Trying to make an ultimate sanding drum!

Hey everyone, I am posting this topic on MYCNCUK because I have found this forum to be very helpful in the past. This topic might not relate to CNC's as such but I am sure you guys will have some answers for me. Recently I purchased an aluminium round bar with an inch wide diameter and 400mm in length. I reduced the diameter on one end down to 16mm using my friend's lathe. This was done so that I could fit the rod in my pillar drill chuck. I am currently using a 60 grit aluminium oxide sanding paper glued on the surface of the rod for my ultimate sanding drum.

The purpose of this sanding drum is to sand the inside of the bamboo poles I use for making bike frames. Now the sand paper that I glued to the aluminium surface has started to smooth out already after my first use. So I am tying this topic over here to get some advice really as I am not sure what I can do to the aluminium surface to make more like a filing surface. If aluminium is not a good surface for that then I can always buy a steel bar to do the job, but I absolutely have no idea what tool or method could make a shiny metal surface into something that is rough like a file. Any help would be appreciated greatly at this point as I am running out of options now :uncomfortableness:. Thanks

Could you use a reamer on a long shaft ?

Reamers and Reamer Sets | taper pin reamers, hand reamers
Reamers , Countersinks and Deburrers. Buy reamers online

Hey Eddy, thanks for your quick reply I have actually thought of that but bamboo does not have a uniform diameter and the reamer will simply split the poll once it hits a slightly tapered part. What I am trying to achieve is a much wider and longer version of these http://file.maxtie.com/images/produc...5346989781.jpg. This will allow me to wiggle the poll side to side so that I can shave the inside of the poll nicely without cause the split. Thanks

How about these....

Microplane Rotary Shapers

You could make a carrier to take several of them in a row - a 10 / 12mm threaded bar with spacers trapped between nuts easy enough to make up. They're fairly expensive but good quality.

Axminster have them in stock but a trawl of ebay might turn up something cheaper.

Microplane Rotary Shaper Replacement Blades - Drum Sanders - Abrasives - Fixing, Gluing & Finishing | Axminster.co.uk

Hey FatFreddie, this is very interesting tool. I think rather than putting a threaded bar through the middle I might just put these shapers of my round aluminium bar. I might just give this a go and see what happens. Thanks a bunch man!!!

Hey Slim,

Would these be of any use to you: 20pc Drum Sanding Kit Fit Drill

I use these in my drill press all the time and they work quite well, I was thinking you could bore a hole in your current ali bar to fit the shank on these, this would then get the reach you may need?

.Me

Hey Lee, I do use them when I am not going deep into the bamboo pole but they don't last very long either. Fatfreddies idea of using microplane might be the way forward but after reading some reviews I am not too sure about those either as they are expensive and I am not too sure about the quality too. I wonder how they actually make the filing surface on the tools used for filing really. It would be the best option for my tool. I will keep pondering I guess. Cheers

you could knurl the ali bar, thou it might be more lasting if you did it to a steel bar and used that like a file.

You could maybe use a grade of steel that's easy to harden, machine it to just under the diameter you need on a lathe, knurl it, then harden it.
Attachment 12320

That's pretty close to a file. You could mill/grind some flutes so the swarf has somewhere to go.

Thanks Jonathan and Tornado, I think I have my answer. Will get a steel bar and knurl it. Do the knurling tools come with various pitches so that I can knurl it in such a way that the protrusions are long a sharpish? Thanks

Flap wheels ? rotary rasps ? http://www.hand-stitched-rasp-riffle...tre-25-mm.html

i think my kit i have has 2 course, 2 medium and 2 fine kurl wheels.
the best one to get it the clamp type, that clamps on top and bottom of the workpiece.
the single wheels ones have to push against the workpiece and can stress the lathe bearings

Can you recommend a course wheels one please? Also can the top and bottom wheels reduce the wobble in my round bar too? Not sure why a think piece of ali is wobbling when it turns?

cant remember where i got my kit from. it was either rdg tools or chronos.

it will depend on what thickness bar your planning on knurling, just make sure it can do the thickness of bar your planning on using.
it wont reduce the wobble as the clamp type can move up and down as it knurls.

really the only way to get rid of that would be to put it between the chuck and a centre in the tailstock and turn it down.
unless you can bend it back the otherway to straighten it.

I think it may be worth your talking to "Permagrit". They bond their abrasives onto timber and ally. Iuse their products quite a lot. G.

Would one of these be any good -

1" Diamond Sanding Drum

?
- Nick

Hey Guys, I am back again. After trying my luck with knurling on to my ali bar I realised that knurls don't work well for something that is 400mm long and spinning. So now am looking for other solutions. One is that I buy a half round file (which is 400mm long) or try something even more insane. The insane idea is to mill (or ask someone here to help me) and produce a long version of this BLACK AND DECKER 90546472 POWERFILE 13MM ARM + PAD FOR KA900 KA900E | eBay. Now I know a sanding belt spinning at that sort of length is definitely going to cause many issues but i am running out of ideas. Can someone please help me figure this out? Any thing at this point would be of great help. Cheers

You need a rasp for wood, not a file, http://www.axminster.co.uk/bahco-half-round-200mm-rasp, on an extension then fitted to a reciprocating saw such as this one, Titan TTB533RSP Reciprocating Saw 240V | Corded Reciprocating Saws | Screwfix.com

Funny how you say that I just got off the phone with a guy who sells half round rasps and he told me that the blades on the edges of the half round rasp burn out easily. A round rasp on the other hand will be really handy. I mean I can always work at it with my hands rather than a machine as long as I could see the material pealing off lol. So at the moment I am looking for round rasps which 400mm long lol. Thanks for the advice though

how about one of these guys products ive yet to try one myself but planning on it in the near future Saburr-Tooth :: Carbide Coated Rotary Tools

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Originally Posted by charlieuk

how about one of these guys products ive yet to try one myself but planning on it in the near future Saburr-Tooth :: Carbide Coated Rotary Tools

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Very interesting man. Will ring them now and find out more about it. Thanks

I suggested to you early in this thread. Talk to Permagrit, he can bond whatever grade you require onto any length/diameter of wood/metal that you want. the end could be turned down to fit in a drill chuck and you will have a very simple device that will doo exactly what you want. G.

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Originally Posted by GEOFFREY

I suggested to you early in this thread. Talk to Permagrit, he can bond whatever grade you require onto any length/diameter of wood/metal that you want. the end could be turned down to fit in a drill chuck and you will have a very simple device that will doo exactly what you want. G.

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I remember you saying that but I never knew that they make custom tools? Another thing to remember is that I can only go slow in my pillar drill with something this long because the other end is not fixed so any wobbled in the rod makes the thing spin wildly and could possibly kill me lol. Will speak to them tomorrow and see what they say. Cheers

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Originally Posted by fatguyslim

Hey Guys, I am back again. After trying my luck with knurling on to my ali bar I realised that knurls don't work well for something that is 400mm long and spinning.

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u need to face the end off, then centre drill it. then put it between the chuck and a live centre in the tailstock.

thats how i kurl long stuff.

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Originally Posted by T0rnado69

u need to face the end off, then centre drill it. then put it between the chuck and a live centre in the tailstock.

thats how i kurl long stuff.

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That's exactly how I did it. Knurling is not the problem here it actually the knurls that are formed are not sharp enough to shave the bamboo off at low speed thats all

maybe because its ali bar. alot softer then steel.

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Originally Posted by T0rnado69

maybe because its ali bar. alot softer then steel.

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That's true but I am still not sure if the knurls would actually do the job? There is something else I have in mind though may buying a brake cylinder hone with an extension rod and trying that to see if that works. Any clue how good will a 180 grit stone perform on wood?