I cant figure out why the two brand new foot pedals to control speed in my wrapper.They are both overheating and smoking if I use them for 3 or 5 minutes.The motor is new and came with the foot pedal which overheated.The model of motor is 5 ring sewing motor model fm10150 output 75 w amps 1.5a ac 50/60hz made in taiwan rpm 8300/7500.I bought another foot pedal which is also overheating. Can someone enlighten me for was is happenning?

Chances are, in a wrapping application the motor's drawing more amps than it did in the machine that it was meant for. You may have to try a different pulley ratio to get the load down.

Mark Griffin
[]
C&M Custom Tackle
San Dimas, California

The fact that it is a 50 hz may be the problem. European countrys use 50 hz power, USA uses 60 hz. The motor may be trying to burn up. I am not an electrician , but I know if you travel to European countrys, dont take your hair dryer, it will burn up. What do you think Mark Griffin?

JBH

I think he's in Europe...

Mark Griffin
[]
C&M Custom Tackle
San Dimas, California

I noticed in his post he stated "50 / 60 hz". Could still be a problem maybe ?

JBH

So, "He's in Europe" ain't good enough, huh Jay? lol I saw your first post as we were headed out the door and hoped it would do!

I don't THINK that a universal motor running on 110/120V cares if it's on 50 or 60 cycles. I have quite a few tools that are listed for both. I've had this come up shipping power tools overseas to 50hz Countries and have always been told that even tools listed at 60hz work fine on 50hz. These are brush type motors from 3 to 15amps @ 110V. I have a few NON-brush motors (fractional amperage) that are listed 50&60Hz as well. i think induction (capacitor start) motors are where it's an issue. I'm sure there's an electrical engineer sitting out there just waiting to go "WRONG", but that's my past experience.

I can tell you that the foot pedal (rheostat switch) is the week link 90% of the time in this situation. It will generally fail from too much load before the motor will cook. Way before.

I stock foot pedals but you won’t see them for sale on our site. They’re made for a Dremel type tool and are rated at 3amps. On the internet, people just buy them without paying any attention to the amperage, hook them up to their home made line winder or cork lathe powered by a 6amp ½” drill and the first time they put a real load on it, the foot pedal gets hot and burns out.

I’d bet that Angel’s motor were plugged in sans the belt and run for any amount of time without a load, the pedal wouldn’t get hot. Chances are the load is greater on the motor in the wrapping application than the sewing machine application, which is overloading the rheostat. Especially at slow speeds. Gearing/pulley ratio plays a big role in reducing the load directly to the motor and if it’s not right, I could see it overloading that foot pedal.


Mark Griffin
[]
C&M Custom Tackle
San Dimas, California

Mark is right.



Edited 1 time(s). Last edit at 12/22/2006 10:03AM by Walt Galen.

I KNEW YOU COULD DO IT MARK !! Seriously , now I have learned something. I am glad you posted back. I will definately make sure mine is matched up correctly if and when I get one. I am useing a wood lathe to turn my cork and I ain't changing. Angel knows what his problem is now.

JBH

If he is in europe than the problem is not 50 or 60 hz but the voltage there is 220 vac instead of the 120 vac. that the motor is rated for.

This is my opion only.

Rolly Beenen
Rovic Custom Rods

If the european voltage is 220 as opposed to 110, therin lies the problem. The specs that he provided tell that the motor is operable on 50 or 60 cycle power. If the motor is rated for a 1.5 amp current draw at 110 volts, that indicates that the internal resistance of the motor is around 70 ohms. If you supply 220 volts through 70 ohms you will have a current draw of 3+ amps, double its rated capacity. Amperage pretty much translates into heat.

This amperage is consistant through the entire circuit (wall plug-components-back to wall plug. The motor , even if not equiped with an internal fan will move air because of rotating. The resistor, in the foot control does not have this to assist it, so heat will continue to build there making it more apt to failure.

Thanks Mark,
You got me in the right track.I did ran the motor all full speed and it did not overheat.Only when I slow down the speed is when I get in trouble .What pulley ratio would you recommend ?.My main goal at this moment is wrapping in which I dont need so much speed.If Im better off; buying another motor, which would you recommend?
Regards .....Angel

First off Angel, what IS the voltage you are plugged in to? Is it the same as the motor's rated voltage for the RPMs, amps, etc… you listed? All very good points in the posts above.

Too bad Walt killed his post because he did all the math for you already. It was all there, and the next time I looked it was gone! Walt? Come in Walt...

You shouldn't have any problem with a Sewing Machine Motor, though yours is a bit on the fast side. The best selling wrapping machine in the U.S. runs a 1.5amp 6000rpm motor. The motor's output (drive) pulley is about 15mm and the chuck (driven) pulley is about 100mm. In my opinion, it's STILL way too fast at the chuck. 6.76:1 ratio (almost 900RPM wide open) if I figured that correctly.

As you can guess, I don't come anywhere close to running mine at full speed. Mine has two rheostats. One at the motor and one in the foot pedal. Sort of a rough & fine adjustment. I’m sure they build them that way so that they’re not dealing with a giant driven pulley.

Your motor is turning at a higher RPM than mine, you're going to need at least a 200mm driven pulley with a 15mm drive pulley IF you have a second rheostat in line. Even a 400mm driven pulley is going to give you over 300rpm at full power.

The problem with this type of set-up (IMO) is that since the motor's running at a fraction of it's rated output, by the time you adjust the rheostats down to get the chuck turning at a reasonable working RPM, you've lost a lot of torque. In a perfect world (my math considered) with just the foot pedal and no inline rheostat, you'd want a driven pulley of about 650mm on a 15mm drive pulley which would give you a final RPM of about 200 when run at full speed (which you’ll seldom do) .

Help me out here Walt!


Mark Griffin
[]
C&M Custom Tackle
San Dimas, California

Mark,
The voltage in San Juan Puerto Rico is 110 v for most household equipment.We can go up to 220V but only if needed for air conditioner etc.The sewing motor s 110v. and it awfully fast 8300 / 7500 rpm.
Thanks.....Angel

First off I pulled the post because I felt my explanation of the problem was not concise enough and would be misinterpreted creating more confusion than help. Also the tone of the reply came across as being dogmatic which I wanted to avoid.

With a lot of help from reading posts on this site, I have personally just completed my first build, a SW1087 Rainshadow , a 20 lb bait stick for slinging sardines from charter boats out of San Diego. Bought all my tools, guides ,thread, epoxies, grips, seat and all the necessary do-dads from Mark (actually Colleen). So my rod building is at the “Rookie” level. Considering all factors my first try came out great and am ready for the next build learning as I go. However the problem in this thread is not a Rod Crafting problem its an electric motor application problem.

So lets get into this and I will try my best to convey my thoughts clearly.

current = amperage
** Assumption.... definition of: The mother of all screw ups.

Overheating in any motor or motor control circuit is always caused by excessive current in the circuit. Excessive current is caused by either incorrect voltage or overloading the motor. From reading the above post we know the voltage is correct. That leaves excessive current as the cause of overheating. In this case more torque is required to turn the rod to apply the wraps then is available so Angel puts the pedal to the metal so to speak in an effort to produce additional torque from the motor to turn the rod. In doing so excessive current applied through the control creating the overheating. There are 3 cures.
1. Get a control that is rated for 5 times the current rating of the motor. The control will thus handle the excessive amperage required to develop the necessary torque. But then you may start overloading the motor which takes longer to overheat and in the long run burn it out.
2. Gear the motor down to at least as low as Mark recommends, about 45 to 1 , that would be the minimum. In order to take full advantage of the motor and still be able to use your control, you would need something on the order of 80 to 1 which is of course not practical.

The motor develops 8300 RPM with 60 HZ voltage and 7500 RPM on 50 HZ voltage. (RPM is not proportional to HZ on a universal brush type motor but it is on sychronous type motor)
This motor is a high RPM low TORQUE type motor, if your present reduction ratio is let say 5 to 1 and you need a maximum of 150 RPM to wrap, the drive motor is only turning 1660 rpm, not even close to its maximum efficiency of 8300 rpm so to get the torque required excessive amperage must be applied. HP is a factor of Torque X RPM, the motor HP is .1 hp ( 746 watts per HP, 75 watts divided by 746 = .1 HP ) .. thats .1 HP @ 8300 RPM, at 1660 RPM thats only .02 hp about enough hp to drive a wall clock. What is required is a low RPM HIGH TORQUE motor with the same amperage and voltage. If HP = Torque X RPM, then when the RPM is reduced the Torque must go up in order to maintain HP. About a 2000 rpm 100 watt motor would be about right. Mark states that the best selling wrapping motor is rated at 6000 rpm , is durable and works fine. It is geared down enough to supply the necessary torque and keep the amperage at manageable levels. But it is still not the proper motor for the application. I am sure that cost is a huge factor here and the wrapper vendors have used their ingenuity to construct a durable product at a reasonable cost. They may not be “Technically Correct” but they do a fine job of suppling wrappers that are cost effective and they work. What more can we ask.

The above is long winded I know, all you had to do was read Mark’s first post..... “Chances are, in a wrapping application the motor's drawing more amps than it did in the machine that it was meant for. You may have to try a different pulley ratio to get the load down.”... and you would have all you needed to know. LOL

As a former Rod Wrapper Wanna Be, I would encourage anyone out there considering a build to just DO IT! This is loads of fun! Minimal cost to get started, $100.00 plus blank. And like another guy on another board said....”it sure beats watching sit coms”

Hope this helps.

Walt Galen
Sales / Engineering
G.P. Elect Co.
Electric Motor Sales and Service, 50 to 5000 HP
Pomona, Calif.



Edited 1 time(s). Last edit at 12/24/2006 08:44PM by Walt Galen.