Grinder Repair - Replacing the Field (Makita Part # 621706-3)

www.ereplacemen... Click here for more information on this part, installation instructions and more.
This particular field is specific to Makita manufactured brands. To find a field specific to your model, visit eReplacementParts.com.
If your grinder is showing any of these symptoms; replacing the field could solve your problem:
1) Smoke coming from the motor
2) Armature (or spindle) not rotating
3) Burning (odor) from the motor
4) Field wires burnt or melted inside motor
eReplacementParts.com part number: 621706-3
Tools used for this repair/replacement:
1) Phillip’s screwdriver
2) Pick or small screwdriver
3) Long-nosed pliers
4) Large screwdriver
Get model-specific repair help from eReplacementParts.com. Learn how to troubleshoot, diagnose and repair your power tools and equipment with illustrated instructions, hundreds of step-by-step repair videos, and our DIY forum. If you have a power tool or appliance problem, we can help. www.ereplaceme...

[@richbraithwaite]

For anyone who's interested swapping the brush connectors round reversed direction - now my drill works!

[@sanjayjoshi5713]

Very nice video very useful to replace

[@mohammadmustafa722]

Nice procedure....loves from India

[@jurajsuda7418]

very good.

[@thirdmasteraamirkhan5410]

Good job
Best way to replace stator

[@hameedp6934]

All the best
Nice explanetion
keep it up
all the best

[@winstonclarke9221]

Great Video Mark, it was properly explain,

[@FIXTechGuides]

Thanks, Winston!

[@pauldaniels5181]

Very informative thanks

[@MaldonadoisHandsome7]

Excellent video, and responses to the questions below

[@aamilhussein5300]

Nice video 👍👍

[@hameedp6934]

Good work

[@chesterlynongtdu1959]

Where did i get a field

[@premnarayan297]

nice to see you video

[@khalandarmujavar2349]

Sir pls how do check in series feild coil..

[@marymeena1987]

Can i use any motor from any angel grinder?

[@DanDan-tk8ci]

Hi, what is the reason for Armchir overheating?

[@sreejithts9798]

good & best one

[@zahidking2942]

Excellent explanation

[@hameedp6934]

Thanks

[@kudapadi5429]

My friend bring back a grinder from where he working at, they say the grinder have a problem then he took it back to maybe can fix the problem.. I just see it when the grinder turn on then it smell some burn and create a little noise... Are there is the problem is came from bad field or armature winding ? The brush still good ,i dont think the noise came from brush but i'm not sure if the noise created from commutator plate that scratching the brush hardly... Sorry my bad English, but i hope there would be anyone could give some explaination to my question.. thank for your concern...

[@FIXTechGuides]

Hello, with the conditions you have written, I would think you have a burnt armature.

[@dannymesa2055]

Good job very nice explanation.

[@ernestoguisadio3446]

How to test if the armature is burnt?

[@mdabulkasem2053]

Thanks a lot

[@Cheese_1337]

hello, what is the rotor and stator impedance? (assuming on rotor two opposite connectors)

[@BENGKELHOBI]

Ia this way working for grinder MAKTEC MT 954

[@TheLostMillionaire]

Hi sir...what makes my angle grinder heat up fast even no load operation....in 2mins of testing i observed not normal espcially the gearbox or the head ot the grinder..pls help me how to fix it..thanks

[@67BigBadWolf]

Check if the bearings are not dry if so change them. If that's not it just check if something's creating friction between the parts

[@richbraithwaite]

have changed assembly in makita 8419b drill; however, armarure is spinning in wrong direction. How do I fix? Would swapping brush connectors solve Issue? Thanks in advance for any advice.

[@FIXTechGuides]

You didn't say what assembly you replaced. Flipping the wires on the brushes won't help. Usually if the wires get reversed going from the switch to the motor it will cause the armature to run backwards.

[@VinayKumar-hk9hz]

Good

[@migueldejesus307]

Hi I see in your web site this part is discontinued. do you have any other replacement part number?

[@FIXTechGuides]

Hi Miguel, I have checked our website and we still have stock of the part. If you would like to order click on this link: www.ereplacementparts.com/field-115v-p-78804.html or call us at 1-866-322-9842 and we can place the order for you.

[@migueldejesus307]

eReplacementParts.com
Hi if this part is can use on model GA4530?

[@kylet2959]

Does anyone know what the silver around the field is made of?

[@vandravany6797]

Silicon steel I read on Teh internet

[@YTenginearmanoj]

All tyaps of power tools repairing video opplood in youtub

[@sufyanhussain1875]

I'm mechanic and I did this every day...😳😳

[@zawtunpathee6559]

Good!!!!!

[@goutamkumarsharma2514]

katar masin me New armature lagana par karbon point se aaga nikalta hai

[@livetv7952]

i wind an angle grinder but its carbon spark too much why? and what can i do ?

[@FIXTechGuides]

If you have replaced the field and it is still arcing, you may have a shorted armature. You can pull out the armature and visually inspect it for burnt windings, or take it to a local tool repair shop and have them test it. Most
people will not have the testing equipment that a repair shop has. Check the wires to make sure that they are connected to the correct terminals. Your brushes may be worn to the point where they are not making good contact with the armature. They also may be hung up in the brush holder, which would not allow them to make good contact. A switch that is going bad may also create arcing.

[@neilfroggycrompton2466]

what purpose do the brushes serve?.

[@FIXTechGuides]

The brushes and brush springsmake contact with the Commutator on the Armature to provide the electrical current that creates the magnetism which makes the motor turn.

[@siyaramram96]

Makita mixture ka Kitna rate hai

[@cristitoalano7628]

You did not show how to test the field coil so i would know the field coil resistance. I would have given you 5 stars in 5.

[@shamsudeentrikaripurshamsu8405]

GUd. ok

[@charvanto1511]

Tolonq janqan ditampilkan teknya sanqat ganqqu

[@minhokim5384]

tank.. i can repair my hammer drill..stator...

[@amerikanstafford]

++++++++++++

[@usmanrazzaq8199]

Good