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+-- Thread: Roubo Design Questions (/showthread.php?tid=7040105)
Roubo Design Questions - Jonny Rocket - 06-23-2015
So this past weekend I was stacking fresh cut lumber in the family barn and my grandfather came out to "supervise" the process. He started pointing at some wood and other things that have been in that barn since before I was born and telling me what they were and where they came from. I've honestly seen the stuff for so many years, I look right by it when I am in there.
At any rate, one of the things he pointed out were some beams, roughly 6-8" wide and 4-5" thick and longer than I could measure with a 12' tape, but I'd guess they're easily 25' in length. There were two of them and he couldn't recall if they were poplar or maple and he's not sure where they came from, but he vividly remembered trying to get them in the loft. Their length alone meant they couldn't be put up side ways had had to be slid into place.
Now, I was pretty set on making a split top roubo ala the Benchcrafted plans, but now I am thinking about those beams and wondering if a big slab top wouldn't a little more "fun" to make. My concern with the big slab is the wood movement and keeping the thing portable. I've had to move 3 times in 6 years and I'd like to be able to break the bench down if needed.
So I'm wondering if anyone has made the large slab bench and how much work was it to install the benchcreafted hardware, is wood movement a big issue (I can almost guarantee these beams are dry, but their MC is still likely 10% from just being in a barn), should I rip an edge off for the dog hole strip or just drill round holes?
Re: Roubo Design Questions - joemac - 06-23-2015
Isn't that essentially what was done last year in Georgia with timber sourced from France? If I recall Jameel, Jeff Miller, Raney, Ron Breese and others were involved in that project and Chris Schwarz?
At any rate, I believe that they are doing it again this year. Contact Jameel for more information.
Re: Roubo Design Questions - Jonny Rocket - 06-23-2015
I should remember that. I just spoke with miller about his bench. I think they used the traditional leg joint though. I'll probably stick with stub tenons so I can take the top off if needed.
Re: Roubo Design Questions - bridger - 06-23-2015
Those big beams should have very minimal movement. Being stored like that- indoor air dry for decades- should have worked out whatever stresses were in the wood as well as possible.
Re: Roubo Design Questions - DNA - 06-23-2015
I plan on using 12in wide 5in thick soft maple slabs to make my split top roubo in a few years. That wood was felled 2009, cut in 2012 and has been in my basement since 2013.
I have no doubt that the inside will still be very wet and I will have to deal with movement, but the Schwarz had the same issues and was able to overcome them.
I have not decided about laminating a square dog strip or just using round. My current bench has round but I did that just for ease of construction.
Also, if you truly want it movable, use Benchcrafted huge barrel nuts and only drawbore the end assemblies.
Good luck with your build.
D
Re: Roubo Design Questions - Guest - 06-23-2015
IIRC, Jameel made a small knock-down Roubo style bench to travel with. He uses it to display his bench hardware at the various shows. Contact him and ask him about it. He may have a write-up on it somewhere. I think it's a split-top.
Re: Roubo Design Questions - Jonny Rocket - 06-23-2015
DNA said:
I plan on using 12in wide 5in thick soft maple slabs to make my split top roubo in a few years. That wood was felled 2009, cut in 2012 and has been in my basement since 2013.
I have no doubt that the inside will still be very wet and I will have to deal with movement, but the Schwarz had the same issues and was able to overcome them.
I have not decided about laminating a square dog strip or just using round. My current bench has round but I did that just for ease of construction.
Also, if you truly want it movable, use Benchcrafted huge barrel nuts and only drawbore the end assemblies.
Good luck with your build.
D
I am far from the Schwarz. I bought the BC hardware at Handworks this year and forgot all about the barrel nuts they ran out of until about 4 days before I moved and box showed up with them. Right now I am leaning toward just boring out round holes and carving out whatever I need to do for the tail vise. If I had any guys, I'd use the sliding dovetail and tenon joint on the legs and move it around like I do the big machines, but I'd rather get to using the bench than working on it for months.
Re: Roubo Design Questions - Wilbur Pan - 06-23-2015
My Roubo’s top is made from KD Douglas fir 4x4’s, so I can’t help much with the wood movement issue, other than to say all workbench tops move.
What I can help with is that my workbench top rests on the base using double mortise and tenons. Gravity holds it in place, and I know that I can get the top off the base if I need to move the workbench.
More details here: http://giantcypress.net/tagged/roubo/chrono This used to be an epic WoodNet thread, but it fell victim to the 1 year expiration rule.
Re: Roubo Design Questions - dlgWoodWork - 06-23-2015
Jonny Rocket said:
I should remember that. I just spoke with miller about his bench. I think they used the traditional leg joint though. I'll probably stick with stub tenons so I can take the top off if needed.
I did the stub tenons to attach my top. I don't plan on taking it apart so I drawbored them, but did not use any glue. If for some reason I need to remove the top, I can still drill out the pegs and get the top off.
Re: Roubo Design Questions - Funky Space Cowboy - 06-23-2015
I have a traditional Roubo top glued up from three, 8" wide, air dried 12/4 ash beams. I've no idea what the moisture content was when I built it a few years ago or what it is now but I've had minimal movement in the top. I've had to flatten it twice in the five or six years I've had it. I'm using drawbored, stub tenons for the leg to top connection.
If it were my build, I'd go for the giant air dried slabs and not worry about it too much. The essence of the Roubo design is getting a big heavy slab of wood secured to a simple, stout base without much crap cluttering up your workholding. Any way you go about getting that setup will work just fine for years and years.
If you do stub tenons and don't glue or drawbore them I bet you'll be fine for portability without giving up enough strength to notice. You'll still have the massive top to deal with but even with the weight it should be manageable since it's a simple shape.
Good luck and keep us posted!