- Thread starter Turbo
- Start date
Thanks for your suggestions, I'll try & answer your questions in a general post, apologies if I miss anyone. 
I always use roller stands either side of the saw for cutting long stuff so I don't think that was the cause of the warping.
I don't really want to cut/grind anything off it. As well as being difficult to do accurately it will further weaken something that is obviously already weak. I'll try to measure how much the bow is to see how much has to come off.
I am dubious too about heating it but I might try it.
My favourite suggestion is to plate it over with a lump of hardox or stainless plate, fixed with csk bolts, shimmed at the bolts to get it level & bedded down on chemical metal in between the bolts. That will allow me to get the base square with the vertical swing of the bow (it has always been slightly off square). If I talk nicely to a local engineering company they could supply the plate as well as cut the slots on their cnc plasma!
I think the 2 ends of the base where there's no slot is not bowed so it would be a good reference to mount the plate level.
I always use roller stands either side of the saw for cutting long stuff so I don't think that was the cause of the warping.
I don't really want to cut/grind anything off it. As well as being difficult to do accurately it will further weaken something that is obviously already weak. I'll try to measure how much the bow is to see how much has to come off.
I am dubious too about heating it but I might try it.
My favourite suggestion is to plate it over with a lump of hardox or stainless plate, fixed with csk bolts, shimmed at the bolts to get it level & bedded down on chemical metal in between the bolts. That will allow me to get the base square with the vertical swing of the bow (it has always been slightly off square). If I talk nicely to a local engineering company they could supply the plate as well as cut the slots on their cnc plasma!
I think the 2 ends of the base where there's no slot is not bowed so it would be a good reference to mount the plate level.
Screwdriver
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I would definitely machine the bed flat before bolting anything to it. I cannot see how bolting two flat surfaces together could cause the bed to bend. Have you checked the vice for flatness?
If you are going to bolt a Hardox plate over it then it will vastly strengthen the part so even if it is made weaker by machining it first, that shouldn't be an issue.
If it is not cutting straight, have you checked the alignment of the pivot shaft compared to the bed? You could use winding sticks to measure it visibly. If it is way off it might be a twist in the chassis which has caused the bed to distort.
If you are going to bolt a Hardox plate over it then it will vastly strengthen the part so even if it is made weaker by machining it first, that shouldn't be an issue.
If it is not cutting straight, have you checked the alignment of the pivot shaft compared to the bed? You could use winding sticks to measure it visibly. If it is way off it might be a twist in the chassis which has caused the bed to distort.
slim_boy_fat
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Know anyone with a decent-size linisher?
Screwdriver
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It's one of those situations when you want to find the cause of a problem before you decide how to fix it. If the bottom of the vice is flat, it might be unevenness underneath where the nut pulls up from. If that's out of plane it could cause uneven stress.
So I did a bit more measuring & it turns out that the section of the bed below the slot is spot on parallel with the pivot pin for the bow & square to the vertical swing of the blade. So the resulting bed after any processing will have to be parallel to that.
Using a straight edge & feeler gauges I worked out that I had to remove 0.3mm from the lower side of the slot to get it level with the lowest part of the upper side. The rusty bit is beyond the throat of the saw so I decided to try leveling there first as it wouldn't matter if I screwed it up.
I started out with a newish flat file, it was working but very slow. I ended up hogging the bulk off with a flap disc on a grinder at its lowest speed until I was under 0.1mm then switched to the file.
Didn't get it perfectly flat but its under 0.05mm. I found that if I went any further it was getting worse due to the file rocking at the end of the stroke.
Since it worked so well I kept going, around half way there!
The rest will have to wait a few days. We ran out of heating oil so I had to climb onto the oil tank & pour in 3 x 25l drums to keep things going until we got an oil delivery. Today my left shoulder feels somebody is sticking a knife in it! The right shoulder is ok so the steroid injection I got in it last week is obviously working! Got an appt today to get the other shoulder injected next week, can't wait!
Brad93
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have you got a small surface plate?
Use contact adhesive, stick some 120grit wet and dry to it.
