Gearbox suppliers in uk or the Eu????

[Guest]

Hi all,

Im looking for a supplier in the uk or Eu

That would produce a gearbox at 5:1 for use with a

Graupner 720bb torque motor. Or perhaps the 900bb motor with suitable ratio.

It's to power a 80" long hull that is around 60lb in lead weight alone prop size 5" i believe.

Kind regards

adam

[Guest]

Re: Gearbox suppliers in uk or the Eu????

it's also been suggested that i could use a lower rpm motor and therefore go direct drive.

http://www.modelslipway.com/motor_packs/MS%20900BB.htm

Might be suitable any thoughts.

[Guest]

Re: Gearbox suppliers in uk or the Eu????

I think you're going to be looking at a prop RPM of 1000-1500RPM top whack if that prop has any decent amount of pitch, and really that is going to mean a gearbox or belt drive of some description.

MFA/Como do a comprehensive range, and they're reasonably priced too, e.g.-

http://www.mfacomodrills.com/gearboxes/986d_series.html

Another possibility, is to check out breakers yards. Motors from radiator fan drives, heater blowers etc. can be suitable to run direct drive, as they're wound for very low RPM and high torque, but it can be a bit of a gamble, plus good breakers yards are getting a bit thin on the ground nowadays.

[Guest]

Re: Gearbox suppliers in uk or the Eu????

Hi Andy,

I had a feeling you would reply.

From what i can remember from discussions with Al and Chris, Al uses a 720bb torque with a 5:1 reduction.

And if im honest im not a fan of gearboxes, too much whine and more thing's to go wrong.
There's not any good breakers my way there like my hair style Thin.

Im curious about brushless motor's for this application,
Tbh i dont have a clue about brushless motors and what type of requirements they have and would you need to use a gearbox with this also?
Finally can they be run on jell cell batteries?

Anyone any thoughts on brushless?

Adam

[Wheelerdealer]

Re: Gearbox suppliers in uk or the Eu????

I'd go with the same brusless motor Robbe supply as an option on their 1/40 scale (slightly larger scale than your boat) 212 kit.

[Guest]

Re: Gearbox suppliers in uk or the Eu????

Ramesh,

Robbe roxxy?

Is that direct drive or gearbox???

And just curious what size is the prop on robbe kit??

Like i said above no clue about Brushless!!!
Also what voltage requirements?

Adam

[Guest]

Re: Gearbox suppliers in uk or the Eu????

They're just outrunner style brushless motors (google that). Some of the Robbe Roxxy range are wound for low RPM.

Brushless will give you more power for size and weight, but the controllers tend to be more expensive (for a good one) and motors with the right characteristics can be difficult to track down, although for larger boats it's a bit easier.

The other issue with brushless is low speed control. If you want to creep about at scale speeds underwater, then you may find that brushless motors with a sensorless controller are inferior to a good brushed motor.

[Wheelerdealer]

Re: Gearbox suppliers in uk or the Eu????

The Roxxy 5055/45 specs claim it will hande a 100mm Sickle prop on direct drive and is 100KV.

[Guest]

Re: Gearbox suppliers in uk or the Eu????

Yep that'll pull it round with ease.

[Guest]

Re: Gearbox suppliers in uk or the Eu????

Hi,

Guys.

I managed to locate a gearbox thats exactly the same as Al's . 3:1 it comes with a 720bb torque motor and runs at 1300rpm@12v.
I also located a cheap 900bb turbo so i might purchase that and try either or. Way off in the distance though chaps,
Need to get hull etc 1st.

It's also been suggested that i try a 560kv motor using it along with above gearbox.

Next thing i need some help with if your both up for it/ Andy-Ramesh.

Thinking about using piston tanks, However from listening to Traplet dvd re Alfa it says it require's 3ltr of water to dive.
Does anyone produce tanks suitable for application?? Engel 1000ml largest.

adam

[Guest]

Re: Gearbox suppliers in uk or the Eu????

What is it you're building?

Generally piston tanks used on their own suit small to medium size boats, but you might be okay if your boat has a low freeboard- Alfas don't.

You can make a hybrid system using say a water pump for a large central tank, and a pair of smaller piston tanks to trim the boat to neutral or negative buoyancy.

[Guest]

Re: Gearbox suppliers in uk or the Eu????

Andy,

It's a 1/42 scale Alfa

I thought someone might have produced 1500ml or 1800ml tanks. But as above 1000ml Engel.

2nd thought was central unit with pump and perhaps two, 750 or 825ml Tanks either end for trimming as you suggested

3rd thought is Rcabs but unsure.

Im sure, yourself, Ramesh, Chris sheerline, and rob from subt uk as he's 3mile from mine and is a crazy boy...

Will manage to help me out or suggest alternative's.

I need to update the capacity it turns out it's a 7ltr tank but once water was pumped in it compressed the air to 3.5 litre therefore i need something in the range of 4ltr to be safe.

Thanks again all.

[Guest]

Re: Gearbox suppliers in uk or the Eu????

I wouldn't recommend RCABS. Sourcing a 3 litre bag could be interesting!

No one I know of produces tanks of that volume commercially. You would need fairly large pistons- 80mm minimum to keep the tank length to sensible proportions.

Got a lathe?

[Guest]

Re: Gearbox suppliers in uk or the Eu????

Andy. i dont have a lathe.

With regards to wtc dimensions i believe it's 6" and the length im unsure of it's been suggested 42".

I really like the idea of tanks though.

Maybe a central pressurised module of say 2.5ltr and two 825ml tank either end as you suggest.

Im trying to reduce original dia from 6" done to 4" as i would like to place the batteries underneath the wtc in free flood area.

Looking at pic's you and ramesh posted ages ago showing Al's boat the wtc sit's fairly low in the lower hull and there's no room for jell cell. so thought remove 2" from wtc and might be enough room for batts. + Engel tanks are in the region of 3" overall incl motor.

What you think??


regards
adam

[Guest]

Re: Gearbox suppliers in uk or the Eu????

Wouldn't use a pressurized centre module. Use a vented tank water pump system- that way no exposed water surface, which is an inherent disadvantage of the pressurized system.