[dertsap]

there are instructions somewhere on the little machine shop site that shows how to do a tear down

[nateman_doo]

I just looked all over there. I remember a forum member here had a tear down on his web page.

[mhackney]

You might be thinking about CreviceReamer's page. Scroll down for the link to tear down.

cheers,
Michael

[nateman_doo]

THATS the one. the LMS has a tear down procedure, but its not as picture friendly as CR's page. PLUS LMS doesnt sell the bearing kit anymore. Probably not very hard to make.

[dertsap]

are you doing the mod for more torque or speed , the reason that i ask is because the high speed is increasing the brush wear , enough so that after 2 good runs I've already had to clean the contact area on the armature because the motor took a dive . Once cleaned up it runs perfect again
Still there is no heat and everything in the motor is as new but the brushes leave a coating and the contact gets less and less as time goes on . So I'm going to knock back the rpm some
Even though (aside from brush wear) this has worked well for me and blows away the crap board that came with my mill , I wouldn't recommend that someone do this mod if what they have is already working for them , don't fix whats not broken


.

[nateman_doo]

torque. I am not in a rush when I machine, so the speeds can be slower (although I won't complain with a speed increase), but I just can't have it stall mid project and the motors are still trying to move the part.

Can you show me this area with the wear that required the cleaning?

[Al_The_Man]

Still there is no heat and everything in the motor is as new but the brushes leave a coating and the contact gets less and less as time goes on . So I'm going to knock back the rpm some
.

I think i read you are running the motor at 7200?
If so, that is way higher than the average DC brushed motor, especially if it is not that high a quality to begin with.
As a rule 3000 is considered a fairly common high rpm limit for most DC brushed, there are some specially made for 6000, but they are not that common.
Al.

[nateman_doo]

I want to be able to walk away from the machine, and NOT have to worry about it stalling drilling holes. I mostly work on copper and its such a gummy material that drill bits bind in it. Plus I don't know what im doing either, so I probably need more muscle to begin with.

I shortened the length of wire from the box to the motor just to help cut down the resistance in the wire.

The new board should be at the house by the house by the time I get home tonight.

[dertsap]

fair enough , I understand , I just wanted to make that point because I'm not exactly a trail blazer , I've got the do or die mentality , which usually works for me because I try not to do things blindly .
the way I see it is in the worse case scenario I'll only be having to buy a new motor for a couple hundred

the needed cleaning is where the brushes make contact with the armature , its a 5 minute job , the top motor cap needs to get pulled off and its right there , a little piece of scotch brite cleans it quickly .
I'll be taking a run down and talk to a friend to see if he supplies better quality brushes , who knows what these brushes are made out of

[dertsap]

I think i read you are running the motor at 7200?
If so, that is way higher than the average DC brushed motor, especially if it is not that high a quality to begin with.
As a rule 3000 is considered a fairly common high rpm limit for most DC brushed, there are some specially made for 6000, but they are not that common.
Al.

these motors show 6000 rpm , once fully warmed up the spindle itself is now turning at 7400 rpm so at 7400 with the belt reduction I'm spinning that motor faster than 6000 ,
I know I'm pushing it a bit too hard , i just needed to experiment to see if it will take it . its definitely going to need a bit of a drop in rpm

[nateman_doo]

I would love to make a new belt kit that would reduce the RPMs to near nothing just to have all the torque possible, and the other pully to be much larger to have all the speed. I don't need much inbetween.

[dertsap]

i think the belt drive is the best way to go , its smoother and I don't have to worry about destroying anymore gears , I considered making my own as well but lms sells them at a fair enough price so it was easier to just buy the setup .

[nateman_doo]

I have the belt drive conversion from LMS. If I could make my own I would make some crazy ratios.

Edit:
The bearing replacement write up from LMS: http://www.littlemachineshop.com/Ins...ndle%20Kit.pdf

[dertsap]

oh ya there it is , when you said that you couldn't find the info then i searched the site for it but couldn't find it for you , i thought that maybe they pulled it

[nateman_doo]

no, they pulled the kit to do it, so now I will just have to make it.

[Vogavt]

i think the belt drive is the best way to go , its smoother and I don't have to worry about destroying anymore gears , I considered making my own as well but lms sells them at a fair enough price so it was easier to just buy the setup .

Got mine here.


Working fine and a little bit less expensive. Note that is does NOT have a cover, but I don't put my hand on top of it when running anyway and a cover would be easy enough to make.

[dertsap]

thats a pretty decent savings over the other one , covers only get in the way anyhow , mines buried somewhere under a pile o crap , and will probably stay there till the next annual cleanup

[nateman_doo]

KBLC board is finally at the house.

[dertsap]

did you also get the proper resistor for your motor ?

[nateman_doo]

Yup. Hasnt arrived yet though