About these ads

Chevy – Nearing the finish line

I had a good couple of hours in the shop yesterday and nearly finished the seat assembly for the Chevalet.

In my previous post I was on the fence about whether to use hand or poser tools for the joinery.  This is not a philosophical debate for me, it’s more about pragmatics.  What approach is going to get the job done most efficiently with the best result?  For example, on tenons I’ve done bunches of them using a dado stack on my table saw with the tenon face horizontal.  The fence controls the height of the tenon and the blade height controls the depth.  With a bit of scrap wood I can dial the tenons in to a very precise measurement.  The downside is that I have to change over to the dado set and set up for each unique tenon face.

In a similar way, my mortiser is very handy and I love it.  But changing over to a different chisel requires a bit of setting up and making test cuts to ensure it’s cutting parallel to the fence.  I’m also not 100% happy with the finish on the mortise walls (I recently read about some tune up procedures that are supposed to help with that, something to do on a rainy ray this winter!)

So I decided to use as many hand tools as I could yesterday.

First the mortises, I had two blind mortises and two through mortises to do.  They are large enough that I didn’t want to try to chop them alone, so I drilled out the bulk of the waste and pared the remaining material in little bits until I got to the wall.  For mortises up to probably 1/2″ wide I’d probably have just chopped them directly, but the smallest of these was 1″ wide.

This is the blind mortise for the toggle arm that actuates the clamp.  The clamp assembly is bolted from below.  I used a 1" bit to clear most of the material, being careful to hit the same depth each time.

This is the blind mortise for the toggle arm that actuates the clamp. The clamp assembly is bolted from below. I used a 1″ bit to clear most of the material, being careful to hit the same depth each time.

After paring the waste back to 1/16″ or less from the walls I set the chisel in the knife lines and chopped straight down.  I’m really pleased with the results, it took very little time and didn’t require any special jigs or tools.  I know there was a stage where I would have done this by making a jig and using a router, which would have been time consuming and noisy.  And I’d still have to square the corners.

Nice looking mortise, if I say so myself!

Nice looking mortise, if I say so myself!

What makes this work for me is taking small bites with the chisel, and having the work oriented so I’m always looking at the side of the chisel to ensure it’s plumb.  I work my way around the mortise nibbling away until I’m about 1/32″ to 1/16″ from my knife lines everywhere.  Taking small cuts is more controllable and easier to keep the chisel vertical.  I never let the walls get out of control.

Small cuts are the key, this is typical of what I'm pulling off the walls.

Small cuts are the key, this is typical of what I’m pulling off the walls.

On the through mortises I followed the same approach.  I knifed in the layout on both sides as accurately as I could, drilled though to remove the waste, and pared back to the line evenly before cutting directly on the knife line.  The only difference was that I worked from both sides towards the middle of the board.  I got one side to within 1/32 of the line, flipped it over and did the same on the reverse.  Finally I dropped the chisel in the knife line and finished it from both sides.  There is a tiny bit of unevenness in the middle (the board is 1.75″ thick), but it’s tiny and won’t affect the fit or strength in any significant way.  Again, happy, happy.

Through mortises on the bottoms of the legs

Through mortises on the bottoms of the legs

I mentioned yesterday that there was a problem with the big dovetail joint not reaching the surface of the seat.  Sure enough, when I measured the seat blank I discovered that I’d left it over-thick.  It was supposed to be 1.75″, but I’d left it at something like 1.860″.  Before I could thickness it to correct that I had to finish with my layout lines on the top, so I cut out the profile, rough cutting it on the bandsaw and finishing the radius with my spokeshave.  I used a rasp and scraper on the front transition sections.

Seat base shaped, the top edge will get a generous rounder later.

Seat base shaped, the top edge will get a generous round over later.

Which just left the tenons and maybe a few details.  I wanted to cut the tenons my hand, but you’ll recall the problem I was having with my Bad Axe tenon saw (the saw plate was getting floppy in the cut).  Mark at Bad Axe said that can happen if the saw gets torqued in a difficult cut, and that his use of a folded back on the saw is an advantage.  Here is something I didn’t know: on saws with folded backs the blade doesn’t seat all the way to the depth of the back.  The back only grips 3/16″ to 1/4″ of the saw plate.  You can read his re-tensioning procedure on his web site,

The gist of “re-tensioning” is to tap the saw plate a tiny bit further into the folded back at both the heel and toe.  Honestly, any problem I can solve by whacking it with a great huge hammer, I’m all for.  So two taps of the hammer later and my tenon saw is magically healed.  Who knew?

So I laid out the first tenon, that goes into the seat bottom and checked it against the mortise.  Thank God, because I mad my mortise gauge set to the wrong dimension.  Take two; I laid out the tenon.  Again.

I sawed the tenon down to the shoulder lines.  I think the tenon saw is a little coarse for shat I’m doing, or maybe I’m just not used to it.  I need a bigger handle too (or smaller hands), this one pinches my hands.  On one of the tenon edges I angled waaaaay off the mark, likely it was into the waste.  I pared the mistake away and then planed the tenon faces to fit.  I intentionally cut the tenon oversize to give myself room to screw up.  I sawed the shoulders on my knife line without cutting a “V” like I usually do, and was left with a whisper of excess all around that I could chisel away,  I ended up with a snug fit and a decent shoulder in the one place on the project that no one will ever see!  Two more tenons and a couple of holes to go and the seat will be done.  I’d better start on the CAD layout for the toggle arm and foot clamp mechanism.

One tenon done, two to go.

One tenon done, two to go.

About these ads
Categories: Uncategorized | Tags: | 3 Comments

First seat joint done

It doesn’t seem like much of an accomplishment, but I got the dovetail joint for the seat cut and fit yesterday afternoon.

I spent some time sawing practice joints first on a tick scrap of Sapele.  My LN dovetail saw didn’t quite reach deep enough, and it was a lot of sawing — but the cut was crisp and arrow straight.  I decided on using my nearly-new Bad Axe 16″ tenon saw and made a bunch of practice cuts to get my arm tuned up.

Practice cuts.  The micro-thin cut labeled "DT" was done with my LN dovetail saw.  The cut on the far right was done with the sun in my eyes and is nowhere near the pencil line.  I probably made 15 or 20 warmup cuts before I cut the actual joint

Practice cuts. The micro-thin cut labeled “DT” was done with my LN dovetail saw. The cut on the far right was done with the sun in my eyes and is nowhere near the pencil line. I probably made 15 or 20 warmup cuts before I cut the actual joint

While I was sawing the cuts I noticed that the saw seemed to want to wobble in the kerf.  When I checked the saw the plate was “loose” or “floppy” along the toothline.  Not good.  I set it aside while I laid out more practice lines, and then noticed that the wobble was gone.  Almost like it was heat related.  I made another cut and it came back.  Crud.  I bought this saw a couple of years ago, but I’ve hardly used it at all.  I emailed Mark at Bad Axe and he suggested that the saw plate needed to be reseated in the folded back, so I’m going to try that today.

Beautiful saw, hopefully Mark's retensioning (http://www.badaxetoolworks.com/retension-a-backsaw.php) advice will resolve the issue.

Beautiful saw, hopefully Mark’s retensioning (http://www.badaxetoolworks.com/retension-a-backsaw.php) advice will resolve the issue.

I sawed out the tails and checked them for accuracy.  There were a few spots where they weren’t flat and a couple of areas where they were slightly out of square with the face of the board.  I pared out all of the problem spots and jury rigged this setup to transfer the tail layout.

Transfering the tail layout to the pin board

Transfering the tail layout to the pin board

If you are particularly observant you’ll have noticed the scraper between the end of the tail board and the plywood alignment stop.  Somehow I had the baseline for the dovetails about 1/16″ too shallow.  That means the end of the tails won’t reach the face of the seat.  Not a structural problem, but a little annoying.  I’ll have to check the thickness of the seat, maybe I didn’t finish it to the right thickness, that would be an easy fix.

I sawed and chopped out the pins, and got the joint mostly fit up in time for dinner.  There is a little tweaking left as one side isn’t seating completely yet.  I’ll deal with that after I get some coffee.

The beginnings of the seat

The beginnings of the seat

The rest of the joinery on the seat should go more quickly.  I’m on the fence about whether to do the work by hand or use power tools.  I’m leaning towards hand tools, if I can re-tension the saw plate on my tenon saw I can practice sawing the tenons, and if they are not perfect it isn’t a huge deal as I haven’t yet convinced my wife to put the Chevy in the living room.  We’ll see.

 

Categories: Uncategorized | 4 Comments

Shop Update

I plan to make a dent in building the seat for the Chevy today, but first I had a few details to wrap up.

Last year I got a set of Lie-Nielsen bevel edge chisels for Christmas.  I picked out the 3 or 4 chisels I needed most, flattened and polished the backs and sharpened them.  That left a lot of chisels standing in the wings, I finally decided to flatten the backs on all of them, re-doing the ones I’d previously done too as I wasn’t happy with the job I’d done.  I finished flattening and sharpening them this morning, and I’m very glad to be done with that than-you-very-much!

A few thoughts stand out in my mind.  The most obvious is that if I never have to flatten another chisel or plane blade that would be OK.  Second, the world needs a good sharpening jig.  I have the Veritas Mark II and the Eclipse.  Suffice it to say that neither is what I would call a good sharpening jig.

While I’m thinking about it, Jonathan at The Bench Blog asked about the London pattern handled chisel in the background of a recent post, so here are a couple of pics.  It’s a big chisel, but frail thin.  The blade tapers in thickness from maybe 5/16″ thick near the handle to 1/8″ at the start of the bevel.  The bevel is a very low angle, and when I sharpen it I put I higher secondary bevel on it.  The back could be flatter, but that’s a flattening session I’m not ready for.

Sorby Paring Chisel

I. Sorby Paring Chisel

Close up of the name stamp on the blade

Close up of the name stamp on the blade

Close up of the nifty London-pattern handle

Close up of the nifty London-pattern handle

In other news, I wrapped up the last details on the saw frame, I feel pretty good about it.  I tuned up all of the surfaces with a plane, followed by scraping.  I also added a cove detail on the two outer corners.  And I made and glued in the blocks that clamp onto the gimbal mechanism.  I got a nice snug fit on the mortises, so with a little glue this should be plenty strong.  I’ll give it a light sanding after I take the clamps off later and set it aside with the other finished parts.

Cleaning up the surfaces on the saw frame

Cleaning up the surfaces on the saw frame

Screen Shot 2014-11-15 at 12.19.21 PM

Gimbal blocks glued into mortises (the extra cross brace is just for clamping).  The cove on the outer corners of the frame is done too.

Gimbal blocks glued into mortises (the extra cross brace is just for clamping). The cove on the outer corners of the frame is done too.

Which brings me to sawing the giant dovetail at the front of the seat assembly.  I decided to make some practice cuts in an off cut and there are a couple of issues.  First, my dovetail saw doesn’t have the depth to go to the bottom, it’s at least 3/32″ short.  The blade is also a little fine for a 1.75″ thick rip cut.  I can use my tenon saw, but it’s coarser than I’d like for a dovetail.  I think I can make either work though.

I saw “I think”, because I can’t actually see what I’m doing to make the cut.  The sun coming through the shop window in the mornings is really bright, and the cut line is essentially invisible.  The picture below gives you a sense of this.  So while I wait for the sun to move I’ll grab lunch and then chop some of the mortises for this assembly.

Where the heck is the line?

Where the heck is the line?

Categories: Uncategorized | 1 Comment

Benjamin Seaton Dovetail Saw

Apparently Brother Cadfael feels we need a nifty dovetail saw for our virtual dovetail toolkit too.

This is modeled on the Kenyon dovetail saw from the Seaton tool chest.  The front of the handle is different on the Seaton saw than on most of the “reproduction” Kenyon-patterned dovetail saws I’ve seen.

There are a few details I want to nudge, then I’ll make some patterns.  Just for fun, mind.

saw3

Categories: Uncategorized | Leave a comment

Cadfael: Dovetail Chisel

Brother Cadfael has been distracted lately with thoughts of participating in the ongoing Dovetail Tool Swap on Lumberjocks.

Background: Apparently the lumberjocks community does these “swap” events a couple of times a year.  The premise is simple; you sign up to make a particular thing, you have a few months to get it done by a fixed deadline, you mail a picture to the moderator and they tell you who to send your widget to.  In return you get something back.  They recently did a saw swap, and there were some pretty nice saws built as part of that event.

I’ve never participated in one of these “swap” events, and I’m not yet participating in this one.  Yet.  Most likely.

But it’s fun to think about what I might make.  Ya know…if I was participating.  I’ve looked at more marking knives, marking gauges and dovetail saws in the past week than I have in a long time.  For fun, I thought I’d model a small chisel for chopping and paring dovetails.  It had to be something most guys could make with tools they’d have on hand — no forging or machining allowed.  It had to look good, and be able to chop as well as pare.  Here is what I came up with:

Rendering of a devetail chisel I'm not making

Rendering of a devetail chisel I’m not making

The business end is ground from a 1/4″ square O1 tool steel blank, and it’s probably the hardest part.  The handle is styled in the London pattern, but with a retaining hoop on the back.  The brass fittings are made from common brass tube and a small piece of 1/8″ sheet brass…like the one laying on the floor of my metal shop…which is just a coincidence.  I don’t have any O1 steel anywhere.  Really.

I even drew up some plans so *you* could build one.  Please build one, and send me a picture so I’m not tempted.

Click on the picture to download these plans

Click on the picture to download these plans

Categories: Uncategorized | Leave a comment

Chevy Update

I got the saw frame finished yesterday and glued up.  This was the last bit that I was worried about being able to make, mostly because of the  large finger joint between the arms and back.  The key was doing a careful layout, working from the reference face on all the parts and assembling them the same way.  Accurate sawing is important too of course, but the bandsaw fence took care of most of that.

Layout for the finger joint

Layout for the finger joint

On a related note, I have a practice project to get my hand sawing skills tuned up in this area.  I’m going to make a couple of wooden squares, but I didn’t want to make a mistake on this part.  I’d chosen the straightest quarter sawn Sapele for this part, rough dimensioned it and let it acclimate for several weeks…

Once the points were cut and fitting well I added in the details.  The arms taper in thickness from 1.125″ at the saw back to 0.5″ right before the wounded ends.  I also cut a step in the arms (in use this is where you hold the saw, not at the knob) and a curvy-swoopy thing in the back of the saw.  Is that an Astragal?  No, that’s not right.  Cyma Recta?  I think that’s it.  Or Curvy Swoopy Thing.

Dry fit of the detailed saw frame

Dry fit of the detailed saw frame

It will need the edges chamfered and a final sanding after gluing, but it’s sitting in the clamps right now.

Glued up.  I need some shorter clamps, these are a pain for small parts...

Glued up. I need some shorter clamps, these 5 footers are a pain for small parts…  The plywood in the center is to keep the arms parallel.

With the saw frame mostly done (I need to add the gimbal brackets on the back, but it’s already morticed for them), I moved on to preparing the stock for the next major subcomponent — the seat.  Once that is done I only need to make the clamp and clamp actuator and I’ll be done.

The seat parts are all 1.75″ thick.  I dimensioned the lumber, and laid out all the joinery from my drawings.  Next time I get to work in the shop I should be able to cut and fit all of this, it’s all straightforward (if large).

Parts for the seat assembly.  From the top: seat, front and rear legs, lower stretcher.

Parts for the seat assembly. From the top: seat, front and rear legs, lower stretcher.

The dovetail joint at the front of the seat / top of the front leg will easily be the biggest dovetail I’ve ever cut…

Mondo-Tails!

Mondo-Tails!

Categories: Uncategorized | Tags: | Leave a comment

Chevalet Plans Update

I’m pretty close to finishing the saw arm for the Chevalet, so I figured I’d better get the rest of the project modeled in CAD so I can sort out the joinery.  Things go much more smoothly in the shop when I can focus on doing rather than juggling dimensions in my head while I’m trying to saw of chisel.  At least for projects with this many parts.

So I pulled the major dimensions off of the blueprints from Patrick Edwards and modeled them in CAD — adjusted for the materials I’m using.

Chevalet3

CAD rendering of Chevalet — still missing the actuator for the clamp, but mostly all together.

The joinery for the “stool” portion is mortise and tenon for the stretcher and the rear leg, but the front leg connection to the seat is an odd recessed dovetail to make room for the spring arm for the rear clamp.

Dovetail joint at the front of the seat is recessed to make room for the spring arm that forms the rear of the clamp

Dovetail joint at the front of the seat is recessed to make room for the spring arm that forms the rear of the clamp

I’ll probably have another iteration of the plans later when I get to the clamp actuator, but this should keep me busy for a while.  This version of the plans can be downloaded from here.

Nearly-complete Chevalet plans.  The clamp actuator is the only significant piece missing.

Nearly-complete Chevalet plans. The clamp actuator is the only significant piece missing.

 

Categories: Uncategorized | Tags: | 3 Comments

Chevy Saw Frame

I got the joinery done on the saw frame for the Chevalet this morning.  I was worried about getting the giant finger joint to fit and be straight — it turned out to be pretty straightforward.  It’s not perfect — the shoulders could be a little tighter in a couple of spots — but it lays absolutely flat on the bench and the joint is nice and tight.

I need to do the rest of the details on it after lunch, the mortises for the brackets on the back, the mortises for the blade clamps and the shaping/tapering.

I started by laying out the joinery, and marking the waste.  I sawed the faces on the bandsaw with a fence.  It tried to be careful to account for the kerf and just remove the scribed line (from the correct side!).  Then it was chiseling out the waste and some tune up here and there.  I want to be able to do this with a hand saw, but this wasn’t the project to experiment on.

Joinery laid out

Joinery laid out

After sawing on the band saw, chopping out the waste and general clean up it all fits pretty well.

After sawing on the band saw, chopping out the waste and general clean up it all fits pretty well.

This is where I’m headed.  I need to do all of the details and glue the saw up next, that should feel pretty good.

The saw frame -- I rendered the CAD model using different materials for the arms and the back to show the joinery more clearly

The saw frame — I rendered the CAD model using different materials for the arms and the back to show the joinery more clearly

Categories: Uncategorized | Tags: | 2 Comments

Less Messy

My shop has been getting a little messy lately.  That tends to happen when I’m in the middle of a project, but also I’ve been accumulating the detritus from several completed projects.  The kicker was gluing up the blanks for the Chevalet, so I decided to get serious about improving the situation.

First I bribed my 14 year old with a new video game to do a super good dusting/sweeping.  Shameless, check.

Second I decided to make some racks for my clamps.  That took a little more doing, but not much.  Leftover scraps of plywood, metal L-brackets, and presto — no more booby traps on the floor or in the corners.  This should also make is easier to clean up.

Before.  This makes it tough to sweep up.

Before. This makes it tough to sweep up.

After

After

After

After

After

After

Categories: Uncategorized | 1 Comment

The Saw Frame

So here is the little bit of joy that is next on my hit list: the saw frame for the Chevalet.

The saw frame -- I rendered the CAD model using different materials for the arms and the back to show the joinery more clearly

The saw frame — I rendered the CAD model using different materials for the arms and the back to show the joinery more clearly

It’s not really a tough piece, but I’m worried about getting the fit of the finger joints just right.  If they are too loose it won’t be strong enough, if they aren’t straight the arm will be crooked — and useless.  Or, as we say around here, “kindling”.

I’ve updated my working copy of the plans, you’re welcome to download and follow along.  I’m just making plans to sort out the details in my head, based on the materials I have on hand.  On the saw arm, I haven’t resolved the gimbal attachment mechanism.  In the plans it’s not shown clearly, although my understanding is that it’s a weird wedged mortise and tenon construction.  I’m not sold on the idea of cutting mortises into the back of the frame, so I’m still noodling on that detail.  And of course the seat assembly and front clamp are still to be done (virtually and actually).

(incomplete) Chevalet Plans

(incomplete) Chevalet Plans

Categories: Uncategorized | Tags: | 1 Comment

Blog at WordPress.com. The Adventure Journal Theme.

Follow

Get every new post delivered to your Inbox.

Join 127 other followers