Construction Boring Machines: Top Versus Bottom

Considering the pros and cons of boring from the top or the bottom. November 15, 2011

I'm in the market for a new horizontal/vertical construction boring machine, and am weighing options. My preferences is to either bore vertically from the top or bottom. What are the advantages of each? My current machine bores vertically from the top and the problem is worn quick change (insert and twist) collets often drop their holder and bit when the machine stops. It seems gravity would eliminate that on a bottom that issue.

What's the preference on brand? I'm leaning toward Ayen or Gannomat as those seem to be the two top rated machine brands. Any advantage of one over the other? Any particular model to look for or avoid? Use will be initially for confirmat but I may pursue dowel at a later time.

Forum Responses
(Cabinetmaking Forum)
From contributor L:
I've had (in the past) a drill from bottom machine, advantage - dust falls clear, disadvantage - once in a rare while it would have been nice to see the drill point during setup. Side note on later using the machine for doweling - this would imply using a hand held dowel inserter or doing it totally by hand. Neither are good options if you do much of it. For doweling you'd want a machine that drills, injects the glue and drives all the dowels in one shot. Then you'd want a case clamp to be able to fully seat the dowels quickly. I don't know what your anticipated volume or product is but confirmats work well until you can justify more automated equipment. We went to doweling using a CNC bore and insert machine because we do a lot of odd sized items. For kitchen cabinets the machines with fixed, multiple inserters seem like a better deal.

From contributor B:
Have you considered a CNC boring machine? We went from a Ganonmat tilting machine to a Accusystems vertical and horizontal machine with dowel insertion and it changed the whole shop. Very accurate, very fast, and very flexible.

From the original questioner:
About 95% of my business is custom residential frameless kitchens, baths, and entertainment centers. I currently do confirmat off a Striebig vertical and an older HolzHer 19 spindle horz/vert. I averaged 2-2500 sqft houses a month but have a larger, 13,000 sqft projects on the books. I just completed an 8000 sqft project. It seems the larger projects are becoming the norm in the new economy. Also labor is increasingly hard to come by. Is there a recommended model on the Gannomat? I am looking at either a Gannomat Mentor (6k) or a Gannomat Combi 110 (4k).

From contributor L:
One of my depth stops is set so that the tips of the drills just touch/mark the panel so that I can check my setups. End drilling is always done with the outside of the box/panel against the table to insure that the holes are an equal distance (drill head to table distance) from the outside of the box regardless of variations in material thickness, i.e. it doesn't matter if the face drilling is done from the top or bottom.

Any properly designed fences/stops will insure that the joints always line up. I don't know either machine so I cannot comment. Assuming both are well designed, the only advantage of face drilling from the top is both face and end drilling are done with the outside of the box/panels against the table. I much prefer the tidiness of drilling from the bottom. I even bought a prototype hinge boring machine that drills from the bottom - a great idea, but poorly designed and I haven't had time to work on it.

From contributor O:
I have operated four Ayen OSB23's of the years and they have all been fantastic machines. They are extremely accurate and very reliable. I currently own two of my own for which I mainly use for drilling 16mm holes for Entry Door construction. I have run eight 16mm drills with no problems on these things - they are very powerful. I do know that a lot of guys have had problems with the pneumatic systems, but usually it's from sawdust or trash that finds its way through the system. That’s when you have to dismantle a valve assembly or two till you find the problem.