Hollow Chisel Mortising System Opinions

[rambo2981]

If anyone has the Hollow Chisel Mortising System 555810, what’s your opinion of it? Does it cut clean, square mortises? Is there anything about it that you don’t like? I’m trying to decide whether I want to buy the Shopsmith kit for my Shopsmith, or buy a standalone benchtop mortiser. Thank you.

[beeg]

Which ever one you purchase. SHARPEN it before use.

[chapmanruss]

I have used the Shopsmith sets on a couple of projects with good results. As Bob said keep them sharp.

[reible]

Well I have the shopsmith version and yes it works but.........

I got this early on and was using it with my 500. I was having issues and it took me a while to figure out what was happening. Back in those days there was no googling or user groups to ask questions of, you were pretty much on your own.

First problem was that the chisels do not come sharp enough to use. Like lathe chisels and other such tools they have an edge but it is far from sharp (unless told other wise). The shopsmith tools at the time were on the lesser side of quality, no recent experience, the bits were OK, just the chisels were the issue.

Second the table would tilt due to the pressure required to plunge the chisels. I ended up making a 2x4 support that had a notch for the table and lowered the table on it it then adjusted from there. At some point shopsmith came up with a table support which I'm guess they still sell. If you have a 510/520 table system then you have the ability to use the legs with that but I personally have never tired it on my 520's.

It requires a great deal of force to make mortises this way. The shopsmith has a short handle and lacks leverage. If you are doing say a dozen mortises it is fine but if you plan to do lot, well I could never do that any more. Mortising machines have a big advantage there.

There are many ways to cut mortises. They all have advantages and disadvantages. Then there are loose tenon versions which would be something else to look at. Routers also have big following and would be looked at as they often make the best holes..........

I still have my shopsmith set up and even got a 5/16" size chisel from I believe delta that fit the holder from the shopsmith. However I have not used it in years and while I did look at a dedicated machine I found I like making these joints in different ways and now it is really rare for me to even make anything with them. Woodworking is that way.

Conclusion would be make sure you really want to go with this method and then decide how many joints you think you might be wanting to make. A few then shopsmith is fine, a lot, well you could do it........

Ed

[rambo2981]

Thank you Ed, and others. I have a horizontal mortiser with a router, but since these mortises will be visible I’d need to square the corners. That’s what I’m mulling over. A chisel mortiser would give me close to finished mortises. I did read about deflection in the table with the SS mortiser, and I see the single leg support that’s available to mitigate deflection. Regarding the SS chisels, I doubt I’ll use them if the Lee Valley premium chisels fit, and I think they do.

[edma194]

I would assume the mortiser will have an easy time finishing the ends of a mortise already started with the router. You only need to use a corner chisel to finish a routed mortise.

[reible]

Here is one of my posts related to the subject from 2017:

viewtopic.php?p=232543&hilit=lee+valley+chisels#p232543

Ed

[benmcn]

For those interested, Scott from My Growth Rings has a video on the hollow chisel mortising system. He does a really good job explaining and demonstrating the use of this tool.

https://www.youtube.com/watch?v=89TwGU8U0Ss

[rambo2981]

Great video. Thanks for the link.

[chapmanruss]

Scott's video does do a great job of explaining the use and limitations of the Shopsmith Mortise. I did neglect to mention in my previous post the force needed to use it and how much it helps to have extra support for the table. My bad. I like Scott's use of a block between the carriage and base/arm for support. I have the extra leg but since I do my Mortising on my Mark 7 (upgraded 520), I use the floating table connector tubes and legs for the extra support. I have both the older original Shopsmith style chisel/bit sets as well as newer ones Shopsmith sold that are made in Taiwan. The word to remember here is SHARP!

One thing in Scott's video I found interesting is him saying he had to use a 3/16" Allen Wrench to tighten the cap screw to attach the mortise to the quill. I don't recall him saying anything about the set screw size when tightening the sleeve in the casting and the chisel in the sleeve. I have Mortising sets from the Model 10 era which use a 3/16" Allen Wrench for that cap screw and the sleeve set screw with a 1/8" Allen Wrench size for the sleeve set screw to lock the chisel. The Greenie, Goldie and later Gray Mortising sets I have use the Shopsmith Toolbox 5/32" Allen Wrench for the cap screw and the two set screws. The set screws for the Hold Down's match the Mortises for each era. I am not sure of the age of my newest set but it does pre-date the introduction of the Mark V 510/505 and I upgraded the Hold Down for it with the "T" nut setup. Standardization may be the culprit as both the 3/16" and 5/32" Allen Wrench size cap screw threads are 1/4" - 20 x 1-1/4" long. Maybe Shopsmith had to change to a 3/16" Allen Wrench size cap screw on newer Mortises or Scott's mortise is from the Model 10 era. I am sure someone will let us know if that happened. As you can see from the picture below the Mortises have changed little in all these years. The Hold Down casting is the biggest change in the set.

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Model 10 - greenie and current.jpg (74.06 KiB) Viewed 20756 times