Harbour Freight 1" x 30" belt sander: initial impressions and questions

That's most likley a self-inflicted wound. When you begin a sharpening pass, it is usually at the plunge. You tend to be tentative and use a lighter touch until the blade is just touching the belt, then you move on to sharpen the rest of the edge. That often leaves the area where you begin the pass undersharpened, so the wire edge forms everywhere but there. To compensate you either use a steeper angle to start or you go back and use more pressure in that area. That then can result in going from undersharpened to oversharpened or just poorly sharpened so you have to do it again. The net effect is that unless you're careful you can remove more metal in that area.

This is most likely to happen on a blade that's pretty badly out of shape. The symptom is pretty easy to spot. Whenever you see the wire edge develop in one area or another first, well before the rest of the blade, you are clearly not applying the sharpening belt to all areas of the edge equally.

Be careful about moving on to finer grits before you have the wire edge established along the entire edge. Trying to fix an undersharpened area with a finer belt is likely to result in more pressure, creating a steeper angle and more metal removal to get a wire edge in the neglected area. In the end you can get more erosion in that area while never getting it satisfactorily sharpened.

Once your blades are all evenly sharpened, you can start with a finer belt to keep them all tuned up.
 
Jerry,

Are you talking about HF's sander, or a variable speed grinder that you can slow down? I find that HF's fixed high speed makes it awfully hard to follow your advice and still stay out of trouble. My preferred bevel geometry is a full convex blend, and I've been bit by me2's issue. Now, when forming the bevel, I stay off the edge itself with the belts, and use the waterstones to smooth the bevel and form the actual apex of the edge.

I do use the 180 and 320 grit belts, but carefully, oh so carefully.

Ray
 
Ray, what kind of trouble do you mean and why don't you want to finish the edge with the belts?

I use the HF when I do sharpening demo's, but I admit most of my sharpening is with one of my Baders. In some respects the Bader is more difficult, especially with smaller knives because of the wider belt.

Just so everyone doesn't think I'm just a spoiled brat, I made knives for about 15 years with only fixed speed machines. Most of that time was with a Wilton Square Wheel Grinder that runs at 4600sfpm, which is faster and definitely much rougher running than the HF. The HF is a pussycat. :D

If you don't use the same angle, time and pressure for the entire length of the edge, you are creating problems that will usually result in varying degrees of edge erosion along the edge.

You have to trust the Force... ;)
 
Jerry,

When I prepare that convex blended bevel, the edge gets pretty thin on the thinner blades. With better steels, my bevel starts at 15 degrees per side, and just a hair's breadth back from the edge, shallows out. The combination of a fresh coarse belt and HF's high speed just eats metal and I lose control.

My solution is to stay off the edge apex with the belts, and use a broad flat waterstone to avoid recurves. On an already thinned blade, it doesn't take long to manually finish an edge. I generally start with Norton's 1000, set the terminal angle and get a burr, then move to 4000 and 8000 stones, and then polish with power strops on the HF.

I wish I had the fine touch of you pro's, but I don't, so I just take it slow and easy.

Edge maintenance is a different story ... I love the HF for that.

Ray
 
Let me suggest a couple things. Fresh coarse belts can be problematic when doing fine work. There are actually two problems. The edges tend to cut more aggressively than the middle so they can cut into an edge before you know it. Use a rock or better yet a piece of brick to break the edge of the belt before you use it. Just hold it against the edge of the belt for a short while as it's running. Secondly, you can use a piece of mild steel or something similar to break off the coarsest parts of the abrasive across the belt. Just a light touch of a mild steel bar (Home Depot sells mild steel bar stock) held across the belt for a couple turns tames the beast quite a bit and makes that initial sharpening pass a lot less dicey.

I usually keep some well used belts around for just that sort of thing. I also have a wheel dressing stone (used to flatten grinding wheels that I think I got from Brownells) for breaking the edges of fresh belts when I'm working on smaller blades.
 
does the HF motor get hot after 10 -15 mins of sanding?

My 4" x 36 belt sander gets very hot. Too hot to place hand on motor after 15 mins.

No idea if its normal.
 
Who cares, just don't put your hand (or your cool beverage) on the motor! :eek: :foot: ;)
 
gustav said:
does the HF motor get hot after 10 -15 mins of sanding?
Click to expand...

Not really. I have 2 units, and the second runs with a lot less friction than the first. Both have a cooling fan and a plastic cover over the motor that doesn't conduct a lot of heat. You should check carefully that the fan doesn't bind on the cover.

Just BTW: I paid $40 for the first, caught a sale on the second for $30. I saw the same identical model, labeled with a different name on another web site, for $78.
 
gustav said:
does the HF motor get hot after 10 -15 mins of sanding?

My 4" x 36 belt sander gets very hot. Too hot to place hand on motor after 15 mins.

No idea if its normal.
Click to expand...

It has been thirty years since I worked with electric motors.

Back then the old timers told me that there is a problem when you can't hold your hand on the outside of the motor because it is so hot.
 
Just a word of warning to those using the Harbor Freight sander. The drive pulley on mine moved on the shaft and cut/burned a hole in the plastic wheel cover before I figured out what that smell was. It still works. I just need to figure out how to keep the wheel from moving again. I'm going to try to shim it, and if that doesnt work, well, they're only $40.
 
There is a set screw on that drive pulley, accessible on the hub from the side. It probably loosened. I didn't remove it to check, but the screw probably tightens against a flat on the shaft so you need to make sure you're on the flat when you tighten it.
 
As an update I've been receiving uniformly positive reviews from the neighbors whose kitchen knives I've been sharpening.

I still haven't topped my best ever results from hand sharpening and stropping, but I'm getting close.
 
Jerry Hossom said:
There is a set screw on that drive pulley, accessible on the hub from the side. It probably loosened. I didn't remove it to check, but the screw probably tightens against a flat on the shaft so you need to make sure you're on the flat when you tighten it.
Click to expand...

You must be talking about the set screw that doesnt touch anything anymore. Yea, its in there, but it doesnt help now. Its as tight as I can get it, but the wheel still walks and wobbles. I guess a bigger wrench would help, so I'll try that before shimming.
 
Tightned up the screw with a crescent wrench and an allen key. It helped for a little while, so I just used a small nail to shim it tight.
 
1Bigdog said:
It has been thirty years since I worked with electric motors.

Back then the old timers told me that there is a problem when you can't hold your hand on the outside of the motor because it is so hot.
Click to expand...

this was what i heard too
 
You must log in or register to reply here.
Back
Top