Small mod to K3 crosscut fence

[Derek Cohen]

I suspect that most here with Hammer K3 sliders have an outrigger with the crosscut fence at the farther end of the slider. This mod is for the K3s with the shorter sliders, such as mine, which is 49", which have the crosscut fence at the start of the slider.

https://i.postimg.cc/L6hNJDzn/Hammer.jpg

The problem I have with this crosscut fence is that it cannot be aligned with the edge of the saw blade ala a zero clearance. If a sacrificial board is attached to the front of the fence, the fence loses its ability to be set to the angle scale.

Some of you may have worked out a better method, but this is what I did today (while the glue dried on my current project - what do you do while the glue dries?) ...

The inside of the crosscut fence ..

https://i.postimg.cc/4yQZtw67/1a.jpg

A chunk of UHMW ...

https://i.postimg.cc/WpGsQpBN/2a.jpg

This ...

https://i.postimg.cc/kg496QBG/4a.jpg

... inserts into ...

https://i.postimg.cc/9F1CQ8Xs/5a.jpg

... creating this zero clearance section ...

https://i.postimg.cc/B6WGVRNP/7a.jpg

https://i.postimg.cc/XvBbxnK0/8a.jpg

Regards from Perth

Derek

[Dan Friedrichs]

Neat idea, and well done! I use my fritz and franz jig when I want zero clearance, but I could see this being useful, too.

[Derek Cohen]

Dan, I built a traditional F&F jig, but I realise now that it is incorrect for my slider. The F&F jigs on YouTube are designed for sliders with a crosscut fence at the far end, which acts as the zero clearance. I need to reverse this for mine, which is one of the reasons for adding this mod. I have not seen anyone do this.

Regards from Perth

Derek

[Dan Friedrichs]

Oh, interesting. I have a longer slider, and with the outrigger attachment, it's easy to slide the fence fore/aft depending on if I'm using it the way you are (with the fence "behind" the stock) or with an F&F jig (on the other side of the fence). At least with the outrigger, it seems more useful to have the fence at the far end, as this maximizes slider travel, but I prefer using it like you do - with the fence behind the stock.

On yours, it is possible to relocate the fence to the far end? ie - can you flip the miter gauge around and mount it on the other side of the fence?

[Derek Cohen]

Dan, relocating the fence would mean forgoing the mitre angles. Also, it makes more ergonomic sense to crosscut in front of the fence. The rear positioned fence is really designed for sheets (which I do not use).

As mentioned earlier, I built a traditional F&F jig, which required a fixed end ...

https://i.postimg.cc/g2fKrMmY/10a.jpg

https://i.postimg.cc/Dyw6NJxK/8a.jpg

This now needs to be reversed to suit my crosscut fence.

Regards from Perth

Derek

[Rod Sheridan]

Derek, I must be missing something.

Why didn't you simply slide the fence extrusion over so that it's beside the blade?

The tape can also be moved over...........Rod.

[Derek Cohen]

Derek, I must be missing something.

Why didn't you simply slide the fence extrusion over so that it's beside the blade?

The tape can also be moved over...........Rod.

Rod, while the fence can be moved closer to the blade, my aim is to align the edge of the fence with the teeth of the blade. All my (300mm) saw blades are exactly the same with width (3.2mm), which means they are interchangeable for zero-clearance.

I was crosscutting yesterday, and this new set up works like a dream :). Align mark with edge of fence, and cut.

Regards from Perth

Derek

[Jim Becker]

I have a similar miter bar on my SCM/Minimax slider...it's what I use primarily and it's also mounted in the same position as you show yours. I prefer the fence behind the workpiece for support for critical cross cutting. My fence has an OEM plastic zero clearance piece like you made so I can appreciate why you took the time to make this enhancement. Mine is getting a bit worn and I've milled up some scrap oak to make a replacement.

[David Stone (CT)]

That's very nice. What did you use/make for the nut in the end of the fence extrusion? Is it a piece of UHMW that you tapped or is there a metal insert in there somewhere, or what?

I have an outrigger with the fence installed always in the forward position, ahead of the workpiece, so this wouidn't help with chip-out when the blade exits the cut. But being able to line up the mark with the edge of the fence and cut, with no trial and error, sounds great. You've inspired me to finally make one. Thx.

[Mark e Kessler]

i did a similar mod on my k700s fence.

425751425750




I suspect that most here with Hammer K3 sliders have an outrigger with the crosscut fence at the farther end of the slider. This mod is for the K3s with the shorter sliders, such as mine, which is 49", which have the crosscut fence at the start of the slider.

https://i.postimg.cc/L6hNJDzn/Hammer.jpg

The problem I have with this crosscut fence is that it cannot be aligned with the edge of the saw blade ala a zero clearance. If a sacrificial board is attached to the front of the fence, the fence loses its ability to be set to the angle scale.

Some of you may have worked out a better method, but this is what I did today (while the glue dried on my current project - what do you do while the glue dries?) ...

The inside of the crosscut fence ..

https://i.postimg.cc/4yQZtw67/1a.jpg

A chunk of UHMW ...

https://i.postimg.cc/WpGsQpBN/2a.jpg

This ...

https://i.postimg.cc/kg496QBG/4a.jpg

... inserts into ...

https://i.postimg.cc/9F1CQ8Xs/5a.jpg

... creating this zero clearance section ...

https://i.postimg.cc/B6WGVRNP/7a.jpg

https://i.postimg.cc/XvBbxnK0/8a.jpg

Regards from Perth

Derek

[Derek Cohen]

That's very nice. What did you use/make for the nut in the end of the fence extrusion? Is it a piece of UHMW that you tapped or is there a metal insert in there somewhere, or what?

I have an outrigger with the fence installed always in the forward position, ahead of the workpiece, so this wouidn't help with chip-out when the blade exits the cut. But being able to line up the mark with the edge of the fence and cut, with no trial and error, sounds great. You've inspired me to finally make one. Thx.

Hi David

The zero clearance add-on is attached to the fence with a steel bolt into a section of UHMW epoxied into the fence. This was tapped for the bolt.

https://i.postimg.cc/qMpp0Vr8/3a.jpg

I am contemplating one slight modification to make, and this is to lower the Zero Clearance fence add-on. As it is, it can just run under the blade guard when the blade is at full height (about 100mm). I generally only use it that way, but lowering the ZC fence (to say 30mm) will allow the blade to be lower. I suspect that Mark (above) discovered this as well (nice one Mark!).

Cutting off the excess shows the heights involved ...

https://i.postimg.cc/2SKY41Zw/6a.jpg

Regards from Perth

Derek

[Mark e Kessler]

Derek, yes i have always made them this way so that the guard can be lower. However I found one more slight modification that I will make, I have the overhead guard and I leave it unlocked because it is a slight pain to unlock when I need to swing it out of the way. The other day I was making a cut and the guard was floating ( it has a roller front and back) when i was pulling the slider back the roller didn’t roll over the lower part of the “L” and it started to push the guard away into the blade. So, I am going to put a bevel on the “L” if that make sense. Long term i plan on devising a remote release for the overhead guard so it can be locked/unlocked from the operator side


Hi David

The zero clearance add-on is attached to the fence with a steel bolt into a section of UHMW epoxied into the fence. This was tapped for the bolt.

https://i.postimg.cc/qMpp0Vr8/3a.jpg

I am contemplating one slight modification to make, and this is to lower the Zero Clearance fence add-on. As it is, it can just run under the blade guard when the blade is at full height (about 100mm). I generally only use it that way, but lowering the ZC fence (to say 30mm) will allow the blade to be lower. I suspect that Mark (above) discovered this as well (nice one Mark!).

Cutting off the excess shows the heights involved ...

https://i.postimg.cc/2SKY41Zw/6a.jpg

Regards from Perth

Derek

[Steve Wurster]

The zero clearance add-on is attached to the fence with a steel bolt into a section of UHMW epoxied into the fence. This was tapped for the bolt.

I was wondering how you kept that piece installed within the fence, but it seems you epoxied it. I will have to make my own copy.

[Brian Holcombe]

I don’t like the idea of having a machine screw near the blade like that. If an operator is not paying strict attention and rotates the fence does the screw have the possibility of being put into the blades path?

If you had to have it like that I would think an aluminum flat head would be a better choice.

If you did accidentally cut the machine screw then additionally a small piece of plastic now wedges between the blade and fence and will rocket out. So an accident likely destroys the blade, sends a machine screw head flying along with the saw teeth and a piece of plastic also becomes a missile.

It may also bend the saw teeth scaring the machine internals.

In the machine shop I worked in the head machinist taught me to never build anything in which a loosened bolt is given the opportunity to fall into the motor, I think the same thing applies here.

[Derek Cohen]

Brian, the bolt is pretty far from the blade. It cannot come loose. The insert is epoxied into a channel. There is no way they could make contact. To be absolutely safe, I shall hunt down an M8 nylon bolt.

https://www.ebay.com.au/itm/Metric-M3-M4-M5-PVC-Phillips-Round-Head-Screw-Machine-Bolts-Plastic-Gray-ISO7045/324003789118?hash=item4b7021793e:m:mkC4fn2dJK9KKFF qRJBjgzQ

Regards from Perth

Derek

[Mark e Kessler]

Just out of paranoia, using an aluminum\nylon bolt was my plan as well just haven’t got around to it...

Mk


I don’t like the idea of having a machine screw near the blade like that. If an operator is not paying strict attention and rotates the fence does the screw have the possibility of being put into the blades path?

If you had to have it like that I would think an aluminum flat head would be a better choice.

If you did accidentally cut the machine screw then additionally a small piece of plastic now wedges between the blade and fence and will rocket out. So an accident likely destroys the blade, sends a machine screw head flying along with the saw teeth and a piece of plastic also becomes a missile.

It may also bend the saw teeth scaring the machine internals.

In the machine shop I worked in the head machinist taught me to never build anything in which a loosened bolt is given the opportunity to fall into the motor, I think the same thing applies here.

[Mike King]

Here's David Best's photo exposition of his similar project.

https://www.flickr.com/photos/davidpbest/albums/72157706537836331