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Author Topic: New box joint jig by Carl Korschgen  (Read 15680 times)

Offline specialkayme

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Re: New box joint jig by Carl Korschgen
« Reply #20 on: April 18, 2013, 08:51:36 am »
I ordered the jig from Carl a few weeks ago. I had also ordered a new table saw, so I couldn't get the jig calibrated until I got the table saw fully set up and tinkered with properly (which was more difficult than originally anticipated). I finally got the jig put together and ready to go last weekend, cutting my first set of boxes last night. Here are some of my thoughts so far:

1. Some of the screws that need to be assembled, and of which are included in the kit, have square heads. I didn't have a screwdriver with a square head (only philips, flat head, and various hex wrenches). So I had to go purchase a new screwdriver, just to assemble the kit. I think it ended up being like $18 (for a screwdriver with about 20 different heads, the only one I could find that would work). Not a big deal, but a little bit inconvenient, as I doubt I'll ever use the square head screwdriver again.

2. Setting it up wasn't as easy as I thought it would be. It took some tinkering to get it all where it should be. The instructions were spot on, and I used the calibration board included with the kit to line the jig up nicely on the miter slots. Once set on the miter slots, it was difficult to secure the runners to the jig. Not a flaw in the design by any means, but it's a little difficult to look at something on the table and figure out how you are going to drill THROUGH the jig, THROUGH the runners, without moving the jig from the table (as if you move it, it may be off by a fraction of an inch). I got it all attached and ran it through the saw, but found out I was off by approx. 2 mm. I figured the runners wandered while installing, but when I double checked with the calibration board, it was spot on. So now I had to shift the runners 2 mm to the left, which wasn't too easy as holes were already drilled. So I had to drill some slots where the holes were so the runners could move from side to side, then get some larger washers to hold it in place, 2mm to the left. It all worked out in the end, but it took me some time.

3. I'm not certain, but I think the offset key is a little "off". I ran a set of boards through the saw with the offset key, and the box was shifted slightly higher on one board than the other. I flipped the joints over (to do the other end of the board) and this time used a scrap 1" piece of lumber instead of the offset key, and it lined up just right. I haven't taken the time to see whether it was human error on my part, or if the offset key is "off".

4. Personally, I think Carl needs to make a choice on whether this jig is for beekeepers or not. He told me that it is designed to be used for any type of box joint, not just for beekeepers. Which makes sense, except if you step back and think about who needs to make repetitive box joints. Jewelry box makers and beekeepers are the only two that come to mind easily. 3/4" or 1.5" box joints on a jewelry box are worthless, so I think this jig is really supposed to be used for beekeepers, at least my two cents. If that's the case, the dimensions of the box should be adjusted to fit beekeeping equipment only. Right now it's larger, to accommodate other size lumber. While I appreciate the versatility, I think it would perform a little better, and more consistent, if the dimensions of the sliding box fit two deep boxes exactly. Maybe I'm wrong though.

5. I had some difficulty with the clamp system. It's designed to house a pipe clamp on the right (through a hole), and a second to the left (lapped over the edge of the sliding box). The clamp on the right pulled the wood a little to the right when I secured it (could be my pipe clamp), and the one on the left couldn't go down far enough to stop the boards from separating a little at the bottom. I told Carl he should just put a second hole for the pipe clamp on the left where deep boxes go, a little further down. He reminded me that it wasn't just for deep boxes (or beekeeping boxes), which I think gets to my earlier point. When I had it running though, the pipe clamps went loose (the vibrations of the saw ended up loosening the clamps). It could have been with my clamps, but I ended up having some test boards become useless as they were moving around left, right, up and down in the box. I solved the problem by using two vice grip clamps.

6. I hear Carl talk about how versatile it is, but I don't see that. It's designed for a specific purpose: to make 3/4" and 1.5" box joints on one table saw. And it does that well in my opinion. But, because you calibrate it to the right blade of the dado set, and my arbor opens on the left on the table saw, if I moved to a 1/2" finger joint, or a 7/8" finger joint, I'd have to recalibrate the whole set, not just add/remove some blades/chippers and have some new flippers as Carl makes it seem. Which is just fine for me, as I don't foresee that I'll be making any 1/2" finger joints in my foreseeable future (or getting a new table saw).

7. As far as the 1.5" box joints goes, I don't see the advantage. Carl said many people like them because they require less nails for assembly, and hold the joint stronger. I disagree. It takes just as much time to cut on a table saw using this jig, so you don't save any time there. The strength of the joint has nothing to do with the face of the finger joints too. It has to do with how much side grain is secured to other side grain. In that respect, the more fingers you have the stronger the joint (all things considered equal). It's just not economical to make 1/8" fingers. You also don't have to put a nail in EVERY finger of a 3/4" box joint, if you don't want to. The nail doesn't do anything to the strength of the box, other than hold it in place long enough for the wood to dry. Two nails will usually hold it in place ok, but 5 or 6 would probably be where I'd limit it, adding in potential warpage.

In the end, I like the product. I would buy it again if I had to. I'd recommend it to others as well. But, I don't think I'd recommend it to a complete novice woodworker, and I wouldn't say that it's a "universal" jig, although when you initially set it up you can have it set for just about any size finger. Switching is the problem.

 Well, there are my thoughts. Feel free to comment yourself if you'd like.

Offline CarlinMO

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Re: New box joint jig by Carl Korschgen
« Reply #21 on: April 18, 2013, 10:58:18 am »
I really appreciate the time that specialkayme took to write this review of my product.  In a venture like this you learn from every customer.  I will address his issues point by point, not to be critical, but to be informative.

1)  I use #1 square drive trim screws to assemble the jig because lamination strength in Baltic plywood is not that strong even though the product is very stable.  Two of these screws are included to fasten the safety guard to the front of the sled.  Any type of 1 ¼”  2 cent screw could be used because lamination is not an issue at that surface.  

2) I believe specialkayme  missed an illustrated step in the setup manual.  I provide 4 machine bolts to affix the runners to the bottom of the sled.  These are mounted on the outside extensions of the bottom of the sled where everything is completely visible.  I even mark the center line of the runners.  The runners are cut a couple inches longer than necessary to bring everthing into view.  You drill a pilot hole through the 3/8” bottom of the sled into the runners.  Then you remove the runner and complete drilling the hole, countersink the bottom side for the head of the bolt, and tighten up.  If for some reason you are not satisfied, you can offset the runners and repeat the process.  You do not need to have an issue with a previous hole.  The other simple solution is to affix your miter gage to the front of sled (shimming away the 5/8" extension).  Then you do not need to affix my runners or both of them.

3. I highly recommend that everyone who buys this jig also invest in a digital caliper.  A “ 1” scrap” is really a ¾” board that might be a few thousandths difference than the offset key that I provide.  It is very easy to be off that much if the boards are not clamped correctly or are not cut exactly the same width.  If there is a fundamental problem I definitely need to figure it out.

4. These are excellent points but it is impossible for me to make a specific jig for each application.  An inquiry last week was asking about making jumbo deeps for instance.  These would fit into the length of the sliding box.  I said in the video that the jig is scalable.  By that, I meant then entire jig.  Someone making ¼” joints in jewelry boxes would definitely need a smaller version.  If someone wanted to make ½”  joints with my jig all you would need to do is copy the flipper pattern and make them exactly 1” in width.  Someone yesterday asked about 0.700” joints – they need 1.400” flippers.

5. Clamping is an important issue and SKM and I had many discussion about this that I learned a lot from.  I even provided him with a special shimming box.  You can resolve a lot of the clamping issues by making customized shimming boxes that are used inside the sliding box to take up room for the specific size of pieces that you are working with.  In my setup guide I say that you can drill as many clamping holes in the sliding box as you need for your specific applications.  I cannot anticipate where everyone would want holes – that is the nice thing about having a wooden product – very customizable.

6. Another valid point that I address in my setup guide.  Powermatic saws for instance load the dado stack from the opposite direction as a Delta saw.  The solution is to keep the calibration board that I provide and to not permanently attach the runners.  Another solution is to affix your saws miter gage to the front of the box (adding a 5/8” shim across the front).  You then do not even need to use the runners that I provide and you have good metal on metal slides.  Even better would be to have two miter gages.

7. There are have been discussions on bee forums about joint size and it was my impression that some people wanted larger joints since some of the large woodware manufacturers were increasing their joint size.  I figured out how it can be done on a homeowners saw.  

Thank you specialkayme !

PM me if you would like me to send you the 115 page setup guide.

CarlinMO
« Last Edit: April 18, 2013, 10:53:09 pm by CarlinMO »

Offline greg755

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Re: New box joint jig by Carl Korschgen
« Reply #22 on: April 18, 2013, 07:42:24 pm »
This may be a dumb suggestion but here goes.   Instead of bar clamps, why don't you make a slot in the back of the outside box, put a long screw though it, then a piece of wood connected to the screw on the inside of the inside box  and a turn handle on the out side of course the Slide part of the inside box would have to have threads set in it.  Then you would have a wood press to keep all the boards pressed together...  Just seems it would save on costs and you wouldn't be missplacing your bar clamps.  By the way could some one PM me the price of this, I sent an email but maybe it hit Carl's Spam/junk box?

Offline specialkayme

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Re: New box joint jig by Carl Korschgen
« Reply #23 on: April 18, 2013, 08:42:42 pm »
2) I believe SKM missed an illustrated step in the setup manual.  I provide 4 machine bolts to affix the runners to the bottom of the sled.  These are mounted on the outside extensions of the bottom of the sled where everything is completely visible.  I even mark the center line of the runners.  The runners are cut a couple inches longer than necessary to bring everthing into view.  You drill a pilot hole through the 3/8” bottom of the sled into the runners.  Then you remove the runner and complete drilling the hole, countersink the bottom side for the head of the bolt, and tighten up. 

This may have been so personal to my set up it wasn't worth mentioning, but I have a granite top table saw, and I wasn't interested in drilling right over top of the granite. If for some reason I drilled to far and hit the granite, I could have done some serious damage and/or cracked it. Very rare, but we all know Murphy's law. So that's why I didn't drill it in place on the table top.

I also didn't have a drill bit long enough to perform that function on the front of the saw, as the instructions indicated. I really wasn't interested in purchasing another drill bit just to install the runners, and since I had the concern above I did something different. Maybe my own issues.

3. I highly recommend that everyone who buys this jig also invest in a digital caliper.  A “ 1” scrap” is really a ¾” board that might be a few thousandths difference than the offset key that I provide.  It is very easy to be off that much if the boards are not clamped correctly or are not cut exactly the same width.  If there is a fundamental problem I definitely need to figure it out.

I can provide a picture of the joints done with the "offset key" and joints done with the "scrap" piece if you'd like. While digital calipers may show that the "scrap" piece isn't exactly 3/4", the plain eye can see which of the two joints fits correctly. Who knows why.

Powermatic saws for instance load the dado stack from the opposite direction as a Delta saw.

Which one is more common? I've only had saws that have stacked blades from the right, but maybe I always bought uncommon saws.

The solution is to keep the calibration board that I provide and to not permanently attach the runners.

I'm not so certain this would solve the issue. If I moved from a 3/4" joint to a 7/8" joint, and I have to slide the box 1/8" in one direction, the calibration board will help, but redrilling holes for the runners to attach at that are 1/8" away from the old holes, and not having the holes cross, is not an easy task. Especially considering that the screw is probably 1/16" wide itself.

Thank you SKM!

A pleasure Carl. Thanks for providing the excellent product.

I think I should add here that Carl's customer service has been phenomenal. I asked him probably a dozen questions before I ordered, and he answered them all. He included some extra shims to help me make medium boxes as well. I don't make mediums often, but I appreciated it all the same. Then he sent a handle for the box after the original jig shipped. I didn't even ask for it.

I should also probably add that it is very well made. You can tell he put some considerable time into making each one.

Offline cbinstrasburg

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Re: New box joint jig by Carl Korschgen
« Reply #24 on: April 19, 2013, 10:38:35 am »
specialkayme what brand of saw do you have?   Steel City?

Offline specialkayme

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Re: New box joint jig by Carl Korschgen
« Reply #25 on: April 19, 2013, 08:40:38 pm »
Yes.

Offline capt44

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Re: New box joint jig by Carl Korschgen
« Reply #26 on: April 20, 2013, 10:06:08 am »
Capt44,  How is it working for you?  Would a guy with very limited wood working experience have any trouble aseemeling or using this?
Thanks
G
calibrating the jig to the table saw is a breeze.
I used a framing square to make sure my fence and miter gage were square with the saw.
I put the calibration board (comes with the jig) and put it along side the fence and moved it just to the right of the dado blade.
I placed the jig on the saw and place the guides into the guide rails on the saw.
I used metal ones from Rockler.
I had to buy a long drill bit to drill the holes straight.
I put the screws into the guide rails and put the boards into the jig.
I used wood clamps, one on the right I set at an angle to clamp the boards (8) to the jig then placed one on the
top left of the boards.
I placed the spacer blocks in and let one flipper down.
I made all my cuts.
I flipped the boards over and made the next set of cuts.
I then placed the short boards in an put spacer blocks on each side of the boards and clamped the boards in place and let 2 flippers down.
I made all the cuts.
I removed the boards and they fit perfectly.
I then cut my frame rest on the routing table and then cut my hive handles using his hive handle jig.
I then glued and brad nailed the joints.
I used Tite bond II glue.
All joints are snug and flush.
I have not used the 1 1/2 inch joints yet.
This is a very good thought out design.
Richard Vardaman (capt44)

 

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