Thread: Sandvik carbide scrapers

Yes, I think a group buy is in order. I'll give that some thought over the next couple of days.

Greg

The ledges allow easier clamping to the tableland way back when I was told not to trust the first six inches in from the edge of the large surface plates we used. I was taught to slide parts and tools on from the edges so that may have been the reason. I still don't measure critical dimensions near the edges for that reason. You may want to ask Shars directly if all the tables have ledges as the sometimes use the same pictures to show multiple sizes of a tool if the differences are minor and they may have plates in stock without the ledges.

Pete

Thanks Pete...I'll do just that. Here's another question: do you think hockey pucks would be suitable pads for surface plates?

Greg

Originally Posted by Greg Q

Thanks Pete...I'll do just that. Here's another question: do you think hockey pucks would be suitable pads for surface plates?

Greg

You have hockey pucks? I don't see why not. They are hard and consistent in size. I have no interest in the game, or any others for that mater, so am not necessarily the best guy to ask.

Pete

A surface plate is certified across its whole surface, if the edges are inaccurate I can't see how it's making cert.

Greg you don't want anything compliant under that plate if you ever hope to use a level on it. I'd think the hockey pucks would be a lousy idea I'm afraid. I used 3 jacks at the airy points on mine. My current plate is 600 x 400 and the 25 x 2 SHS I used as a stand is waaaay too compliant as it is, the weight of the level is enough to tip the plate. Next stand I do I'll completely change the design such that the support is much better. Despite the noodle material, the way it was designed I thought it would be rigid, but it's not good enough for me.

Pete

Originally Posted by QC Inspector

You have hockey pucks? I don't see why not. They are hard and consistent in size. I have no interest in the game, or any others for that mater, so am not necessarily the best guy to ask.

Pete

Me either, thats why all my pucks are still new. Well, that and no ice. I get the hard-as-hell ones from Canadian Tire whenever I am back east.

Pete F...they really aren't that compliant compared to say, teeth and skulls, but I take your point.

GQ (freezing this morning in +1.5º weather-had to wear two shirts today!)

Originally Posted by Pete F

A surface plate is certified across its whole surface, if the edges are inaccurate I can't see how it's making cert.

Greg you don't want anything compliant under that plate if you ever hope to use a level on it. I'd think the hockey pucks would be a lousy idea I'm afraid. I used 3 jacks at the airy points on mine. My current plate is 600 x 400 and the 25 x 2 SHS I used as a stand is waaaay too compliant as it is, the weight of the level is enough to tip the plate. Next stand I do I'll completely change the design such that the support is much better. Despite the noodle material, the way it was designed I thought it would be rigid, but it's not good enough for me.

Pete

Pete, I understand about the 25mm being too whippy-do you have your stand on castors? I really wanted to put my plate atop the tool box I'm making from 40mm square aluminium extrusion and MDF, but I can see heartache in my future going that way.

Greg

Yes mine is on castors with levelling feet on the stand, that's where the compliance problems come in. Clearly the castors and feet can't be in the same position and I chose the castors to be outboard for stability while moving. This plate isn't that heavy (50kg???) so I thought the material I used would be stiff enough. In fact I could have used material twice that size and I would have seen the same thing, just less. I think more important is to design it so there is a vertical load path from the support points to the leveling feet on the floor. The path should be as straight as possible. In my case I made a stand with a bunch of drawers within it. But next time I'd design the stand to support the plate, and then work out what drawers I could get in after.

Of course all of this is immaterial if you don't need the plate to stay level, in which case all the stand need do is keep the plate off the dirt. However a level is a mighty powerful instrument and it's a shame to not be able to use it.

I agree Greg, when frozen and travelling at 100 mph toward one's head a frozen hockey puck doesn't seem very compliant (btw you blokes claim to be from Canada and don't like hockey? What's the world coming to the current Stanly cup series is a cracker!!). But there's no need for ANY compliancy beneath the plate. I used some 12 mm bolts and rounded the heads IIRC, but some commercial stands use pads. I don't think it's necessary to have 2 lots of leveling as I have done. You will something other than castors though as they're also too compliant.

Unfortunately once a heavy casting is placed on a plate, invariably slightly off-centre, things will move in ways you'd possibly never expect. I know when I went through the process it was extremely frustrating and something I'd p hope others could avoid.

Pete

Pete, thanks for the info. I really did have my heart set on using the top of the tool cart, which is going to be already dealing with 400kg of contents. The big plates weigh about 170 kg.

I too like levels for survey, and own a bunch of them. The last ones I bought strictly for machine repair as opposed to set-up. Having a plate that is not only flat, but horizontal* too makes everything much easier. Easier said than done though.

*or at least normal to the local gravity vector.

Greg

Agreed Greg, this the type of thing that makes the whole process difficult. As far as I'm aware, a plate is only guaranteed in cert if it's supported in the same way, and I believe that in the case of granite plates that's st the airy points. It would be much easier to support by the edges but I don't think that's according to "the rules".

Pete

You are correct about the airy points. I am just trying to avoid creating a top-heavy thrill ride with 170kg going into divergent oscillations A civil-engineering cautionary tale in small scale!

GQ

Hi Greg,

Here's an alternative mounting for a surface plate.

I've gone to a bench style mounting for my tiny (400x400) surface plate, the bench has a light box behind the plate (which kind of washes out the picture) but is a nice clear light for checking edges. The Avery Rockwell hardness tester ( which is the "real" reason for building the bench) lives at the other end.



There are only the 3 levelling points for the plate, the other points are to stop rocking, and don't actually contact the plate.

Drawers for bits and pieces will go underneath and shelves on the back.

The legs are 65x65 SHS, the pads are Aluminium for the levelling pads sitting on M20x1.5 Bolts, tapped into 10mm plate.

Regards
Ray

To answer Greg's earlier question, and to confirm other's input, the scraper handle comes with 1 insert installed, an allen key and plastic type handle. The extra inserts are $56 + gov rip off each and come in a dandy holder, just a bit bigger than the insert with a spring loaded plate that pushes the insert up, a bit like a rifle magazine. Alan.

Ray I've never seen a light box like that but an excellent idea, sometimes it's difficult to see the light squeaking through squares. I take it by rocking you mean if something tipped the plate? Otherwise if it's on 3 points it clearly shouldn't rock.

Pete

Edit: looking at the picture again Ray, I'm pretty sure I did the same thing with mine (sorry it was a while back & I can't recall the specifics now) for the same reason; a bit if a safety net in case the plate tipped at the end where it's supported by just one point