tool repair

[i=p/u]

hey, hi, yo...

i have a hitachi H45MR hammer drill, and when i pull trigger the fuse pops so obviously shorting out... any fault finding techniques guys, ?

the person that gave to me said needs new carbon brushes, but hes a plumber..

is there any good repair shops i could consider sending this too which you have expierience with..

it looks good heavy drill for chasing and yes it was for free but dont know if free has any clout yet..


cheers

 

[Knobhead]

I hope you’ve got patience and a meter that can make low ohm readings. You need to test the resistance between each segment of the comm., hence the need for patience. To give better readings you can test between a gap of say 5 segments and work your way around. Your looking for equal readings all around the comm., you'll also be looking for the paracetamol. Any bright flashes on the comm. usually points to a shorted winding. If you do find any have a look for a new housing for it (wheelie bin, cardboard box).

As you say it was a freebie so what you got to loose by stripping it. You could gain a good drill.

 

[i=p/u]

aye i know, if you lived near me guess where id be, yes yours

 

[ipf]

Sometime in the future just think back to where you started on machine repairs. Another string to your bow.
I remember when I was a junior apprentice, a long time ago, maintenance contracting with my old fella, working on a massive factory where he had previously been electrical gaffa. He'd just set up on his own doing all sorts, from domestic to heavy industrial. The bloke then in charge sent me to sort out a machine breakdown and I didn't have a clue where to start (bricking myself). I had a word with the old man and he told me to clear my head and give it a go. After a while I found what I thought was a problem with a solenoid (pure luck) and reported back. I was met with a slow nod of the head and sent sent off to make about 15 brews. And I didn't dare get any of those brews wrong.

 

[Knobhead]

aye i know, if you lived near me guess where id be, yes yours

You’d be welcome, but it’s a bit of a long way to bring a drill.

 

[GLENNSPARK]

you could pat it...but dont forget that a pat tester conducts a `limited` IR test...thats L and N connected together to earth...so will not confirm short circuit....

 

[i=p/u]

il megger it when i get home , just on short vacation. i can see the short comming from the windings or the segement cage d wich i think is the commutator....

have a phone number here from markie sparkies post but if i ring and leave down he could say 200 and i wouldnt know what for....

 

[i=p/u]

ok back at this drill, when IR test i get>299 M but when i hold the trigger in i get 0.02M.

ive also found the carbon brushes just pop out , what would you be looking for on these brushes, they look same size as new ones on internet... thanks trev

 

[i=p/u]

ive stripped the drill and eventually got the armature out which looks considerably damaged in one section, black scorch mark in one area..

i put my buck on the first reply post now within telectrix its the armature .. it does say 240v part is obsolete contact service agent , after all that .... so... thanks

 

[i=p/u]

another question mr question bank, what tests could i apply on the armature to defo prove it is this...?? im thinking continuity but from where to where..

should the cage segments be completly separate from windings of copper

 

[MarkieSparkie]

The quickest way to test the armature would be to use a device called a Growler. Ask your Tutor if the College has one you could use. Back in the day most Colleges ran motor winding and repair courses and therefore had all the necessary kit, sadly this is another of the electrician skills that are disappearing. Below is a link describing a Growler and how it's used:

Growler (electrical device) - Wikipedia, the free encyclopedia

 

[Knobhead]

You old bugger Mark.

Finding a growler in the dark recesses of a store cupboard is one thing, finding someone that knows how to use it is another thing.

I’ll be honest I’ve not used one for 30+ years.

 

[MarkieSparkie]

You old bugger Mark.

Finding a growler in the dark recesses of a store cupboard is one thing, finding someone that knows how to use it is another thing.

I’ll be honest I’ve not used one for 30+ years.

When I was an apprentice we had to make a set of Growlers for fractional horsepower motors as part of our tool kit. I've still got mine in my test gear.

 

[alarm man]

id just buy a new one,the price of a repair isnt worth it,it may may free but it dont work

 

[mickys86]

id just buy a new one,the price of a repair isnt worth it,it may may free but it dont work

Free drill or not, nothing more satisfying than fixing it up

 

[derek preece]

Would I be correct that you could convert the tool to 110V , if you can no longer get 230V parts (and if you've narrowed the fault to either the armature or stator), by changing the armature and stator assembly (parts 70 and 73 in the following schematic)? They are the only parts listed aside from the cord that appear to be specific to the voltage.
http://www.hitachipowertools.ca/upload/fmproduct_fileh/H45MR_BD_7028.pdf#

http://www.powertoolspares.com/tool/hitachi/spares-and-accessories-for-hammer-h-45mr/h45mr/spares/ It looks like they have an armature assembly available here for £71