Bandsaw table/Good machinists shops in west yorkshire?

[YorkshireMartin]

Hi all,

Finally finished the semi-refurb on the 351. I'm left with calibrating it and the elephant in the room is the table. It's nowhere near flat, having a dip of 1mm oriented with the blade, extending around 4cm each side of the blade virtually to the full table length. Table is approx 2mm thick so I don't have much material to play with. It might be beyond redemption but I hope not.

Does anyone happen to know of a machinist shop in west yorkshire which they could recommend for flattening it? I've heard stories of high cost and so on, but I'd like to call around and as always, its better to go somewhere by recommendation.

Many thanks.

 

[custard]

I've never come across that before. I think removing metal should be an absolute last resort, only after everything else has been tried would I even think about going that route.

Is the table still distorted when it's removed from the machine? Maybe the way it's attached is actually introducing some distortion? Maybe there's a way of shimming the underside to correct the distortion? Just a thought.

 

[RobinBHM]

Is it a cast table? It looks like it, so It could be warped I suppose, the blade slot must mean a bandsaw table is not that rigid.

As Custard says, it would be worth unbolting it first and seeing if is still as distorted.

Im sure the metal bashers on here know the best way to grind it -blanchard grinding?

 

[beech1948]

I would not grind the table.

The advise to remove the table and check for flatness with all clamping stress removed is a good one. If this 1mm dip is caused by that then some judious shimming might remove the problem.

A better option than grinding would be to fill the dip with an epoxy metal eg JB Weld to try to level it. JB Weld will not set as hard as metal and would need to be skimmed on with maybe several thin coats. If too much is put on then it can be sanded back to level using the large flat sander strips used by car body people.

Once level this way then fix (rivet, glue, solder) a metal plate over the table. 2-3mm steel or aluminium would probably work ok. You will have to drill a hole and saw a slot for the band.

Al

 

[biskit]

I made a thick ply table to go over mine, rebated and dropped down. I wanted a slightly larger table anyway so I leveled it up as well. \/ turned out really good.

 

[beech1948]

Having a second thought about this....just put a piece of 12mm decent ply over the top. It will bridge the 1mm gaps and dips and provide a level table. Has the benefit that you can fit as large a table as you like.

 

[heimlaga]

Regrinding a table is sometimes a very apropriate fix but in this case I think th table is just too thin to grind.
2mm is very thin for a cast machine table. Are you sure that you have measured correctly?

Could you post pictures to help me underatand the problem?

 

[Jelly]

Regrinding a table is sometimes a very apropriate fix but in this case I think th table is just too thin to grind.
2mm is very thin for a cast machine table. Are you sure that you have measured correctly?

My thoughts exactly!

As a starter for ten, a magnetic chuck would likely pull it flat at that thickness (unless I'm misunderstanding and the dip is worn rather than warped into the table), resulting in it removing material but leaving an identical warp when the magnet is released, not to mention how flexible the remaining 1mm piece of material would be!

 

[flh801978]

Lots of the cheaper startrites have pressed steel tables I would imagine if its only 2mm thick thats what it is

Ian

 

[YorkshireMartin]

Lots of the cheaper startrites have pressed steel tables I would imagine if its only 2mm thick thats what it is

Ian

Hi Ian,

Is there any way to tell? It's an early 90's machine I think.

 

[YorkshireMartin]

Thanks for all the replies. Sorry I've been slow getting back to you, little lad has had a tummy bug so I've spent most of the past few days mopping up sick. Fun times.

Judging by what you have all said, grinding might not be the best option. I think first of all I need to identify whether the table is cast iron or steel. I'll get some pics to illustrate the problem, or actually a video would probably be better to show the variations across the table.

 

[DennisCA]

There's always the spark test, if there's a sacrificial area you can touch lightly with an angle grinder:
https://www.youtube.com/watch?v=cFf_x97vcQ0

Perhaps there are better ways.

 

[sunnybob]

If its really only 2mm thick, it has to be steel rather than cast. 2mm cast would be almost as fragile as a china plate.

 

[flh801978]

If you look underneath the table it should be obvious how its made
cast is one piece..... pressed steel is built up and welded

 

[blackrodd]

If you're 351 is the same as this vid,link below, I'd be inclined to either fill with a decent liquid metal and scrape back to flat.
Or mark out and bolt 2 stiffening pieces each side of the blade, front one would have to swivel, using csk machine screws and wing nuts, to allow blade changes
Perhaps a 15mm dural alloy strip and countersunk bolted to the stiffeners.
Maybe a bit of both to save anymore distortion
Using a false ply table will surely mess up the mitre slot and fence arrangements.
Regards Rodders


https://www.youtube.com/watch?v=mzgGFHt1Dts

 

[YorkshireMartin]

Hi gents. In keeping with family tradition, I caught my sons stomach flu so hence havent been online.

Thanks for the further comments in my absence.

I'm certain this is made of steel now rather than cast iron. I've enclosed a couple of photo's but I couldnt get a good picture of the unevenness of the surface.

I note the comments on liquid metal filler, but I think I'd be likely to mess it up. I'm not too worried about the mitre slot as I have other means of making such cuts and I dont have the mitre gauge for the 351 anyway. The fence has been removed and I have a Kreg to go on it, so if I do use ply to create a new table surface, I can simply position the fence rail to fit.

Would this change anyones recommendation? Is there any other way I could look at?

Cheers.

 

[DennisCA]

That's not cast. Perhaps you could go to a metal supplier and get some... maybe 10mm verfied flat steel plate and screw that onto the top? A cutout for the saw blade would be needed in the correct place.

 

[flh801978]

I would put that on my hydraulic press and push the bend out
If you fancy a trip to sheffield I'll do it for you

 

[woodfarmer]

I would be inclined to get a sheet of industrial plastic such as acetal about 10mm thick to put on top. Its relatively slippery and easy to cut an shape. best of all for slipperyness is ptfe but that is very expensive.

 

[YorkshireMartin]

I would put that on my hydraulic press and push the bend out
If you fancy a trip to sheffield I'll do it for you

would that be possible given the support structure underneath? I dont think it can be removed short of getting a torch out etc

Kind of you to offer!