Model Boat Mayhem
Mess Deck: General Section => Model Boating => Topic started by: Wheelchairman on June 02, 2017, 10:45:14 pm
-
I am a disabled OAP and bought a ready built Maasbank, I was told it needed a 6 volt battery, it is a 5 - 15 v motor, The Component shop said it will take 12 volt, the problem is I just can't get the stern down low enough to drive the boat with any power,
1/ with 7.2 NiHm just get froth at the stern and no reverse or very little,
2/ 6 volt battery takes bow down and same result
3/ put 12 volt in and about 1ib 4 ozs of lead round back just before rudders about 600 grams+ goes alright forward but awful slow reverse but answers rudder, do I need to put more weight in? the instructions I downloaded (googled) says 8.4 NiHM battery,
Any help would be really appreciated,
Thanks
-
could you post some close up photos of the propellers that you have on your model.
it might be that the pitch on the blades might be too fine, thus causing froth rather than bite the more power you put on, and very little in the way of reverse movement for the same reason.
Jim.
-
Dear Jim,
Thanks for reply, everytime I add a photo, it says file too big, how do I reduce the size, looking at it it does seem a shallow,
-
Dear Jim,
I would never have thought of that, so the deeper the prop angle the more power it gives? can I add a photo to Mayhem on Facebook,
Thanks,
-
Look at this picture and it shows how your model should be sitting in the water to put the prop under far enough.
-
Thanks for that photo, I cannot get photo on Forum, but have managed to put them on Facebook, marked for Jim, the prop looks like the right one but am not getting the power I have with a pusher tug I use
Thanks
-
The photos on Facebook are being checked by admin so aren't up yet
Thanks
-
Dear Jim,
Thanks for reply, everytime I add a photo, it says file too big, how do I reduce the size, looking at it it does seem a shallow,
hi, go onto google and type in free image resizer the one I use very simple is called Light Image Resizer...........
as for the prop shaft angle..........didn't mean that.......the pitch of a propeller refers to the angle of the blade on the boss, and how far a hull will sail with one revolution of that prop......the greater the angle the further the boat will go as with propellers for steam engines..........the less the angle of the blade the shorter distance until you come to the point that if the blade is at right angles to the shaft with no twist to the blade..........it won't go anywhere at all.
jim.
-
Thanks for info, I'll download that downsizer, but it is 4mm shaft and a 40mm dia prop, and is very shallow, how do I get to see the posts others have put on? I have to go to search for Maasbank to get to my posts but I can't get photo, tug mad sent,
Thanks
-
Sorry I've worked out how to get to message and photo Tugmad sent,
Ta!
-
Photo resizing - http://www.modelboatmayhem.co.uk/forum/index.php/topic,23.0.html - lots of discussion, but if you are using Windows 10, the facility is built into the Paint program, it is also built into the MS Photo program, both under the "Image" tab.
The prop might be profiled (the curved shape of the blades as seen from the end) for best effect going forward. If it is too near the surface, it can will pull air down and create froth in reverse.
Using a lighter battery will give you the need to add ballast. The advantage is that you can put the both ballast and battery where you need them, rather than having all of the weight in one, possibly inconvenient, place.
-
Thanks for that info, I have learnt so much in a few posts, going to try a 8.4 Nihm battery a lead weight at the rear,one post I found on google someone said they used a 40mm 4 Blade 544-040 prop, on 6 volts No idea where to get one - what does anyone think?
Still got to try it in pond, going to put a float on top so I know where it goes down ;-) {-)
-
Probably meant the one of that number on this page - http://www.cornwallmodelboats.co.uk/acatalog/4bladem4.html
-
Dear Malcolmfrary many thanks for info, it is out of stock at the moment, but maybe able to get a plastic one, that prop looks as shallow as the photo I put on Face Book,
Thanks again
-
Dont forget, the prop will still be near the surface because of the shaft depth, the only way is to lower the stern with ballast, without a radical re-build to lower the shaft in the hull
Mark
-
Hello Jarvo, thanks for that, just rang Cornwall Model Boats they have not got the Prop I was thinking of, but they said a 4 blade would not increase power, and in fact would slow it down, I would be better putting a 400 motor in, after trying it on pond. Going to pond tomorrow - hopefully we've got torrential rain, and gales at the moment, I have put a lead weight in the rear at least now the rudders are under water, it seems to help, looking at the motor I am sure it is too small 5v - 15 volt is all it says on it.
Thanks
-
Hi Mate, your profile shows you in cheshire, where abouts, im a member of Etherow club, near Marple.
Mark
-
No I am with the Runcorn club, good people there I wanted to get tug ready, I have ordered a Mtronic 400, mount and and insert, so if it is not right tomorrow, I've got the bits to try extra power. ok2