mortar bed

[Zulu]

I pulled this picture from a thread by Mike and Tracy.
Note the patterned edges of the bed.  If small enough, this could be accomplished with a router and beading bit.  How is it done if the bed gets too large for a router bit?  Is it carved?
Zulu
 

[Cannoneer]

Zulu,

If you're asking about the originals, I believe a moulding plane would have been used.

[Zulu]

Cannoneer,
I am asking about the originals.  But I would like to know how to do it myself.  Even something as small as a 7/8" roundover bit is a hundred dollars.
Zulu

[Ex 49'er]

Zulu have you seen these router bits from MLCS: http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_round_over.html
 
I don't know what the quality is; but, they are cheaper than $100.

[gunsonwheels]

So are you offering to return someone a nice hardwood bed in exchange for their sending you the bit?
 
GOW

[rampa room artillery]

I dont know about originals but i have seen them done in full scale a few ways,  with a bridgeport milling machine,  and onther way is a table saw and a hand plane. thats the way i plan to do mine.


   rick bryan

[ironball]

It looks like a fairly tedious job with hand tools. Plus, your are planing across the end grain.
 
That's why I'm going with a Confederate style base.

[Max Caliber]

Zulu,
 
As Cannoneer said, they would have used molding planes. If you could lay your hands on an old Stanley number 45 plane with blades you could probably do the job with two blades. Since you would be cutting across grain you would need to tightly clamp an extra board on each side to prevent chipping the edges of the bed.  I like to use the old hand tools whenever possible.

[lendi]

zulu,

i would lay out the pattern on each side.  cut the straight cuts with the table saw.  next i would remove as much of the waste as possible than with a back saw cut a series of kerfs to the pattern.  remove the material with a chisel and finish with a pattern makers rasp, files and abrasive paper.  a bit time consuming but than working with hand tools is fun.

lendi

[GGaskill]

For this half scale one I did, I cut the vertical parts with a table saw and 45° chamfered the middle of the curve, then attacked the remnants with a belt sander.  Kinda looks like I should have sanded a little more on the right hand curve.

There are three documented styles of US Coehorn bed; one like this, one with plain rounded over corners and one with 45° chamfered corners.

[Double D]

Taking a bit from what every one else is suggesting, would this work?



Cut away the two flat sections leaving a smaller square cornered section. 

Remove the bearing from router bit and and with a guide clamped across the work cut the radius.

I have limited skills as a metal butcher, and virtually no wood butcher skills so I do not know if this is feasible.

 

[irishman]

It will work Douglas and not as labor intense as one would think. There is something spiritual about freehanding.
 
                                   Michael

[seacoastartillery]

     Hope I don't sound like a nag on my suggestion for this and hundreds of other jobs, but there is a two word answer here:  Bandsaw.
Gentlemen, a vertical bandsaw will allow you to cut this shape entirely, accurately and quickly.  This whole job can be easily accomplished in one hour including the layout, the cutting and the sanding.  Once again, our bandsaw has been used several times per week, every week for 32 years.  Delta 14" Vertical Bandsaws are featured on fleabay all the time. Usually they go for around 400 to 600 dollars.  I saw one recently for 450 in great condition which is exactly half of what we paid 32 years ago!  With 3 speeds, you can cut wood or steel.

Just a suggestion,

Tracy

[Zulu]

Tracy, The bandsaw crossed my mind.  I have not tried a 7/8" radius with my 1/4" blade so I don't know if it will cut tight enough.  Might have to get a smaller blade.
 
GOW,
I'm not thinking along those lines yet.
 
Irishman,
Hand work is spiritual.  Its also expensive.
 
Thanks for all the suggestions.
Zulu

[gunsonwheels]

And don't forget the bandsaw with the belt sanding band and attachment is perfect to finish that radius right down to its inside corners...
 
GOW

[GGaskill]

My Delta's throat isn't big enough for a half scale but a three tenths scale one would fit easily.

[intoodeep]

Taking a bit from what every one else is suggesting, would this work?



Cut away the two flat sections leaving a smaller square cornered section. 

Remove the bearing from router bit and and with a guide clamped across the work cut the radius.

I have limited skills as a metal butcher, and virtually no wood butcher skills so I do not know if this is feasible.

 DD,

  Yes, that will work. That's exactly what I did with two of my mortars. I have also used the band saw (little 10" in the ghetto garage)  to cut cut the radius on the individual slates before laminating them together then a final sand on them (see below).

[Double D]

     Hope I don't sound like a nag on my suggestion for this and hundreds of other jobs, but there is a two word answer here:  Bandsaw.
Gentlemen, a vertical bandsaw will allow you to cut this shape entirely, accurately and quickly.  This whole job can be easily accomplished in one hour including the layout, the cutting and the sanding.  Once again, our bandsaw has been used several times per week, every week for 32 years.  Delta 14" Vertical Bandsaws are featured on fleabay all the time. Usually they go for around 400 to 600 dollars.  I saw one recently for 450 in great condition which is exactly half of what we paid 32 years ago!  With 3 speeds, you can cut wood or steel.

Just a suggestion,

Tracy

What model is your saw.  At what rpms does it cut? 

[Cannonmaker]

A Bandsaw is what I use on the 24 pound Coehorn then finish with a small  sander. I use a 3/8 blade to make the cuts and also trim the ends also.  If you have a bandsaw that don't go up the needed 7-1/2" for a half scale then remember that the organial beds were in two pieces. Cutting two seperate and matching pieces for the bed will take more fileing and sanding to make a good mate on the two pieces,

[Zulu]

     Hope I don't sound like a nag on my suggestion for this and hundreds of other jobs, but there is a two word answer here:  Bandsaw.
Gentlemen, a vertical bandsaw will allow you to cut this shape entirely, accurately and quickly.  This whole job can be easily accomplished in one hour including the layout, the cutting and the sanding.  Once again, our bandsaw has been used several times per week, every week for 32 years.  Delta 14" Vertical Bandsaws are featured on fleabay all the time. Usually they go for around 400 to 600 dollars.  I saw one recently for 450 in great condition which is exactly half of what we paid 32 years ago!  With 3 speeds, you can cut wood or steel.

Just a suggestion,

Tracy

What model is your saw.  At what rpms does it cut?

DD,
If this question was directed at me, my band saw is a 14" Craftsman.  I have had it about 14 years and it has done well and paid for itself 20 times over.
I have no idea what the RPM is.
 
Cannonmaker,
I think the band saw idea is the best idea for larger projects.  I am concerned about a smaller model with a 7/8" or 3/4" radius.  That's pretty tight for a band saw.  But I admit I haven't tried it yet.
Zulu
Zulu

[jamesfrom180]

Though like DD I am more of a metal hack, I have some experience in wood.  My parents house is done Taos style and has corbel features and was framed with PT telephone poles.  Lets just say I have become proficient with a chain saw and cutting and sanding. 

http://en.wikipedia.org/wiki/Corbel

The procedure was to start with a timber usually 2x10 or 3x12 dimensional not nominal, and work the shape.  Contractor first tried roughing out the shape with a marine band saw but burned two blades.  Next they let me loose at 16 years old with a recip saw and belt sander.  By the end of it I found using a chain saw and kerf cuts I could attain a pretty good rough and with a sharp chisel finished it with a 10 inch 3/4 horsepower disk grinder and final with a belt sander.  Most of the shapes were both internal and external radius.  Best advice would be to sand the last 1/4 inch down to shape.  I would use a large marker and "leave the mark" on the tracing. 

Picture is not my work but a fair approximation of my results. 

[Zulu]

Though like DD I am more of a metal hack, I have some experience in wood.  My parents house is done Taos style and has corbel features and was framed with PT telephone poles.  Lets just say I have become proficient with a chain saw and cutting and sanding. 

http://en.wikipedia.org/wiki/Corbel

The procedure was to start with a timber usually 2x10 or 3x12 dimensional not nominal, and work the shape.  Contractor first tried roughing out the shape with a marine band saw but burned two blades.  Next they let me loose at 16 years old with a recip saw and belt sander.  By the end of it I found using a chain saw and kerf cuts I could attain a pretty good rough and with a sharp chisel finished it with a 10 inch 3/4 horsepower disk grinder and final with a belt sander.  Most of the shapes were both internal and external radius.  Best advice would be to sand the last 1/4 inch down to shape.  I would use a large marker and "leave the mark" on the tracing. 

Picture is not my work but a fair approximation of my results.

I have done hundreds of corbels and brackets out of 4" X 8" material.  That's how my band saw paid for itself.
Are you telling me I need to cut a 3/4" radius with a chain saw?    Probably won't try that.
Zulu

[seacoastartillery]

     Hope I don't sound like a nag on my suggestion for this and hundreds of other jobs, but there is a two word answer here:  Bandsaw.
Gentlemen, a vertical bandsaw will allow you to cut this shape entirely, accurately and quickly.  This whole job can be easily accomplished in one hour including the layout, the cutting and the sanding.  Once again, our bandsaw has been used several times per week, every week for 32 years.  Delta 14" Vertical Bandsaws are featured on fleabay all the time. Usually they go for around 400 to 600 dollars.  I saw one recently for 450 in great condition which is exactly half of what we paid 32 years ago!  With 3 speeds, you can cut wood or steel.

Just a suggestion,

Tracy

What model is your saw.  At what rpms does it cut?

    DD,    The metal tag with the model # on it was scraped off years ago, but it is the Delta model with the oil bath 4 speed geared transmission in the base.  The speeds are NOT in RPMs, but in far more usefull SFM (Surface Feet /Minute) which is what is specified in all the woodworking or metal machining books.  The speeds are 35, 60, 100, 300 for all types of metal and with a pulley change you can get a 3,000 SFM for wood cutting.   We used it for both metal and wood until we bought a 20" triple wheel, INCA, Wood Cutting bandsaw about 28 years ago.  We have left it on the 100 SFM speed for a long, long time as we cut steel 99% of the time.

[Double D]

Thanks Tracy.

[jamesfrom180]

Nope not everyone is dumb enough to try. Was saying rough it out and let the wood speak to you.  You sir are more than capable of "freeing the sculpture from the block of wood".

[little seacoast]

If you have access to a 1.25" spindle shaper, I can lend you a cutter to cut that in one pass. A bandsaw with 1/16 or 1/8" blade and plenty of tension will make the cuts easily too. Added a 12" riser block and a 1HP to the Delta years ago and it works great on thick stuff.

[Zulu]

If you have access to a 1.25" spindle shaper, I can lend you a cutter to cut that in one pass. A bandsaw with 1/16 or 1/8" blade and plenty of tension will make the cuts easily too. Added a 12" riser block and a 1HP to the Delta years ago and it works great on thick stuff.

I don't even know what a spindle shaper is.
I think the band saw with a 1/8" blade is the answer.
Zulu

[little seacoast]

Think of a 600lb cabinet mounted router with cast iron tables and interchangable spindles that has power feed and variable rotation and speed.  What can I say, I like toys.