gouging of material when surface grinding

F

fetz

Joined
Dec 30, 2003
Messages
88
hey, have any of you guys ever had this happen? when suface grinding a
piece of bar stock, say 1/4 inch thick by 2 inch by 10 inch on my 4x36 belt
sander at times i start getting gouges taken out of the surface, it almost looks like a dremel with a small grinding bit was taken to the surface of the material, i have had this happen on 440c material and 1095, it has happended
when holding the material with a magnet and also with duct taped rolled up for holding, i know this machine is probably not designed for this but i have
had it work flawlessly too, anyone have a clue what i am talking about?
thanks!!!
 
it always seems to be on the bottom third of the piece i am working on, it started doing it last night on a piece of 440c, i was moving the stock around
alot hoping to avoid a bad spots but that did not work.
 
Check for trash on the back of the belt, and the wheel. Look for trash built up on the belt as well.

try hand feeding the belt around on some soft material.....aluminum maybe...and look for the wear marks you have been seeing. Hit the belt with the sole of an old rubber soled tennis shoe. It will clean the junk out of the grit.

Post pics of the marks too. I woudl be interested in seeing waht you are seeing.

Doc
 
Yes, a pic would work wonders here. Sounds like a condition known as galling to me.
 
do you have an aluminum platen? if you do look and see if you're getting grooves in it?
if you have then it's part of your problem. it's boogering up on you :(

jeff beat me to it :( :) gauling :to booger up :p :D
 
Dan Gray said:
do you have an aluminum platen? if you do look and see if you're getting grooves in it?
if you have then it's part of your problem. it's boogering up on you :(

jeff beat me to it :( :) gauling :to booger up :p :D
Click to expand...

Hey Dan, you need a hankie fer them boogers? :footinmou
 
I have had this happen a LOT on my 4x36.
it seems to happen when you're taking the steel off or just making contact and the belt is lifting up in spots and hitting it, you might want to try adjusting the tension on the belt a little tighter, it worked for me and haven't had the problem since.
I always thought it was from junk building up in behind the belt as well, but every time I checked it was clean. :grumpy:
then someone finally came up with the above solution for me. ;)
if it doesn't happen when you're just running single passes (instead of holding it on) with your stock then this sounds like your problem.
good luck, Steve
 
yep, thats when i happens, when i hold it down and try to surface the material, i went home at lunch and pulled the belt off, looked pretty clean underneath, i have never adjusted the tension so i will try that!!!
thanks!! thats what i like about this forum, sooooo much info and good
guys willing to help each other!!!!!!!!
 
I just got mine fixed up within the last month, that's why I even still have that info on my mind LOL
it was driving me nuts, I almost stopped before I ever got started in making knives, it was hard enough to learn to grind, but when all you have is a 4x36 and then when you get the grinding down pat it starts doing things like that! woooo I was mad! hahahaha :D

Steve
 
Doc Hollywood said:
next IG will be suggesting his relish to make your nose run so you don't have to blow it..hahaha

Doc
Click to expand...
Is that application before or after you start grinding????? :confused: :confused:
I wonder if they make pyrocrem that wide??? I would thing that may help. :)
 
oh, by the way, i usually run the belt in the verticle position, (not pivoted into the horizotal position) dont know if that has anything to do with it
 
I run mine vertical as well, have you tried running a few single passes on it with your steel and see if it happens that way?
if you can't get it any tighter you might want to try sliding the steel off of one side instead of lifting it straight off the belt, as soon as you stop pushing the belt into the platen is probably when it's happening, so if you slide it off to one side it might help.

Steve
 
getting ready to leave work, i will go home and play around with it a bit
tonight and let you guys know tomorrow, there might be someone else out
there with the same problem waiting for cure!!! ha ha ha!
or ho ho ho
 
I have had this happen - scared me half to death - but I think Doc Hollywood is on the right track - check under the belt - a little bit of grit or shard can make this happen - I found a small burr or something - that's all it takes. When changing belts, I now wipe the platen and run a cloth inside the belt I am putting on.
 
I think there are enough fixes here for him to try that he is bound to find something that works. I am looking forward to finding out what it was.

Makes me think that it would be good habit to run a test piece through the grnder before doing anything important too.

Doc
 
well i went home and worked on it, i took off the belt, took off the top roller,
took the axle out of the top roller, cleaned and lubed the axle bushings, stacked a washer under the tension spring to apply a little more tension since
the tension is nonadjustable, took some 400 grit and a sanding block to the
platen and cleaned it up, put the works back together and grabbed some material and held it with a magnet holder and started suface grinding, worked
awsome!!!! so i dont know what exactly fixed it but its fixed!! yahoo!!!!
 
You must log in or register to reply here.
Back
Top