Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Engineering Techniques and Materials. => Topic started by: Brian60 on October 03, 2015, 08:34:15 pm
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Planning for my next project I'm going to need some bevel gears. In total it's about 16 of them :o But they can't be any larger than 9mm diameter across the face, teeth number is not important (more the better for meshing)
Couple of other things, shaft size big as possible and must be made of brass. So has anyone a supplier they can suggest please
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Brian.......an American steam locomotive called the SHAY, uses conventional 3 cylinder vertical steam engines, but the power is transmitted to the driven wheels via pairs of bevel gears ....I have seen examples of model engines with 2:1 ratio bevel gear sets with the wheel being approx. 10 mm diameter :o
...here is a link to a model build with plenty of detail of the gear sets .............Derek
http://www.modelenginemaker.com/index.php/topic,3778.msg69261.html#msg69261
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Try looking up Davall Gears on google, they do loads of gear related things, had a catalogue once and it made interesting reading. Small orders and model size products were available.
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http://www.davall.co.uk/ (http://www.davall.co.uk/)
book marked for future reference.... some good stuff on there
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meccano gears any good?
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even the small meccano bevel gears are about 13mm minimum, and you would be looking at a small mortgage for that quantity - lego do small bevel gears that might suit.
heres the smallest meccano one http://meccanoman.co.uk/catalog/product_info.php?cPath=1_14_17&products_id=1159&osCsid=bcd6b38b89006cfe9fe8d1ef4416ed01
at just over £5 each
heres the lego ones at just about 3p each http://www.brickowl.com/catalog/lego-tan-bevel-gear-with-12-teeth-6589. you would probably need lego axles to suit.
I too have a copy of davalls gearbook as a reference.
you might also find some bevel gears in old inkjet printers, I regularly rescue old printers and strip them down for gears shafts and small bolts.
Grendel
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Motionco.co.uk may be able to help.
Barry M
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Have a look here ,if only this was in good old Blighty .
http://www.smallparts.com.au/technical/timing/. Ahhh I see its pasted the bit I was reading ,it will get you in the right area as usual follow the links to the bit you want .
Is it really dear to get things from OZ .
David
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One of the books / catalogs I got from Davalls was the handbook of metric drive components by SDP SI, which has a bit of everything - gearboxes, timing belts and pulleys for them, magnetic slip clutches - a bit of everything you will be likely to need.
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Thanks everyone, as mentioned meccano ones are way too large, at 18mm diamter. The motionco ones are just about right size but in Delrin, their brass ones are not small enough.
I'll take a look at the other links this evening when we are back from afternoon lunch with our daughter and son in law. Then the journey back to Spain to think about tomorrow, we leave early on Turesday morning.
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OK, nobody else has asked and so I will: just what is this project that needs so many bevel gears?
Remember we have ways of making you talk. Not excluding exposing you to Martin's shirt wardrobe. (Insert appropriate smileys here unless, like mine, the system won't cooperate.)
Barry M
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With four bevels to a drive, I reckon Brian is building something that in real life would need very accurate drives for positioning, so perhaps an exploratory vessel or something the Oil companies use with four schottel drives?
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Think you are on the money here Ian.......a few weeks back we saw a vessel with a combination of multiple Voith drives & used for constant GPS positioning....
From memory {-)...it had markings for twin bow tunnel thrusters, however the Chinese build only showed one single athwart ship thruster, in subsequent images we detected a Voith schottel type drive just aft of the tunnel thruster that could be lowered for use & raised when not needed
I wonder if a model gyro from a helicopter be used in this application?..................Derek
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OK to put you out of your lust for info. I need four of these, 2 forward, 2 aft. But having spent an hours searching for gears, they came to over a £100 I am now on a different track!
Basically I was going to fabricate the housing, have a through prop shaft with a bevel gear in the centre, then a down shaft with a matching gear to mesh together. The top end of the shaft would have matching gears to go to the motor drive. The whole unit would be revolved around at the top by a crown gear and suitable waterproof seals.
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Can you not mount the motor vertically and eliminate one set of gears?
Not sure of the size of things but have you googled gear sets from slot cars? They use bevel gears but I'm not sure of the sizes. There are slot cars up to 1/24th so might be big enough.
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Hi Brian
Not sure if this is of any help but I used some nylon gears from HPC gears in my working outboards http://www.lifeboatmodels.co.uk/atlantic.htm (http://www.lifeboatmodels.co.uk/atlantic.htm)
I did try and make some brass ones they did work but slipped on the shaft after a time so I'm back to using the Nylon ones and they work well.
John
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Hi Brian
Not sure if this is of any help but I used some nylon gears from HPC gears in my working outboards http://www.lifeboatmodels.co.uk/atlantic.htm (http://www.lifeboatmodels.co.uk/atlantic.htm)
I did try and make some brass ones they did work but slipped on the shaft after a time so I'm back to using the Nylon ones and they work well.
John
This why I didn't want to use nylon/delrin, I reckoned they would slip on stainless steel shaft. I thought using brass gears I could solder to brass brass shaft.
Can you not mount the motor vertically and eliminate one set of gears?
Not sure of the size of things but have you googled gear sets from slot cars? They use bevel gears but I'm not sure of the sizes. There are slot cars up to 1/24th so might be big enough.
I checked out what I could and like above those that are bevel gears and small enough are nylon. The larger sizes use standard sprockets made of aluminium, the motor mounted transversely to allow its shaft to line up with the sprocket on the axle.
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Once you get the gears on the right place why not drill through the shaft and collar and drift a pin through
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Put the motors in the pods and surround them with fine weave fabric so that while they might get wet, the weave will keep the very worst of the silt and glop out of the workings. I am sure that a chap of your skills could make two part pods saving oodles on gears etc, probably simpler to make as well. Could you utilise technology that model submariners use to keep their motors dry?
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Ian that was my first thought. But there isn't as far as I know a small enough motor with the torque required to drive 55mm props pushing a 1metre displacement hull.
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Even in the brushless market? Hm.
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Even in the brushless market? Hm.
Brushless I have no idea over Ian, I've never used them. I did ask advice on another site, but so far have not had luck. If there was a small enough brushless that somebody could suggest I'd certainly give them a go.
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what is the outside diameter of the pod housing ?
john
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Motors could be up to 20mm diameter or a little more, certainly no more than 23mm or the outer pods will look too big for the scale.
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As far as I know you will nit find anything suitable in the RC sector.
All motors gave too much rpm/V.
You could check at Maxon and Faulhaber. They make very decent motors with 22mm diameter.
Maxon EC22 is what you are looking after. Maybe you are lucky at ebay.
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Maxon EC22HD $1200 each :o :o no not a misprint! I need four. Seeing as I don't have the odd $5000 to spare I think these are in the NO category :embarrassed:
Thanks all the same Timebandit.
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Regular price should be between 100-200£, not so sure what you found there.
You'll find them pretty often at ebay at leadt here in germany.
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Tobias that pricing was from the parent site in USA, the model I looked at is very high tech, way more than I ever could need. Produced for underwater work down to 17000ft.
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On the motor side I think you will struggle to find a motor that can swing X2 55mm 4 blade brass props and be smaller than 23mm in diameter . I have seen it done on a single prop pod but not a double
john
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I've located a supply of either nylon or brass or aluminium gears. Made for customising slot cars (Scalextric) they come in various ratios and are secured by grub screws, they are not bevel gears but crown and pinion, so they will do the same job in a different way! Not bad pricing either-- I can afford these :}
http://www.pendleslotracing.co.uk/spares.html
thanks everyone for your suggestions and input.
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This is a good find,it's gone into the could be useful folder.
Thanks Brian
David .
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I am glad you have found something Brian. I read somewhere on the forum recently that Nylon expands to by a finite amount when/if submerged in water. It might have been in a thread about washers or prop shafts, I thought I would bring it to your attention so you can gauge tolerances when designing your pods.
You don't want gummed up pods now do you {:-{
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I am glad you have found something Brian. I read somewhere on the forum recently that Nylon expands to by a finite amount when/if submerged in water. It might have been in a thread about washers or prop shafts, I thought I would bring it to your attention so you can gauge tolerances when designing your pods.
You don't want gummed up pods now do you {:-{
:-))
Especially when they will be sealed for good once built.
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expensive but what you want
john
http://www.bauer-modelle.de/modules/wsShop/index.php?cat_id=83511&location_id=151