Micro 90rpm Motor Hign Torque

Question

Looking at making a 1:2 scale r2d2(not in crazy detail) from wood and just for reference I was wondering if anyone had seen a pretty small motor with high speed and if possible, a mount? The wheels I'm looking into are 3" diameter by 0.2" wide but I could change quick. Needs to be under 4" as the feet cover is only 7" at the bottom and 3" at the top. A servo style motor would fit best but don't see any 90rpm high torque servos. Any suggestions?

Troy · Answer

This probably isn't as high torque as you wanted but here is a suggestion. 90rpm 70oz/in 12vdc motor Here it is without the enclosure. sparkfun motor

CardboardHacker · Answer

Forgot to mention I was hoping for a 6v one so I can use AA batteries. That motor at 6v only does 2 pounds 8oz. of torque. Thanks for the link though! Decided to change the inquiries. small* motor with min of 90rpm and 4 pounds torque. if someone knows a setup that could work to give these stats let me know. Thanks for the help! Tech

Troy · Answer

Sorry that didn't help. That's going to be a tall order at those specs. I will still look around. eBay1

Dunning-Kruger · Answer

If your're talking alkaline AAs, they won't last long with gear motors (especially with the specs you want)... alkaline batters just can't supply enough current... You'll kill them rather quickly. Consider an AA or sub c 6V niMh pack instead...

Troy · Answer

Yep, anything with that high torque will drain fast. I figured after he got it moving with the motors he needed he could always upgrade the power source. Oh wait. Youre looking at 1/2 scale R2D2 and want to run on AAs?

Dunning-Kruger · Answer

Not sure how heavy your R2 will be, but judging by the size you want I would suggest 12V motors coupled with a SLA battery... What are you making your R2 out of?

Rich · Answer

The best AA batteries I've ever found and used were 2600mAh, I've not found anything higher. At 2600mAh, considering the motor will be drawing around an amp on load (average, check the actual motor for accurate calcs) and there are two of them, 2600mAh will last around 1 Hour 20 Minutes (2600mAh/2A = 1.3 hours). Cheaper AA batteries have average capacities of around 1000mAh in my experience. 1000mAh/2A = 0.5 hours... Consider something with a larger capacity, as recommended above. 7.2v 5000mAh LiPo would last 2.5 hours, almost twice as long as the best AA batteries.

CardboardHacker · Answer

I have ni-mh AA batteries. 2200mah each. started to consider 12v.

Dunning-Kruger · Answer

You're on the right track... 12V gear motors will give you the power you need... I have bought some from eBay... Robotshop.ca is an awesome place for robot supplies too...

CardboardHacker · Answer

Just rechecked the specs on the last link troy posted. HOLY COW! 44.8Pounds/cm!?! I find it hard to believe but even if its half that it would work.

CardboardHacker · Answer

So, if I use this motor, has anyone seen a 6mm hub and wheel? www.ebay.com/itm/6V-90RPM-DC-Gear-Motor-Large-torque-20KG-CM-540-Motors-Shaft-D-6mm-L-15mm-/221000643446

Dunning-Kruger · Answer

Yep, most of my robot chassis use motors with 6mm shafts... Robotshop.ca has wheels that will fit those motors... Lynxmotion uses them for their 37mm gearhead motors too...

CardboardHacker · Answer

Could you give me a link? only could find one on servocity. Might save some $ if what your talking about is cheaper. All about the cost! Thanks, Tech

Dunning-Kruger · Answer

I buy from these guys all the time... Gear Motors Hubs

Troy · Answer

The one I listed (20kg/cm) converts to approx 278 oz/inch or 17.3584 lb-in. So I guess it might be.

CardboardHacker

Micro 90Rpm Motor Hign Torque

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