Hank Fletcher

Instead of burning out the FA-130 motors that come with the Tamiya gearbox sets by running them with a greater voltage than the 1.5V nominal the datasheet recommends, I thought I'd look around to see if there are any motors that are drop-in compatible but rated for a greater voltage.

The hardest thing is finding one that has the same physical dimensions as the FA-130, so that the replacement fits well into the pre-fab Tamiya gearboxes. It looks like there might be some out there, though, possibly even available on surplus. F(x) -130 seems to indicate motors with identical dimensions, with the (x) being some sort of indicator of voltage rating.

A test done at Pololu appears to prove that running the motor a bit over-voltage does result in considerably wear. If I'm going to increase the stress in the Tamiya gearboxes over specs, I want to try with a higher voltage motor, and cross my fingers that the gears will be up to the task of the extra torque.

But I'm still on the hunt. Can you help me find a motor with identical specs to the ones that come with the Tamiya gearboxes, with the exception of a higher voltage rating? The dimension details of the FA-130 can also be found at Pololu. Thanks!

zanes

I'm not sure you'll be lucky, but I'm interested all the same, as my gearbox should arrive this week. I expect all small motors will be similarly rated. I expect it wouldn't be too hard though to adapt the gearbox to take larger motors though.

Hank Fletcher

Hey! I'd thought the Mabuchi website would be harder to navigate, but I found this pretty quick.
http://www.mabuchi-motor.co.jp/en_US...ct/p_0304.html
Looks like I was right about the motor number/motor dimensions thing, at least at a glance.

Still, I need somewhere I can buy them (the FA-130 alternative, I mean), if anyone has any leads! I'm looking forward to finding out what effect this will have on the Tamiya gearboxes!

Hank Fletcher

Comparing the FA and FC datasheets side-by-side, they're identical with the exception of one dimension on the right-hand side image. I've never been able to figure out exactly what that dimension refers to. Any ideas?

Hero999

A greater voltage won't give you more power if the current consumption is halved, in which case you'll have exactly the same amount of power.

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nickelflippr

The FA-130 motors from the gearbox set show a torque table for the different gear ratios. As a footnote they specify...Torque of type RA-130 motor (3V). So you may have the 3V nomimal voltage model already.

So how do you tell which model of FA-130 you have?

3v0

A while back I was looking into motors for the gearbox too. Here is what I wrote.

I stumbled onto these motors which may or may not work with the Tamyia Double Gearbox. They come from the same family of motors. They are the same physical size as the original.

At the bottom of the page

Alternate Part Number:9-032 R&D0967 FA-130RA sold in sets of 2

The original Tamyia motors are FA-130RA 18100's.
http://www.pololu.com/file/download/...f?file_id=0J11

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Hank Fletcher

Wouldn't life be easier if they came with the FC-130RA instead, do you think?

3v0

EDIT: Maybe not... They only show 5 units in stock and I can only find the motor when I am not signed into their site. Keep looking.

These guys have the original motor .
http://www.kysanelectronics.com/Prod...php?recordID=2

The link in my previous post did not work try this for the motor specs.
http://www.pololu.com/file/download/...f?file_id=0J11

EDIT:
It looks like of the 3 motors listed the one provided is the better to use.
The above link wants less then $2 for them but I have not looked at where they are or shipping.
At about $3 or $4 a set on could afford to replace them?

Keep in mind that you may loose some voltage going through the H-Bridge or transistors that control the motor. With a simple h-bridge created with cheap transistors it can be quite a bit.

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blueroomelectronics

What's your supply voltage? 5V?

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Hank Fletcher

Yeah, I think I'd planned on 5V for the recorder. I know I spurred on a rather lengthy thread awhile back re PWM to use the SN754410 within its >5V limit, but if there's a product swap (via the FC-130) that's more compatible, I'd rather do that. How do you manage on the mongoose with the SN754410 and the FA-130, just run them at 5V? Given the Pololu test, and what you could read into the results, there's arguably little difference in how long the product will last (particularly with respect to total revs) at the various voltages.

blueroomelectronics

The SN754410 drops the voltage by 1.4V perfect for the RA130.

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Hank Fletcher

Hmm... I had thought I had checked the outputs of the SN754410, and I don't remember noticing that. Do you mean that with the motor, there's a voltage drop due to the resistance of the motor? Would there be the same drop if using a regulated supply for motor power?

blueroomelectronics

The transistor drivers drop the voltage by 0.7V each.

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zanes

I would just like to thank whoever negative repped me for the above post. Yes, perhaps it wasn't wonderfully helpful, but I did make a suggestion, and it wasn't "can Haz help plz?"

Perhaps whoever it was would like to justify it?