Jig for slotted backs.

[swagman]

A newly designed jig for resizing the slot on my backsaw hardbacks.

*Do not attempt this without the correct safe guards in place.*

The jig is 12 inches in length.

Stewie;

 

[Jelly]

How's does it feel in use stewie?

By virtue of brass needing high speeds and a near 0 degree clearance angle I can see the router/router tooling being effective as an alternative to a shaper or Slitting Saw and mill, but I'd be worried about the back and jig being launched off the machine at great speed, perhaps I'm overestimating the force required to feed it?

 

[swagman]

Hi Jelly. If I can correct you on point. These slitting blades are not designed to be run at high speed. My router is pre set at its lowest speed setting. Matching the correct O.D. on the slitting blade to the running speed is also extremely important. Too high an O.D. , you then risk introducing chatter. You need to avoid that at all costs. Especially when working with metals like brass. The last thing I am wanting to do is encourage others to follow my example.

Stewie;

 

[Jelly]

Hi Jelly. If I can correct you on point. These slitting blades are not designed to be run at high speed. My router is pre set at its lowest speed setting. Matching the correct O.D. on the slitting blade to the running speed is also extremely important. Too high an O.D. , you then risk introducing chatter. You need to avoid that at all costs. Especially when working with metals like brass. The last thing I am wanting to do is encourage others to follow my example.

Stewie;

I see your point, High speed is relative though, I've been machining D2 and P20 for the past few weeks... Compared that even the slowest speed on a router is pretty rapid!

 

[swagman]

Hi Jelly. If I can correct you on point. These slitting blades are not designed to be run at high speed. My router is pre set at its lowest speed setting. Matching the correct O.D. on the slitting blade to the running speed is also extremely important. Too high an O.D. , you then risk introducing chatter. You need to avoid that at all costs. Especially when working with metals like brass. The last thing I am wanting to do is encourage others to follow my example.

Stewie;

I see your point, High speed is relative though, I've been machining D2 and P20 for the past few weeks... Compared that even the slowest speed on a router is pretty rapid!

Hi Jelly. Thats a fair comment.

regards Stewie;

 

[Jelly]

Seen as I'm also in the midst of preparing to make saws, (albeit handsaws rather than backsaws initially at least) i'm curious as to what drew you to use a slotted rather than folded backs?

 

[swagman]

Seen as I'm also in the midst of preparing to make saws, (albeit handsaws rather than backsaws initially at least) i'm curious as to what drew you to use a slotted rather than folded backs?

Hi Jelly. By answering that question, it could end in a lengthy debate on the merits of 1 over the other. I have no wish to go there.

regards Stewie;

 

[swagman]

1st run using the new jig assembly. The newly cut slot is for 0.025 saw plate gauge. You will note outboard fence in place that controls the depth of cut. 3 full passes were taken to reach the required depth of slot.



The new slot is parallel in both axis. No apparent heat build up or vibration was observed during the test.



I did notice within this 2nd photo a false impression that the front 1 1/2" looks slightly wider than the rest of the slot . That is not the actual case. That slot is perfect in width and depth along the brass backs full length.

Note: I have 2 round handles (currently on order) that will be fitted to the top of the jig when they arrive.

regards Stewie;

 

[Trafalgar]

Isn't a folded brass back supposed to be better, allow for retensioning should it become necessary at some point?

 

[pedder]

Isn't a folded brass back supposed to be better, allow for retensioning should it become necessary at some point?

Ever seen a slotted and glued saw, that was in the need of "retensioning"?
I don't and if, it would be easy. take it all apart, clean the spine and glue the blade back.

 

[swagman]

Isn't a folded brass back supposed to be better, allow for retensioning should it become necessary at some point?

Hi Charles. I think I covered that question already.

A bit of self control would be appreciated.

regards Stewie;

Jelly wrote:

Seen as I'm also in the midst of preparing to make saws, (albeit handsaws rather than backsaws initially at least) i'm curious as to what drew you to use a slotted rather than folded backs?


Hi Jelly. By answering that question, it could end in a lengthy debate on the merits of 1 over the other. I have no wish to go there.

regards Stewie;

 

[Jelly]

Isn't a folded brass back supposed to be better, allow for retensioning should it become necessary at some point?

Hi Charles. I think I covered that question already.

A bit of self control would be appreciated.

regards Stewie;

Jelly wrote:

Seen as I'm also in the midst of preparing to make saws, (albeit handsaws rather than backsaws initially at least) i'm curious as to what drew you to use a slotted rather than folded backs?


Hi Jelly. By answering that question, it could end in a lengthy debate on the merits of 1 over the other. I have no wish to go there.

regards Stewie;

With this in mind, a seperate thread, so this one is not de-railed.

Good work on the jig, it seems to be doing the trick in use (and looks lovely and neat too, like all your other work).