53 - How to Make a 20 Inch Disc Sander For a Lathe 1 hour project

Make a 20 Inch Disc Sander Using a Lathe
I make a lot of Keepsake and jewelry boxes, as well as doing segmented turning on the lathe. I needed a big disc sander to flatten things out.
When I make a keepsake box and cut off the lid, then the surface of the lid where it was cut, and well as the top part of the box, are now rough with bandsaw or table saw marks. So I need to sand them down to be Perfectly flat and in a single plane.
I needed a 20” disc sander to do this. But after looking on line for one, I see they are not cheap. At $1500 to $2000, they are not something that I can afford. Luckily I have a lathe.
With my lathe I can turn it into a perfect disc sander, using only scrap wood. And the only specialty tool I needed was a Spindle Tap. Which was in the $20 - $25 range.
And the cool thin about this, is that I can make 3 or 4 of them, and put a different grit on each one! I can just spin off the first one and in under a minute, I’ll be sanding on the next finest grit, and so on. You can’t do that on a Disc Sanding Machine.
The whole build took me about an hour, and I was sanding away immediately. In the past, I would often spend an hour or more flattening all of the ends of my boxes on a sanding board. It now just takes seconds to do the same on this big disc.
Note: If your lathe doesn’t have a rotating headstock, you can still make this. You will just have to make a smaller one. Maybe a 12” or a 10”
One more Note: If you are considering making this, make sure you buy the Spindle tap that fits your lathe. Mine was a 1” x 8 threads per inch. I will put the links to various sizes below.
Here is the article on the Case Western Reserve glue strength study done by their engineering and materials science department:
www.titebond.com/Libraries/New...
Things we used for this project:
Tools:
BOSCH 12 Inch Sliding Glide Miter Saw - amzn.to/3j331SU
Kreg Trak and Stops Kit - amzn.to/3ZVgnkB
Kreg Self-Adhesive Measuring Tape - amzn.to/3DGNpLU
Steel Ruler Set - amzn.to/3jvY2ua
6-Inch Compass - amzn.to/3ZVfQ25
Grizzly Bandsaw - amzn.to/3XUUobR
Dewalt Power Tool Combo Kit with 2 Batteries and Charger - amzn.to/3johJUr
Milwaukee Drill Bit Set - amzn.to/3IeEOTb
Drill Chuck - amzn.to/3KOvKGj
(Make sure your lathe taper fits this)
Best Carbide Forstner drill bits - amzn.to/2zdGZ3e
Steel Taper Tap - amzn.to/3J8yNrL
Hand Sanding Block - amzn.to/3Rnsx1F
Empire Framing Square - amzn.to/3XRfnvX
Dewalt Circular Saw, Tool Only - amzn.to/3DplHTx
5 Minute Epoxy - amzn.to/3xiiHoM
Dewalt Pre-Drill Countersink Bit Set - amzn.to/40wTMer
Materials:
Sandpaper Set 5-Inch - amzn.to/3Wygb7S
Tack Cloth - amzn.to/3XRezYh
As an Amazon Associate I earn from qualifying purchases.
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[@KingsFineWoodworking]

Join our KFW Community Page. Woodworkers helping other woodworkers. Share pictures of your work & get help if needed. Also share advice and get project ideas. Free tips & insider information. Get the best deals on lumber & tools. facebook.com/groups/KingsFineWoodworkingCommunity/

[@tbac2432]

Sorry sir. No more FB for me.

[@nathangarn9922]

Brilliant, you just saved me $2000. Thank you!

[@ombewphitol6968]

Kerjanya sangat baik , perlu jadi contoh buat yg baru memulai You are best worker and getting better. Godbless you.. From jakarta

[@dgodrummer8110]

i dreamt of this the other night and then WALLA, you made the video and have shown me how to do this. thanks much

[@viscache1]

These videos demonstrate to all the high school kids who say “I’ll never use this in real life!” That mathification is a NECESSARY life skill after school!

[@bocchieri]

never saw those spindle taps before! thanks for showing that

[@matthewwysocki5019]

Great idea and well executed. Thanks!

[@alfredneumann4692]

That was the reason, i bought a used not so big cheap lathe. Now it waits for the disc. :-) Thanks for the inspiration!

[@KingsFineWoodworking]

Awesome! You’re welcome!

[@carlbrothers]

I love the idea behind this! I know timing was a driver in this and I do tend to over complicate things, but I might give this a try with a router circle cutting jig. Especially for making the part that connects the lathe to the larger disk. More glue surface as well.

[@ThePapabear2012]

Now I want to upgrade my lathe. Nice project.

[@ManCrafting]

This is a great project. I love my lathe, but it’s completely under utilized in my shop. Thanks.

[@KingsFineWoodworking]

Thanks Chad!

[@billm4560]

Nice job there James and girls! 👏 Now...I want one! 😁 Thanks for sharing!

[@KingsFineWoodworking]

Hi Bill! Thank you!

[@Jeff_369]

James thanks again for your videos. You and your family are putting out some great content!

[@KingsFineWoodworking]

Hi Jeff! Thank you!

[@wbarber1102]

Wow, that’s a smart idea. Great project.

[@KingsFineWoodworking]

Thanks William!

[@tonyb6194]

What an excellent use of the lathe, great project.

[@KingsFineWoodworking]

Thanks Tony!

[@felixfromnebraska8648]

Nice addition to any shop, Great project, James!

[@KingsFineWoodworking]

Hi Felix! Thanks

[@mountainviews5025]

Love it making one thanks and thumbs up my friend

[@cdrive5757]

Personally, I would have cut a shallow Mortise on the Platen & a stubby Tenon on the Spindle Block and then glued them. Also, other than the exceptional flat properties of factory fresh MDF,... I loath everything else about the nasty stuff! Especially its propensity to suck up as much S. Florida humidity it can! Over time the periphery absorbs far more than its surface. Consequentially, its flat property becomes but a memory! Thanks, Chris

[@hassanal-mosawi6049]

Thanks fore showing how & sharing that, it helps

[@edadpops1709]

Thats huge 👍🏻👍🏻

[@jarmstrong2843]

Great idea! Thank you!!!!!!!!

[@HarnealMedia]

Nice Job. I never thought of turning my headstock for sanding

[@KingsFineWoodworking]

Thanks Steve!

[@silvergrizzly316]

AWESOME build james!!! , Jay.

[@KingsFineWoodworking]

Hi Jay, thank you!

[@markmaestas1129]

Great job James!. I'll have to make one.

[@KingsFineWoodworking]

Thanks Mark!

[@SCRAPWOODTOCRAFTWOOD]

Nice job james turned out really good if only I had a lathe thanks for your videos

[@KingsFineWoodworking]

Thanks Warren!

[@smithsoncreationshandcraft5770]

That is a cool project and idea. 👍

[@KingsFineWoodworking]

Thanks Shaun!

[@miketrotter2975]

Great idea.

[@alladinandarilhobrazuca6357]

Great job. Congratulations!

[@KingsFineWoodworking]

Thank you!

[@Patricksworkshop]

nice project James I made one just like that for my 12 inch lathe works great in my shop

[@KingsFineWoodworking]

I know buddy! I saw that. As I was building mine, I went on KZbin and searched to see if anyone else had one like it. Your video was fantastic! For anyone curious, go check out Patrick’s video! It’s a fantastic one! kzbin.info/www/bejne/qKSwlHajec6WsJY Plus he’s got a great channel in general.

[@nedbulken4790]

+1 sub, excellent step by step, making it look easy! Thanks!

[@ianmurray6112]

I have made similar disc sanders and used valco stick on pads on disc- allows for quick change out of various grits.

[@Bootzey73]

That is awesome!!!

[@KingsFineWoodworking]

Thank you!

[@grandpasgaming5232]

Wow!! I bet a lot of comments will be... Wow!!! Love it!!

[@KingsFineWoodworking]

Thank you!

[@vibsosu]

A good quality tool

[@barstad-9591]

Awesome 👏👏👏!

[@KingsFineWoodworking]

Thanks Barbara!

[@jGoodloejr]

Happy New Year! Good job!

[@larndavies6954]

Not half bad James, you can also mount them as you would a bowl to your chuck, allows you to have multiple quick change discs also and saves having to buy a tap for mounting to your spindle that way also.

[@KingsFineWoodworking]

Yes sir! Sure can!

[@WOEBGON]

Great idea!

[@KingsFineWoodworking]

Thanks Don!

[@Z71Ranger]

Nice Build...

[@sumosprojects]

Pretty awesome mate, I saw Paul Jackman build a similar thing & this is an incredibly good shop edition

[@KingsFineWoodworking]

Thanks Dirk.

[@StMoritzGuitars]

Sweet Idea James. One thing I would have done differently. Before attaching the sanding disk I would give it a couple of coats of oil based poly-urethane. Would make removal of adhesive disk easier and lessen the risk of tearing out the top layer or two of the MDF.

[@KingsFineWoodworking]

Great Tip. Thank you!

[@dalewilliamson1125]

Great idea James. I made a 12" out of an old motor but it has a wobble in it yet.

[@KingsFineWoodworking]

Thank you!

[@BobAmarant]

I think this is a great idea and would also consider making some type of table that can fit on the tool holder and banjo, or build a separate table that would snug up against the sandpaper. I'd also consider just attaching the MDF to my large faceplate instead of the maple block since I rarely use it.

[@KingsFineWoodworking]

Great ideas. Thank you Bob!

[@mlt3258]

Nice addition to the shop. For me, I would have made the adapter block out of aluminum or used a Heli-coil for yhe threads in your maple unit. I'm sure you will know if the threads start to fail after repeated use. I'm all for threads in hardwood. However with the forces created I'd hate to be the one using it if they do fail. Just keep your eye on it and it should be a warm welcome to your shop.

[@Colinmac1]

Great job

[@KingsFineWoodworking]

Hi Colin! Thank you!

[@tedgaunt3044]

Nice share! I love mine too. Warning for those new to a large disc sander- the sanding speed (and thus power) is much smaller towards the center. This is due to the center traveling at about 0 linear ft/sec. So be careful if you are trying to sand something flat, else you can actually sand uneven if you don’t move the item around to average out the sanding from middle to outside.

[@KingsFineWoodworking]

Thank you so much for the great tip, Ted!

[@mkdesignsfinewoodworking]

Haha. Now I know why you were asking for some place local to get that monster. As always, great video.

[@KingsFineWoodworking]

Thank you!

[@NYWoodworker]

Nice!

[@KingsFineWoodworking]

Thank you!

[@williampugh6699]

I think a washer on the back of the mounting block and CA glue the wood threads might be a good idea.

[@micstica]

About threading wood. Its good idea to add high vis ca glue to the threads. The ca glue soaks in and acts as a wood hardener with little to no change in thread size.

[@Dingbat217]

Great idea, I just have one question: How is the threads you cut into that maple block holding up now that you have had it a while and a used it in anger? Will they last?

[@FishersShop]

Nice work, James. That would sure come in handy in my shop. But the real question is... You received a new order for 2 items at $0.00?? Am I the only weirdo that paused to read that off your watch? Great stuff, keep it up!! :)

[@KingsFineWoodworking]

Haha, you saw it! It was for a couple of the free items on our website. I was debating whether or not to edit that out. Good eyes!

[@JohntheSchreiner]

Well that's just another reason for me to get myself a wood lathe!

[@KingsFineWoodworking]

I couldn't agree more, John! And just in case you're interested, here is the exact one I use. It is a full size unit, all cast iron but it is budget-friendly. amzn.to/2GEuPZj

[@JohntheSchreiner]

Oh awesome, thanks! Unfortunately though it doesn't look like that one ships to Canada. Though it definitely gives me a good reference point.

[@WoodUCreate]

I was thinking it might be difficult to replace and a coat of poly would be a good idea.

[@dawgpoundbutch]

Hi James. Nice build. I just subscribed to your channel! Hey, you've had this sanding disc for just over 9 months. If you were to build a new one, would you change anything now that you've used it? Are you happy with the sanding discs you bought or would you buy a different brand/type going forward?

[@Nowere1234]

another top video as usual .just got your plans for the mitre station looks daunting only be doing it 2 month .how many sheets of ply will I need

[@Aprendiz-de-Marceneiro]

This is a great project. Like 290

[@KingsFineWoodworking]

Thank you!

[@stanrescigno5093]

Why are all your videos so satisfying!?

[@yspark5930]

언니야 멋쟁이 Good.

[@MichaelJohnson-jt5cu]

If you have a metal nut with the same thread as your lathe spindle you can epoxy this to your wood round or weld the nut to a flat plate and secure the plate and nut to your wood round. You can also saturate the wood threads with CA glue to provide a longer life for the threads.

[@mattlewandowski73]

I am surprised you did not have or make a circle cutting jig for your bandsaw.

[@robertevans6481]

Good thing is you most likely have the materials in your shop....well maybe not the tap...lol. Great tool build James

[@KingsFineWoodworking]

Hi Robert. Thank you!

[@xxxjOnEbLaZexxx]

Hi James, great video! Any links to the items you used such as the sanding pads and the tap?

[@garyrodencal1902]

Awesome build James. I'm surprised you don't have a circle cutting jig for your bandsaw. (ALA Norm Abrams). I enjoy everything you and your girls put up on this channel.

[@KingsFineWoodworking]

Hi Gary! I do have one! But sometimes I try to show that certain things aren't always necessary. If I were doing a table, though, I would certainly have used it. Thank you. ~James

[@clydedecker765]

I LOVE this one BUT... I'd need a separate room like an infectious disease lab to keep all that dust down. BUT I'd have great sanding capability!

[@KingsFineWoodworking]

Thank you!

[@markfields9841]

I made my 10" disc with 1 piece of .75" plywood and attaching it to a faceplate.

[@Hellsong89]

If you have lathe this is decent option, but you can make your own stand still disk sander using 2x4, two big bearings, axle and electric motor. No axle or bearings needed if motor is sturdy enough. This way you could also build enclousure of sort around it, where compressor push positive pressure air from top and vacuum is removing the dust. Sure its not perfect, but its best you can get for something like this.

[@KingsFineWoodworking]

Good idea. Thank you!

[@cjmendoza8599]

where can i buy 20" or 12" sanding paper?can you share the link of online store.thanks

[@martinoamello3017]

I'm thinking the whole thing can be mounted to a used (or new) motor since my lathe is an ancient old pre-war Craftsman model. And since I don't really use the lathe THAT often I may be able to just swap out the motor to it or just add another mandrel and utilize the extra pulley sizes off the side of the lathe...or something like that. Cheap motor? Almost any motorized junk from Harbor Freight. The motors are generally worth more than the actual tools.

[@er.7755]

I just used a 6” back plate and glues 2 3/4” sheets of fir plywood together then screwed the 6” back plate to the plywood. Theirs no chance of the wood threads failing.

[@arawakmendoza]

Bonjour, une bonne idée à creuser, ou peut-on trouver les disques abrasif de cette taille svp ? Merci

[@johnbarnette3916]

lol a one hour project in 15 mins, good time lapse lol

[@KingsFineWoodworking]

Thank you!

[@roBLINDhood]

Does that ratchet wrench have all three drive sizes on it? That’s pretty cool.

[@KingsFineWoodworking]

It sure does!

[@roBLINDhood]

King's Fine Woodworking that is really innovative. What brand is it?

[@MrMarkraffaele]

What is the speed of the motor when using your mega disc?

[@KingsFineWoodworking]

I set it at 1000 rpm

[@rawbacon]

Well I don't really need a 20 inch sander but the part about Titebond being better than epoxy was interesting for sure. Although the link doesn't work I was able to go to the "Wayback Machine" and get the study.

[@elizeardalusung7283]

What do you call the machine you use?

[@rolandkeys8297]

my poor old lath wouldn't turn the 20" MDF let alone with a sanding pad attached

[@bobmonday925]

What is a safe speed to run the lathe with the sander on it?

[@KingsFineWoodworking]

Hi Bob, it depends on how well you have it balanced. But never over about 1500 rpm. I use about 600-800 for most things, but mine is not dead on balanced perfectly. It still stands beautifully, but I’d probably kick it up to 1000 rpm if I had it perfect. But whatever you do don’t go too fast. If your lathe is vibrating and shaking around, you’re asking for an accident.

[@bobmonday925]

Kings Fine Woodworking thanks..

[@NZErehwon]

My Dad has a smaller one he made from an old motor a drive belt & a shaft off some machinery parts

[@KingsFineWoodworking]

Hi Andrew! That's cool. I've been meaning to do it forever, but just got around to it.

[@NZErehwon]

his is ideal for sanding stuff true & for making the small pieces for his model boats

[@tofou9726]

Salut toujours très intéressent à voir et à reproduire,j'ai envoyé une demande pour le groupe sur Facebook,à plus bise à la famille.

[@KingsFineWoodworking]

Merci beaucoup.

[@barry.w.christie]

A bit late to the party .... when mounted on the lathe why didn't you just mark the centre using your tailstock ... soo much easier ... other than that, brilliant. My own miniscule 12" version was done using a faceplate to mount it, laminate flooring on the sanding surface and discs were hook and loop, meant I could switch between grits easily 👍

[@budwoodman1716]

Wow !! That's the second largest nut I have ever seen.....

[@KingsFineWoodworking]

Bud!! What are you talking about!!! Now I have to go find a bigger one!!!

[@steveheavyside6023]

Big Nut for a wood shop, for sure. I'm in the Primary Steel Industry, and I have worked with nuts up to 14" before. The cool thing is bolting technology now allows for us to not use nuts like these and instead use a system such as Superbolt - kzbin.info/www/bejne/iZKsn6CboJygmtU. James, I've never thought of using these things as gravity clamps. Think I'll have to repurpose some to the shop :D

[@KingsFineWoodworking]

Love that video! Thank you for the information!

[@toysoldier46552]

Too bad I have an old hand me down lathe, don't have all of the bits and pieces but have an idea with an old dryer motor I kept just won't have variable speed unless I figure out a pulley and belt system for it.

[@KingsFineWoodworking]

If the RPM on your dryer motor is between 1,000 and 1,750, you can use direct drive. You don't need a belt and pulley/

[@carbonitegamorrean8368]

Size Queen.... ;-) those huge nuts are awesome, you need bolts for them.

[@KingsFineWoodworking]

I certainly do.

[@leonardburns1780]

very kool good idea ehhh

[@KingsFineWoodworking]

Hi Leonard. Thank you.

[@KeithDiSarno]

Not gonna lie...was a little disappointed you didn't put epoxy on the disc itself, in addition to the chuck portion. Don't you always say to apply glue to both sides!?!? I'm gonna let this one slide, but just know: we're always watching over your shoulder!

[@KingsFineWoodworking]

Hi Keith! Haha. As a general rule, epoxy should be applied to one side only. It does make me sad, and I must say, I don't like following those rules. But thanks for keeping an eye out!

[@clydedecker765]

I LOVE this one BUT... I'd need a separate room like an infectious disease lab to keep all that dust down. BUT I'd have great sanding capability!

[@KingsFineWoodworking]

Thank you!