Is something wrong with my belt sander or am I not using it right?

[krow]

I have this http://www.harborfreight.com/1-in-x-30-in-belt-sander-60543.html and have had a problem with it sanding only the edges of a knife (e.g. http://i.imgur.com/AIKZkC7.png) ever since I received it. This is what made me put everything away for a year and now I'm back at it again. Is this where the back plate is supposed to come into play to straighten the belt out? Assuming that this is the case because the belt curving around the knife would cause only the edges to be sanded.

 

[Bill DeShivs]

That is called the "platen," and yes-you grind flat objects against it.

 

[krow]

Whenever I push against it, the knife would rattle and knock against it repeatedly, causing it to be pushed back. How can I prevent the knocking from happening?

 

[Bill DeShivs]

Buy a better belt sander. Good belts don't have a noticeable bump at the splice. Try different, high quality belts.
Your link doesn't work, so we can't see your pictures.

 

[krow]

I was hoping you wouldn't say that because I can't afford to buy anything more for this. Guess I'm done with this hobby then.

 

[Itsthegrizzly]

you can just get a few better quality belts. i know that plate wiggles a bit on that model so the vibration plus the pressure with that cheap belt is probably what is causing the hop

 

[HeavyHanded]

Do whatever it takes to get rid of any play on the platen. I do not own this model, but maybe it can be shimmed, wedged etc to take out the slop. I had some good results on belt systems by clamping a thin piece of wood next to the belt to bring the level of the tool about even with the belt - a tool rest. Then you can work against the rest and not the belt, takes a lot of slop out of the system as well. Lower speed will help too.

 

[Jason B.]

IMO, you shouldn't be using a belt sander to sharpen anyways. The HF 1x30 does work better with high quality belts but the machine itself is still bottom of the bucket and moves way too fast. The platten can be modded to run smoother by attaching a strip of delrin plastic but the tracking will always suck. If you feel belt sharpening is the only way then save up and get a 1x42, more belt options and better machines.

 

[ricklee4570]

Maybe changing a pulley could reduce the speed? Instead of 3000 plus a better speed would be around 900

 

[T.Saslow]

For about 170$, you can get a relatively good beltnsander with a built in disc sander. It is made by sears craftsman but it's better than what you have. Just don't give up on the hobby, that is not a very good option!

http://www.sears.com/craftsman-21513-1-3-hp-electric-belt-disc-sander-21513/p-00921513000P

 

[Bill Hoffman]

Never give up! Try better belts. You might even try to remove the lump
where the belt is glued together. The HF grinder really isn't what you should
be using. It will simply cause frustration, as you have discovered.

 

[G. Scott H.]

I used to sharpen on that same sander (since switched to WSKO), and it worked okay for that. Trying to grind anything flat against the platen was nigh on impossible for me, though, no matter what I tried.

edit: I do recall Cliff Stamp talking about successfully grinding blades on an HF some time ago. You might google his forum (assuming it's still around, I haven't been there in ages).

 

[krow]

Well unless someone wants to volunteer to buy me a better belt sander, then I'm done with all this. I've had enough problems and frustration with that HF sander already (like waiting a month for customer service to not reply because the box was damaged on arrival) so I'd rather not try and "fix" it. I'd rather not try out new belts for the same reason, as well as money.

 

[Jason B.]

Buy a stone, call it good. A Norton India and a strop will probably be less than the HF sander and with a little practice will produce edges sharp enough for about any task.

 

[Bighaze51]

I have this sander and use it all the time. I used it to grind a file into a knife while still I the hardened state. I noticed the "bump" on the plate as well. The best solution I found was to glue a thick pieced of leather to the platen for the belt to ride over. It reduces a lot of the bounce during the grinding process. The leather will wear out but it helps. I too can't really afford a nice setup so I'm living with this as well. Adding some 400 and 800 grit belt will make life a little easier. As others have said, it runs a little to fast for sharpening but if you practice on some cheapies, it can be done. You just have to keep the blade moving and use a light touch. It's great for quick reprofiling and then just use a fine grit stone to knock the burr off. Don't give up!

 

[HeavyHanded]

On another belt sander I've used for sharpening, I made a platen from a piece of oak sanded smooth and waxed it up. Left a lip on either side approx the height of the belt as a tool rest. Fast moving belt grinders are a menace, but with practice one can certainly use them. Bumping seams, woobly platens, too much vibration in the belt, belt running too fast - sharpening isn't rocket science, but once you get beyond the very basic, the level of precision climbs rapidly and these issues have to be addressed.

In all cases, before using powered systems it would really benefit to learn some freehand skills - the India stone is a good choice.

 

[kn4wd]

most all knifemaker supply houses sell glass platen liners, the hf sander is a wood sander at best. best bang for the buck is a viel 1x42.

 

[Komitadjie]

I use a Kalamazoo 1x42 for all of my sharpening, with the sole exception now of my Moritaka kitchen knives, which I sharpen with an EdgePro, or freehand. If you intend to keep sharpening, I'd suggest that the Kally ($200) is worth every dime.

Don't get discouraged, your 1x30 CAN sharpen! As a number of people in here have mentioned, it's not ideal for the job. Primarily, it's far too fast of a belt speed to be optimal. However, with some care, you can still get a good edge just fine. I would suggest sharpening off of the platen, not on it, because with lower grade belts (as you've noticed) the belt splice causes a terrible amount of clunking and banging as it passes between the blade edge and the platen. My prefered place to sharpen is in the slack of the belt, between a half inch and two inches above the top of the platen. That way, the bet is still supported and not tremendously slack, but doesn't have that repeated, contacting "bang" as the splice passes. The belts I learned to sharpen with were just the EconAbrasives cheap-o aluminum oxide ones, so learned precisely the same lesson you did about that.

The trick is light, LIGHT pressure, and using the coarsest belt you can for the edge you want to achieve. A coarse belt will remove the same amount of material faster and with far less heating than a finer one. So make sure you don't step up in grit until you are really ready for it, and pinch the edge tightly in your fingers IMMEDIATELY as it comes off of the belt. If you can feel any warmth at that point, give it a dip in some cool water. As long as you check every pass, you won't burn a blade. Also, just go down to your local second-hand store, and buy a big handful of cheap old Chinese kitchen knives. You can usually count on any given GoodWill to have a fair pile of 'em. Serrated or not, doesn't really matter, because you can pop those serrations off of there in seconds. Do your practice with those, and gain confidence in your ability. I have a half-dozen that I used for my learning, I'd sharpen them, then drag the edge across my concrete shop floor or stab it in the dirt outside a few times to blunt it down again. At one point, I actually shoved the tip in the vice and broke off an inch or so, just to gain some practice re-shaping tips (since that was one of the more common things people would ask me to fix).

I'd suggest having belts down to at least 120 grit, and I find myself reaching for my 60s and 80s fairly often as well. Reshaping a broken-off tip or something is very quick and easy with a heavy-grit belt!