surface plate Brisbane

[mic-d]

My two bobs worth.
I probably know less about woodworking than I do about metalworking (which is not much) but I seem to remember reading somewhere that the base of a plane should be concave. Could this be to allow for wear?
Russell

A plane can have a bit of a concave in it, like the plane in my blog here:
#4 restoration Installment Three - Woodwork Forums

But this plane still has coplanar bearing points at the toe, heel and mouth. If a plane was truly concave, ie the toe an heel were proudest points, then as the rear end of the plane comes onto the work in a planing stroke, it will cause the mouth to ride upwards, diminishing the thickness of the shaving, maybe even to nothing. As the front starts to leave the work, the mouth will come back down to the work and the shaving will get thicker. You'll end up planing an outside curve into the work. Conversely, if the plane is convex you'll end up planing an inside curve into the work. The plane needs to be flat. But within reason. I don't mean laboratory grade flat. I'm going to add another entry to my blog soon about this.

As the OP, I'd really like to get back on topic to my original post (shoulda never mentioned a plane)

Cheers
Michael

[soundman]

You may be able to lay your hands on a spare wing from a table saw......then get it precision ground..... but you would want one that had some age in it..so the casting had settled down.

Lots of people are replacing one wing on their TSB saw benches and fitting one with a router hole in it.

Might be worth a trip to the local scrappers and see if they have a big old cast flat thing... and get it precision ground.

cheers

[new_guy90]

i can tell you now most tool making shops or fitting and turning shops will have ground plates from old jobs just sitting around, if your lucky you maybe able to find a suitable plate that they would probably sell you if you ask

[mic-d]

Hi Patrick, can you tell me what you mean by ground plates from old jobs? Are these plates that are offcuts from larger jobs? I suppose I should just call some shops, but don't really have a clue what to tell them I'm looking for!

Cheers
Michael

[new_guy90]

Hi Patrick, can you tell me what you mean by ground plates from old jobs? Are these plates that are offcuts from larger jobs? I suppose I should just call some shops, but don't really have a clue what to tell them I'm looking for!

Cheers
Michael

well some times jigs are ground for gang jobs and customers need stuff like plastic molds surfaced ground when these are no longer needed they just sit on the shelf and rust i cant say you could find a suitably large plate nor that it will be flat, with out holes or surface rust but it maybe worth a look into, a tool and die shop would be the best to go to as your average fitting and turning shop wont have the grinding equipment they do

[mic-d]

Thanks for the extra info Patrick.

Cheers
Michael

[mic-d]

Well call me stoopid but I just realised that I'll get a 500mm diagonal on a 400x300 granite plate and the longest thing I'll be scraping is ~540mm. Will I be able to get away with a 400x300 plate for work that length? I can get that size mcjing plate for $185 delivered to the wood show.

Cheers
Michael

[Graziano]

Well call me stoopid but I just realised that I'll get a 500mm diagonal on a 400x300 granite plate and the longest thing I'll be scraping is ~540mm. Will I be able to get away with a 400x300 plate for work that length? I can get that size mcjing plate for $185 delivered to the wood show.

Cheers
Michael

According to one scraping expert who posted on another forum recently, you can scrape up to twice the diagonal "with care". I'm assuming he's using lots of overlap when blueing/scraping.

[mic-d]

According to one scraping expert who posted on another forum recently, you can scrape up to twice the diagonal "with care". I'm assuming he's using lots of overlap when blueing/scraping.

Bewwdy! thanks for that, do you have a link to that thread? Looks like I'll go with that one then, at 35kg it's a bit more manageable than the 75kg 630mm one.
thanks

Cheers
Michael

[Graziano]

Bewwdy! thanks for that, do you have a link to that thread? Looks like I'll go with that one then, at 35kg it's a bit more manageable than the 75kg 630mm one.
thanks

Cheers
Michael

Here it is: Which cast iron straight edge type is better? - Practical Machinist - Largest Manufacturing Technology Forum on the Web

My memory must be going, it's the first post by a guy named Forrest Addy and he states that it's "chancy" with it getting trickier the longer the straight edge is.

[mic-d]

Here it is: Which cast iron straight edge type is better? - Practical Machinist - Largest Manufacturing Technology Forum on the Web

My memory must be going, it's the first post by a guy named Forrest Addy and he states that it's "chancy" with it getting trickier the longer the straight edge is.

Cool, Forrest is the man... Since it's only 40mm longer than the plate and light easy to manage I reckon it's doable. I'll get that smaller plate.

Cheers
Michael