# Attach sprocket to threaded rod for Drum Sander build



## RyanBWood (Sep 10, 2018)

Hey everyone,

I am working on my design and build plans for a thickness sander / aka drum sander. I am doing a combination of Stumpy's 2 in 1 with top access, as well as 4 post height adjustment from Johnzo, Tom, GeorgeM, . http://lumberjocks.com/projects/37885 , http://lumberjocks.com/projects/43625

I am collecting parts in the next few weeks and I am stuck on the sprocket type and mounting them to a threaded rod.

Being in Canada, I have less of the cool hardware stores to pick from. I have Princess Auto… which if you don't know if bottom of the barrel stuff in a lot of cases. They carry pulleys I plan to use, which are basic keyed v belt, totally workable.

The sprockets and chain are very limited and ONLY carry the weld on sprockets that mount on hubs.

Another local commercial supplier here carries higher grade stuff, but a basic sprocket x 4 + chain will run me $80 alone… at #35 chain. but still have a mounting issue with them. they were 3/4 fixed bore, set screw, no key versions.

How do you secure them to a threaded rod ? I figured this would be an easy answer on the google… not so much.

My initial thought is either one of the fixed bore types, with JB weld, lock nuts on top and bottom of the sprocket. ( or lock washer and regular nut job )

Fixed bore, no key, set screw type
fixed bore with key and set screw
hub and weld on sprocket

Which would you use, or have used in this situation ?





























Second question , sorta

the shaft for the drum. I was planning on using a keyed 3/4 shaft. with has a key way on the entire length… i can then cut ot size, but easy to mount whatever pulley i deside on. Any concerns you see on a full length keyway, or should I also use a 3/4 threaded rod for the drum shaft just like the above plan.


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## lumbering_on (Jan 21, 2017)

Being from Ottawa, I feel your pain.

Have you checked out Mattias Wandel's site? There's a collection of sanders there.

https://www.woodgears.ca/sander/index.html

Best of luck.


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## RyanBWood (Sep 10, 2018)

yah, lots of great ideas there too. but not detailed enough on what I was looking for.

I have never used pulleys or sprockets, so no experience in the mounting to the drive rods or bearings. bit of a learning curve on this one for me.


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## TheFridge (May 1, 2014)

I've used sprockets on threaded rod. It sucked.


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## RyanBWood (Sep 10, 2018)

ok, but how did you use them and what do you think would make them work ? I would need it to work somehow.

what sucked about it ?


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## MrRon (Jul 9, 2009)

This place will have everything you need for your project at very low prices. https://www.surpluscenter.com/ They ship to Canada, but I don't know the cost involved.


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## HokieKen (Apr 14, 2015)

If I were mounting the sprockets on threaded rod, I think I'd grind flats for the set screws to seat on and use a file to make sure the flats were parallel to one another and the set screws. Another thought would be to fill the threads with JB Weld or similar and slide the sprocket over it a time or two while it's wet to size it. Then you basically have a threaded rod with a solid end. Finally, If you can get a sprocket that has a bore diameter close to the minor diameter of your thread, you may be able to tap threads into the sprocket to fit on the rod. That's highly dependent on how hard the sprocket is though.


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## RyanBWood (Sep 10, 2018)

I will probably go with surpluscenter for sure. prices are better.

i am leaning to do this:

Fixed bore sprocket with our without a key won't matter
flattened spot for set screw 
threaded filled with job weld and sprocket set in place
Lock nut on top and bottom.

Next, how to cap each end of the rod into a bushing / bearing to keep it from wobble and also allow easy rotation.


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## DrDirt (Feb 26, 2008)

WHy sprockets? Most sanders went with belts and pulleys rather than a chain.

ANyway - For the threaded rod, you can take a grinder/Dremel and make a flat spot for a set screw

I personally would go pulleys, but even they need to be secured, so I would use the keyed shaft instead of a piece of allthread.


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## peck76 (Aug 25, 2020)

Ryan, I am curious to know if you managed to make something work out for this? I have a delta 31-250 and no matter what I do the belt always slips on one or two of the belt pulleys and it's a royal pain to get the table back to being even after this happens. I've tightened the belt tensioners, installed a new belt, cut out more hole for the cheap plastic belt tensioners, taken it completely apart, cleaned and greased the bearings, raise and lower the table slowly, and it still manages to slip. I have read that this particular machine has issues and other things, but I have it and it would be nice to be able to fix the poor engineering done by Delta and be able to use it. I'm looking into converting it to a chain drive system that I think will be much more reliable. My 31 year old Delta planer has a chain drive that's only been greased and I've never had an issue with it! This is what I've "dreamed" up so far: a 1/2" diameter left hand threaded lead screw, so it will raise and lower like the rest of my equipment, turn to the right, it raises etc., a t nut for the lead screw, a chain sprocket, a 2 bolt flange bearing, and thrust bearings. My thought is to bolt the sprocket to the t nut, run the t nut through the flange bearing, thread the other side of the t nut and place a jam nut that would rest on thrust needle bearings to hold the weight of the table and to hold the t nut. The concept is to turn the t nut and the lead screw to stay stationary. I'm struggling a bit with holding the t nut to the flange bearing, having enough t nut above it to be able to thread it, and put the jam nut on it. Pretty much the same concept as what is on the machine already, but hoping that it will function without issues. I was just curious to know if you possibly got something to work for you? Thanks.


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