Steel/Ally strength for a Biesemeyer style table saw fence.

[Tugalis]

Hi,

My Mrs runs a small furniture making shop and has asked me to build her a Biesemeyer style fence and rails. The majority of plans I seem to find ask for 16 guage steel for the rails and steel plate for the T section of the fence.

I was hoping to use ally extrusion for the actual fence so got to thinking of using it for the whole system. It would certainly make it easier to lift and move the T section.

I've not done a huge amount of work with Ally so thought you people might have some ideas, do you think 1.5mm ally would be ok for the rails or would I need to go for around 3mm? If the fence is ally then it will hardly weigh anything so it's just the strength needed to ensure the fence is secure. I think the main problem would be when I come to clamp the fence to the rails using a standard toggle stay clamp, would it dent the ally? Would I be spending a huge amount more buying box section ally instead of steel? Is there any real need to do the rails in ally now that I'm thinking about it, they wont move from the table....

Here is a link that shows the sort of design I will be going for http://m.instructables.com/id/Table-Saw ... /?ALLSTEPS


Thanks for all the help in advance,

J

 

[SpoonsbySven]

Hi Tugalis,
Thanks for the link to the instructable- that looks like a nice fence.
Speaking from a theoretical point of view (ie: I've done some research and thinking about a TS fence, not actually done one!): I would go for steel over ali for two reasons:
1) Strength/durability: steel is stronger and more durable than ali, so less movement and better able to withstand knocks;
2) Cost: easier (and cheaper) to obtain steel of the correct dimensions than ali (unless you have some appropriate ali knocking about)

Ali is obviously lighter than steel, but given it's part of a fairly heavy setup (table saw and cabinet), for me, weight would not be high up on the "design considerations" list.

Also, although the instructable doesn't call for any welding, welding the T-square is a good (although not essential) option, and welding steel is MUCH easier than welding ali!

You may have seen it, but if not, check out John Heisz's website ibuildit.ca for a good article on building a fence. There's a downlodable Sketchup model of his fence too: http://www.ibuildit.ca/table-saw-4.html

Good luck! Let us know how you get on.
Cheers,
Sven

 

[Tugalis]

Cheers for the website. I've never seen that one before, I'm going to enjoy looking over what he has built. Very impressed with the table saw!

I think I will go with steel, no need for the ally. I might use some extrusion for the fence so I can slide jigs onto it with ease....well that's the plan lol. It's been a while since I've welded, might be an excuse for a other tool though so good call! If not I can just bolt it together, has anyone tried to braise steel...would this work for fixing the T section? Think I would just need to work some way of fine adjusting the fence to keep it in line with the blade. Maybe weld/braise the T section solid and then have some sort of fine adjustment where the extrusion is connected to the T section. I would be tempted to create slightly large slotted holes for the fixing bolts to go through but that might give it a little too much movement if it was knocked....decisions decisions

 

[Normancb]

At the risk of starting a safety thread, you may want to have a look at some of the HSE guidance on safety of circular saws, which are responsible for a lot of accidents. There's lots of stuff on the HSE web site, but avoid anything from the US - their saw practices are dangerous.

Of course, you can do as you please in your own workshop, but in Europe it's generally considered a significant safety risk to use a fence which extends past the blade as the US designs do. The rear part of the blade is moving upwards. If the work gets trapped between the fence and the blade you can get pretty violent kickback, which can't happen if the fence isn't there.

I have an Inca saw which has a fence made from box-section steel locking to an alloy rail running across the front of the saw. The fence extends just past the front of the blade. It's absolutely precise and rigid, and very much safer that the Biesemeyer design because, with the proper riving knife in place it pretty much eliminates one major cause of accidents. There's really no need for a fence which runs right across the table.

 

[Bigbud78]

From looking myself a lot of people use a sacrificial fence up to the blade to create the gap after the blade.

I personally have got all the steel now for my fence build so will be starting fab this weekend hopefully, my new fence rail will hopefully carry the original Axi alu fence's. Both the long and short one with the ability to rotate them for the lower fence height.

 

[Tugalis]

Thanks for the thoughts guys. It's very much appreciated. Apologies for not getting back sooner, we have been busy in the workshop!

I understand what you mean Norman in regards to the length. In all fairness we mostly cut down plywood boards on the table saw (majority is done on the band saw now) but we do use other woods. I agree kickback can be a bit of a pipper, there is a nice dent in a cast iron rad where a piece of 12mm birch flew into it (the other wide hit me in the guy) lol so I am VERY aware. The idea was to run a long fence however use a sacrificial piece of wood that only goes as far as the blade. This would be helped by using the extrusion so that I can slide and lock it onto the main fence if that makes sense....I love my jigs!!

Aby ideas of where to get the steel from, have you guys bought online or is there somewhere easier to get it? I'm going to pop down to the local blacksmiths, we actually have one but he makes huge fences and gates for the rich, to see if I can just buy it off of him. Might even be able to get him to cut it down to size for a few beers if I'm lucky!

Cheers again!