What should I expect from a drum sander
SLCLarry
| Posted in Power Tools and Machinery on
I purchased a Woodmaster Drumsander. I have used it on beech boards about 50″ or 60″ long and widths from 6″ up to 14″. I used successively finer grits, ending at 220. Upon finishing, the boards all have consistent ripples, or rotation marks. There was also a tiny bit of snipe, but you had to look hard. I was lead to believe the machine would sand flat stock to be ready for finishing.
My question: was I mislead, and in fact, the flat stock will always need more sanding after the drum sander, or do I need to keep looking for a problem in my machine?
Larry
Replies
Larry,
I guess it all depends on your idea of a "finish ready" surface. A 220 drum sanded surface would be pretty rough in my opinion. I lean towards a hand planed or scraped surface followed by a 320-400 grit light sanding to remove the blade lines. If you drum sand a surface, I suggest you finish with with a sanding before finishing. The lightest grit I use on my drum sander is 120, and it looks like I tied it to the back of my truck and drug it on the asphalt when it comes out. I can't imagine 220 would be much better. There aren't any shortcuts in finishing, but if it was easy, everyone could do it.
Regards,
Sean
Thanks for the input. I used 220 as the final sanding on the dum sander. You mention the paralel scratch lines, I presume parallel to the line of travel through the machine. In my case I expect those lines. My problem is the ripples, or rotation marks that are perpendicular to the line of travel. Do you see these on your stock sent through your drum sander?
I have attached a picture, I think (I don't see it attached in this window).
Larry
I see what you mean now. My drum sander doesn't leave those kind of marks, nor does it snipe. It looks as though your drum is loose and bouncing on the wood, or the drum is out of round. Sean
Here is another try at attaching the picture of the ripples or rotation marks.
Larry
just guessing but the depth is set to low or the speed in to slow.
Larry,
I have a drum sander which has made many a precisely-thick part - the only reason I keep it. A drum sander has the ability to make things of a thickness accurate to around 0.05mm if required. These days mine mostly makes stringing and similar stuff - items that have to fit very, very closely in a groove or some other gap.
You never get a finish suitable for a tansparent final coating from the drum sander. I've even tried 320 grit,which does leave a very smooth-feeling surface; but hold it up agin' the light and you will still see a myriad of parallel scratches which have to be either planed, scraped or RO sanded away before applying the oil, wax or whatever.
The drum-sander finish is very suitable as-is for painting though - it has a good key but the micro-scratches won't show through paint.
If you have no need for ultimate thickness-precision, I would recommend a European-style planer/thicknesser to prepare stock (mine gives accuracy to around 0.2mm thickness, or less in "easy" timbers) followed by a handplane, scraper or RO sander as you prefer. My planer/thicknesser has rubber feed rollers allied with a fast drum rotation and slow feed rate, which gives a very smooth surface in which no ripples are evident, assuming the knives are kept sharp and nick-free.
Snipe: one cause is a lesening of pressure on the workpiece at the begining and end of it feeding into rollers. If the bed on which the work is lying remains stiff, such snipe is reduced or eliminated. It also helps to ensure the roller pressure is not excesive.
Lastly, try supporting the work at the opposite ends to that being sniped with a roller stand or even your hand, to prevent the plank's own weight from making a slight tip-up as it pivots under the infeed roller up into the blades, before reaching the outfeed roller where it is pressed down flat again. Similary at the exit of the plank, as it leaves the infeed roller when the other end has a tendency to tip up into the blade again, pivoting now on the outfeed roller). The same principle must apply to a drum sander asked, as yours is, to handle long planks.
Lataxe
Edited 6/15/2008 9:55 am ET by Lataxe
I have a Performax 16-32. In my experience to avoid ripples use a v e r y s l o w feed rate and take tiny bites - less than a 64th. I also have many hours logged on a Performax 37 and a Woodmaster 36. In both situations, random orbit sanding was needed after drum sanding.
I now use my 16-32 only when I'm making something of precise thickness, as mentioned by another poster. It's too slow for most other sanding tasks.
Ed
If you have time and the inclination, take a look at the picture I posted a bit earlier today and tell me if you get these kind of marks, across the stock. (I expect to have sanding lines parallel to the direction of travel.)
Larry
Larry -
I no longer have access to the Woodmaster and my experience was 6 years ago so I'm going from memory. The machine I used had a sort of astroturf covering on the feed belt. It was compressible. If too much feed or depth was used, the drum or stock would hop as material fed through. Have you tried to vary speed and depth to see if it made a difference?
Ed
You are recollecting correctly, The steel drum is covered (wrapped) with adhesive-backed Velcro (the hooked side), and the sandpaper is felt backed, which sticks to the Velcro.
When I am trying to eliminate these marks, I run 220 paper that is set to just touch the wood. One Quarter turn of the crank stops contact with the wood, so it is set to remove 1/64". Changing speed of feed just changes the distance between the ripples.
I don't recall the drum attachment method on the machine I used. The feed belt had the astroturf-like material on it. The machine I used was new circa 2001 - 2002. Specs might have changed over time.
Quarter turn sounds right for depth advancement.
Long boards, I recall, need support on infeed and outfeed to avoid snipe.
On my Performax 16-32 I ran some tests to determine the appropriate feed rate for a given grit and depth. I mic'd a board, ran it thru, mic'd it again, ran it thru again with no change to depth, and continued until the thickness in = thickness out. So I had the amount removed. Then I slowed down the feed rate incrementally until the machine took off the entire amount in one pass. It is a surprisingly low speed. Sorry I can't characterize it in feet per minute. Obviously, different grits required different feed rates for the same depth of cut.
Can you determine depth of ripples using a dial indicator? Or check the drum for roundness? Speak with the maker?
If the ripples can be easily sanded out I'd just move on.
Ed
Any drum sander will need to be hand or random orbit sanded before going to finishing to remove drum marks. Widebelt sanders have platen to eliminate this issue. 35 years of industrial sanding machines experience.
Hi Larry,
I own a Woodmaster Drum, it's a nice machine, but you will never get finish ready parts out of the machine, at least that has been my experience. I use it to thickness sand veneer and parts, we are talking about depth of 'cuts' of 1/64" or less.I mostly use 100 or 120 grit in the machine, once I used 150 on some parts that were going to painted, still used the ROS to finish sand them.
I will say that the photo you posted looks like the ripples from planer knives, not a drum sander, almost looks like you didn't sand anything. The typical finish from the drum will be long surface scratches parallel to the feed direction. Might want to try lightly putting pencil marks all over the board and see if the sander removes them
Edited 6/16/2008 8:39 am ET by BOBABEUI
Those are not planer or jointer marks. Believe me I sanded those boards. First with 150, then 220. Tried many different feed rates. Slow rates make the ripple s closer together, and fast rates make them wider.
A major source of my frustration is that I had milled beech stock for shelving that utilizes housed lap joints to slide together with the verticals. I had milled to just over the thickness needed, expecting to only clean up the boards on the drum sander. This is my first project with this new machine. When all these ripples showed up, I had to sand off enough that the lap joints ratlle around in the verticals, not fit as designed.
Experience is a great teacher, but the lessons are sometimes harsh.
Thanks for the input,
Larry
Larry,
I'm gonna take a wild guess but those marks look like a band or bands might be overlapping or there is a slight bump somewhere in the windings of the sanding belts mebbe?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
This is my first project with this new machine.
I would think a bit much for the first time using the tool!
Experience is a great teacher, but the lessons are sometimes harsh.
I'd have to say that I have NEVER used Beech!
I don't own a belt sander, but just as a thought have you examined the feed table for inconsistencies?
Maybe you aren't wrapping the sand paper in the right way leaving an overlap or perhaps the axal (arbor) is slightly out.
Did you check with the previous owner or consult your manual? IT could be a matter of a small adjustment!
I know first hand how frustrating setting up a new machine can be. especially one you aren't familiar with.
I just purchased a 14" band saw and am frustrated with the machine! Live and learn LOL!
ChaimMake your own mistakes not someone elses, this is a good way to be original !
Based on the feed rate statement, I would guess that the roller that the paper wraps around is out of round. Overlapping paper issues would result in serpentine groove. A dial indicator might be useful.
Sorry for your frustrations,, Tom
Ps , I am assuming the paper on this type of machine wraps in a spiral around the roller.
Edited 7/12/2008 10:07 am ET by gofigure57
Edited 7/12/2008 10:08 am ET by gofigure57
Just my opinion and may be worth nothing because I would not consider myself anywhere close to being an expert finisher. Nice finish most of the time but hardly what somebody that knows what they are doing could. I do not have the patience for it.
My daughters bought me a small 13" drum sander. Something that I would never bought on my own. I LOVE IT!
I only use 80 and 120 grits, depending on the wood and how rough the board it.
I use my drum sander more for dimensioning the thickness of the board. Not for final finishing.
The bed extensions are a bit short (as with my planner) so I have made a table (waxed MDF top) about 4 foot long that supports the stock as it exits the machine. With the support extension I get very little 'snipe' from either machine.
With the woods I use, 120 grit will leave a reasonable surface for final hand work. I mostly use a hand scraper and hand sanding for that. I'm sure a plane would make a better finish, but frankly, I only use them on a shooting board and on edges of the board. I'm not skilled enough to use a plane on a wide surface. The planes I have are SHARP and work well but just seem to 'slide' on the surface of Jatoba, Purpleheart and some of the other HARDwoods I use like an iceskate!
I tend to pick boards with wild grain for my projects. I almost always have to run them several times through the planner so I do not get tareout. I take very light cuts and sometimes, as in most times, I will get some tareout. The drum sander almost always cleans it up!
Before I got my drum sander I would spent hours of hand work 'cleaning up' the tareout. The drum sander can do that in a few minutes! I do not take very aggressive cuts with any tool I use so the sanding belts last along time.
consistent ripples, or rotation marks..
I have seen some when the grit belt was a 'bit' loose or I used a 'fast' feed rate? Not sure.
Just my long winded way to say that it is just another tool that has limits.
Maybe a stroke sander is the perfect answer? Maybe...
Have a Great Day and enjoy you new tool!
Larry, Did you get the ripple problem resolved? Has it ever worked correctly?
I just read something in the Performax manual that ripples are caused by one or more factors:
1. Uneven feed rate attributed to an issue with the conveyor belt. The belt could be slipping over the drive roller, or the board could be slipping on the belt. Problem with the conveyor belt gear motor slipping. The drive train connections may be loose. Check all set screws, etc, Here was a surprise: The conveyor bushings may be dry.
Have you disconnected the conveyor drive and moved it by hand to feel any abnormalities?
Have you set a dial indicator on the drum to assure it is cylindrical? If so, there may be an imbalance at higher speed.
2. Excessive depth of cut. Have you tried a lighter pass?
Greg
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Exo 35:30-35
Performax .. Mine works BUT I never use it to expect FINISH work.. I do not think that is the task they were made for.....
Stroke sander sort of!
I think alot depends on how tight you get the belt attached.. HARD with any I ever used... Just a thought..
Edited 7/11/2008 8:28 am by WillGeorge
How is it for uniform thicknessing. My main use is to resaw boards to about 3/32 then sand them to uniform thickness, removing resaw marks.Greg
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Exo 35:30-35<!---->
I have no idea! I understand removing saw marks though!
My main use is to resaw boards to about 3/32 then sand them to uniform thickness..
Geeeeeee.. 3/32 inch. No hate here but I think you expect a wee much from a little machine!
I'd bet some of the grits on the belt are taller en' that from the factory!
Just a thought.. Pain in the butt to change but I save my old but not worn out strips for finish.. NO... I do not expect a perfect surface.... I'd say it takes a human eye (in VERY GOOD LIGHT) and patience to do that..
EDIT: I was thinkin' again 3/32 inch and perfect both sides? MAYBE Stradivari could do that to a sound board!
Edited 7/13/2008 4:20 am by WillGeorge
Greg,
I have been working for weeks the VP of Mfg at Woodmaster. He says, by the pictures I sent, "something is amiss".
I have tried all you suggested and more. We have replaced the Velcro, replaced the front belt roller that seemed to vibrate, based on a dial indicator. All else seems okay, based on dial indicator readings. The other thought is the belt drive motor, but I have yet to hear back again, after changing the roller.
If I have to live with the rotation marks, I just need to leave enough stock to random orbital sand out the marks. I didn't do that on the first project, and my housed lap joints didn't fit as expected.
I have an old Makita jointer / planer that I use to square and flatten stock. The drum sander does work better when working with large flat stock, as it has less tendency to squeeze the thinner stock flat, the way the planer does.
I'll keep after it, as well as "live and learn."
Larry
I feel your pain. You should not have to live with rotation marks.You have probably thought of nearly everything that might be causing the problem and already know dozens of things that it is not.In reading your repy, one flag arose: You said it tends to do better with wider stock. I have three questions: 1. Have you ever had it work properly?2. Have you tried feeding two narrower boards side by side — perhaps one near each end of the drum then a combination of one at the ends with one in the center? The forces on the roller/support assy change with the differing stock widths. One trick I used to tell if vibration was a problem in high speed centrifuges was to stand a nickel on edge on the flange. When it would not remain as load was applied, we knew the bearings were wearing.I'd try this with your sander. It may not stand during start-up as the machine passes thru vibration modes. But after running at steady state without a load I'd try it, then watch what happens when you put a board into it. Just a suggestion.Greg•••••••
Exo 35:30-35
Edited 7/11/2008 2:31 pm by Cincinnati
Based on your picture and your description that a slow feed rate moves the ripples closer together and a faster rate moves them farther apart, I'd wonder whether the velcro on the drum is correctly attached - i.e., no overlap. If the backing material overlaps, it would create a slightly harder spot on on part of the drum, and depending on the feed rate, would result in the defect you're seeing.
If the store clerk really told you that wood out of the machine will be finish-ready, I'd say you have grounds for returning it. Then I'd strongly think about a handplane (a smoother). A handplane will prep a surface for finishing far, far faster than any sander, and if you've a planer to do the hard work that would've been handled by a fore plane and a jointer plane in the past, all you need to do is make at most two passes with a smoothing plane and it's done, no random orbit sanding needed.
As some other posters have said, a drum sander is a great tool if you have to level cross-grain constructions like kitchen cabinet doors, or thickness very thin stock that would be dangerous on a planer, but it's not a finishing tool. Even the commercial cabinet shops I've been in use a wide-belt sander to roughly level doors, then have a lackey use a random-orbit sander through 3 or more progressive grits before sending it to the finishing room.
Larry, if a drum sander has one distinguishing feature it is the fact that it will always leave a Directional Finish because the actual sanding length of paper on the drum is only equal to the circumference of that drum and more importantly the drum does not oscillate as in better quality wide belt sanders-which also have a much longer sanding belt.
The planer-like ripple marks are a function of feed speed, depth of cut, type of paper and setting and backing surface of the platten-in other words it will always be there to a lesser or greater extent. Snipe is not an acceptable option and you should be able to at least eliminate that, and the extra ripple that a bad paper join makes.
At any rate you should expect a surface that only requires a minimal amount of work to obtain a surface suitable for furniture standard polishing.
If you are going to daub on some milk paint or wave a paint sodden paint brush then it DON'T MATTER.
Based on the issues, and the post where you mentioned going through several different troubleshooting efforts with Woodmaster, I'd say they owe you a new machine, and you shouldn't have to pay for pick-up and shipping either.
It's not your responsibility to have to troubleshoot for them, and you've put out a reasonable amount of effort to do so already. Ask them to ship a new one to you and take the old one back for factory refurbishment.
I agree.
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