Drum Sander Issues - Looking for Input

[Mike Chalmers]

I have had a King 16/32 Open End Drum Sander for about two weeks.

I am very unhappy with this tool.



The drum seems to flare at the ends. When I measure table to drum with my Oneway Multi Guage, the last inch (roughly where the paper clamps are) measures about .01" closer to the table then the rest of the drum.
I follow the directions to adjust the drum to be parallel to the table (paper off). According to my dial guage, I have succeeded. However, once I put a piece of wood in to be sanded, it flexes up on the outboard side. I would say it is about .02” higher from the table on the outboard end than the inboard end. The outboard end barely touches the wood, the inboard side sands much too aggressively. I have ensured the “Elevation Tension adjustment Screws” are adjusted properly as directed in the manual. I am even thinking about putting some kind of weights on top of the drum housing on the outboard section to try and hold it down. I could also try adjusting the machine so that the outboard measurement from drum to table is smaller than the inboard one in an attempt to compensate for the flex, but, I should not have to. I assure you I am not trying to take too much off. I am only turning the wheel abut 1/16th of a turn.
The board enters the machine, it starts sanding. Then approximately 3 inches of the board gets sanded, then the sanding stops, The same thing happens to the far end. Looks like snipe does on a planer. It is like the drum is raised from the wood when it goes under the outfeed roller, and back down again when it passes the infeed roller. There is nothing in the manual about adjusting the height of the rollers.


Any insights as to what I may be doing wrong or tips on how to overcome these issues would be much appreciated.

[Keith Outten]

Its not uncommon to sand only one side of a board when you start sanding. In almost every case the board isn't flat and it would be very rare if any board was within 10 to 20 thousandths of an inch across the width. I suggest you measure the boards first and send the thickest side through the sander on the side of the support post, once the board is flat check it to verify that the thickness is within a reasonable tolerance.

[Carroll Courtney]

​(the inboard side sands much too aggressively) Mike are you trying to sand to much at one time?I have a 16/32 but I make multiple passes after each adjustment,but its still not perfect.Try to avoid the buildup of dust so the drum won't ride up.A VG dust collector is a must---Hope this little tid bit of info helps or put things in your favor----Carroll

[Robert Parent]

I think you need to take several measurements of the base machine to know where the issue is. First, you need to confirm the drum is the same diameter over the entire length. Second you then need to determine if the drum is concave, convex or ok from end to end. Third, check the table and ensure that it is flat. Forth, check from the table to the drum to verify it is equal distance at both ends. If these are ok then the issue is in the table belt feed system or in the sandpaper and how it is attached to the drum.

Robert

[Mike Chalmers]

Its not uncommon to sand only one side of a board when you start sanding. In almost every case the board isn't flat and it would be very rare if any board was within 10 to 20 thousandths of an inch across the width. I suggest you measure the boards first and send the thickest side through the sander on the side of the support post, once the board is flat check it to verify that the thickness is within a reasonable tolerance.

I fully understand already. End product is also varying in thickness of the same amount (more or less) as I am measuring the drum to be.

Thanks anyway.

[Mike Chalmers]

​(the inboard side sands much too aggressively) Mike are you trying to sand to much at one time?I have a 16/32 but I make multiple passes after each adjustment,but its still not perfect.Try to avoid the buildup of dust so the drum won't ride up.A VG dust collector is a must---Hope this little tid bit of info helps or put things in your favor----Carroll

I do not think so, hence my statement above of turning the wheel not more than 1/16 of a turn. I have a 2 HP DC hooked up, but the sander has a 2 1/2" port. Can't help that. Thanks anyway.

[John TenEyck]

Put a straight edge across the drum. If it's concave like you think you'll see light under the straight edge in the center. If that's true, I would get rid of the machine or have the drum turned true by a machine shop because it's useless like that. If the out board end flexes as much as you say, something's not adjusted right, you are trying to take way too big a bite, or the machine is flexing. All open ended drum sanders flex a little; I'd guess my Delta 18x36 opens a couple of thousandths when taking a big bite which is around 0.005 - 0.010". But a flex of 0.020" would be completely unexpected and render the machine useless to me. You could always tie the outboard end to the lower frame with some angle iron and then you'd have a 16" wide drum sander. Not an attractive solution in my mind.

John

[Mike Chalmers]

I think you need to take several measurements of the base machine to know where the issue is. First, you need to confirm the drum is the same diameter over the entire length. Second you then need to determine if the drum is concave, convex or ok from end to end. Third, check the table and ensure that it is flat. Forth, check from the table to the drum to verify it is equal distance at both ends. If these are ok then the issue is in the table belt feed system or in the sandpaper and how it is attached to the drum.

Robert

Rog. Have done most, will try others.

Thanks anyway.

[Edwin Dodds]

Check everything out as Mike said, plus one more thing. Mount the base of a dial indicator to the outboard end of the table, with the indicator tip on the outboard end of the sanding head. Then grab the head out at the end and see if you can move it up and down. There is likely going to be a bit of flex in the frame, but there should not be any excessive "play". How much movement does the indicator show? If there is play in it, then try to determine what is causing it so you can tighten it up. Is there a way to adjust the tightness of the head where it slides up and down in the frame?
I bought the King (KC-16-1-D) 16" closed end sander for the very reason that I didn't want any flex in the machine. It sands dead flat across the whole table, even with a heavy cut. The downside is that it won't sand anything wider than 16", but it meets my needs and I'm very happy with it.

[ken masoumi]

I have a King 16/32 drum sander and it is set up exactly the way you describe ,(open end a few thou higher)but when I insert the shim that came with the sander under the conveyor belt,then the drum will be even(parallel to the belt) on both ends,this is how I left it set up(shim normally removed) so when I sand a board wider than 16", I don't end up with a sanded line in the middle of the board.
I only use the shim when I sand pieces 16" or narrower,that shim allows the drum sander to sand evenly on both ends.

[Mike Chalmers]

I have determined that the head has some play due to the tightness (or lack thereof) on the mount to the main frame. When it is up where my dial indicator can fit under it is very tight. As I lower the drum, it gets looser. Am going to try tomorrow setting the height with the dial indicator, lowering the drum to where it will be used (3/4 - 1 1/4" thick) and then tightening the mount again. I may also set it so the outboard end is a little low. That way, I can use a shim when sanding small pieces, and have the shim out when sanding wide pieces, and it should flex up to the proper height. Should have bought the Supermax.

[John TenEyck]

I just looked up the King 1632 drum sander because I had never heard of them. Canadian company I see. Anyway, that is a very light duty machine. The specs. say max. capacity per pass is 1/64" which is about 0.015". That's 2 - 3X what I typically sand with my Delta 18x36, which is a much more robust design. My machine chokes if you try to take off that much. Looking at the construction I would guess that it's much more comfortable taking off no more than 0.002 - 0.003" per pass. It's just a very light duty design and uses die cast parts. You can't expect much from it. Set it up so the head and table are parallel and try taking off a couple of thousandths. Assuming the drum is flat and not concave as your OP indicated, if the board comes out sanded on the inboard side but not on the outboard side I'd be looking to return it. If the drum turns out to be not true, that's another issue that warrants return. If you bought it used, hmmm, not good.

John

[Edwin Dodds]

John, I agree with your statement - "That's 2 - 3X what I typically sand with my Delta 18x36, which is a much more robust design".
I usually take .005 per pass. I mounted an igaging 6" digital gauge to mine so I can easily tell exactly how much I'm taking off.
http://www.igagingstore.com/6-Magnetic-Remote-Table-Mill-Saw-Fence-Digital-p/203926.htm

[ken masoumi]

. As I lower the drum, it gets looser.
That's where your problem is ,get rid of the play when the drum is lower,tighten it a bit but no so tight that when you raise the drum it will be too hard to crank.
As far as the quality goes,I only heard praises for this drum sander by hobby woodworkers and luthiers,many of whom compared it to Suppermax with 2" extra height capacity,I still think for the money it is a great sander ,it's short comings is no different than any other open end drum sanders.

[Mike Chalmers]

I just looked up the King 1632 drum sander because I had never heard of them. Canadian company I see. Anyway, that is a very light duty machine. The specs. say max. capacity per pass is 1/64" which is about 0.015". That's 2 - 3X what I typically sand with my Delta 18x36, which is a much more robust design. My machine chokes if you try to take off that much. Looking at the construction I would guess that it's much more comfortable taking off no more than 0.002 - 0.003" per pass. It's just a very light duty design and uses die cast parts. You can't expect much from it. Set it up so the head and table are parallel and try taking off a couple of thousandths. Assuming the drum is flat and not concave as your OP indicated, if the board comes out sanded on the inboard side but not on the outboard side I'd be looking to return it. If the drum turns out to be not true, that's another issue that warrants return. If you bought it used, hmmm, not good.

John

Agreed. That is why I posted that I turn the wheel about 1/16th of a turn at a time. 1/4 turn is 1/64.

As far as what do I expect? For $1,000 more than I appear to be getting.

[John TenEyck]

Agreed. That is why I posted that I turn the wheel about 1/16th of a turn at a time. 1/4 turn is 1/64.

As far as what do I expect? For $1,000 more than I appear to be getting.

Did you check the drum with a straight edge and find that it's not true (flat)? If so, you have grounds to return the machine for a refund and get out from under your nightmare. 1/16 of a turn is 0.004". That may still be too much for that machine; wouldn't surprise me looking at it. Try half of that. And what grit paper are you using? I never go finer than 120 grit.

John