2nd Electric Motor has died!!

flatgrinder

flatgrinder

Joined
Dec 20, 2005
Messages
2,045
I've had 2 electric motors from Harborfreight (1HP, TEFC, 1750RPM, 110V) crap out on me. They suddenly just stopped working. Anyone else had this problem?

They advertise it as an electric motor that can be "continuously" run. I ran it for about 1 hour grinding a large bowie and a small hunter, when it stopped. My first motor, the same specs, stopped after about an hour of continuous use. I've had both for several months before this happened. If I just use it for 30 minutes, and then switch it off -it seems like it can run forever. It's when I run it for long periods and really push a blade into the platen when I hear the motor slow and suddenly stop.

Should I step up to a 1.5HP or 2HP motor using 220V? Am I being too hard on the motor? Is there anyway I can troubleshoot this myself to figure out what keeps causing these failures? Maybe hook up an ohm meter and check out the resistance? I tried the reset switch on the side, but it doesn't do anything. :(

Any advice would be appreciated! I'm tired of killing motors, they cost quite a lot to replace! :thumbup:
 
Baldor, Reliance, or Leeson m'boy. Preferably 1 1/2hp-2hp based on what Rob Frink told me in another thread. 220 3 phase with a VFD is the HOT set up btw. Used ones can be had pretty reasonably

I do believe you get what you pay for in motors these days.........

Syn
 
flatgrinder said:
Any advice would be appreciated! I'm tired of killing motors, they cost quite a lot to replace! :thumbup:
Click to expand...

Quit getting Harbor Freight. They might cost less than Baldor or some other good brand, but if you'd bought a good one in the first place, you'd have saved money by now. ;)

I've gotten GE motors from Tractor supply. They're reasonably inexpensive, and good quality. Get the TEFC kind. They last longer in dusty environments.
 
I've got a 1hp baldor that just keeps on chugging. You have to remember, HF sells the cheapest product chineese labor can produce, you really do get what you pay for.
 
Check the voltage at the source. If the voltage is low, less than 110V, then the amperage is rising too high causing the motor to overheat.

Test the line voltage with the motor off and then when it is running. If there is a big drop when the motor is turned on, then you may need to upgrade the wiring going into your shop. This is often a problem when the shop is on a long line from the house pannel. If that is the case then upgrade to a heavier cable this is a simple fix, or put the shop on its own pannel separate from the house.
 
I bought one from Grizzly industrial TEFC that's been working for over 2 years now and has never had a problem. it was around 155 bucks for a 1 HP TEFC.
 
Tractor Supply 1-1/2 Hp 110-220V TEFC W/ cord a switch 185.00
Been running this one for 2 years on my KMG.
 
I think Bufford has a very good point. Do the lights in the shop dim when you're dogging it? Low voltage, due to voltage drop, is hard on a motor. Might need larger wire out to the shop.

I get good quality motors on ebay for cheep. HF motors ain't too good.
 
2nd Nathans suggestion of ebay. I just got 2, 3-phase motors, a 2hp and a 5hp for under $150 each (cost more to ship the 5 horse than to buy it). A few yrs ago I got 3 for $150 delivered. Just need to get a VFD and you'll be all set.

Chuck
 
Step up in horsepower - you are working the motors to death! I would go to 2 HP minimum. This will help even a horrible freight motor last longer but get a better quality if possible.
 
You Really need to go with 220v if possible. Much easier on the motor. However I used a 1/2hp montgomery wards motor for years. Wired 110v but it was on a disc not a belt.

Chuck
 
Not everyone has 220 volt just floating in their house though. If you live in a more modern place, chances are it's not set up for 220 volt. I think the key is to just buy a good brand reliable motor. There are differences in the things that are made in china depending on the company you're ordering it from. Or Taiwan even. Harbor Freight stuff is good when you need a cheap tool to do a job a few times and then pretty much junk it because that's about all it's gonna last you and at those prices, who can really blame them for making equipment that doesn't last. There's no warranty, no one to call when it's not working anymore or how to remedy the problem, etc etc. I don't think you actually need a 2 or 5 HP Motor. a 1 to 1.5 HP motor will work just fine if it's well made and has good customer support/tech to help if it ever dies on you. I find that eventhough Grizzly industrial products are made in taiwan, they have EXCELLENT customer service helping people figure out what went wrong or simply how to wire something or whatever question you can ask them. Even by email they will respond within 24 hours with a very intelligent answer. If you spend less now, in the end you'll end up spending more than if you were to have done it right the first time. Ask me! I would know! Had had several buffers, bandsaws, etc etc before I found the right one (all before I joined bladeforums damnit!) I think those harbor freight motors aren't all that cheap either!! lol go buy something made in USA! you'll never have a problem again.
 
I had a Baldor 1.5HP motor, but sold it as I needed the cash a couple years ago. I purchased a Harborfreight 1HP motor for $99, also got the $20 warranty, so when the motor croaked I got a freebie. Now the second one's died, I'm just curious as to what happened? I'm thinking about having a shop troubleshoot it to determine what went wrong. Maybe it's a single component that needs replacing ... I'll keep everyone posted.
 
Why bother? Curiosity? Many people have advised you the HF Motors and customer service suck...................

If you invest the time and $$$ you'd spend on tilting at the "what hoppened to it?" windmill you could buy a decent USED motor and get on with makin' some knives. Some things just aren't worth the effort. Burn me once etc etc.

Personally I've had great luck buying used Baldor and Reliance motors. I have a brand new old stock 1hp reliance in my garage that I bought at a tool shop auction for $20 last year. Maybe you can pick one up that way that you won't have to worry about down the line.

Just my 2 cents.

Syn
 
Flat grinder

You have answered your own question if I read it right However I can eplain it at length.
---
If I just use it for 30 minutes, and then switch it off -it seems like it can run forever. It's when I run it for long periods and really push a blade into the platen when I hear the motor slow and suddenly stop.
----
Continuious duty means at full load current. The motor is designed for a specific load current and will run continuously at that load level.
However when a motor is locked or parcialy slowed beond the designed level it can draw up to 6 times the " full load Current" designed full load when running at 1750 rpm. The more you slow the motor the closer to locked rotor current you get. If you lock the rotor for a very short time it will either blow a fuse or burn out the motor.

Part of the problem may be the friction on the platten if you think og how a set of disc breaks work on your car that is the same as the blade and the platen squeasing the belt. your putting the breaks on the rotor turning the harder you push. It does not happen quite as much when useing the wheel because the you often have a smaller contact area and less braking effect.

Now your disision is do I want to be able to push hard if yes get a bigger horsepower motor. An expensive 1hp motor is still a 1 hp motor there are marginal advantages with more expensive motors their bearing are less likely to slip in the housings and flog out may be run a little cooler.

Another posible problem if you analys the belt condition. If your belts are worn out and you are pushing harder to get the last bit of use out of them you are also probably puting more braking stress. A sharp belt is costly but so is a burnt out motor.

Another valid point is the lot drop. If your shed is a long way from the house and is on thin cables you may be getting volt drop along the lines. There are formulars that electricians use but too long winded for the moment. This is unusual to happen unless you are on a farm and the lines were not put in by a proffessional.

My advice sharp belt less pressure may be even a bit of graphite on the platten. Or a bigger motor. I was always taught electric motors run on smoke
if you let the smoke out of them they stop working. I was an electrician for 10 years. Good luck be gentle but in a rugged way.
 
Reg ELLERY said:
Flat grinder

You have answered your own question if I read it right However I can eplain it at length.
---
If I just use it for 30 minutes, and then switch it off -it seems like it can run forever. It's when I run it for long periods and really push a blade into the platen when I hear the motor slow and suddenly stop.
----
Continuious duty means at full load current. The motor is designed for a specific load current and will run continuously at that load level.
However when a motor is locked or parcialy slowed beond the designed level it can draw up to 6 times the " full load Current" designed full load when running at 1750 rpm. The more you slow the motor the closer to locked rotor current you get. If you lock the rotor for a very short time it will either blow a fuse or burn out the motor.

Part of the problem may be the friction on the platten if you think og how a set of disc breaks work on your car that is the same as the blade and the platen squeasing the belt. your putting the breaks on the rotor turning the harder you push. It does not happen quite as much when useing the wheel because the you often have a smaller contact area and less braking effect.

Now your disision is do I want to be able to push hard if yes get a bigger horsepower motor. An expensive 1hp motor is still a 1 hp motor there are marginal advantages with more expensive motors their bearing are less likely to slip in the housings and flog out may be run a little cooler.

Another posible problem if you analys the belt condition. If your belts are worn out and you are pushing harder to get the last bit of use out of them you are also probably puting more braking stress. A sharp belt is costly but so is a burnt out motor.

Another valid point is the lot drop. If your shed is a long way from the house and is on thin cables you may be getting volt drop along the lines. There are formulars that electricians use but too long winded for the moment. This is unusual to happen unless you are on a farm and the lines were not put in by a proffessional.

My advice sharp belt less pressure may be even a bit of graphite on the platten. Or a bigger motor. I was always taught electric motors run on smoke
if you let the smoke out of them they stop working. I was an electrician for 10 years. Good luck be gentle but in a rugged way.
Click to expand...

Thanks for the advice Reg!

I actually spoke to a repair shop the other day and he said that wiring the motor up for 110V could also be the culprit, as the current draw is much higher than if I had wired it for 220V. I also did notice that the belt was getting worn ... but I just had to finish off the bevel on one more side and was pushing pretty hard! :p

Well, lesson learned, flat grinding is much harder on your grinder/ motor than hollow -and don't use worn belts. Plus, 1 HP isn't well suited for grinding 5/16" thick choppers:

campknife.jpg


I purchased a new 1.5HP motor and I'm going to run it on 220V. It'll be interesting to see how long it lasts. If this one goes out, I'm stepping up to a 3HP monster!! :D

Thanks again for the advice! :thumbup:
 
I would always recommend getting a name brand motor, you pay a little more for a motor that could last decades. Seriously though maybe you should make sure whatever motor you buy has a protection circuit that will stop with overheating and stalling. I have read stories about a 40+ year old baldor motor that came out of a soap production plant that looked a million years old but ran like new.
 
Flatgrinder
Fistly that is a nice looking blade you got there. Well worth the effort.

A formula for watts is amps times volts. 1 hp = 746 watts

that is 746 devided buy 110 = the amps drawn ie 6 and a bit
746 divided by 220 = half as many ie 3 and a bit

I am in Australia we use 240v every where for single phase.

Again nice knife and keep them comming
Reg
 
Reg ELLERY said:
Flatgrinder
Fistly that is a nice looking blade you got there. Well worth the effort.

A formula for watts is amps times volts. 1 hp = 746 watts

that is 746 devided buy 110 = the amps drawn ie 6 and a bit
746 divided by 220 = half as many ie 3 and a bit

I am in Australia we use 240v every where for single phase.

Again nice knife and keep them comming
Reg
Click to expand...

Thanks Reg.

Reminds me of when I accidentally got electrocuted when I was in my teens (I was raised in the UK and they're on 240V as well), I was able to use my other hand to pull the wire away from my left hand, which has scars from molten skin. I was later told that if I was in the US, I'd be a goner. Current kills, not voltage -hence the million volt stun guns the cops use.

Apparantly, not only does current kill people, it kills motors! :eek:
 
Nice lookin knife.

I'm running two B-III grinders with 1-1/2hp DC motors and they are grossly under powered. Especially flat grinding large blades.

Rule of thumb in industry: 1 hp per 1 inch of belt width. Works for knife making also :)

I'm fixing to set up a KMG with a 3hp VFD.

And like has been said above, stay away from cheap imported motors.
 
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