Slitting Brass for Sawmaking

[RayG]

This is the setup used for slitting the brass used in the sawmaking class that was held in Melbourne recently.
http://www.woodworkforums.com/f11/melbourne-backsaw-making-workshop-174387/



http://youtu.be/UQoAsL5mtZw

The cut is 10mm deep with a 20 thou or 25 thou slitting blade, which is very flexible and tends to run off track if you aren't careful.
In the video above, I'm re-cutting a piece to 25 thou that was previously slit to 20 thou.

The secret to getting it to track better was to climb cut... no idea why that should be better?
Maybe the swarf was catching one side of the blade and throwing off tracking. Whereas climb cutting the swarf is on the other side..


Regards
Ray

[Ueee]

Now that is a thin blade......

Even with a 1/16" saw I find they can wonder, but putting in a really shallow cut first seems to really help them to stay straight on the deeper cuts.

Sure is far more interesting than watching the grinder go back and forth. Grinding the second 450x180x20mm piece for my sine plate....

Cheers,
Ew

[RayG]

Yep, just ask Josh about grinding.. very hypnotic..

The guys from the class really excelled themselves and made some very sweet looking saws. Here's some of the saws they made.



http://www.woodworkforums.com/attachments/f11/294150d1384828918t-melbourne-backsaw-making-workshop-100_0535.jpghttp://www.woodworkforums.com/attachments/f11/294151d1384828932t-melbourne-backsaw-making-workshop-100_0537.jpghttp://www.woodworkforums.com/attachments/f11/294214d1384925288t-melbourne-backsaw-making-workshop-x-cut.jpghttp://www.woodworkforums.com/attachments/f11/293121d1384152695t-melbourne-backsaw-making-workshop-2013-11-11-10.38.40.jpghttp://www.woodworkforums.com/attachments/f11/293088d1384134281t-melbourne-backsaw-making-workshop-sam_0789.jpghttp://www.woodworkforums.com/attachments/f11/293004d1384069118t-melbourne-backsaw-making-workshop-saw-making24-copy.jpghttp://www.woodworkforums.com/attachments/f11/293002d1384069087t-melbourne-backsaw-making-workshop-saw-making20-copy.jpghttp://www.woodworkforums.com/attachments/f11/292944d1384044872t-melbourne-backsaw-making-workshop-img_0532s.jpg
http://www.woodworkforums.com/attachments/f11/292945d1384044874t-melbourne-backsaw-making-workshop-img_0535s.jpghttp://www.woodworkforums.com/attachments/f11/294430d1385117655t-melbourne-backsaw-making-workshop-abupyty7.jpg294856

Regards
Ray

[eskimo]

Yep, just ask Josh about grinding.. very hypnotic..

The guys from the class really excelled themselves and made some very sweet looking saws. Here's some of the saws they made.



http://www.woodworkforums.com/attachments/f11/294150d1384828918t-melbourne-backsaw-making-workshop-100_0535.jpghttp://www.woodworkforums.com/attachments/f11/294151d1384828932t-melbourne-backsaw-making-workshop-100_0537.jpghttp://www.woodworkforums.com/attachments/f11/294214d1384925288t-melbourne-backsaw-making-workshop-x-cut.jpghttp://www.woodworkforums.com/attachments/f11/293121d1384152695t-melbourne-backsaw-making-workshop-2013-11-11-10.38.40.jpghttp://www.woodworkforums.com/attachments/f11/293088d1384134281t-melbourne-backsaw-making-workshop-sam_0789.jpghttp://www.woodworkforums.com/attachments/f11/293004d1384069118t-melbourne-backsaw-making-workshop-saw-making24-copy.jpghttp://www.woodworkforums.com/attachments/f11/293002d1384069087t-melbourne-backsaw-making-workshop-saw-making20-copy.jpghttp://www.woodworkforums.com/attachments/f11/292944d1384044872t-melbourne-backsaw-making-workshop-img_0532s.jpg
http://www.woodworkforums.com/attachments/f11/294430d1385117655t-melbourne-backsaw-making-workshop-abupyty7.jpg294856

Regards
Ray

can I have one of those..any one will do ..honest

beautiful:2tsup:

[DSEL74]

Ray what would happen if you reinforced the arbour? Since the lade is only cutting a small depth could you add a custom made "washer" top and bottom of the blade to make the blade more rigid. Same thing the arbour does now but at a larger diameter? This may help reduce any wandering.

[Ueee]

Some very nice work there. Maybe not the right part of the forum, but whats the go with the wavy backed saw?

Has Josh had any more thoughts about the pitch changer? (something Josh and i were working one, primarily for grinding saw blade stock) I ground some more blocks up for Mk2, this time with thicker poles but i have not gone any further. It may just be worth keeping an eye out for a smaller fine pitch chuck like the one i got for the sine plate. Although making these mag transfer pitch changing blocks sure is interesting.....

Ew

[RayG]

Some very nice work there. Maybe not the right part of the forum, but whats the go with the wavy backed saw?

Has Josh had any more thoughts about the pitch changer? (something Josh and i were working one, primarily for grinding saw blade stock) I ground some more blocks up for Mk2, this time with thicker poles but i have not gone any further. It may just be worth keeping an eye out for a smaller fine pitch chuck like the one i got for the sine plate. Although making these mag transfer pitch changing blocks sure is interesting.....

Ew

Hi Ewan,

Josh has been grinding chisels till all hours, so I don't think he's done any more on the pitch changer. I figure the saws are mostly metalwork, so this is the best forum :)
Matt did the fancy filing... more pictures here.. http://www.woodworkforums.com/f11/melbourne-backsaw-making-workshop-174387/index3.html#post1719419

Regards
Ray

[planemaker]

Hi Ray. Great video. Thank you for that. Just a couple questions. If you were slitting the brass from scratch how many passes would you be recommending to achieve a 10mm depth, and at what rpm did you find gave you the best performance to accurately achieve the desired slit specs.

Stewie;

[RayG]

Ray what would happen if you reinforced the arbour? Since the lade is only cutting a small depth could you add a custom made "washer" top and bottom of the blade to make the blade more rigid. Same thing the arbour does now but at a larger diameter? This may help reduce any wandering.

Hi Dale,

Worth a try, my "gut" feel is that as long as it's climb cutting and the blade doesn't get hot and warp it tracks pretty accurately.

Hi Stewie,

I cut 10mm deep in one pass. Speed depends on the blade diameter, I'm out on-site on a job at the moment, when I get back I'll check the actual speed for you.

Machining brass, generally doesn't need lubricant, but a bit of coolant seems to help.

The other strange thing, is that I've had pieces that were straight, twist and bend after slitting.. so I'm wondering if the extrusion should be annealed before machining?

Regards
Ray