Tool post grinder Build

GoceKU

Registered
Registered
Joined
Jul 14, 2017
Messages
2,445
I've been needing an tool post grinder almost as long i've had the lathe and after not be able to found one to buy i've resulted to building one. The plan is to build one that i can mount in my tool holder and can adjust stone stick out as an tool cutter, this will allow me to do inside grinding and outside grinding with minimal stick out. For the motor i've chosen this old pressure washer motor to use, but the shaft is way to short to mount a pulley, so i've disassembled it and started with extending the shaft, i've done this process couple of times before and wanted to share how i'm doing it, in my next post.
 
This is the motor i'm planning to use in this build because is compact and powerful, is rated at 2Kw (2,72Hp) around 3000rpm. The first thing to sort out is the short output shaft, so i've take it apart and and found that i'll need to buy an sealed bearing and the insides look good no corrosion and the copper looks clean, then i chuck up an 18mm piece of C45 and turn down one end to 6mm and made a taper for the weld then i traded it for M6. The rotor has M6 threads so only thing i did is to chamfer the edges on my bench grinder then i faced the shaft i made earlier tight, to hold straight when welding, than i wrapped the rotor in a piece of leather to protect it and welded the shaft.
DSC_0006.JPGDSC_0014.JPGDSC_0018.JPGDSC_0022.JPGDSC_0025.JPGDSC_0029.JPG
 
This process is not finish, now i need to chuck the rotor in the lathe and cut it to run straight, i make my extension shafts 2-4 mm bigger then what i need to have enough material to cut them straight, this one had moved a lot, i wrapped the rotor in some thick duct tape i chuck it pu in the lathe and indicated it from the seal journal, drilled and supported the other end with and live center, and began taking cuts but i was in a hurry and tried to take too much at once and the the rotor move on me, so i stopped and will continue letter when i have more time.
DSC_0031.JPGDSC_0034.JPGDSC_0035.JPGDSC_0037.JPG
 
why not use brass shim or something like that where you can grip it better. The tape will always give a bit, and also is not as consistent thus can be off center Just a thought. Looking nice.
 
I usually use copper shim but could not find any so i used first thing that came to hand, ( duct tape).
 
Today i continued working on this shaft, yet again i've changed the tool i'm using and took my time making small cuts and got it finish to size, the bearing jarnal is 17 mm and made the shaft extension 16mm so i can use oem belt pulley, i left the length longer than i need, i'll shorten it later when i figure out my drive pulley.
DSC_0041.JPGDSC_0043.JPGDSC_0046.JPG
 
Looking good!
I've used the same method on a 3600 rpm fan shaft but TIG welded.
It ran in a corrosive enviroment and lasted over a year till the fan lost balance weights.
It then shook itself pretty hard. Had to do a static balance, new bearings n seals, and it was running again.
Had been greatly concerned that such a long shaft added on would be a problem.
 
I'm not still done with modifying the motor but i wanted to start on the spindle and its housing, i plan to use 25x25 mm square solid piece of 4140 which seems to be the sweet spot for my tool holders, but i don't own an 4 jaw chuck so i made this sleeve, started with solid 45mm 1045 steel, drill and bore the inside to the outside diameter of the square stock, then i cut slot using an angle grinder and test fit it in the chuck, unfortunately that was all the time i had for tonight.
DSC_0002.JPGDSC_0004.JPGDSC_0008.JPG
 
Back
Top