Ofna Starter Box Assistance

[Monkey Wrench]

Folks, I have an Ofna model 10257 starter box with included power panel that I recently got from eBay: http://www.ofna.com/start-box.html. I also have a 12V, 7.5Ah AGM sealed battery. Today I took it out to start my Hyper 7 with Hyper .21 8-port mill. The battery had a full charge and I changed the starter wheel itself last night, but today, it would barely turn the mill over, even with the plug loosened to the point of falling out.

Eventually, I got a mushroom-like cloud of smoke out of it, and the following pictures illustrate what happened:

I freely admit I am "not one with the force" when it comes to electrial motors and the like, but I do know that smoke and melted insulation are not good! The motors both still work (though they need a good cleaning) and I have no manual or wiring diagram to reference (but have a request into Ofna now). It seems that there is an impedence of energy throughout the circuit and I am unsure how to wire two motors in series so they spin the same way.

I'm asking if anyone has a box similar to this or the electrical knowledge necessary to repair and clean this mess up? While having the panel is a nice touch, I do not necessarily need it, so if it is suggested that I ace the panel to improve performance, I'm open to it.

Thanks in advance!

 

[jetmechG550]

Damn Monkey, first you bust your rides now you go and break your starer box! WTF? Seriously though, it looks to me like it was wired wrong. I'm trying to look at the pix on my Blackberry and can't get detailed enough to get a good look. If your motors are shot go for the single big boy like they put in the chrome top (my truggy starter box).

 

[Monkey Wrench]

I cleaned the motors up and I think they are just shot. Even after cleaning and oiling them, one motor spun for 5 seconds then just seized (but, on the upside, verified the smoke detectors in my workshop work!) The other spins, but the RPM's fluctuate and I can see sparks around the commutator. I am hooking them up directly to the battery.

So, assuming these are smoked for sure, would the suggestion be to scrap the whole box and go for a new one (like chrome top) or is it practical to replace the motors. They are 550 size motors. My gut says the majority of the cost of a starter box goes into the motors, so I'm curious if it would be cost effective to replace the motors. I'm going to price some motors and see, but if anyone has insights, I'd sure appreciate them, particularly if non-R/C motors may be an effective alternative.

Yeah Jet, I'm having a bad run of luck here, lately and it all seems to center around starting the actual engine! If I don't have OWB's tanking on me, I got a starter box smokin' like a Cheech and Chong movie!

Thanks again!

 

[mr_bob]

well getting everything wired up and really easy

i can draw something up for you but it does sound like the motors are bad

i would say just go for a new box but its up to you

 

[ZANDOR]

You were not shitting Bro..You burned that beotch up good!
Ofna crome top..(AKA) ofna true start.1 Big ass motor.

 

[Monkey Wrench]

Yeah, I think they're toast, fellas! There were ceramic-like pieces falling out of the cans (I think from the ends of the armature). The score marks on the can in the second picture are actually a result of the wire melting against the can!

I did find replacement motors, but the cost is $47.00 for two (which isn't as bad as I thought they'd be) but add that to what I paid for it, it's more cost effective to just buy a new one. Since I just sold my dirt bike, I think I'll just get the Ofna chrome top and rack this up as a lesson learned!

Thanks for the assist, fellas!

 

[SIRMAXXALOT]

I have one with the twin motors and it barely turned over my Hyper 21 8 port then I bought the big daddy Ofna Chrome Top with the single motor, never a problem since...I say scrap the box, sell it for parts and invest in the Ofna Chrome Top with the single motor....just my humble opinion though.

 

[sweetdiesel]

I have a sweet OFNA box for ya bro. Has a big honking motor, and no messy chrome top to deal with. It's also the perfect color for you. LMK

 

[Monkey Wrench]

I have a sweet OFNA box for ya bro. Has a big honking motor, and no messy chrome top to deal with. It's also the perfect color for you. LMK

Look, simply because you are struggling with gender issues, don't try to pawn your "Barbie's R/C Starter Box" on me! Real men like chrome!

 

[sweetdiesel]

At least my box works! ooops that was low.....

 

[ZANDOR]

Look, simply because you are struggling with gender issues, don't try to pawn your "Barbie's R/C Starter Box" on me! Real men like chrome!

LMFAO bro you kill me!

 

[Monkey Wrench]

At least my box works! ooops that was low.....

True, true! I deserved that! Not too low, I'd of said the same thing had the roles been reversed!

OK, so now my question is, will I deep fry another motor by using a 12V, 7.5Ah (I assume that refers to amperage) battery in it?

 

[ZANDOR]

Now this is manley

 

[SuperMaxx83]

monkey wrench if you want i can send you the motors out of one of my old starter boxes they worked good when i took them out but then i bought the manley chrome top box and havnt had any use for the other one but i have like 2 or 3 of them that are in parts so if you want to pay for shipping then i will send them to you but if you do decid on getting the chrome top one then you can still use your power panel on the new one i just found that out about 2 weeks ago when i called ofna and they said they are universal and they fit and ofna boxes as long as they have the wholes for them but shoot me a pm and let me know

 

[Karl M]

I've seen something simular with aircraft starter/generators, internal short in one or both motors. Bad day on the winding machine and with inspection. The fact that either one turned over after word is amazing.

 

[rocknbil]

Monkey Wrench sorry I missed this but was out flying my heli.

I have a box exactly like that minus the power panel. Looking at the pics I can tell you a thing 'r two . . . I have had **BOTH** dualies and single motor boxes, and have sold all but my Ofna dualie.

Yes they can more than handle 12v @ 7amps. The motors weren't the problem here, it was poor maintenance and abuse.

There are three main areas that cause this (we won't count user abuse.) The problem starts with those push-on connectors, the ON/OFF switch, and the spring switch. These points cause resistance, the resistance heats the wires, add a little abuse by the previous owner (pushing down and leaning in instead of bumping it, doh,) and the wires heat enough to melt the insulation. You can clearly see the burn mark across one of the motors, once that happened it shorted the whole thing out.

I swear, if it weren't for shorting the battery against the motor casing, I'd bet those would have still run. Those Mabuchi cheapies are like cockroaches, they don't RPM much but have torque up the 'yang and are hard as hell to kill.

REPLACE THE ON/OFF SWITCH. This is the only real weak point about these. Don't even try to find a similar rocker - rocker switches are just not designed to handle this amperage well. Use a high amp toggle switch. I would say take the toggle switch out completely but too many of these boxes get thrown in a trunk, they flip over, and get jammed on the on position with the wheel jammed, then meltdown or catch fire.

I hope you haven't bought the motors yet. The PERFECT solution for these boxes are two 19T mod motors. I've been meaning to do that with my box, but the original stockers are still cranking along. If you replace all that crap wire with heavy gauge RC wire and SOLDER all connections, this box will be solid as a rock and start anything.

Take apart the spring switch. You will find a brass washer in there, one side is probably dinged up and black like some welder on crack got at it. Polish that thing up, and polish up the contacts that touch it. When you reassemble it, get some dielectric grease from the local automotive store and liberally slather that area with it, this will stop the arcing that goes on here.

I've had both types of boxes, and bigger 750 motors DO NOT provide more torque than these! They provide higher RPM, but NOT more torque, and torque is what you need. The two motors combined provide way more torque than one 750 motor.

Two 19T mods are **more** than enough torque to turn over any RC engine, old or new, if the power source is good and strong. In my experiments, even a CAR BATTERY doesn't power these boxes as well as a 7A SLA. I don't know why, don't care. All I know is I get more kick out of the SLA's than a good car battery.

The wiring is pretty simple, let me know if you need help with that part. These are good boxes.

 

[Monkey Wrench]

Thanks a bunch, Rock! Didn't consider the switch or connectors, but I did polish and apply the grease to the brass contact points before I even fired it up.

My primary question surrounds wiring the motors in series. Do I connect the positive of motor one to the negative of motor two, whereby the positive connection point on motor two becomes my negative lead to the battery? I'll try drawing a schematic of what I am asking, but if this makes any sense to you, am I on the right path?

Thanks again! The assistance is greatly appreciated!

 

[mr_bob]

mw i think your on the right path


its just like making a battery pack where the negative of number 1 gets connected to the positive of number 2 and then you have the positive of number 1 going to the positive battery and then the neg. of number goes to the neg. of the battery

 

[HeartBreak]

Look, simply because you are struggling with gender issues, don't try to pawn your "Barbie's R/C Starter Box" on me! Real men like chrome!

You know, the sad part is, I actually had one of those boxes (the XTM one that was grey) for a long time. I used it to bump over an ofna engine, until the motors finally wore out. Wanna know what I did for a replacement...?

Before reading on; swallow all drinks now, or else they will end up on the monitor/keyboard/dog/cat.

One day, while driving around (on my way to pick my 17 year old niece up at highschool), I spotted a Powerwheels Barbie Jeep with a "FREE" sign on it. Now, you're prolly thinkin "why would you want a powerwheels jeep... much less a barbie one?". Simple; they're powered by TWO 550 motors. Ya just have to hack the snot out of 'em to get the motors out.

Anyways, after knocking on the door to ask if it was indeed free (and getting a "yes it is, thanks for asking" reply), I proceeded to load it into the trunk of my car. Hanging half out. Bungee corded in. With the words "BARBIE POWERWHEELS" clearly visible.

But the fun doesn't stop there..... This is on the way to my neices' school. So, I proceed to pick her up, with the jeep hanging out of the trunk. That poor kid has never been so embarrassed. We even got to wave at her boyfriend (even though she was hiding under her books).

Granted, new motors are $20 or so each, but for the embarrassment value, you can't beat free.

 

[sweetdiesel]

Admit it Heartbreak, you only pulled over because it was a Barbie Powerwheel. I bet it's sitting in your living room right now fully restored to working condition.