# Homemade disk sander or something else?



## Mark A (22 Jul 2011)

I've got a 3/4 hp 2800rpm induction motor from an old tile cutter which I'd like to use to make something like a disk sander but is 2800rpm too much and scorch the wood? If it is, what else can I make from it, but not too complicated : :roll: ? And don't say a tile cutter! 

Mark


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## spg (22 Jul 2011)

mark aspin":35d793a4 said:


> I've got a 3/4 hp 2800rpm induction motor from an old tile cutter which I'd like to use to make something like a disk sander but is 2800rpm too much and scorch the wood? If it is, what else can I make from it, but not too complicated : :roll: ? And don't say a tile cutter!
> 
> Mark



You could use a couple of pulleys and a belt to reduce the speed.

S.


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## bosshogg (22 Jul 2011)

A search 'home-made disk sander' in Google > images will bring up so many, you won't believe...bosshogg


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## Mark A (22 Jul 2011)

I've looked at pictures of them in the past on google and have now drawn up a design for what I'd like to make, but am unsure about the speed scorching the wood. All of the commercially available disk sanders seem to have a speed of around 1400 rpm, but my motor is double that. 

Mark


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## custard (22 Jul 2011)

Mark, I'd make two comments.

1. Unless you spend a lot of money on a disc sander I'm sceptical that they're any better than a home made alternative. I now have the Record DS300 which has a 300mm disc and a cast iron table. It's okay, but no better than okay. Changing the sanding discs is a fiddle, the mitre track isn't particularly accurate, and the mechanism for adjusting the table inclination is disappointingly crude. It's probably okay for finish sanding end grain, but it's not really precise enough for dimensioning components for boxes/picture frames, or for use with a Domino machine where the ends need to be precise in both axis to a fraction of a degree in order to produce a perfect Domino mortice and tenon joint.

2. Twice 1400rpm is way too fast. Before getting the Record disc sander I had a home made disc sanding jig on my lathe which has a variable speed control. On a 300mm disc I'd rarely go over 1000 RPM. It's difficult to appreciate just what an aggressive shaping tool a disc sander can be until you've used one.


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## Mark A (22 Jul 2011)

That's what I thought too. I'll have a look for some pulleys and belts on ebay now. Anyway it would increase the torque on the disk wouldn't it, reducing the speed to 1:2.5 with a 2" pulley on the arbor and a 5" pulley on the disc. 

Cheers, Mark


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## wobblycogs (27 Jul 2011)

I made a belt sander last Christmas with the design including a disc sander (which I've not fitted it yet). It's certainly possible to build one yourself but I honestly wouldn't bother unless you are doing it for the enjoyment of trying to make your own equipment.

I priced the sander up after I'd finished building it and the parts came to about the same as it would have cost to buy a decent sander. On a more positive note though I now have some experience of building my own equipment and all major the parts of my sander can fairly easily be re-used if I choose to break it down and build something else. Good luck if you choose to give it a go.

http://www.wobblycogs.co.uk/index.php/woodworking/projects/belt-sander
https://www.ukworkshop.co.uk/forums...ct-belt-sander-t46192.html?hilit= belt sander


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## Mark A (27 Jul 2011)

Hi wobblycogs 

Yes, it is for my own enjoyment mostly, but also because I was going to throw away the tile cutter so I thought that I might as well make something out of it. 

I've had a look on ebay for pulleys but they're more than what I was willing to spend so I'll try a local scrap yard and see what I can scavenge from an old washing machine or engine. 

But in the meantime I've got some wardrobe doors to make.... 

Cheers, 
Mark


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## woodbloke (27 Jul 2011)

Mine is shown on the 'For Sale' forum and runs off a Brooks Gryphon motor. It does spin a little too fast for comfort, but tbh that's never bothered me too much as I don't use it as a precision sander. What's more important IMO is to fit it with a dust extraction port as I've done. It's served well for a number of years but it's going to be replaced with a more compact bench mounted unit - Rob


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## jimi43 (27 Jul 2011)

A homemade disc sander need not cost you anything other than scraps and bootfair bits....







This is pulley driven to reduce the speed but was an old motor from a lathe...






It's probably the cheapest bit of useful kit that I have ever used...costs way less than a commercial one...they are usually rubbish and grossly overpriced.

With clever use of the table you can do very square sanding...have virtual zero clearance and changing "disks" is easy as pie. Rip the old one off...stick on a square of ordinary paper (cheaper than discs) when dry...cut around it.

How difficult is that?

I even ground plane soles from castings on this..no problems...a few sparks though!

Jim


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## brianhabby (27 Jul 2011)

Jim, that looks brilliant, an inspiration

regards

Brian


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## jimi43 (27 Jul 2011)

brianhabby":2pdccnao said:


> Jim, that looks brilliant, an inspiration
> 
> regards
> 
> Brian



Cheers Brian...it does me ok.

Word of warning with these homemade jobs though....if you look at the commercial ones...you will see there is a quadrant guard on the side that is rising (RHS in this one moving counter-clockwise). This is to prevent you sanding wood on that side with the result that the stock flies skyward towards your face at quite high speed!

Since I know this I avoid using this area of the disk...and I highly recommend you do the same! :mrgreen: :wink: 

Jim


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## Mark A (28 Jul 2011)

Jim that's very similar to the design I've planned, but much better!

Thanks,
Mark


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## Eric The Viking (28 Jul 2011)

Mark, 

I think you can get pulleys from Machine Mart (they certainly do motors). You might get a suitable reduction, or possibly even a set, to give a range of speeds.

Cheers,

E.


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## Mark A (28 Jul 2011)

Thanks Eric 

I've just checked now - they do sell pulleys, but they're more expensive than ebay. 

I'll try a scrapyard sometime, and if not, I'll search on google 

Cheers, 
Mark


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## Tusses (28 Jul 2011)

could you not make pulleys from MDF ?


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## wobblycogs (28 Jul 2011)

I got the pulleys for my belt sander from ebay, they were by far the cheapest option after a very thorough googling.


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## Eric The Viking (28 Jul 2011)

Tusses":3p4cd67p said:


> could you not make pulleys from MDF ?


Actually, I have a jig for doing that... 

To be honest though, unless it's only for children's toys, etc., I'm not convinced you can balance them well enough for high RPM. 

I've successfully made V-groove pulleys out of MDF, but it's significantly softer in the middle than near the faces, and that's where the wear may happen when running round belts. For my application (flushing the loo - don't ask!), it didn't matter, and the pulleys were quite small anyway (2 1/8" diameter). If you want a big V-groove pulley you might laminate it up from ply - you'd then only theoretically need to bevel two disks. Other candidates are Tufnol and Perspex.

Weight-wise you can balance by drilling holes carefully near the edge, as long as you have a good bearing to test on (rolling the shaft on two level knife edges might work, but would be difficult to set up)., but that doesn't solve the problem of varying diameter - fine if cut on a lathe, but mine weren't!

I'll post the groovy jig in the other forum when I get a moment...

[edit]Pulley grooving jig is here.[/edit]


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## Mark A (28 Jul 2011)

It just so happens that I've recently made an adjustable circle-cutting jig for my router so a DIY plywood pulley could be done. But on the other hand I don't know how well plywood would hold up over time.

I'll try ebay again!

Cheers,
Mark


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## RogerBoyle (28 Jul 2011)

jimi43":jan5y0d1 said:


> A homemade disc sander need not cost you anything other than scraps and bootfair bits....
> 
> 
> 
> ...



Can i ask what glue you used to stick the sheets on ??? and if you dont mind I will copy your design 

Roger


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## Tusses (28 Jul 2011)

if you are worried about MDF, how about hardwood ? Ply ?

it only take a few mins to knock one up, so easy to test the theory.

This sanding disk above looks home made, and would have the same balancing issues as any pulleys !


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## jimi43 (28 Jul 2011)

> Can i ask what glue you used to stick the sheets on ??? and if you dont mind I will copy your design
> 
> Roger



I use spray adhesive. The sort for card. If you use linen backed abrasive sheets they just strip off if you use paper they leave a sheet of paper on the MDF. If you want to clean up the MDF use the disc sander to do that running an abrasive block against it!

Of course you can copy the design...it's only a simple box after all.

Two things...the top slides back and forth and locks into place with screws...you need to be able to push it up against the revolving disk and screw tight for zero slot at interface. This stops little bits getting stuck.

Balancing...just use a sharp chisel on the edge until if forms a perfect circle while running...simples!

The dust box has a little wall sticking out (you can just see it...) this creates voricies within the box to some extent and aids removal of dust which is sucked out by a wet and dry vac (Aquavax) from a bootfair.

The motor/pulley etc came from my next door neighbour but any motor/pulley will do.

Jim


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## RogerBoyle (28 Jul 2011)

Many thanks for the information :mrgreen: =D> =D> 

Roger


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## Tusses (29 Jul 2011)

dont forget to accompany it we can do this ...


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## CaptainMarvel (12 Mar 2013)

Greetings . . . . I realize I am late to the party here, but I ran across this homemade disc sander idea on Pintrest and I wanted to see if anyone here might know of any plans - or have any ideas - about how to take this idea, but have the disc sander as a horizontal/flat surface ... kind of like a motorized lazy susan type deal? (hope I described that clearly enough)

The reason (and goal) for my question is because I like to build my own custom drums (as in musical instrument) and rather than attach a big ole sheet of sandpaper to a table surface (for a kind of truing surface to level out the shell edges), I would love to have a motorized horizontal disc sander onto which I could lower the shells - varying from sizes 8" diameter to 22" diameter - and sand/true them evenly with the circular sanding motion.

make sense?


Thanks for any thoughts, ideas, reference/resources you may be kind enough to share. 



TOM


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## jimi43 (12 Mar 2013)

CaptainMarvel":1m6wuw7g said:


> Greetings . . . . I realize I am late to the party here, but I ran across this homemade disc sander idea on Pintrest and I wanted to see if anyone here might know of any plans - or have any ideas - about how to take this idea, but have the disc sander as a horizontal/flat surface ... kind of like a motorized lazy susan type deal? (hope I described that clearly enough)
> 
> The reason (and goal) for my question is because I like to build my own custom drums (as in musical instrument) and rather than attach a big ole sheet of sandpaper to a table surface (for a kind of truing surface to level out the shell edges), I would love to have a motorized horizontal disc sander onto which I could lower the shells - varying from sizes 8" diameter to 22" diameter - and sand/true them evenly with the circular sanding motion.
> 
> ...



Hi Tom

I would say that you need a type of thicknesser sander which has no top...I'd say that would be more controllable.

If you want to go down the circular route..I would say you would be better off fixing a motor so the shaft plate pointed upwards...take my idea and lay it over on it's side.

Then you will need a table with a clearance hole cut in the centre and a mechanism which raises and lowers the whole table surface around the spinning disc.

You have to be careful because you need almost zero clearance otherwise anything may get trapped in the gap and pull things into the rotating disc. 

I don't have plans for my vertical circular one as I just threw it together from an idea my next door neighbour started...he gave me the ex-lathe mechanism from an old lathe he had.

Hope this helps

Jim


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## Lons (12 Mar 2013)

Eric The Viking":33m3scdm said:


> . For my application (flushing the loo - don't ask!),




Awe common E :wink: I've waited for someone else to ask but I can't be the only one who just HAS to know - spill the beans........Go on....promise I won't laugh  

Bob


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## Eric The Viking (13 Mar 2013)

[thread hijack alert!]

Cor. I'd forgotten all about that!

I built a cheap cistern into our top bathroom a couple of years ago. This wasn't _just_ because I'm a cheapskate, but because I wanted a syphon flush (can't stand those EU-flap-valve disasters, and a lever went with the design better than a push button). The only one I could easily get didn't let me arrange the mechanism as I needed to. 

It's built-in back-to-front (hangs on the framework, not the wall behind). There's a built-in cupboard bang next to it on the left, and the lever and the inlet valve are both on the right. 

Normally, the handle is on the same side as the syphon inside the cistern. It had to have a side-entry valve, otherwise you couldn't maintain it (couldn't get at a service valve underneath because of the boxing-in). So... valve, handle and syphon all needed to be on the right side, but they wouldn't all fit! So I ended up with this:




It's roughly to scale, and you can see it's a right toadstool*. You're looking from the front, through the boxing-in. The handle is out front (obviously), with a long shaft going through into the works. I cut a slot in the lid, so that the bigger pulley could stick out above. That's partly for the aesthetics of the front (handle needs to be up high), partly to ensure a good flush (water level needs to be as high as the syphon allows).

The green circles are the pulleys I needed. They are different sizes so that there is a mechanical advantage - less force needed on the handle for an easier flush. This doesn't mimic the normal arrangement with a crank, because this one is actually a chrome door handle and already has internal springs. they were too strong and I had to fettle the mechanics too. Getting it "just so" was rather a pain. 

The drawing is wrong: the big pulley does NOT have a central pivot. It's offset. The flush starts with maximum leverage, and as you continue to turn the handle you get more movement and less leverage (the radius increases). It's more like a cam than a pulley really. That's why making the disks was tricky - I couldn't have a central through hole as it would have got in the way later. I _think_ the smaller one is a double pulley, with two sizes glued together to finally sort out the gearing, but to be honest I've forgotten!

I'll take a pic of the finished arrangement if you're not bored by now, but heck, it's only a toilet! 

The V-grooving jig is more interesting, but I'm not sure if I've still got it - that worked really well. My 'small circle jig' for the router table is OK-ish, but I learned enough to make several improvements, and because the original is a bit, er, hostile ("how far can _your_ router table chuck MDF disks?"), I'd rather wait on that until I've got a better design fully tested.

E.

*no mushroom anywhere! (I've got me coat already).


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## Richard T (13 Mar 2013)

Nice to see this thread revitalised. Someone was asking recently about cleaning up bronze castings one might find on Ebay. 

Would seem to be ideal for the task. (Sander not toilet)


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## Tomsk (2 Jul 2013)

If anyone is still reading this thread, when using MDF for a home made disk sander, is it better to seal the surface of the MDF before attaching self adhesive disks or leave it 'natural'?

Cheers

Tomsk


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## Eric The Viking (2 Jul 2013)

I'd seal it very well first, or be ready to replace the MDF disc because you can't get the worn out abrasive off without taking chunks of MDF with it.

E.


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## jimi43 (2 Jul 2013)

Tomsk":2af3eo20 said:


> If anyone is still reading this thread, when using MDF for a home made disk sander, is it better to seal the surface of the MDF before attaching self adhesive disks or leave it 'natural'?
> 
> Cheers
> 
> Tomsk



Hi Tom

I just left it natural. 

In actual fact the abrasive paper you get...the rough cheaper stuff...de-laminates when you tear the old disc off leaving a perfectly flat layer of paper on the MDF and you just glue another disc to that....If it gets a bit lumpy just hold a sanding block up to it and sand it flat! :wink: 

It's a very self-supporting system as you can see.

I also found that 300mm discs from Axminster work out well but they are for fine stuff...and leave a great finish.

If you want the sander for fast stock removal or metal grinding...use 60G yellow stuff...the AlO I think.

Cheers

Jimi


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## jimi43 (2 Jul 2013)

Post passed in the ether!

I don't find the piece of MDF I used does break up but I have a feeling (if my memory serves me)...that it's MR MDF which may be stronger.

J


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## Tomsk (2 Jul 2013)

Thanks for the two very speedy replies!

I have Axminster 120g disks coming tomorrow. Eventually I thought I may replace with velcro however Axminster seem to have no 300mm velcro disks at the moment and I was in something of a rush as usual...

I have read that using a heat gun first helps to debond the adhesive, but my concerns were that either the unsealed MDF would absorb too much of the adhesive or that it may not stick properly if sealed...

I guess I may have to do half and half!!

Cheers!

Tomsk


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## John51 (3 Jul 2013)

afaik you can can't use a speed controller on an induction motor but how about using one of those yellow 110v transformers as used on building sites?

2800rpm to 1400rpm or less?


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## Myfordman (28 Mar 2014)

There is no way to reduce the speed of a single phase induction motor either with a speed controller or by reducing the voltage with a transformer or any other method.

The speed is solely defined by the frequency of the supply.


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