Toy or Power Tool

[Ray LyonsParticipant @raylyons29267]

[Ray LyonsParticipant @raylyons29267]

Several months ago, before the onset of winter I was making a disk sander but family commitments took me away from the shed and the cold weather until now. Realising how much time was being taken up on making simple items I decided to spend some of savings on a new combined disk and belt sander from EBay.

After unpacking, I tried it out just to make sure that the motor worked and tested with a piece of wood and all seemed ok. Today, I went up to the shed to use the sander only to find that it would not start with the belt under tension. Releasing the belt, the motor started but any real pressure on either the belt or disk will stall the motor. At first I thought that it could have been dampness caused by over winter in the unheated shed (actually the back end of the garage) so I left the machine to run for about 1/2 hour but found little improvement in the power. After running, the end cap on the belt sprindle was very hot as was the motor. The motor is rated at 375W and when I compare it to the same power motor on my drill, it is only about half the physical size.

Looks as if I have bought another lemon and now thinking of making a shaft to replace the motor and drive this by a larger motor positioned away from the sander.

Anyone with experience of these machines, your comments please except for chucking it in the bin.

[Peter G. ShawParticipant @peterg-shaw75338]

Can't help thinking that perhaps there is something wrong with the belt, especially as you say that it seemed ok on initial testing. Which suggests that to me that a fault has developed.

Excessive heat suggests something binding somewhere as does having to release the tension to allow the motor to start.

I assume that the sander motor is an induction motor whilst the drill motor, assuming a hand held pistol drill, will be a series wound universal type of motor and hence totally different, a bit like comparing cheese & chalk.

I have a vertical drilling machine with a 180W motor which can be fairly easily be stalled. However, when stalled, the motor complains with rather loud buzzing sound. As indeed do my pistol drill and portable electric saw. What does your motor do when stalled?

Sorry, can't be much more help

Peter G. Shaw

[Ian L2Participant @ianl2]

Could it be motor not switching from start circuit to Run?

[Bill RobleyParticipant @billrobley]

Hi Ray.

If it's the machine I think it is, I have one too and can say with reasonable confidence that the issue is not with the motor but the idler pulley that the sanding belt runs on at the other end. On my machine there is no real bearing for it, just a bronze / brass bush. Over time this dries up and gives exactly the same problem you describe.

My solution was to strip down the assembly (watch out for the spring!) clean, lube and re-assemble. This should sort your problem.

Hope it helps.

Bill.

[Speedy Builder5Participant @speedybuilder5]

I have a "cheaper" BLACKSPUR 240watt belt sander now for 15 years or more. When I put a new belt on, it stalls and I have to give it a chance to warm up with the belt a bit slacker than normal, but after that, it copes fairly well with both wood and metal. This is noticed more with the coarser grades of belt than the finer ones. However with yours, it sounds like the bearing could be at fault on the belt spindle bearing. Does the motor get hot with no belt on? What does the belt spindle pulley feel like when you turn it by hand (belt off).
As a thought,make sure that the belt is adjusted so that it does not rub on its edges against the side guard.
You did comment about the load on the belt "Real Pressure" I don't think you should expect these little machines to remove large volumes of material. When I use mine, I only apply light pressure especially when sanding wider sections – having said that, I use it most weeks and would not be without it.
By the way, can one buy emery belts for these machines?
Let us know how you get on.
BobH

[Ray LyonsParticipant @raylyons29267]

Thanks all for your suggestions. I have just been up to have a look and strip down to identify the problem.

The motor is a capacitor start so I was surprised that it could be stalled at 1/2 HP but looking again, it appears to be "geared" up where the drive belt cover is larger at the motor end than that at the sprindle. Its all constructed with pressed steel sections, bolted together with mainly 2mm Phillips head screws.The main drive sprindle is fitted with ball races, the outer being held in place by a pressed metal cap secured to the side plate with 3 small screws. I suppose the things must be jig or robot built to get the alignment right. Anyway, I found the problem to be the bottom cover plate where it had come in contact with the belt and the two fixing anchors have been ground away.

Now all back together and test run. The motor only gets warm after running for an extended period but Bob is right, light pressure is only required to get results. After all, it is only a DIY machine. Many thanks to all, I think this one can be put to bed now, although I still have to devise a fitting to secure that bottom cover plate.

[Clive HaynesParticipant @clivehaynes74488]

Hi, I bought a small disc/belt sander from machine mart a few years ago and although I think it was designed for woodworking I assumed that it would handle light use with aluminum, wrong. The motor which was 375W burnt out so as I could not find the receipt I binned it. I have since bought a larger machine from Warco which does the job with ease.

Clive

[Gordon WParticipant @gordonw]

I used to have one and it worked OK for wood. I lent it out and got it back with a blown motor. The motor had a small amount of metal dust in it and this had done the damage, had been used for polishing steel.

[Clive HaynesParticipant @clivehaynes74488]

A neighbor of mine borrowed a 8" circular saw from me a year or so ago and when I asked for it back he totally denied having it. What do you do?

Clive

[John OlsenParticipant @johnolsen79199]

A lot of the small Chinese made belt and disc sanders are quite underpowered. They may be taking the advertised power from the mains but they are not delivering much of that as mechanical power to the job. They are OK for light work.

The problem with loaning things is that you don't have any real comeback. You can't go to the police or claim on your insurance, since you voluntarily let them have it. (I am not a lawyer and this is not legal advice….) Best not to loan things at all, or only to people you really know you can trust.

John

[Jesse Hancock 1Participant @jessehancock1]

Gordon: I now have a policy of never loaning tools out to anyone any more …. I tell them to, "go and buy one" (Always add "They're only" X amount of pounds to give them an idea of how much you have invested.) Or if they whine about only needing it for a couple of jobs, "I tell them to go hire one." I've been had over too many times.

If they are close friends then I do the job for them. At least then if the job is shaping and finishing a 4"X 4" fence post I can select the right tool for the job.

Just for the record I find wood usually puts more demand on the motor than metal as it drags more but the small sander I have now is meant only for finishing small items in my estimation.

Edited By Jesse Hancock 1 on 27/02/2015 07:00:17

[Gordon WParticipant @gordonw]

Loaning things out- yes but, We live in middle of nowhere and borrow as much as I lend out, if I break something and I have , I mend or replace. Currently have a heavy breaker and 110V transformer on loan. But my point was that it was the small amount of metal dust that caused the problems, not overloading.

[Ian S CParticipant @iansc]

Neither a lender or a borrower be( Shakespeare) Merchant of Venice (I think).

Last thing I lent out was my Osciloscope, my sisters brother in law is into manufacturing electronic farm gear, weather stations, scales for weighing stock, and a few other odds and ends. He thought it might be useful, two years later it came back with the comment that it was a bit useless. Its a CRT type and I can't focus it anymore, so it has a thick fuzzy line for the trace.

I want a digital one anyway.

Ian S C

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