Urgent help please...

[Clw]

I have and am very happy with the Startrite SD31 P/T. Somehow today the blades got a little ding which is leaving a ridge on the wood. I have a lot of cherry that I need to machine before I can proceed with the job which is on a very tight deadline. I have the new blades already but this is the first time I have needed to change them. The machine came with a jig (pictured, hopefully) which I have no idea how to use, the manual does not help, and I can't find anything online. I don't really have time to wait for a better jig to arrive.

Any help would be greatly appreciated.

Thanks, Colin

 

[Trevanion]

I'm not sure what purpose that bit of aluminium extrusion serves, but this thread might help you out:

https://www.ukworkshop.co.uk/forums/post1283170.html

 

[Clw]

Thanks, don't have plate glass but do have a straight edge so will put that on some paper and try that method. Was hoping that the aluminium jig was something that would make the process quick and easy. If anyone knows how to use it I would like to know...

 

[Sgian Dubh]

Any help would be greatly appreciated. Thanks, Colin

Here's a short term solution that may be able to put off changing blades until after the big push.

Slacken the gib (wedge) screws (bolts) of one of the knives until the knife is free. Slide it along three or four millimetres to the right, ensuring the moved knife end doesn't hit the fixed machine casting at the end. Retighten the gib screws. Rotate the cutterhead to the next knife, slacken the gib screws on this knife, and move it to the left a couple of three millimetres. Lock this knife, making the same check regarding clearing the machine's castings.

Now you've offset the chips in two of the knive's cutting edges, and you should find you get a clean cut, or at least a cleaner cut, even if your machine has three or four knives. In addition, this temporary fix shouldn't take more than a few minutes to accomplish. Slainte.

 

[porker]

Take a look at this video where Peter shows his new toy and has a similar jig to the one you show and how to use it.
https://www.youtube.com/watch?v=YuTkYUCX3ao

 

[dzj]

Moving blades laterally is the usual course of action with these things.
But even if you do nothing, sanding or a smoothing plane will do away with these ridges easily.

 

[Clw]

Thanks very much for the advice, next time I get a chip I will offset the blades as suggested. I was starting to get tear out anyway so this was the push I needed to actually change them. Just got back from the workshop having gone back after the little one was in bed to align the blades. I had already swapped the blades before properly considering the alignment problem (showing my inexperience) I think I have got it using the wood and pencil mark, but will now watch Peter's video so if when I go back in the morning I'm not happy with what I've done I can follow his advice (not for the first time!)

I'm internet/magazine taught so every new situation seems to be a steep learning curve...