well i tried out my new sander from harbour freight,its that cheap variable speed… seems like a real piece of crap it sounds like its about to blow up and send a gear through my head…well thats not really the point, im used to a makita random orbital sander ,and the feeling is much different…yeah the orbital is alot slower getting the job done but much smoother…and about 7 pounds lighter…well see i had a problem with this sander /polisher…i seem to have a hard time keeping it from wanting to jump around…so bad im suprised the board diddnt bounce of the rack a time or two…i tried using more pressure, and then tried using light pressure, and it still happened. my rack never seemed too high before but this time it felt awkward like i was having to try and sand almost up at my chest,maybe thats the problem…maybe im just not used to the new one. anybody have an idea what im doing wrong?
What type of pad are you using and are you keeping it flat? I have the same sander and have had no problems. Your pad should glide not jump around.
Hey Have, working with sanders takes a while to get comfortable, especially if it’s your first experience with this type of sander. Give it some time and practice and you will get into it eventually. I’d still use the random for the fine sanding. With practice they both become and extension of your hand.
Sand away. And keep your tools maintained, they last longer. Fibre and resin dust are not tool friendly
Howzit have, check the archives for a tip by Herb spitzer about changing the grease in the gear head. It’s supposed to make a big improvement in the grinder. By the way where is Herb these days. Aloha, Kokua
also check the pad you have is flat not warped from being dropped etc
well the pads a 3M 9" foam thing for sanding but anyway,i took it to work and spun it on the lathe cause i figured it was warped maybe… well its not warped…so i figure try it when i get home,must have been im just not used to it…but thats not it either. i spin it on the sander and it obviously wobbles but the hard velcrow pad that came with the sander doesent wobble so its not the sander or the pad its the combination of the two. so back to the store again
How’d you attach it to the lathe? I suppose it’s possible that you attached it to the outside of the nut which is centered but the threaded hole is not… though I highly doubt it.
Perhaps it was off center: that wobble is not going to budge a lathe, but it will a 5 lb sander.
no you dont get it , i put a 5/8’-11tpi bolt on the pad like how it screws onto the sander, put the bolt in the chuck on the lathe and spun it to LOOK and see if it wobbled (not like its loose but just out of line)…looked fine. put it on the sander and it does wobble. and thats no good dont know why …its a mystery.
Could be a defective pad, out of balance somehow. It’d be nicely centered and all, but the weight of it isn’t and when spun up it’s throwing the sander around like a tire/wheel that’s out of balance. You wouldn’t see it on the lathe without mebbe a dial indicator to check the pad sides, which might deform a few thousandths at speed from the imbalance, but you’d definitely feel it on the sander.
Question is, does it ( the sander) vibrate the same way with the buffing/polishing wheel setup it came with or maybe a 5/8"-11 backing pad of some kind? That’d indicate it’s the sander and not the pad. HF is usually pretty good about replacing stuff: http://www.harborfreight.com/cpi/ctaf/cs.taf gets you their customer service.
hope that’s of use
doc…
I’d find out which of the two suck,and return it.Then again if it really sucks???Hummmmm…do you really want to…anyway,replace the grease in the head??? with a marine bearing grease or what I use is Slick-50 bearing grease(if you can find it anymore???I bought my tub about 6 years ago on a close-out sale).I also suggest keeping it clean…but that any tool.Herb
They still make it: http://www.slick50.com/ and Ace Hardware carries it, though in tubes for a grease gun rather than tubs. Quite a few others too, check http://www.slick50.com/locations.htm for 'em.
Thanks,I need to get a bottle of S-50 radiator tx for my truck’s new rad.(steel and brass instead of plastic).My factory rad lasted 135,000 miles before the center seam split.Herb
hello have, despite my confessions of bad glassing I am a much better sander and was shown how to do it by a professional.
I think Wildy might be on the right track thats its a technique problem as you did say you were used to the orbital. Nobody else has elaborated so I’ll have a go.
Although it might seem that a round disk is not the obvious thing to produce a flat hull surface or smooth rails it does work by pressing the leading edge of the pad only onto the glass. I wonder if you trying to press the entire flat surface of the disk - in this situation it will grab and jump around. If you weren’t sorry about stating the obvious.
Anyway by leading edge I mean slightly tilt the disk such that only a portion of the edge of the disk is in contact with the board and the side that contacts is the one in the direction of travel. There can be a temptation to just use the weight of the sander to apply the pressure but this will lead to the pad following undulations in the glass (I’m assuming that the shaping was accurate and undulation free, but glassing may have added some) so you need to hold it steady and make long multiple passes - even if the first few passes only take off the high spots still leaving shiny patches. Don’t cough in the middle of a pass.
i say, return both. then buy both again. if the same thing occurs… most likely its not the tools
no its definately the way the new pad fits…i dont know why exactly but if i fun it at a low speed i can see the pad wobble like its bent somewhere but the one that came with the sander spins just fine its just alot harder of a pad than i feel like i want
i think it sounds like your shaft is bent! not enough to see on its own but when you put the pad on…you can see it
no its definately the way the new pad fits…i dont know why exactly but if i fun it at a low speed i can see the pad wobble like its bent somewhere but the one that came with the sander spins just fine its just alot harder of a pad than i feel like i want
Okay, it’s definitely the pad. Otherwise anything you put on the sander would wobble.
Bring it back, get another one. Might be a plan to take the sander with you to test pads, could be that a bad lot of pads came through or something along those lines.
Also, scrounge 5/8"-11 backing pads, beat up or whatever, that somebody else has tossed - there’s some very good info in the Archives on making your own custom pads, as soft or as hard as you like.
hope that’s of use
doc…
cool i need to look that up
MrJ has, I believe, the answer.
I note that you’re used to a random orbit sander (almost never use one myself). With that tool the entire working surface bears on the board, which is exactly NOT the way to use a disc sander.
When using a disc, the pad has to be at a slight angle to the work. The downside is that this produces an arc-shaped working area on the pad, which can cut arcs in the work if you aren’t moving enough.
Sounds to me like you just need to become acquainted with your tool and use it correctly. I have several disc units, an old Black and Decker 7 amp, an ebay cheapo 7 amp and a recent 11 amp Milwaukee beast. All will vibrate and jump if you lay 'em flat. It’s just not the correct way to use the tool.
well i checked it all out again now , i cant even tell if its the sander or the pad. im not talking sanding on a board im just holding it and watching it run . ok , its that cheap 30 variable speed from harbor freight, it came with a hard rubber pad for the polishing pad, and a pretty hard foam pad with velcrow for sanding, i wanted something softer for sanding so i got a 8" 3M. pad …when i put the 3M on and run it , i wobbles like crazy, cant really use that,…when i put the rubber polishing pad on it wobbles alot too, but i can understand that just cause its a cheap piece of crap. then i put the sanding pad with the velcrow on and it dosent really seem to wobble at all…and with any of them, while its spinning ,if i put my finger on the shaft of the sander its running smooth not wobbleing even if the pad is…i should just return this whole mess , hell i cant use any of this crap.