Harbor freight 4" x 36" Belt Sander

[McRuff]

I bought one of these several weeks ago to deburr parts and to sand the ends on some parts I rough mill a radius on.



It is not perfect by any means but for $69 + tax it wasn't bad.
It needed some tweaking to make it better. It is mostly assembled when the box is opened. I put the table and sanding belt on and plugged it in. The 1st thing I noticed was the lower outer bearing got hot almost immediately, turns out the bearing was in the outer case crooked, about .050" worth and caused some major drag.



I took the bearing case and flipped it upside down and pressed the outer case down flat with the bearing in my press.

Next problem was the fact that both belt rollers were injection molded out of the crappiest reground plastic I have ever seen. and they were so out of round it was pitiful, they were out of round about .050-.060" which caused vibration when the belt was turning.
I put both of them mounted on there respective shafts between centers and trued them up.
Once trued I crowned both of them 1/2° per end by setting the lathe compound and cutting down there length roughly 1.250" per end. This made them track nicely.

The top pulley being crowned.



And here it is finished.

 

[McRuff]

Once the top pulley was finished I moved onto the bottom pulley, this causes some major disassembly of the machine, not hard but takes about 20-25 minutes to get it all apart.
I put my drive dog on and stuck it between centers, it was out of round more than the top one.

Notice how out of round the roller is?



Bottom pulley finished and crowned the same as the top.



The last problem with vibration is this crappy belt, notice how much slop is in it (this was with no real pressure added), it also put together very sloppy and is crooked where it is seamed which causes it to thump a little when the seam comes around the pulley. I will order a new one tomorrow.



All back together and running much smoother with more power since the bearing and shaft are not dragging anymore. Truing up the rollers probably eliminated 60% of the vibration and noise it had out of the box, I figure a new belt will eliminate another 10% or so of the noise along with a very noticeable decline in vibration.

It tracks perfect now.




While this machine could use more power and more speed for metal work it works fine for general deburring of parts, but I do have another motor laying around that is more powerful, I might add it and make a pulley to speed up the unit about 30% or whatever will fit inside the belt cover.
Hope this helps someone else out looking at buying one of these for general use.

 

[burnrider]

Great fix. They should hire you in China. We can start a whole section on fixing Harbor freight tools. Pay might be low, maybe a couple rats a day.

 

[jfcayron]

Hope this helps someone else out looking at buying one of these for general use.

I own one and will go through your suggested improvements as soon as I finish my lathe.
Thanks.

 

[7HC]

I just picked one up and was expecting to do all the usual mods, but I was pleasantly surprised to find it ran quietly and tracked true.

Maybe I was just lucky, or maybe HF have improved their quality control; either way I'm pretty pleased with it, especially for less than $60.


M

 

[kevin]

Based on this thread and some othe reviews I read, I decided to go ahead and get one of these sanders. I didn't have to do anything to the rollers on mine, but I did make some other improvements: - made it simpler to change belts - adapted the disc plate for hook-and-loop type disks I would also note that this sander (for me at least) basically works out of the box (after a little bit of assembly), so either I got lucky or quality control has improved. I also think my model (97181) is different (and improved) from earlier models, as I noted some changes from other reivews I have read. You can see how I did this (along with a general review and a bunch of related photos) here: https://sites.google.com/site/lagadoacademy/machining---lathes-mills-etc/review---belt-disc-sander

 

[hman]

You might consider doing what I did on a small belt/disc sander some years ago. I just didn't like the disc - especially the fact that it's going upward across half its surface.

So I turned a 1" diameter arbor (with a small shoulder near the motor end) to fit over the motor shaft. IIRC, I used a setscrew to hold it to the motor shaft.

A 1" ID washer fits against the shoulder. The 1" diameter extends about 15/16" beyond this washer. The end of the arbor is tapped for a 3/8" bolt, which goes thru another washer. This allows me to mount a Scotch-brite wheel (6x1x1 - may have this reversed, but it's 6" OD, 1" ID and 1" thick).

Scotch-brite is the absolute best method I've found to deburr, polish, clean up, etc. metal parts. It's really great for getting rid of sharp edges on freshly cut sheet metal! The wheels are available on ebay, and prices vary, but the wheels last a long time. You can keep using one until it get pretty small.

- hman
(John Herrmann)

 

[ML_Woy]

Has anyone purchased their larger floor model belt sander, usually is selling for around $199.00. I believe it is the 6" x 48" belt model? I have been considering picking this one up as soon as the budget can permit.

 

[kevin]

That's an interesting idea. I still need the sanding disk for wood-work (need to be able to change grits), but I could see how Scotch-brite might work for some kinds of woodwoork too.

You got me thinking though: One of these days I ned to replace the wire brush wheel on my bench grinder - Scotch-brite might be a good replacement.

 

[Old Iron]

I got the floor model abut 3 years ago when they were cheaper. They were on sale and I had a 20% coupon so I got it for $89.00 because they were on sale for $99.00.

Its has been tracking ok and I've never had any trouble with it,

Paul