I have a small cabinet shop and might buy a stroke sander to ease my time on finishing work. I've considered drum sanders, and of course a wide belt. How effective for the money is a stroke sander?
I don't own one, but I did just purchase an SCMI 43" 2-head segmented sander. Please explain more about what you are sanding and what finish you need to sand to.
Stroke sanders are a cheap alternative, but you may not require one and your needs may be just as easily accomplished with a down draft table and two plain old vibrators or orbitals loaded with 2-3 different grits. A stroke sander will only be able to sand with a single grit loaded at one time. This is the biggest problem with them, as with a wide belt with a single head. Depending on what you're sanding, it's wise to have all of the parts requiring finish sanded with the same grit, as different grits will lead to different colors or shades in the finish process.
I spent the extra money because I want a system with ease of maintenance. With a 2 head and segmented, I can run any type of part that needs to be sanded through one and only one place, with a grit combination that will ensure a proper finish every time.
You always need to consider the worst case scenario and buy the machine best suited for that. There is no sense in buying a 37" single-head only to be faced with a 42" glass cabinet with an oak plywood back. You have to stand next to your investment with a vibrator and two horses blowing dust all over a $20,000 machine you can't use because you bought it with limitations, be they width considerations or sanding through veneer.
I hear you about the tall or wide unit that won't fit in the machine. And that's a good observation about the "double grit in one pass" move. A double drum sander 24" is within my reach. I could work around its perimeters if I had more feedback on how well they stand up and how user-friendly they are. In summary, most sanding requirements would be less than 6'-0" tall by 24" wide, usually finished to 150 grit with touch-up sanding as necessary.
I think you may want to buy two things, a stroke sander and a downdraft table, and make a sanding "cell".
If I had the space I would have my stroke sander back. There are things it will do that a wide belt won't. The control you have when sanding veneered products is second only to CNC platens of newer wide belts. If you are trying to thickness paneled doors or trim packages, the stroke sander is not very good at this. However, if you are trying to do general sanding, plywood panels and such, it will make you money as compared to the orbital or hand belt sander. I bet you can find a good used stroke sander for under $1000. It will run and run and run. In the end you will need to purchase a wide belt, but you need to start some place.
I have a 20" 5 hp model that looks similar to the Grizzly 24". I wouldn't bother with a single drum sander because I usually sand with 120 or 100 before finishing up with 150 grit. The double drum does both grits in one process.
I bought mine used and have run thousands of doors and panels through it and have only had to change paper and keep the chain and threaded rods that raise and lower the table clean and well oiled.
I'd recommend to the machine's manufacturer to put an extra drive belt on, as when I try to take too deep a cut, the belt can slip (and I've tightened it as much as I dare).
I usually make two passes on each side of my doors and then take out the cross grain scratches on the rails of each door with my random orbit and then send them off to be finished. I am always amazed at how long the sandpaper lasts--many times longer than the paper on my random orbit or handheld belt sanders.
Yes, I find mine user-friendly. The rolled sandpaper is attached to the drum with velcro and is wrapped on in a spiral pattern. The ends are cut on a taper and are taped down with 3/4" fiberglass tape. Changing the paper on both drums takes maybe 10-20 minutes.
If you have good operators or you're only doing solid wood, this isn't the biggest concern. But a wide belt is responsible for the quality and the timeframe without any operator intervention, while a stroke still needs a guy to work it in a timeframe and to a certain quality. The 24" Grizzly is kind of on its own, as well.
It's like the analogy between a jointer and a planer. The jointer needs a guy to hold it straight and make sure the bow is up, it's going in the right direction and it isn't tilted. The planer needs a thickness setting and it's finished and propels itself through the machine in a certain timeframe at a certain quality.
On the wide belt, we usually do a 3 grit process, 60,100,150. Coarse, medium, fine. It takes less than a minute to change paper on a wide belt, so for a real small shop, a single head will work fine. You need about 1 hp per inch of width for a contact drum on the wide belt. The platens on the cheap single-head machine help, but they have considerable limitations.
You will still need to orbit after the wide belt. Cross grain scratches take more effort to get out than you'd think. The stroke sander offers a lot of control, faster stock removal than you would think and, hence, operator judgement. It's also a lot faster than an orbital, but there's that cross grain thing again on frames. That's where the orbital shines.
Comment from contributor B:
I have had great luck with a semi-automatic stroke sander like the old Curtis hydro-stroke machine. It removes material fast and with a half decent operator it does a great job with small horsepower requirement. This type of machine will sand wider material like a 60" table top. The main limitation is really long material as the table length is only 8'.
I also have 24 widebelt time saver and 37 x 103 Cemco widebelt sander. They all have their pros and cons. The stroke sander is by far the most versatile and you do have to learn to dance with it. Some never get it. It also takes up the biggest footprint. Used old ones in my option are dirt cheap. You can sand 1/32 to / 3 feet thick /width endless length depends on machine. You can made odd shapes and curves however it is not a thickness sander. You need to control that. Some have a bar that really helps with that
My 24 time saver will sand to thickness as its a single head. Between the single roller and the seam in the belts it leaves little sanding dents. My 37x103 has a 5 wide graphite covered platem so I just lower that a few 1000s on the last one or two passes almost perfect. The 103 length of the belt makes them run cooler and last forever.