3 hole drill jig

[Frank S]

I have always believed that anytime there are multiples of the same part which must be drilled requiring more than a single hole a jig or fixture should be made for repeatability.
Drill jigs also yield to the possibility of drilling through several parts at the same time as well.
This is the simple little 3 point contact 3 hole small part jig I was working on when the spindle bearings on my mill suddenly went south.
It consist of a top plate a bottom plate 3 equal length cylinders for locating the parts and holding the plates in parallel to each other


Since right now I only have to make 12 of these parts and my hardened drill bushings for the to outer holes had not arrived yet I decided just to forgo waiting and predrill the actual hole size for the parts in the jig rather than waiting I can always re drill the jig and add in the bushings later.
A lot of times I will make my own drill bushings then harden them as in the case of my previous left & right beam drill jig

[DIYer]

Thanks Frank S! We've added your Three Hole Drilling Jig to our Drilling and Drill Presses category,
as well as to your builder page: Frank S's Homemade Tools. Your receipt:

Three Hole Drilling Jig by Frank S

tags: jig, drilling

[metric_taper]

Frank, Do you have a preferred heat treat steel for making the drill bushings? But I'm guessing you have what ever you collected along the way.
My experience with silver steel is typically Oil hardening for making form tools.

[madokie]

now for those larger plates,,too big for a jig,, u can clamp plates together,, or like we did making gravel shaker units, just tack weld them together,then
Drill baby Drill!!!!! and later of course grind off welds..which i think is faster than making a fixture,, especially if fixture is not going to be used again..

[Frank S]

Frank, Do you have a preferred heat treat steel for making the drill bushings? But I'm guessing you have what ever you collected along the way.
My experience with silver steel is typically Oil hardening for making form tools.

When I make my own drill bushings I do pretty much like you said and use what ever I have found but what I like to use and is one reason why I collect them is to use old truck or car axles. Just torch off a section heat it up until it is hotter than the gates of hades allow it to cool slowly, machine out what I want heat again to just brighter than a dull cherry and drop it in a bucket of oil Since I'm not interested in making a knife out of it most times I don't bother doing the tempering step.
But actually in my later years I am getting too lazy to make my own drill bushings unless the ones I need are just ridiculously priced. especially if I need several of them why waste time machining and hardening something that I can buy off the shelf But I do sometimes buy the longer guides and cut them in half with a die grinder and cut off disk

[Frank S]

now for those larger plates,,too big for a jig,, u can clamp plates together,, or like we did making gravel shaker units, just tack weld them together,then
Drill baby Drill!!!!! and later of course grind off welds..which i think is faster than making a fixture,, especially if fixture is not going to be used again..

If I am only going to make a single run or parts then I will usually lay out 1 and use it as the jig for however many repeats I need to make.
But if I am gearing up for a production run of something which may be on going then a proper fixture is the way to go