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Double vs Triple Head Sander2/5
We are a mostly face frame cabinet shop and we also build most of our own doors. We have always used single head sanders. Now we have a 53" Butfering. We are thinking about upgrading to a double head or triple head. I wanted to see what others thoughts were on a double head vs a triple head and if it is worth the extra money for the triple head.
If you can afford the up front costs of the triple head, have the space to place it, and the power to run it, go with the triple head.
I have a two head 43" Apex, and I really wish I could've gotten a three head when I got it. I maxed out what I could afford, it took up too much space in my old shop, and I had to trench in another service. A three head was completely out of the question.
My problem with the two head is I'm pushing it too hard. I'm taking almost .030" off each face using 120 grit on the first drum head, and 180 grit on the combo head. Taking 13/16" material down to .760" for doors and face frames.
My belts don't last very long.
I could make two passes and swap to courser belts for a first pass per face, but the belts are cheaper than paying somebody to feed and tail it.
I would likely triple my belt life or better if I had another head with 80 grit to start out with.
The third head is free in the long run. It will pay for the machine in belt consumption in the life of the machine.
My favorite set up for a small cabinet shop is Drum, Drum, combination head. This is 4 contact points as long as you buy a machine that allows the use of both the drum and platen in the combi head at the same time.
Paper 80 AO, 120 AO, 180 AO is a great sequence.
Be sure to look for machines with dead shafts and air exclusion on all drums and platen.
120 - 180 can remove 0.014" in a pass without damaging your belts, your machine, and the color quality of your parts. An extra 15 minutes to run a first pass with 80 grit on the wide belt can save hours and hours on the hand sanding table with a proper set up.
Feel free to contact me for more information.
We went from a 2 head to a 3 head and it has been a good move. No belt changes now. Our belt sequence is 120 cloth, 180, and 220 paper on a combo head removing .020 per pass. We used to use 120,150,180. We have much less random orbit sanding with our current setup and belt life is better than the 2 head used to be. While we don't seem to need 80 grit, I agree with Adam that an extra pass is better than pushing the machine hard.
80, 120, 180 can last many times longer.
The max for 120, 150, 180 is .020".
If you use 80, 120, 180 it can remove up to .036". You are no longer maxing out the sequence taking your average pass, your hand sanding will be less, and your abrasive life will triple. Your color consistency will be much better. Assuming a drum, drum, combi.
There are articles explaining the reasoning on surfprepsanding.com
Adam - I'm thinking about making this move also. Which brands/models of machines have the specs you recommend?
I cannot express a preference in my position with SurfPrep as a technician.
I can say that dead shaft drums are superior.
Air exclusion on each head is another very important feature.
Drum, drum, combi-head is a nearly perfect configuration. A certain company sells a combi-head that cannot be used as a drum platen at the same time. Only one or the other. Don't buy that. It's silly......
You can email me at Adam @ SurfPrep sanding. com. I left the spaces to avoid spammers.
What does "dead shaft drum" mean? I've never heard that term...
In a live shaft drum the journals are welded into plates on both ends of the drum. The spin inside bearings on both ends.
A dead shaft is one that does not spin. The bearings are mounted on the shaft and the drum spins around the shaft that extends all the way through the drum.
Thanks for the clarification. I'll have look at my sander to see how it's set up...
While shopping don't forget the power needed to run a three head or the dust requirement. If you are short on dist collection "bad things" happen.
I 110% agree with Adam in that the third head is free.
Less belt changes, less handling & better quality make this one of the easiest justifications in the cabinet industry. Good luck!
I would like a 3rd head, but we are able to do a 120 / 180 with 3 contact points on our double head. Only remove 0.018 to 0.020" per pass, and do one pass per side.
The max removal for 120 grit is 0.010" and 180 is 0.004".
When you max out your grit sequence it causes compression of the surface that will lead to color inconsistency and increased hand sanding, not to mention short abrasive life. It's not a good deal in the grand scheme.
If your heads have air exclusion the best set up is to use an 80 grit to flatten the surface using only the first drum. Then switch to 120, 180 for a finish pass. With proper set up it is not uncommon to sand 5,000 to 10,000 pcs on a set of belts.
If you don't have air exclusion then I'll do the set up with 80, 120 using only the drums, pull the platen. Then I would pop the platen back in and run just the last head with both drum and platen with 180.
This will have very similar results and abrasive life and great color consistency. The resulting scratch is beautiful and melts like butter under the random orbital with a 150 or 180 disk.
Ah, I was thinking 0.004" for the drum + 0.004" for the platen bar. Is it 0.004" total max for the two contact points?
Thank you again Adam for your response to my posts as well.
Yesterday was our first real day of a full shift on the 3 head sander - Steel Drum, Rubber Drum, Platen
80 grit, 120, 180
removing .012 .080 .040
running at 25 ft per minute (hard maple rips)
What a difference compared to our 2-head machine - which ended up mostly being used as a 1 head (since it was a drum, platen, which was a real waste of a second head).
I would go with a 3-head - you can pick up a good used one for $10Kish
I would do .003" on the drum and .001" on the platen. Much better graphite longevity.
is there a lineal foot number you could approximate for belt life (assuming you're running your sander correctly)? we have a two head machine that we run 80g and 120g belts in. we're typically removing .010-.015" on the 80g and only use the 120g on the final pass (it is already set up lower than the 80g to remove those scratches).
we sand a lot of table tops and i'm curious about what we should expect from our belts. one thing that might be different is that we're grinding away a lot of glue as our two head is our primary/only way to level our glue ups. how much would sanding dried glue affect our belts?
right now, we're getting about a month out of our 80g belt. i'm not really sure how many lf this equals, but would guess we're getting 3000-4000 lf out of an 80g belt.
Why is a dead shaft better? Does it run truer?
Much more ridged. Easier to set up for air exclusion.
Adam, Could you email me? I think that mine may be getting stuck in your spam filter... jr at harmonic design works dot com