Thread: Sanding disc construction

I think this applies to me very well:

I have not failed 10,000 times, I have successfully found 10,000 methods that do not work.

Thomas Edison.

Originally Posted by Black Bear

I think this applies to me very well:

I have not failed 10,000 times, I have successfully found 10,000 methods that do not work.

Thomas Edison.

Me too!!

If it's any help at all, I built one years ago when my budget was $0 using a 1/3HP washing-machine motor with a 10" disc mounted straight on the drive-shaft. Runs at 1450 RPM and I still use it today - just as good as any of the tailor-mades I've used

Just a thought,
Isn't the periphery of a circle (disk) measured at the circumference?
witch1

Originally Posted by witch1

Just a thought,
Isn't the periphery of a circle (disk) measured at the circumference?
witch1

witch1,
From Wikipedia...Generally, a periphery is a boundary or outer part of any space or object.

So, to be picky, you measure the circumference of a disc at its periphery.

Not sure where this is going though

Ian

Originally Posted by Sturdee

Black Bear, so sorry for bothering to post and try to help you as apparently, notwithstanding you asking for handy hints, you don't appreciate my advice.

As you were trying to make a contraption that ran at 1400 RPM I suggested a cost saving as well as a lot less work. But if you want to do all that work at a greater expense go right ahead but remember only a fool ignores the experience of others.

In any case the difference between the edge and the centre is totally irrelevant as it is minuscule and most of the time you will use the whole width of the left side (only 150mm) of the sander at the same time.

Good luck with your project as you go it alone.

Peter.

I apologise, your help got lost in amongst the other rot and riducule. Even so, I have it all worked out now, all I need is a shed 20 times bigger to put the device in, along with he full size Canadian saw, the swing arm router, which I saw in a magazine constructed so that the work room door was the swing arm and then when all that is installed, I will get in a couple of tons of wood and make lots and lots of sawdust.

For those of you that really tried to help this old codger, Thank you.

BB

Originally Posted by witch1

just a thought,
isn't the periphery of a circle (disk) measured at the circumference?
Witch1

yes:u

Originally Posted by Black Bear

I apologise, your help got lost in amongst the other rot and riducule.

BB

No worries mate.

BTW you will find that the mods will insist that the original question be answered satisfactory before it's allowed to wander a bit of topic. No doubt they felt that my initial post was sufficient and so wandering around it was allowed.


Peter.

Sorry mr Smith,
I believe that the subject matter under discussion was specifically with regard to disk shaped objects.
Not wishing to create a problem by straying off the topic, thereby incurring the wrath of the gentleman in charge of keeping within reasonable distance of the what we are talking about, I chose not to include other shapes. I am pleased that you have drawn my attention to the fact that I was exactly right.
I did not chose to invoke "wikipedia" as I do not have much faith in them because they don't appear to spell their own name correctly.
I drew my tentative answer from a llifetime of interest in all things mechanical, and a reasonable memory.
stay happy
Witch1

Originally Posted by Black Bear

I apologise, your help got lost in amongst the other rot and riducule. Even so, I have it all worked out now, all I need is a shed 20 times bigger to put the device in, along with he full size Canadian saw, the swing arm router, which I saw in a magazine constructed so that the work room door was the swing arm and then when all that is installed, I will get in a couple of tons of wood and make lots and lots of sawdust.

For those of you that really tried to help this old codger, Thank you.

BB

If I said that when my bicycle wheel's hub is spinning at 50 RPM that its rim is doing (let's choose a number) 500 RPM or so, probably you would fall about laughing.

On the other hand, if I said that when the inner end of my spokes are travelling at 50 cms/sec , the outer end is travelling at 500 cms/sec. most people wouldn't bat an eyelid. Some folk might do some arithmetic, estimating the circumference of the circles the spokes' ends travel to determine whether it's plausible.

If you're measuring distance travelled, the outer regions of a disk travel further each second, it's true. But you said RPM. and that's measuring angular velocity which is constant across the radius of the disk.

I know you blokes will be waiting anxiously hoping to hear how I am going with my Disc Sander. ( Am trying to be funny folks, not sarcastic)

I guess I am lucky to have some good friends in my area, as I have been given: 3 v pulleys, some aluminium construction that I can turn into a sanding bench in front of the Disc, A half inch threaded chuck, which will be fitted to the other end of the sander to facilitate drum sanders and stuff.

I have purchased two old, really old, but very well built Plummers Blocks with self-centring bearings for $40.00 which includes the shaft. I have purchased a 2 inch and a 4 inch V pulley at $22.00. This cost is reasonable considering that 2 Plummers blocks with bearings are $25.80 each and the shaft from Metal Land at $10.00 as a cut piece, with pulleys usually set a $15.00 each no matter what size.

I have the motor, and after all my carrying on I have had it tested with a tacho and its speed is 1440. I suggested that it was 2800 previously.

So with 3 pulleys I can get 1440, (2" to 2") and slower speeds with a 3 and a 4 inch pulley. I looked at the variable speeds of my mates wood lathe to determine the speeds I would be using.

I am using one 2" pulley on the motor with a sliding hinge system so that the one pulley will self centre with the 3 pulleys on the shaft up top.

I was going to build an aluminium stand, using those knock ins, but now I reckon I could build a good, not to heavy wooden one. plenty of scrap wood around the various kitchen factories.

If you are really excited I will send a photo when it is finished.

BB

Onyer black-bear!
nothing like a stir-up to get the creative juices flowing
I bet it will be a ripper when it is finished
get stuck in and get it finished so we can see the photos
all the best
witch 1

Originally Posted by witch1

Onyer black-bear!
nothing like a stir-up to get the creative juices flowing
I bet it will be a ripper when it is finished
get stuck in and get it finished so we can see the photos
all the best
witch 1

Wasn't REALLY Stirring....Just having a bit of fun. but thank for your kindly comments.

I think the sliding hinge idea a is good. It comes from my engineer mate. It saves two extra pulleys, which would have meant 3 X 2" pulleys on the motor shaft.

Here is the sliding hinge for the motor mount that will allow one Pulley on the Motor to line up with 3 pulleys on the work head.

I have managed to scrounge all the parts so far.

The aluminium blocks were built for another job, but they were just right for this conversion. The rod and tube for the slider cost nothing as I was able to look through a scrap bin.