Help and advice needed

[grahamat]

Hi all.
I'm really hoping someone can give me some help on a special motor I need.
I have to build a very low speed but high torque rover to mount a camera on and I am struggling to find the right motor and esc.
ideally it would have a top speed no higher than a gentle walking pace but the rover will need to carry a load of around 8 pounds and it will have to start very smoothly.
It will only be 2WD as it will only be used on interior floors.
I would be ideally looking at a 550 brushless setup but am willing to consider any other options that any of you may recommend.
Please let me have your thoughts guys and I appreciate in advance any help you can offer.

[GLwagon]

How many volts for battery?

Many airplane "Out-runner" motors are multi pole, unsensored, & low KV; Yet, develop tremendous torque.
There is a minimum drive speed, but the lower gearing can help.
What type of gear reduction unit or gear box were you using & tire diameter?
Sensored motors have a much smoother startup, but cost will go up, but I have seen a 17.5 turn motor on 11.1volts that has a lot of torque.
A sensored motor like a Tekin 1/8th Buggy or Truggy motor can be found in low KV & are very smooth, but are very low wind & may get hot free spinning at 100% duty cycle.
Any ramps or hills in the building?

[rngrchad]

65 turn Brushed motor. A good one will easily handle 8lb rig and have incredible low speed resolution. Look for something from Holmes Hobbies.

[grahamat]

That's great advice. Thank you.
There are no ramps or hills in the building. All level floors but with different types of floor coverings ranging from wooden floors to deep pile rugs.
The rover will never be operated at full speed.
Smoothness is the most important thing.
Tire diameter will be somewhere between 4 and 5 inches. I intend using ⅛ buggy wheels with smooth or foam tires.
I want to avoid gears wherever possible but will bow down to experts opinions on this matter.
Thanks a lot for your help and advice.

[GLwagon]

Direct drive on any motor is going to be quite fast.
There is what is called a "roll out calculation" to calculate speed.
That big of a tire + 1:1 ratio to avoid gears will cause issues.

What's the budget?

A $10 Mabuchi 540 or 550 may be the ticket, but even at 16:1 Final Drive Ratio you are looking at up to 20mph on 8.4v

One of my crawlers is roughly 50:1 FDR & that does about 8mph on a $10 550 Mabuchi on 8.4v

Here is an old thread on some of it...
Gear ratio calculations and formula...

[grahamat]

As far as budget is concerned, I'm prepared to pay up to $600 for the right setup.
As I don't really know what I really need, other than the end result, I'm willing to look at any options.
if it's a geared setup, then I would be looking for whatever advice I can get from people in the know.
The main important points are the weight carrying, the maximum speed and smoothness of transmission.
I'm pretty good with suspension so the weight carrying isn't a problem. It's primarily the drive unit combination that is foxing me as I have only really dealt with higher speeds before. This requirement is for purely very low speed operation. the 2mph I mentioned earlier is a flat out maximum that will probably never need to be achieved.
I am based in the UK so I would have to ship whatever I need as the prices over here are insane! I looked at a couple of motors here and compared them with the same motors in the US and our prices are around three times the cost!

[Rjohn929]

Holmes puller 500 motor. It's brushed and he can make it anyway you want it. Contact Holmes Hobbies.