Need advice on Kuster brand drum sander i bought

Kelvin · February 02, 2009, 06:51:04 PM

Howdy,
I've gotten a big order of stair treads i have to make up, 68 of them actually (i don't know what this staircase looks like yet, but thats a lot of treads, must be a couple of 'em) and have been wanting to buy a used drum sander for the shop for some time. I figured it would save me a lot of time on this job, so when this 5hp, dual drum sander went on craigslist i bought it. I did some googling on Kuster brand, and its from the mid '80's and appartently Grizzly used the design in their sander. Looks like there 24" sander. This one is dual drum, but only 18" wide. I've been waiting for a 36" or something but nothing is ever in my price range (Not much is) So i thought the 5hp baldor motor was worth what i paid, and took it home after trying it out on some pine. (did in fact make sawdust!)

Wondering if anyone has used or seen one of these before? What i'm wondering about is they made the drums spin in the same direction as the feed belt, and there has been complaints of bad dust pickup and caking of sawdust on the finished face from owners on websites i googled. Even the owner's manual says, "once the board is done being sanded, use a brush to clean off the face before feeding through again" Sounds like they knew it was part of way it worked. What i'm wondering about is reversing the sanding drum motor and having the drums oppose the feed belt, i think this is how most of them work? Any thoughts on this? I'm also thinking of replacing the 4" dust connector that sits on top, in the middle of the two drums, to a larger heating/ventalation type boot on the side of the hood where the dust is being spit too. maybe a 3"x10" or 4"x10", something like that, to a 4" round. Seems like if you get the dust before it gets caked on you'd save yourself some trouble.

What do you guys think? Also what is a good combo for the belts? I was thinking 80 grit followed by 120? Where is the best place to buy belting? I've used Klingspor and USA abrasives in the past for my belt sanders and disks. Anyone got a good secret place?
Thanks
kelvin

low_48 · February 02, 2009, 11:17:00 PM

I would definitely reversed the drums. I can't imagine that it would do an accurate job, trying to self feed. If you modify the dust extraction, I would change to two ports. Static can be a problem with trying to take the dust off the drum. I would bring in a plexi panel as close to the drum as possible and try to "cut" the dust off the drum. The biggest disadvantage to drum sanders compared to the belt sanders, is heat in the abrasive. You can gum up the abrasive a lot easier on a drum. Don't push it too hard and you will work faster, by working slower in the long run. I'm a real fan of Norton 3x paper in the shop, but don't know if they sell it in rolls. What grit depends on what the customer is looking for. On drum sanders, there is no cushion behind the paper, just a hard roller. The grit size will be the size of the scratch. For a comparison, hand held belt sanders basically float on the board and will not leave as deep of a scratch. I suspect you will want to go more like 80, 150.

srt · March 09, 2009, 04:41:25 PM

Hello Kelvin,

I have an old Grizzly 24" dual drum. Here's been my experience. It does a fair job if you don't push it, but defintely get some air sucking through the unit. On pine, it really likes to gum up the belts, which means pulling the top cover and using the belt cleaner a good bit. Running coarser paper will help. As it was already said, heat is the enemy. Low 48's also correct about taking your time. More passes will save you time in the long run.

I can't locate it, but there was an old timer who actually did reverse the direction to what everyong I've talked to says is the correct way. He put some plans out there free. Maybe some deep searching might save you some time. IIRC, he did also modify the duct, and actually put suction nozzles down near the drums so they would suck the dust and help cool the drums a bit. I'll check the files in the shed to see if I saved any of the info I accumulated on that sander.

If I were running a big batch of hardwood, and the stock had some pretty significant planer mill marks, I think I'd try using a fairly coarse paper on both drums for the first run through. Maybe 80, 80. Then change paper to 100, 100, then go from there depending on what class of finish you were looking for. Sometimes, I've had to run stuff through several times, and it just doesn't make sense to me to use a coarse and fine grit on the same pass, unless you can get an acceptable finish from that pass. In my experience, the machine isin't capable of taking enough off in one pass for that to be the case.

If I were going to the trouble to make modifications, I'd look into making the feed rate variable.

Do you have the velcro system, or the *^&%$#%^&*&^^% Clips on the ends of the drums?

Mine has clips. I've sometimes resorted to duct taping the last 2" on the end, plus using the clips. Those that have, or have converted to the velcro seem to say it's a better system. With the duct tape, you just have to be sure you don't get the board over near the side. Duct tape is not a good abrasive.

Speaking of sanding, I need to get back to the shop.

Fla._Deadheader · March 09, 2009, 06:28:58 PM

I've also heard the Velcro is a much better system. Idea is, it doesn't take as much pressure for the belt to sand the board, and, the velcro keeps the belt from getting overly hot.

Look on ebay for barbkat. She is in Ohio, and has excellent prices and service. I use her belt sander belts on HARD wood, and they really hold up. 8)

srt · March 09, 2009, 08:41:12 PM

I can second Barbkat. She's sent me good paper to Jersey, and reasonably priced. I don't remember how, but I was able to contact Barbkat by phone and talk about my order. IIRC, she has a web site, so you're not stuck with just what she has on ebay. I got an absolute steal on a good bit of silicon carbide sandpaper for a project I was doing with marble from her. Cost me pennies on the dollar.

1938farmall · March 09, 2009, 09:13:38 PM

I'm thinking if you reverse the drum rotation the strips will want to unwind. Probably you'll have to end-for-end the actual drums to make your idea work right. al

woodhick · March 10, 2009, 07:51:16 AM

Kelvin does your machine use 6" wide paper strips or smaller?. I used to have a woodmaster with the velcro covered drums and I used a couple of wraps of 3/8" wide filament strapping tape on the ends to secure the paper. I am also using the filament tape to hold paper on another drum sander that I have that has a 10" diameter steel drum and it works pretty good. If you have a need for 180 grit paper 6" wide pm as I have quite a bit and would give you a good price on some. The drum sanders are really slow but will do a good job. I sold mine and got lucky when Amazon put the Powermatic 1632 open sided wide belt on sale for 65% off so I got one of them. I really like it and it will sand circles around a drum sander. Keep your eye out for one of the open wide belts as it will sand 15" wide on one pass and that covers most all of my work. I use a random orbit sander on wider doors and panels. good luck.