Anyone got access to a milling machine?

[Big Mouse]

I've just bought a new morticer chisel and found that the fence is not quite square. At first i thought it had just been badly sprayed so I flatted it off with fine grad epaper but I think its just machined badly.

Its 6mm iron angle i.e. L shaped, I need it squaring off at 90 degrees.

Plus the bed they sent is made of mdf and I'd prefer iron or steel so if anyone has access to a bit of 18mm - 20mm plate about 400 x 120 I'd be interested.

I'll willingly pay for parts and labour because this will take up someones time

[Roadkill]

I may maybe able to lay my hands on the 20mm plate - will see tomorrow.

The workshop we use has a mill but it's an old Bridgeport and I'm not sure if it's up too much.

Not familiar with those tools - what part of the angle needs squaring off ?

[Andy]

Like this?



I would say get us some photos and an idea (fag packet drawing) of what needs doing, but right now its the last week of work before christmas and all my mills are stacked with work. All the same, pop up some pictures. I would personally say if its that far out, get a replacement one. If its of a chinese make, its QA will be so hit and miss.

[Big Mouse]

Thats very similar to what I have. Its a US make.

The fence is the upright you can see along the top of the wooden base; its not a million miles out of square but at one end its leans out, the other end it leans in, probably no more than a degree each end; it just needs squaring to the bottom of the plate so its a perfect 90 degrees to the wooden base along its length.

I'm in no hurry for it to be done, I can use it as it is but on a 4 mortice job, like a table with 4 legs, it can throw the job out quite a bit

[Roadkill]

Ah, I see.  

So you could mill it horizontally with a large diameter cutter / fly cutter . . . . or in its position shown, vertically, using a long cutter (but you'd probably get chatter).

If I still had access to a surface grinder you could skim that off in a matter of minutes using a mag-base.
I don't know anyone with a surface grinder, now, though.

Will make some calls about the plate, later.

[Andy]

If its bolted down is there anyway to check its not just being twisted out of true? Ie, can you unbolt it and put it in a flat surface and see whether it is being forced out of trueness or is just not true.

What I'm thinking is if it has machine marks on it like the one above, the casting could be out, meaning its not the fence but the location that its bolted to. If you were closer I'd have a look this weekend but I'm a bit tied up with end of the month work. I can see what I can do in the new year though.

[Roadkill]

Is it bolted to the MDF base ? - If it is that won't be enough to distort a 6mm RSA . . .

If the angle is hot formed there will be variation end-to-end.  The blue book allows for ridiculous amounts of tolerance . . . I'm guessing the U.S equivalent is the same . . .

Ray, what's the measurements of the Angle - ie. the "legs" ?

[Andy]

If it's like the one above, you generally have an iron casting (like a desktop pillar drill) that the rail is bolted to and the post gets bolted to as well. I'm only thinking if it is bolted to this casting and the height of the two (maybe more) fixings are out, very possible it's distorting the guide rail.

The one I posted a picture of I remember seeing at a model engineering show, the guide rail appeared to be machined rather than just stock angle. All speculation until we get some pics.

[Roadkill]

Ray,

I can lay my hands on either 100x20 Flat BAR or 160x20 Flat BAR x any length by the end of the week.
Flat bar, though, through the cross section isn't truly flat near the edge and tends to taper a little - I also can't get 120x20.

On the other hand if 120x20 is critical I can get the whole thing laser-cut (from plate) but the demand for 20mm being laser cut is low and to dodge minimum order it'd be sometime early next year when it's likely to come up . . . The plus side is that plate is flat and the faces truly parallel.

I'd suggest the plate is probably the way to go . . .

Let us know.

[Roadkill]

Got a second guy getting a price for 20mm Plate, pre-cut.

Price may be a bit more but you could have it just after Christmas . . .

[Big Mouse]

Thanks guys

the fence has a bar fixed to it like the one in the picture above - you can see the bar on the opposite side of the pillar - so it just slides through the central pillar to adjust the width of cut, its not fixed to the bed at all. A surface grinder would do it, the face needs to be square and 90 degrees to the bar. I was going to try and flat it on a glass plate at the weekend, we use to do flat planes the same way but they were generally flat to start with.

The plate would probably be the way to go as it would be more durable. I tried to level the mdf with shims which has helped a bit. I'll mortice a few bits of scrap this week to see how much its out of square so hold fire for the time being.

[Big Mouse]

OK, fence is now sorted after a bit of work but I definitely need a metal base as opposed to mdf.

If you can get me a price for a piece of laser cut plate please Dean, 450 x 150 x 20. It will need drilling as well; 2 holes centred along the centre line at 160 centre; 10mm hole and countersunk to take a 15mm head.  I can give you the exisiting mdf base to work from.

[Roadkill]

No worries - Drop the base in to me and I'll draw something up and get a quote.

[Big Mouse]

Thanks, I'll drop it off next week sometime

[Roadkill]

[Roadkill]

Ray - does this look about right to you.

It's based on the measurements above but is obviously slightly bigger than what I have here.