Bills comment brought up another thought: is one thing like the spindle metric and the other like the cutterhead SAE? Again, more details would be beneficial.
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Bills comment brought up another thought: is one thing like the spindle metric and the other like the cutterhead SAE? Again, more details would be beneficial.
There is a lot more to it all because as the shaft sizes get larger, the classification changes its letter designation even for a given range of numerical tolerances. Or said another way, a given letter designation actually means different numbers for different shaft/bore sizes. And 30mm and 1 1/4" might be in different classes, and 40mm and 50mm could be different again. I got my numbers from Whitehill but can't remember what shaft size that was for.
Probably the other way around, the block would be metric based.Originally Posted by Paul Haus
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I have Whitehill blocks in both 30mm and 1.25”. They fit their respective spindles just right…no detectable play, but they slide slowly and smoothly onto the stack.
Greg
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Bill, not sure I agree with your + and - . g 6 for the shaft in the example of 30mm, 1.25” and 40mm diameters can be exact size or in range of micrometers slightly smaller. H7 for the bore sizes is always larger in micrometers.
Andrew’s shaper looks Euro to me and even with a 1.25 shaft they would be using ISO standards. I suspect if his fit is off it’s the shaft. From the score marks in his video looks like it has been spun many times.
Joe, it's a confusing world, sometimes people refer to the size as deviation from a number, and sometimes as size to provide clearance. Ie the shaft for g6 itself is under a perfect number (-) but made to provide clearance (+) to a hypothetical perfect bore. Doesn't make it easy.
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Brent, not confusing at all. Remember H7 is for the bore not the shaft. Plus is bigger, minus is smaller.
see attached screen shot.
6B98E19B-D1B1-4193-A4B6-CE0FDE0E6480.jpeg
Joe as I already said above the capital letter (upper case, in this case "H") refers to the tooling that goes on the shaft, ie. the bore. What I'm saying is that if you spend enough time in the machining world, you will run into people will refer to that the opposite way. They mean the same thing, they're just referring from a different point. I don't know for sure, but just guessing that it may be what Bill was doing.
[OP]
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If I do get a replacement spindle... I'm guessing I should get one with a female thread on top so that I can run a flush cutter? Is this a design you guys use much / wish you had?
[OP]
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Mine is a 1 1/4" spindle...
Before I had twin tenon cutters I flush mounted mine a lot for tenons one side at a time, so it is a nice feature. Double discs are "better" but with care in good hands, perfect results can be achieved with a flush block for tenoning. Did your combi come with a washer and cap screw for that? Many modern spindles for new machines come with some version of that system. I've had many spindles made for different machines over the years and have always had that system made.
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Andrew, I had that many years ago with a Delta Shaper (1975). On the plus side for cutting one side tenons you can cut long tenons without the shaft interfering and you will save money on cutters. The negative side it is a pain and subject to many inconsistencies due to material thickness, chips under the workpiece etc. if you are a hobby shop OK but if you do this for a living it will add many variables and setup time.
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You will likely need to get a new spindle made (at a machine shop or otherwise) as opposed to finding one already made…unless you find another donor Griggio of similar age and size with the same spindle specs, if you’re going down the road of looking into spindle replacement...
You could also consider Prolock for spindle replacement, though I’d imagine you would be in the ~ $1200-1500 range for that. I had a replacement 1 1/4”, 6” tall “standard” spindle with spacers and top nut quoted from Bobby at Woodworker Toolworks for around half that amount not long ago, fyi.
I’m sure others will add to this, but mounting a cutterblock at the very top of a spindle would call for a shorter overall shaft length ie: “stub” spindle and is typically in addition to a normal length spindle. I have not run into a situation where I really wanted that specific option personally, though I’m sure they exist in certain situations if you didn’t want to buy more task specific tooling like a pair of tenoning discs.
When you say flush cutter are you talking about template work with a bearing / ring fence or similar? On my (smaller) Griggio I can run a 4”x4” helical carbide head with a matching OD bearing on top and the hole that the quill retracts into is larger diameter than that so I can lower the spindle enough for the extra cutters to retract well below the table for top bearing work. I do not have one but have seen Joe and many others post photos of this type of work with a ring fence / dead collar in place which performs the same function as a matching bearing (for the template to reference)
Not shown here, but good to have some type of dust / safety hood in place around as much of the cutterhead for DC and safety reasons. Still working on that in my setup as this machine is new to me.
Last edited by Phillip Mitchell; 06-08-2023 at 8:57 AM.
Still waters run deep.
Phillip makes a good point, that if you plan on tenoning a lot, it's a good idea to do it on a stub shaft as it puts the load closer to the big top bearing. Can be done otherwise of course, but I'll say a stubby is better and is how I do it. Machining time is often a lot lower with a simple bored and threaded hole in the top so might be less expensive. You can get professional quality results tenoning this way ( people do with dado stacks in 120v cabinet saws, and hand saws and chisels before that!) but for larger volumes double discs will pay for themselves. It all depends on what you in your shop do a lot of. It's a balance every shop will find differently.
If you do have a spindle made, it's good to give them your factory one so they can copy the bottom part that ought to be undamaged. This will be critical to fit. Also, if you notice on the bottom and top of most cutterheads there is a small chamfer along the bore. The inside "root" at the bottom of the new shaft needs to be smaller than this so the blocks sit down where they're supposed to. I always give the machine shop a new cutter block to use for test fitting. Nothing like the real thing to go along with number specs for testing
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