Shopsmith Forums

I know why I had problems. I was making a door(3' x 6'+) with 1/2" mortises.

Problem one - Gee it is new, so it must be sharp. I now know better.

Problem two - Yes the table flexed. I now have a telescoping pole for that. It attaches directly under the quill path.

I did know about the 'dime'.

I feel confident using it today, but I do think the negativism(including myself) was due to ignorance re sharpening.

All this applies to a Mark 5.

JPG wrote: but I do think the negativism(including myself) was due to ignorance re sharpening.

All this applies to a Mark 5.

Well, kinda sorta but not exactly.

With all due deference, the chisels (and to some extent the bits) on a bench mortiser and also the SS attachment are designed for casual use and not much can be done to get them to great let alone outstanding condition. The chisels and bits on those machines will never be top quality BUT THEY WERE NEVER MEANT TO BE.

There MAY be top quality chisels and bits that fit a bench top, but if they do exist they will be pricey (and that only solves part of the problem - more later). The professional systems I was lucky enough to use had honing stones sold by the company that made the mortiser. Like a Forrest blade, when the bits got dull we sent them back to the manufacturer for sharpening. We often had 8 complete sets of chisels and bits to keep things running. Honing after hours was part of the job same as sweeping up.

John says he got great results from SS mortise systems. He would be the rare exception. They are not BAD chisels, but they are not great.

To get decent results on a SS I've tried SS hones and after market hones with different angles, Delta, Infinity and Amana chisels and bits. Also a variety of lube systems and methods. The chisels and lack of ability are only a small part of the equation. The distance difference between chisel and bit is as simple as finding the optimum distance then creating a jig for repeatability.

Part of the more referenced above is the actual carriage of a mortiser. Stout would be an understatement! Then there is the motor!! Those machines would make a Timex watch seem like a slacker!! Hour after hour, day after day being pulled on. No bench top was designed to handle that abuse and the SS was DEFINITELY NOT designed for that in mind. Unfortunately, to make a good quality mortise you really need the higher level of quality. That means you either make great or make do!

When you get the opportunity to get into a shop that has a professional mortising machine, the difference will be like steel teeth and carbide!

No, I do not expect a SS to perform like a separate machine. I stopped trying to achieve that after it was apparent it was not probable.

Frankly if re-sharpening were the trick, it would be nice. And... re-sharpening OFTEN! like after a foot of cuts can make for a better cut.

As a Shopsmith is a compromise, so is their mortise system. Any bench top system is more akin to the cheap Chinese HF offering no matter whose name is on the box.

JPG I don't mean to speak for you or your feelings; but maybe your negativism, I think, is because on most projects, the short comings of the SS can be overcome with ingenuity, but not so with the mortise system available for SS. What I personally believe is that few understand just how inadequate ANY mortise system is until you get to the big guys.

I think that few in this forum would try to take down a forest of redwoods using an electric chain saw with a 14" bar. It is theoretically possible with lots of time, replacement chains. sharpening equipment and a lot of fuel for the generator! . Possible, yes, best results, probably not! So my analogy of using a bench top / SS versus a professional machine is like cutting down the red woods... Possible but the results will never be what they would using the appropriate equipment, but then again if you never saw what could be done with appropriate equipment, how would you ever know the difference?

Again, the results which you are personally willing to accept are the only ones you should use when determining what works best!

Be well,
Ben

I used to own the SS system. I kept it sharp, too, by golly. Worked great in pine and poplar for the shallow stuff I was doing. Then I got in to oak, mesquite and boise d' arc and deeper mortises. Not so good. The table just isn't sturdy enough on my MKVs. As Ben states, there are just some things you can't do well with a Shopsmith.
So, I switched to a router and loose tenons and that worked very well for the smaller things I build. But, when these Morris chairs came along with their through mortises in 2 1/2 square white oak legs, I knew I needed something a bit more robust. Hence the Delta. Bad choice. Live and learn, I guess.
When I get it back, it only has to cut 32 more mortises. That's about 320 2 1/2 deep plunges of the bit. Hope it holds up.

Your solution using aluminum angle is impressive. I am now ashamed of what I have been using but that won't be for long.

Thanks for posting this.

Hmmm I don't even have to purchase aluminum angle. I have cutoffs available from a different project.

The deeper one goes, the more critical table rigidity becomes. Binding becomes a problem when retrieving to clear debris. Any deviation from straight due to flexing make that worse.

I do not expect the SS to perform anywhere near what a dedicated, robust mortiser would.

Perhaps the gentleman from Utah could share with us his method of chisel sharpening. He obviously has had more success than I assume us all.

algale wrote:Beautiful shutters!

On the topic of hollow chisel mortising, this is the Shopsmith attachment that seems to get the most criticism. But along comes someone who says it works great. I don't own one so I don't know who to believe.

I always hear folks talk about sharpening the chisels. But I don't hear folks talking about setting the clearance properly as Nick discussed here:

http://www.shopsmithacademy.com/Tips_Ar ... _Gauge.htm

I have often wondered whether the folks who have experienced problems with the Shopsmith hollow mortising chisel have paid attention to this setting.

That setting is certainly just as important as having sharp chisels. I typically set the clearance to 4 or 5 pieces of paper which is about half what Nick recommends. The bottom line is that you need some amount of clearance or you will overheat both the drill and the chisel. Once that happens they are ruined and no amount of sharpening will help.

JPG wrote:The deeper one goes, the more critical table rigidity becomes. Binding becomes a problem when retrieving to clear debris. Any deviation from straight due to flexing make that worse.

I do not expect the SS to perform anywhere near what a dedicated, robust mortiser would.

Perhaps the gentleman from Utah could share with us his method of chisel sharpening. He obviously has had more success than I assume us all.

I certainly don't expect the SS to perform anywhere near what a dedicated, robust mortiser would either. That doesn't mean that it is not perfectly adequate for some jobs. As such why not use it for those jobs that it does work well on?

As far as sharpening, I use the cone shaped stone that SS provides for that purpose. I also hone the outside flat surfaces of the chisel on a granite surface plate using 600 grit and then 1200 grit paper. I sharpen every time before I use the chisel.

I have not used the mortiser with my dedicated MK V drill press yet but with the angle iron support for the carriage and the front table support I am using the table is going no where and not flexing.

jsburger wrote:The bottom line is that you need some amount of clearance or you will overheat both the drill and the chisel. Once that happens they are ruined and no amount of sharpening will help.

AHHHH, but can they be re tempered?

beeg wrote:

jsburger wrote:The bottom line is that you need some amount of clearance or you will overheat both the drill and the chisel. Once that happens they are ruined and no amount of sharpening will help.

AHHHH, but can they be re tempered?

I don't know but if they can I suspect the cost would be more than a new set.

jsburger wrote:

beeg wrote:

jsburger wrote:The bottom line is that you need some amount of clearance or you will overheat both the drill and the chisel. Once that happens they are ruined and no amount of sharpening will help.

AHHHH, but can they be re tempered?

I don't know but if they can I suspect the cost would be more than a new set.

After tempering, they would need to be reground to dimension. That would make them undersized.


Realize (IIUC) tempering makes then 'less brittle' from hardening. Getting them too hot just extends that process.