I've managed to get along without a clamping kit for my Big Red Mill/Drill ( HF 42976) for some time now, but it's time to bite the bullet.. I've seen comments about this Mill/Drill and am checking Ebay for kits... A bit confusing, to say the least. The upper slots in my table are .490" wide, or about 12.49mm and the lower slot very close to .625".... 3/8" kits are available on Ebay, but mention half inch slots... Will the kit on ebay (for example,
In a pinch, yes, but puh-leeze, with what the imports cost, and the time/effort/do-overs/materials required to DIY, no way. You have the machines to make stuff you can't buy at all, or can't buy cheap.
I can't say the nuts in those specific kits will fit in your table slots. I haven't purchased one, but when I was looking at the a while ago, JTS Machinery (in OH), had imported 3/8" sets for about $28 (+ship). Since your table slots are already under .500", that leaves little material at the sides beyond the 16 pitch threads. The 3/8"-16 hardware should be adequate, but the machine accessory parts from China are known to have a few inaccuracies.
The parts in those sets might be useable, but I would anticipate a few goobers. If the T-nuts are of adequate size or oversize, they can carefully be ground to fit. The corner of a bench grinder wheel probably won't do a good job of resizing. The nuts may have some case hardening, and to keep the rabbets straight, mounting them fixtured to the mill vise would keep the faces square. An end mill may or may not be able to cut the case hardening. A shaped/dressed mounted stone would be capable of light removal for dressing them up (dust protection recommended).
You could bypass the nut rework by making a couple of sets that fit, from mild steel. A couple of extra length nuts with tandem holes will be very handy to have at times. Then you just utilize all the kit components with your own T-nuts.
I use T-nuts and clamp bars that I made out of CRS, along with a bunch of grade 5 3/8" hardware. I avoid using all-thread rod, because I believe it's failure prone. The same goes for the cheap ungraded or grade 2.
A source for studs is an auto parts store that has Dorman hardware. I've found some tough 3/8" exaust manifold and engine block studs of lengths that work well for a lot of small parts.
If the nuts don't fit you could anneal them and mill them down. Soap them up with Ivory etc. to cut down the scaling, put in a tin can about half full of charcoal, heat to red with a propane torch, preferably outdoors. Let them cool slowly by covering the can. If they don't file easily, try heating hotter.
If you make your own don't run the tap all the way through. The rod should jam in the threads before it touches the bottom of the tee slot.
This is the sort of job an old surface grinder is good for.
I have the same size T-slots on my Delta DP350 drill press. They appear to be metric (12mm slot, 10-1.25 threads, available from MSC), but US
7/16-inch slot width T-slot hardware (with 3/8-16 studs) fits just fine. Note that 7/16 T-nuts come in two possible threads, only one of which is
3/8-16. I standardized on 3/8-16.
I didn't buy a full clamping kit as it would be overkill for the little drill press. Instead, I bought two adjusta-clamps, some T-nuts, and some studs.
As you suspect, US 1/2-inch slot hardware is too wide.
T-slot dimensions are standardized. Look in Machinery's handbook for details. This is how I was able to figure out that 7/16 hardware would fit, sight unseen.
I got the data from pages 1132-1133 of the 20th edition, which I bought in 1975. What is referenced is ASA B5.1-1949, and it's pure inches, and lists the 7/16-inch slot size.
I just got a copy of the 27th edition, and its data (pages 1664-1666) on T-slots is for some modern merged US-metric that no doubt will someday be used. What is referenced is ASA B5.1M-1985 (R1998), and it's a mixture of millimeters and inches, and has no 7/16 inch size. Nor is it obvious that the Delta DP350 slots conform to this newer standard; there must be a pure metric T-slot standard as well. Does anyone know what it is?
What is your experience using this machine? (What is the concensus of this newsgroup?) I've thought about buying one of these as a replacement for my $50 benchtop drill press -- I dare say it would do better than that little thing, plus give me some limited milling capability ... but how limited?
Thanks for all the info gentlemen!! I've decided to go with the 3/8" kit and re-fab the nuts as necessary. Can't be too much modification here, eh? Just not enuff time on the calendar to make all my own...
I have had mine since they first became available serial number 60. There are some limitations, but itis everything I needed in a light duty mill. If you understand and know you can live with these limitations it is one of the better buys around. Check the yahoo group
Frankly, I see no reason to anneal the t-nuts. It's not like they're hardened; they simply have a black oxide coating for protection against corrosion.
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