Drum sander - attaching sandpaper

[Dominic]

Hey, I didn't want to jump onto the other thread so i thought I'd start a new one. My issue is how to attach the sanding rolls to the drum on commercial drum sanders. I have the carbatec 400mm, pretty standard. A fixed clip at the open end and a spring clip that pulls the paper tight at the other end. Seems simple but I've found it fiddly to set up properly. As the grit wears in the clamp the direction of spin acts to pull it out of the spring clip slightly, the roll get loose which makes a noise and leaves uneven lines, particularly in spruce. I usually get the job done thinking there has to be a better way and then forget it until next time.

I can see a couple of issues. I assume those with these machines are familiar with the layout and have had similar issues.

1. the rolls from carbatec always seem a little long which means I have to cut a bit off so the tab end so it can fit into the spring clamp properly. And this means the drum is not completely covered at the inboard end of the drum.

2. Then the spring clamp is narrower than the slot into which the free end goes and I have to cut out another section across the weave but ensure it is inside the drum so it won't catch the wood. This seems the only way to get it to attach securely and was how the machine was delivered.

So my question is how do others approach this problem? I've been thinking of making some mods, perhaps putting some rubber inside the clamps jaws to get more grip. A stronger spring. I also need a better approach to trial and error cutting of the end off the roll that goes in the clamp.

Cheers
Dom

[Mark Fogleman]

I apply a layer of Duct tape to the first 3-4 inches of the back of the abrasive. It prevents tears (and tears ).

[Allen]

Make yourself a template of the exact sandpaper shape and length that you need. Then it's easy to check the new piece and trim to size.

I've got the Jet and the spring clamp seems to hold fine on anything except the 36 grit I've got for those really hard and stubborn woods that need a fair bit removed. Then it's more that the sandpaper and backing is just too stiff and thick to work well.

[Dominic]

Thanks guys, Allen, making a template is always one of those things that goes through my mind when I start having problems with it. And buying long rolls of good stuff. There's always a long list of those jobs where i think, stuff this, I've got to do this properly one day. I'm getting there slowly.

Mark, I like the tape idea.

Do either of you guys have to shape the ends a bit so they go in the clamp and how do you do it? On the CT one the clamp is about 25mm wide but around double that goes into the slot at the end. I could just cut it right down and lose about 25mm off the end of the drum.

I'm going to have to pull it apart a bit and see if i can come up with something more secure. Its in a hard place to see clearly so i have only really checked it out with my hands and glimpses.

Cheers
Dom

[Allen]

With the Jet they give you the dimensions and a bit of a diagram in the manual. I've got the 10-20 and the Woodworkers Guild has the 16/32. Taper is the same, but length different. I've never really paid much attention to it after the template was made.

[ozziebluesman]

G'day Dom,

I have the same model drum sander as you do and I have had my fare share of arguments with fitting the paper. As Allen said a template is essential. I bought a 60 grit roll when I bought my sander so it is my template as it is a bit too aggressive for my uses.

I bought some 120 grit paper from The Sandpaper Man in Brisbane recently in a continuous roll with enough for four paper changes. The paper is very strong and much better thn the Carbatec stuff. When fitting I taper the ends 30 cm and leave about 25mm at the ends. This last paper change has been successful so far and I think the better paper has been an improvement.

Cheers

Alan

[Phil]

Yes the Carbatec 600 drum sander needs a redesign of the spring loaded clamping mechanism for the belt. It probably works well in theory, but in practice it fails badly.

I am a volunteer in our local Mens Shed, where we have one of these machines. It gets used by all and sundry as a gereral purpose sanding machine. The lifespan of the belt is measured in minutes. I can tell stories......

I also have the same in my workshop, and with care, the belt lasts me many hours of use.

Four points.

First, it is a lightweight machine, open ended, with lots of flex, and a bit of backlash on the height adjustment

So. Sand lightly. One pass, then a second pass, end for end, then flip the workpiece over for a third pass, then a fourth pass end for end. Then, and only then, you can lower the drum 1/3 rd of a turn and repeat the process.
Yes it's slow, but it works well to a very fine degree of accuracy.

Second, Wrap a band of heavy tape (Strapping Tape or Cloth reinforced tape) round the belt on the extremity of the RH side of the drum to secure the end.
In our Mens Shed this fix has extended the life of the belt from minuites into days. It's still going!!!!

Third, The belt stretches and gets floppy on the drum very quickly. Feel the wood as it exits the machine, it gets warm in there. Things expand with heat, sanding belts expand also. but they do not contract when cool Take out the slop regurlarly or bear the consequence of a gouge in your wood and a need for a belt replacement.

Four, clean the belt often with that rubbery stuff. Inspect the belt for build up after even a few passes with some woods, (you get to know which)

I hope this helps. I have a great liking for this machine because it does a good job for me with guitar tables thicknessed within a tenth of a mil side to middle, which is hard to do any other way.

Phil.

[kiwigeo]

The Jets come with a handy tool that anchors the end of the paper on the roll and keeps it taut while you engage the end of the paper in the anchoring clip.

[Dominic]

Thanks guys, it looks like I just need to spend a bit of time thinking about it.

Alan, I have been meaning to get some rolls from those guys. I am glad you say it is good quality. I'll have to get some.

Cheers
Dom

[vandenboom]

I bought some 120 grit paper from The Sandpaper Man in Brisbane recently in a continuous roll with enough for four paper changes. The paper is very strong and much better than the Carbatec stuff.

Alan, I want to order some of this. Would you mind telling me what length you need for a replacement ? I can't measure mine as I am in NT until just before xmas and have a new Carbatec unit waiting for me at home in Melb so want to order some replacment paper before places close for the xmas break. I also seem to remember that the paper from Sandpaper Man (76mm) is a slightly different width to the Carbatec stuff but could be wrong.
I plan to get a couple of replacements of 80 and 120 grits.
Thanks. Frank.

[ozziebluesman]

G'day Frank,

Sorry I didn't get back to you a bit sooner with the information you requested. I have had some health issues and have been in hospital for some tests , xrays and monitoring.

The sandpaper template length I have is 2.3 mtr long. Exactly!

Cheers

Alan

[Dominic]

The Jets come with a handy tool that anchors the end of the paper on the roll and keeps it taut while you engage the end of the paper in the anchoring clip.

Could you snap a pic of this tool when you get a chance Martin? I can't quite imagine what it is doing but it sounds useful. i looked at a jet one the other day and does not look any different. Perhaps better executed.
Cheers
Dom

[kiwigeo]

The Jets come with a handy tool that anchors the end of the paper on the roll and keeps it taut while you engage the end of the paper in the anchoring clip.

Could you snap a pic of this tool when you get a chance Martin? I can't quite imagine what it is doing but it sounds useful. i looked at a jet one the other day and does not look any different. Perhaps better executed.
Cheers
Dom

Will snap a pic when I get a chance. Basically the tool holds the sandpaper tail hard against the drum while it opens the springloaded clamp that anchors the tail.

[Dominic]

Thanks Martin, I've seem a pic of a guy using it but could not see the end so I didn't know what he was doing wi it.

BTW, i ordered 10m each of P80 and P120 from the sandaper man, and turned this morning. Good quality and seems it will last quite a while. So thanks to who it was that suggesed them.

Cheers
Dom