The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: tafollaj on February 27, 2024, 07:40:09 PM

Title: Advice on motor size for relatively portable 4-axis cnc for mortise and tenon.
Post by: tafollaj on February 27, 2024, 07:40:09 PM
Hello again everyone. I am about 70% of the way to completing an office/studio I posted about 2 months ago, and given the amount of labor and pain involved in timber framing, I am brainstorming how to build a relatively portable 4-axis cnc to take care of most of the mortise and tenon tasks involved. I'm envisioning a machine I could clamp to the timber and let it run. If anyone here has experience with cnc routers, maybe you could advise on the minimum size of motor for the spindle head that would allow for a decent cutting speed without being too heavy. I was thinking 2kw minimum, but I just started researching. I'm willing to let it cut slowly, since it takes quite some time by hand, but I've never used a cnc router so I don't really know what kind of speeds and cuts those are capable of. Just thought I'd ask since there are so many knowledgeable individuals in this forum and maybe someone has even gone down this path before. Thanks!
Title: Re: Advice on motor size for relatively portable 4-axis cnc for mortise and tenon.
Post by: beenthere on February 27, 2024, 07:50:12 PM
tafollaj

I've been watching some videos from this youtuber who is using his CNC to make timber framing for resurrecting a circular sawmill. You may get some pointers from his videos.

https://www.youtube.com/watch?v=1q921vcw25s

Welcome to the Forestry Forum.
Title: Re: Advice on motor size for relatively portable 4-axis cnc for mortise and tenon.
Post by: Larry on February 27, 2024, 09:38:50 PM
KW prompts the question as to where do you call home?

I cut a lot of mortise's for furniture using a router. I have a 1.4 kw Festool which isn't enough power for production with a 1/2" upcut bit. My 2.2 kw Dewalt is quite fast using a 3/4" upcut bit. A mortise 2-1/2" deep takes maybe 20 seconds.
(https://forestryforum.com/gallery/albums/userpics/10125/IMG_3913.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=352712)
Can't really help on the tenon part. Could you use loose tenons? If that is possible I would forget the CNC idea.
Title: Re: Advice on motor size for relatively portable 4-axis cnc for mortise and tenon.
Post by: tafollaj on February 27, 2024, 11:13:15 PM
Thanks beenthere, I'll see what I can gather from his setup. 
Larry, I'm in California, but all the spindles I've seen so far are either made in Taiwan or China, so kW is how they're rated, rather than hp. I was thinking a 4 axis cnc because i could cut all the angles I need in one go, but seeing your setup I suppose I could just use my current cnc mill and manual lathe to design and cut some sturdy mechanisms to use a router manually and precisely at a variety of angles. That would save me the expense of the stepper motors and ballscrews. What's the longest upcut bit you've used on that router? do you think it could handle 4" long cut length? 
Title: Re: Advice on motor size for relatively portable 4-axis cnc for mortise and tenon.
Post by: Larry on February 28, 2024, 09:15:18 PM
I do use 1/2" X 4" bits in the routers sometimes. Actual router bits that long are hard to come by so I use 2 flute HSS end mills intended for metal. They cut just fine but don't last near as long as carbide.
Title: Re: Advice on motor size for relatively portable 4-axis cnc for mortise and tenon.
Post by: tafollaj on February 29, 2024, 10:32:48 PM
Thanks Larry, I think I may try that first, unless I really want to punish myself and build the cnc.