DIY Bow Sander

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Project by James E McIntyre posted 08-08-2021 06:53 PM 2591 views 8 times favorited 23 comments Add to Favorites Watch

With a stool project I’m planning coming up I’ll need a bow sander for the legs.

Recently a Lumber Jock (RyanGi) posted a nice bow sander similar to this one that had two dowels that held the 1” sand paper in place, and I thought I can make one that uses a 30” x 1” belt.

What’s nice about the tension knob
Is that it can tighten the belt for more aggressive sanding or loosen it for more contour sanding.

The sanding area is 10” so I can use all the belts surface in 10” segments.

I read some of the comments and one LJ said he’d have to make at least 6 for different grits because he didn’t want to keep changing the paper. This version makes it easier to change the belts.

My wife said it looks like an alien baby sanding bow with a tail. I tried a round end design but liked the tail style better, and it makes a good hook for hanging.

I had a left over piece of 10-1/4 hard maple from a vice jaw I never used.

I didn’t have a 30” sanding belt yet so I used this tape measure to estimate the size of the bow.

I cut a slot in the maple on the table saw w/a thin kerf blade about 1-1/4” deep for the 1”x30” belt.

Chiseling out the slot for the tension knob after drilling three 7/8” holes.

Cutting out the shape on the band saw.

Drilling the holes for the bolt. It has to be lined up just right so the bolt lines up with what will be a wooden nut head. This has to be done before the wood tension nut head can be cut from the bow.

I set a stop on the drill press so the drill bit wouldn’t go to far into the top of what will be the head of the bolt.

Cutting out the tension knob with a circle cutting jig on the band saw.
Sanding it on an oscillating sander.

Softening the edges with a round over bit.

Cutting slots on the dial.

I used the pin hole from the compass I drew the circle with to drill out the 13/64” hole for the tap.
Tapping the dial with a 1/4-20 tap.
I didn’t epoxy a nut in the knob. It’s made of cumaru, it’s very hard at 3330 LBf on the janka hardness scale.

Epoxying the bolt into the wooden nut that tensions the belt.

Thanks for visiting.

-- James E McIntyre

23 comments so far

View oldrivers's profile


3111 posts in 3026 days

#1 posted 08-08-2021 07:39 PM

Handy dandy tool, great job James.

-- Soli Deo gloria!

View Jim Jakosh's profile

Jim Jakosh

27703 posts in 4564 days

#2 posted 08-08-2021 08:09 PM

Neat idea. Nice work on it, James…..................Cheers, Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

View LittleBlackDuck's profile


9454 posts in 2280 days

#3 posted 08-08-2021 08:58 PM

Why do all you guys bring out these great ideas after I spend my shekels buying ones.

Like the idea of using premade belts with the intent of using the full band.

-- If your first cut is too short... Take the second cut from the longer end... LBD

View Eric's profile


5084 posts in 1332 days

#4 posted 08-08-2021 09:07 PM

Nicely done, and I like that you can use a standard belt.

-- Eric, building the dream

View RyanGi's profile


339 posts in 496 days

#5 posted 08-08-2021 10:18 PM

Nicely done. And it does look like an alien….

I like that you can rotate the paper and get a fresh section. I’ve got rolls on rolls of 1”, so I made mine to utilize that, but I prefer your model with the prefab belts.

-- Ryan/// I like chips...and sawdust...but mostly chips...with vinegar

View BurlyBob's profile


10492 posts in 3725 days

#6 posted 08-08-2021 10:42 PM

Definitely looks like something I need to build. Thanks for posting this.

View gdaveg's profile


511 posts in 661 days

#7 posted 08-09-2021 12:13 AM

Very cleaver. Good job.

-- Dave, Vancouver, WA & Tucson, AZ

View swirt's profile


7683 posts in 4431 days

#8 posted 08-09-2021 12:44 AM

I never thought I would say this about a sanding block, but that thing is a work of art. Nicely done.

-- Galootish log blog,

View JCinVA's profile


245 posts in 2289 days

#9 posted 08-09-2021 06:25 AM

Very nice. Great idea to use belts which avoids unused portions of sandpaper. Added to favorites.

View JimYoung's profile


450 posts in 3046 days

#10 posted 08-09-2021 11:59 AM

Very cool tool. Well thought out to use the whole belt.

Do you have to put holes in the belt for the tension nut/bolt? What am I missing here?

-- -Jim, "Nothing says poor craftsmanship more than wrinkles in your duck tape"

View Calvi's profile


66 posts in 1584 days

#11 posted 08-09-2021 01:14 PM

Very Nicely Done James!!

-- Cal, South Carolina,USMC

View English's profile


695 posts in 2936 days

#12 posted 08-09-2021 01:55 PM

Great Idea, superb work, and wonderfully produced post.

-- John, Suffolk Virgina

View splintergroup's profile


6950 posts in 2681 days

#13 posted 08-09-2021 03:14 PM

A utility tool, refined and polished like a fine piece of workmanship! nice one James!

I buy the rolls of 1-1/2” sanding strips, very useful, but can’t really use the ends which are folded over my small sanding blocks. Using your belt idea means all parts are edible!

Sorry about your shop cat, looks like he got kinda bored sitting there waiting for your promise of a new cat toy 8^)

View James E McIntyre's profile

James E McIntyre

1887 posts in 2751 days

#14 posted 08-09-2021 03:39 PM

Thanks for the nice comments Lumber Jocks.
Jim J
RyanGi who inspired this project
Burly Bob
Jim Young

-- James E McIntyre

View James E McIntyre's profile

James E McIntyre

1887 posts in 2751 days

#15 posted 08-09-2021 03:50 PM

Very cool tool. Well thought out to use the whole belt.

Do you have to put holes in the belt for the tension nut/bolt? What am I missing here?

- JimYoung

Thanks Jim.
I took me awhile to figure out how to make the tension nut work too.
I try to explain it.
Only the knob and the top wooden nut are treaded. The bolt turns freely in the bow. As the knob is tighten down the bolt rises and puts tension on the belt. The bolt is treaded and epoxied to the wood tension nut.

No holes in the belt.
I hope this make sense.

-- James E McIntyre

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