hull skins to be 3mm balsa but can I use ply instead for extra strength? According to Glynn the boat is very susceptible to being top heavy so will the use of ply bring the centre of gravity down and so make it less top heavy. Or will it as I suspect be to heavy an not suitable for the hull.

Andy

Okay, so I have done some more testing in the sink. It appears as though the car washer pump I have, twin outlet, requires no air to be in the system. For example, if I run the pump with just the end unconnected to the nozzles they will not squirt water. If I put a kink in one of the hoses and fire it again, it squirts. So I am guessing that when it is in a car, there must be no air in the system, in fact it would probably still have some residual water in the pipes creating an air stop. So, how can this be achieved in the boat? Maybe some sort of one way valves installed in the pipework? Hmm, either that or will a single outlet be better and have a Y piece to split the water flow to 2 monitors. Would you still have the problem of air in the system. I have a big hole in the bottom of the boat now where the pump sits, so cannot easily install one of the graupner pumps, as it would require trying to fill in the hole around the inlet pipe.

Thoughts.

andy

I did some testing this afternoon after stripping the electrics out again. It seem the pump does work and does pump, but it has to have some water already in it for it to work. now the problem is, when you take the boat out of the water all the water in the pump drains out. so next time around it will not work. I have the pump intake through a hole in the bottom of the hull and the pump horizontal. I think on cars it is fit vertical with water always sitting in the pump inlet. I now need to come up with a way of trapping water in the pump when the boat is removed from the water.

I wonder if fitting an elbow to the inlet hole will help. The elbow will face forwards and once the boat is driven it might fill the pump fro the water pressure. Hmm, some testing required me thinks. More soon.

Any other suggestions welcome.

Regards

Andy

Well, that was a tale of two halves, hits and misses, starts and stops etc etc.

Once upon a cold and snowy Sunday morning at the lakeside... Oh hold on wrong website.

Anyway, it works......sort of. Every thing was back to front and wrong side round. Easily fixed lakeside by flipping the reverse switches on the transmitter. So now going forward when asked and left when prompted. Squirters not working still and then she just stops. Near the edge thank goodness. Waiting for wind to push it to the side so we can retrieve and investigate. Seems the propshaft is too tight. Easy I think to sort out. Cold numb fingers not best for handling little 1.5mm Allen keys but persistence is everything. Sorted and back in the water and off she goes again. Then she throws another wobbly and keeps cutting out.

So what is wrong. Well;

1. The servo leads do not have the little tab on them and following the instructions that came with the viper 15, thought I had them the right way round. Seems not, so will swap them and check again.

2. Prop now turns easily enough, but will whack some light grease down the tube to help ease things a little.

3. Cutting out problems. Absolutely no idea. Did not do it before and runs nicely enough out of the water. Could it be pulling to much power and cutting the ESC out. It is running p80 speed controller rated at 20 amps. So should be okay right. Only using a speed 400 motor. How do you test it?

4. Squirters not working. So I thought it might be a problem with the pump not getting any water as it runs well enough. You can hear it. You knoow when you put a glass directly in water it creates an air gap, thought this might be the problem as the inlet is facing directly downwards. Did an experiment in the sink with a glass and a sieve to see if the sieve breaks the meniscus. Yes it does. So added a little gauze over the inlet to see if that helps. If nothing else it will stop bits and pieces getting in at least. Maybe the pump is at fault. May buy a new one and try again. Also now have the viper 15 hooked up so it can pump both nozzles when engaging forward and reverse, but pump cuts out at full throttle forward. Again maybe pull in too much current for it to cope with?

Any thoughts?

Cheers Andy

Playmobil figures look about right too and have plenty of firemen. Will head on down anyway as Tom wants to try it out again.

Andy

So, Tom's boat is nearly finished. Details painted on the sides and water cannons no controlled by a separate speed controller to give independent squirting. Some detail to finish at the stern and people to add. Taking to Bushey park for a sail in the morning for further sea trials.

Cheers

Andy