convivialist

Sometime ago, I found a 48 inch scale tug boat (built from scratch?) with fiberglass hull and electric motor that was pretty much ready to go except for damage to deck that it had suffered while in storage for a few decades. I had it repaired and running beautifully in the creek behind my house until I burned out the motor because I believe I used the wrong battery. I am hoping someone might be able to help me identify what type of motor replacement I should have and what type of battery and RC motor controller I should try to find. One other question: is there any reason to try and restore a boat like this using original 1980s components? Here’s what I know:

Diameter of motor housing is 1.5”
Hull is 48” long x 13” wide
Hull height at bow is 12”
The diameter of the prop is 3” and the pitch looks steep.
Id like to use the existing mounts because making new ones is perhaps something I don’t have the proper tools to undertake.

This tug was designed for power, not speed. it had a motor with brushes that allowed me to slow down the prop to almost nothing or accelerate and push a lot of water out the back. Can someone tell me what parts I need? I am brand new to this site so I will try to post pictures separately in a moment or two. Some sites do not allow pictures to be posted by new members so I am posting text only first. Thank you in advance for any advice you might be able to offer. Best, Bruce

convivialist

Sometime ago, I found a 48 inch scale tug boat (built from scratch?) with fiberglass hull and electric motor that was pretty much ready to go except for damage to deck that it had suffered while in storage for a few decades. I had it repaired and running beautifully in the creek behind my house until I burned out the motor because I believe I used the wrong battery. I am hoping someone might be able to help me identify what type of motor replacement I should have and what type of battery and RC motor controller I should try to find. One other question: is there any reason to try and restore a boat like this using original 1980s components? Here’s what I know:

Diameter of motor housing is 1.5”
RS 550 is model no on motor-Hong kong
Hull is 48” long x 13” wide
Hull height at bow is 12”
The diameter of the prop is 3” and the pitch looks steep.
Id like to use the existing mounts because making new ones is perhaps something I don’t have the proper tools to undertake.

This tug was designed for power, not speed. it had a motor with brushes that allowed me to slow down the prop to almost nothing or accelerate and push a lot of water out the back. Can someone tell me what parts I need? I am brand new to this site so I will try to post pictures separately in a moment or two. Some sites do not allow pictures to be posted by new members so I am posting text only first. Thank you in advance for any advice you might be able to offer. Best, Bruce[/QUOTE]

mfr02

For brushed motors, the usual rule is that the motor can should be a larger diameter than the prop it is driving, and it should have more poles than the prop has blades.
A steeply pitched prop will need more turning power, being effectively a larger diameter. If the motor is capable of producing the basic power, but at the wrong revs, a reduction gear will help. This effectively increases apparent motor diameter.
Avoid at all costs motors intended for racing, these are very common on fleabay searches, but not the right choice. An appropriate size motor (say an 850 or 900 size motor with 5 or more poles) could keep direct drive but would need a new mount, which "might" be available with the motor. A same size motor would need to have its mount shifted to accommodate the gearbox that would be needed, unless one with a built in or built on gearbox could be found, but will probably be below the basic power required.
The "550" indicates that it is 55mm long and probably 3 poles. What the windings on the poles were is anybody's guess. A 545 (54mm long, same diameter and mount, 5 poles, would sort of work if not run on the maximum voltage claimed on the label, but unless geared, would still suffer from driving too much prop.

convivialist

Thank you!

1) Can I use the same speed controller or will that need upgrade? Mine has a governor to limit max output.
2) Does someone still make motors with brushes so I could replace with original and just get the correct battery this time?

Because I am new to this site, I was unable to post pictures which I think would have been helpful. I know that some will post inane comments on a site just to get their count up to the minimum which allows posting pics, but wastes members’ time. In short, you gave me terrific information even without pictures. I am very grateful.

mfr02

1) Not knowing what your speed control is, no idea. Is it electronic or mechanical?
2) Yes, lots of brushed motors and their appropriate ESCs. Searching for" motors will lead you down the path that google decides, which is that the only models in the world are fast, or faster yet. You do need to specify "brushed" (because "brush" is a part of "brushless") and an indication of motor size, like "900". Once you know what motor is going to be used, you can start thinking about what ESC to use.