How thin to make the tip on the grinder?

[merlijny2k]

Hey folks,

I bought a 915x100, 370W toy grinder to have some fun with. Since knife steel is quite pricey around here I figured I would make my first mistakes as cheap as possible and set out to grind an actual knife out of an old Rosenbaum club (you know, the fake german knives they used to sell door to door). 3.2mm thick at the spine and stays that way until a centimeter from the edge and. Since it has no grind to speak of it is essentially a pre-hardened blank. Although I managed to screw things up in more ways than I care to tell it seems it is nonetheless evolving into something actually shaped like a knife. I just keep screwing up the tip. How thin is realistic to do on a grinder and when do you switch to do the rest on stones? Thanks for your answers.

 

[RDalman]

~0,3 mm 😰😝

 

[RDalman]

Seriously it's a good practice. Keep at it and enjoy.

 

[merlijny2k]

Lol. I do enkoy although it doesn't help it's the coldest week of the year and my shed hasn't got heating. This morning I had to take my gloves inside to thaw them as I had left them on the workbench wet yesterday. My bucket of cooling water keeps freezing over and I grind until my toes start to freeze and then take a break. Still really cool to finally try my hands on it after having the itch for about two years. I'll try and see if I can get to .3.

 

[milkbaby]

I grind to zero on my 1x30 inch belt grinder. The main problem is that the belt is small yet moving fast, and the platen is small so managing heat buildup to avoid over tempering the tip is important but easily screwed up. After HT and temper, I use a fresh belt, dip the blade in water as well as spray the belt and platen with water every pass to help keep things cool.

A new coarse lower grit belt will heat up less than a higher grit or old belt, so use a new low grit belt on post-HT blades. If you can't get the hang of it, there's nothing wrong with using plates/stones other than the cost of wearing them down from removing a lot of hardened steel.

Keep it up and keep practicing! :doublethumbsup:

 

[merlijny2k]

Thanks. I already noticed the difference between new and old belt! Don't ask how I found out