CNC Stair-Building Capabilities

A CNC can speed up complex stair-part fabrication, and also improve accuracy. September 28, 2009

I'm considering a 5 axis CNC machine for the stair shop. I've seen some videos of it carving out what appears to be 12-16" sections of twisted rail from blocks of wood. It seems slow, but I'd like to ask others who have done stairs with these machines. Do you find you've increased productivity with this machine and saved time and money vs. doing things manually... For example, ripping 1/4" strips of wood, gluing them up onto a frame (we have a standard/permanent flair stair frame), and then routing the rail with a portable profile router? How has the CNC changed your stair business?

Forum Responses
(CNC Forum)
From contributor R:
Unless you already do a bunch of this sort of work and need to improve production, a 3 axis CNC will give you many benefits for lower price and will be far easier to program and operate. I used to work for a stair company. I helped them choose a CNC, then did the programming and operation.

They were looking at buying a dedicated stringer router, but I convinced them of the value of a 3 axis CNC. It not only milled the box stringers, but also the open stringers, treads and returns, treads for stacked spirals, pyramid newel caps, and a host of other tasks. It dramatically increased their productivity, accuracy and safety. We made some creative fixtures and got really good work out of it.

From contributor B:
I have to agree that a 5 axis machine would be difficult to program, and the form tooling you would have to have made to do the shape of your rail - $500.00 for one tool. We use a 3 axis router and I have done many stair systems on it. The carpenters are very pleased when putting it together, as everything fits so nicely. We do stair systems that are completely custom. We even do the balusters unless they are round. They do save a lot of labor.

From the original questioner:
What items do you like to use the 3 axis CNC on the most? Where do you save the most labor? Is it the custom circular stuff? Can you do handrail with a twist on it at all? Can you throw out some brands to look for that would be well suited for the stair shop and possibly prices that I should expect to pay for CNC and software package? No one seems to list their prices, so the only way to find out is to ask people who've gone through with it. Your help is very appreciated by me and I'm sure others!

From contributor B:
If you are looking at 5 axis routing, your machine will cost $150,000.00 + or - The software will run you about $15,000.00 for 3D 5 axis programming. Tooling is another issue. Form tooling for doing the angled, curved railings can start at $500.00 per tool. The machines don't even come with tool holders, etc. You have to buy all that separate. I use the ER32 collets and holders and they run around $120.00 each and I have 20 of them. Some machines require their own air compressor because the one in the shop will not keep up with the CFM demand of the new machine. That's another 5,000.00 to 7,000.00. Also 3 phase power is required; if you only have 2, you have to purchase an inverter or pay the power company to run the required power. The cost of the machine will be about 25,000.00 per year in expenses, including your payments. But if you are producing stairs that run in the 100K range, you can find a profit there.

I can only do curved rails that are flat. I can also side profile surfaces with ball tools to produce crown molding and curved moulded trim with very little sanding. What I like best about the CNC router is that it can produce fancy shapes very quickly and if you have to make a lot of them, they are all identical. This makes them well suited for making cabinets, stairs, signs, puzzles. You're only limited by your own imagination and talent.

Oh, and one last thing. If you can't program and operate the machine yourself then be prepared to pay this person a tad more than you pay some of the rest. But also let them know not to discuss their pay with others. You can actually google pay rates for operators and programmers for your area. Those are mistakes I've made in the past that turned sour. Find a person with the talent you require and hang on to them.

From contributor C:
We have a 5 axis machine. We draw the stairs with our software. Once we are happy with our drawing we hit the create button. This then creates all the programs for all the parts we wish to machine, be it wreathed strings, wreathed and moulded handrails - no problem. It even creates the amounts you need to laminate for the block for carving the handrail. The machine will groove out for or bore for balustrades. It will do everything you need for making stairs.

From contributor D:
What software are you using?

From contributor C:
Compass. This is what it does:

From contributor A:
I'm also a stair builder looking to purchase a CNC for my shop. I am very impressed with that wreathed rail, contributor C. I could see my shop saving a lot of time. But I'm faced with the same situation on what machine to buy and from what company, who offers the best support, and most of all, the cost. Currently looking at the New CNC. It's priced around 32k with option for a 4th axis (can this produce wreathed rails or do I have to get a 5 axis?).

From contributor G:
We have been making handrails on a 5 axis CNC since 1990. Obviously there is a major investment required to make handrails on the CNC. A CNC allows you to create a more accurate product in considerably less time. It is possible to make almost any fitting or rail required.