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Do you have to have reverse on a grinder

MCW

Somebody's talking crap here & it ain't the tree!
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I wired mine up. Reverse is on the left cutters. Makes a nicer tooth.

It involves reversing the "start" winding. I can re-draw the schematic if anyone is interested. It was on the computer that expired....

-Pat

I pulled down my eBay special (Australian 240v - good little unit though), had a look, then reverse wired a power point to run it in reverse and guess what - it still ran clockwise. I'm normally pretty cluey when it comes to electrics but this has got me stumped? Any ideas mate? If you have any schematics let me know as even though its hard to notice that burr on the cutter when chopping it is something I don't like.
 
Patrick62

Patrick62

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Is it...

220V 50 hz ??

Okay, now open up your machine again.

Is it a tecomec style grinder? Are there 4 wires coming from the coils of the motor? If so, then do some continuity testing. There will be two seperate windings, one is the "run" winding, and it will have lower impedance. On the order of a few ohms. The "Start" winding is higher up around 20 ohms or so.

You would wire up a DPDT switch to reverse the polarity of the "start" winding.

When I have more time available I will re-draw the schematic. Hold on, maybe I saved it somewhere.... Photobucket!!!!

http://s31.photobucket.com/albums/c369/Patrick62/oregon%20511/?action=view&current=reverse.jpg

This is the Oregon 511A (tecomec)

Hope this helps a bit.
-Pat
 

MCW

Somebody's talking crap here & it ain't the tree!
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Hi Pat.
Thanks for the help. I'm not sure if I have a Tecomec style grinder or not? Have pulled mine apart a few times but there are 4 wires coming from the motor coils. Have attached some photos of the unit inself and some pulled down views. Hope they're clear enough for you to get an idea of how the unit is wired. Had a look at your image, and I think our units must be wired similar but is the cap in your diagram the one that comes with the unit (mine is 275v - 0.15 microfarad)? Looks easy enough mate - just have to buy the switch. I'm not overly concerned about the wheel coming off - its a Nyloc nut plus I'll whack some threadlock on it.
Its not only the burr that concerns me but also a tendency to overheat the cutting edge faster when grinding away, instead of into, the cutter. You can also sharpen a chain faster if you have to take a bit of extra meat off for some reason.
Thanks, greatly appreciated.
Matt

http://i394.photobucket.com/albums/pp30/mattward74/DSCN2539.jpg
http://i394.photobucket.com/albums/pp30/mattward74/DSCN2538.jpg
http://i394.photobucket.com/albums/pp30/mattward74/DSCN2536.jpg

P.S. What do the arrows on your switch diagram represent?
 
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Patrick62

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It is different!!

What you have there is a "universal motor". The capacitor you have is mearly to keep the sparking down on the brushes.

Your motor would run just as well on DC as AC.

Reversing it is simplicity in itself. Wire up a double pole switch like I described in my diagram. Think about it a second and it will dawn on you that a double pole, double throw switch with a X wired across the back will reverse the polarity of the wires when flipped....

Anyway, all you need to do is reverse the wires feeding the brushes.

I will be here if you need more info... Private message is okay as well if you don't want to fill up this thread.

-Pat
 
Dimark1009

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Oregon 109179 Hydraulic Assist problem...

Guys,

I have a Small Engine Repair shop that I do on the side, just recently bought a second hand Oregon 109179 Hydraulic Assist chain grinder due to many customers asking for chain sharpening.

I bought the unit from a rental business that went belly up for $50.00. unit works good but has 1 problem.

the dang hydraulic assist will not push the little plunger out to clamp the chain in the chain vise.

I have the book for it, read it many times. says to remove the little allen screw and fill with fluid, did all that.

then explains how to bleed the air. did all that.

still dont work.

did anyone ever experience trouble with theirs?
what did you do?


Thanks in advance,

Mark
 

MCW

Somebody's talking crap here & it ain't the tree!
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Guys,

I have a Small Engine Repair shop that I do on the side, just recently bought a second hand Oregon 109179 Hydraulic Assist chain grinder due to many customers asking for chain sharpening.

I bought the unit from a rental business that went belly up for $50.00. unit works good but has 1 problem.

the dang hydraulic assist will not push the little plunger out to clamp the chain in the chain vise.

I have the book for it, read it many times. says to remove the little allen screw and fill with fluid, did all that.

then explains how to bleed the air. did all that.

still dont work.

did anyone ever experience trouble with theirs?
what did you do?


Thanks in advance,

Mark

Yeah this is a relatively common problem mate. If bleeding it won't work the piston seal is probably worn out. Spare piston assemblies are available and replacing it should work a treat :cheers:
 
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Dennisthemenace

Dennisthemenace

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I have a Jolly bench grinder from cutters choice and seems to work fine, but want to know if i need to have reverse to properly sharpen chains. I have read where some people are re-wiring and puting a 3-position switch in to achieve the reverse. Also would like to Know if anyone has one of these.
Yes, the Jolly (I have the Super jolly) is better when you reverse the wheel direction for LH cutters so it doesn't leave a burr on the outside. Grinders used to come from the factory reversable but of course modern day dumbing down OH&S regs have got rid of that. To reverse your Jolly for the LH side get a 5 mm Allen bit, put it in your cordless drill, insert into screw that holds the wheel on and spin the wheel at full speed then hit the on/off.

burr on outside of cutter?????---big deal--and about three spins of the chain in wood--goodbye burr--and wont change the sharp of the cutter---
I disagree, pros around here knock the burr off the top plate with a stick or wooden file handle forwards (when hand filing) as when the burr is removed backwards by chain rotation it causes damage to the chrome. It would be the same on the side. Anyway it gives a more consistent finish doing both sides outside in. It is a small thing but....
Anyway grinders used to be made reversable for a good reason, then they were not, for dumb down OH&S reasons. I always reverse cause it is so easy
 
LoneOak

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On round ground chain it's completely useless. When grinding cutters inside-out with a wheel, the wheel will "load-up" or "glaze" quicker than outside-in grinding, making it easier to burn the tooth and causing a very thick burr on top and side plates that will not flake off in the cut, but roll over and stop cutting.
Proper wheel maintenance will eliminate burning of the cutter!
It's called a corundum dressing stone get one and use it...OFTEN!!
Dressing Stone
 
blades

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ohsa regs- silicon flying at your face from wheel ( Silicosis ) is the reason grinders are no longer reverseable from factory. Liability issue.
 
Jhenderson

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Turning the motor counter clockwise would really need a left hand thread for holding the stone from working loose. I'm not familiar with all of the sharpening units on the market, but I've not seen any that grinds in reverse. At the RPM electric units turn I sure wouldn't want a stone coming off. It would get real exciting in the shop. I regularly use air driven porting tools that turn 32K RPM and have cutting wheels occasionally break, very exciting.

jerry-
burr on outside of cutter?????---big deal--and about three spins of the chain in wood--goodbye burr--and wont change the sharp of the cutter---

Let the wood take the burr off, duller tooth.Deburr with a fine stone after sharpening and it will stay sharp longer.
Square grinders all use reversing motors, and for good reason. When you put the burr on the inside of the tooth it prevents the chrome from from flaking away with the burr. The chrome, being the only truly hard part of the tooth helps hold the edge. Better edge for a longer amount of time.
 
Skeans

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On round ground chain it's completely useless. When grinding cutters inside-out with a wheel, the wheel will "load-up" or "glaze" quicker than outside-in grinding, making it easier to burn the tooth and causing a very thick burr on top and side plates that will not flake off in the cut, but roll over and stop cutting.
Proper wheel maintenance will eliminate burning of the cutter!
It's called a corundum dressing stone get one and use it...OFTEN!!
Dressing Stone

On round chain it does make a difference just as much as on square chain.


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