drum sander loading

[marcros]

I have just collected my latest eBay purchase- a shop built drum sander. http://www.ebay.co.uk/itm/Drum-Sander-/ ... true&rt=nc

The previous owner had stuck the sandpaper on with double sided tape. it looks like it needs changing, so i have the option of using an alternative- i had in mind buying some self adhesive velcro to put on the drum, and some velcro backed sandpaper, do as it currently is, or do something else.

Any suggestions?

What grit is recommended- I had thought 120g

 

[Bluekingfisher]

Looks like you had a bargain there Mark, even if it turns out to be a junker the new(ish) motor will find a use.

On that point, I would have thought a 1HP motor would be a little underpowered? I have dedicated JET 16-32 model ( I think) the motor is 1.5 HP which can on occasion stall if too much is thickness removal is attempted.

I would have thought a 120G paper would be your best all round choice, seeing as removing is not too convenient.

How is the sanding drum made up? laminated MDF disks? I would, if not already done apply some sort of sealer to the drum otherwise you are going to peel off sections of the drum each time you replace the paper.

On mine, the paper is tapered at both ends allowing it to neatly tuck into a small cam clip at either end. The paper is just wound around the drum and fixed both ends. I don't know if such a means is possible to rig up on yours but it would allow you to change papers quickly.

Good luck with it.

David

 

[marcros]

it is still in the car from last night, but i will have to give it a try. if the motor is too small, then i will take a view, but as you say it was priced to sell. I may just have to take it easy.

I believe that it is laminated mdf, in which case I will slap on some sealer. I will look into a clip fastening, that would make it easier to change. do you get hours of use from paper, or is it more realistically minutes?

 

[custard]

Hello Marcros, a drum sander is a really useful piece of workshop kit, as well as finishing it opens the door to cutting your own veneers and makes lamination work much easier and more precise.

The problem is that the loadings stretch during use, even just taking off 0.1mm per pass there's a substantial amount of force being exerted on the loading trying to drag it back off the drum. Industrial machines use pre formed circular belts so that a tensioner can easily take up the slack generated. The rest of us use spiral wound loadings, but here one of the key things that separates a good machine from a poor one is the quality of the spring loaded take up mechanism that absorbs this stretch. You'll read many accounts from people complaining about torn loadings, in most cases this is because it has stretched and the slack hasn't been taken up, it then forms a loose fold which soon gets snagged and then rips

I've no idea if velcro would be up to the job or not, but you could look at some of the spring loaded tensioner devices and try and build something similar yourself, you could try using a shorter loading to minimise stretch at the cost of losing some capacity, you could only work at the end of the drum where the loading is kept taught by the drag of the workpiece (usually the left hand end), and at the very least you could use a heavyweight backed abrasive like the Hermes cloth backed loading to resist stretching as much as possible.

By the way, I get about two or three hours of constant use on 80 grit, maybe a bit more if I avoid gummy timbers like Rosewood and am diligent about cleaning the loading with a sandpaper cleaning bar.

Good luck!

 

[rafezetter]

That info on the loading stretching is something I hadn't considered, but makes sense. I've had a hankering to make one of these for a while, and now it's been mentioned I think I have an idea how to incorporating a sprung loaded slack system without too much extra work.

 

[marcros]

certainly some food for thought. i do seem to recall somebody on here building one, and having issues with paper backed loading. the solution seemed to be using a cloth backed one, but I cannot remember enough details to find the thread. I think that it used a simple system of screwing through a block into the drum to catch the paper.

From other forums, mainly US, the velcro idea seems popular- it is a buy-able conversion on some of the bought models, although we are not talking top end here- they almost universally have a spring system, although I am not sure how easy this would be to incorporate onto a shop built machine. The velcro backed paper seems to rely on a slightly different method of sanding- it will stretch slightly, or lift, but that provides an air cushion. The proponents says that this cools the paper, and the idea is not to jam the wood between the drum and the table, but instead to adjust it so that it is just barely touching at rest, and on running, the stretch enables it to remove material. It is said to be as accurate as the other methods. I think that I may try this method first, because it is only the matter of buying some tape and velcro backed paper.