Hi,
Happy New Year everyone.
I have an arceurotrade sliding tailstock die holder containing 6 metric and 4 imperial sized holders for different sized die diameters.
I am very happy with the kit except that the ID of the die holders are almost the same nominal ID as the die itself, this leaves no room for slightly expanding the die. Interestingly there is no coned grub screw fitted in the die holders to facilitate this!
I have been reading an article that GHT wrote back in the late 1970’s where he described making a very similar set. However, he measured the dies in his collection and found that the 13/16 dia and 1 inch diameter dies were within a tolerance of 0.000 to – 0.003. He therefore bored out the housings in his kit to around 0.015 (15 thou) larger than the die diameters. Obviously this would create enough “space” inside the holder to allow the die to be slightly expanded if needed. This seems logical. I have also measured the ID of some die stocks that I have that are also slightly larger than the dies I have.
So I have decided to bore out the holders I have in my kit to around 15 thou larger than the die, following the expert advice of GHT.
So my question is though, what is the tolerance of the typical OD of a die (metric and imperial)?, I cannot seem to find this anywhere other than “nominal” sizes.
My kit includes holders for 16 mm dia, 20 mm dia, 25 mm dia, 30 mm dia and 38 mm dia. My kit also includes the imperial set, these being 13/16″, 1″, 1 5/16″ and 1 1/2″ dia. holders. Sorry to mix up imperial and metric, but am I right in assuming that any housing to contain any dia should be slightly larger to accommodate any adjustment i.e. “expanding” the die? (I am talking about “split” dies here).
I am going to modify the holders and replace the fitted cup point grub screws that are ineffectual in expanding the die and fit coned stainless steel grub screws that engage in the “split” in the die for the purpose of “wedging” (expanding) the die.
Interestingly, GHT in the same article, had 4 die adjusting grub screws at 90 degrees around the holder, instead of the more traditional 30 – 0 – 30 degrees, one of these grub screws was coned the other 3 were cup point and simply used to compress the die slightly.
Any comments would be welcomed.
Regards to all
Derek
Bit of a retorical question, but I thought it might be useful information for a prospective purchaser.
Some years ago, before getting my current mill, I purchased a used Seba 6″ horizontal / vertical rotary table. It was a bargain buy at an amateur radio rally. Fast forward to this week and I need to make a 115mm diameter hole for a cooling fan in a aluminium panel. This is for an electronics project and the panel is from a 4U half rack case that I’m repurposing. Having aquired a mill (from ARC Eurotrade) last year it seems a no brainer to use it and the rotary table to cut the hole. But would the large 6″ table fit on the little SX1-LP mill? And second can I rotate the 240mm x 130mm panel through 360 degrees with the center of the hole offset to one side?
The answer is yes, I can.


The plate and thin ply backing are held to the table by screws in the fan mounting locations (105mm square) into nut plates in the rotary table T-slots. I made the plates a little long and they fouled the table clamp screws. It was easier to remove the clamps than shorten the plates and re-align everything. The rotary table centerline is on the center of the mill table. The only problem I had was the aluminium was a bit soft and stuck to the cutter so I used lubricant. I also made the initial cut inside the requred diameter and then finished with a light cut. I need to get a MT2 center to make alignment easier. A good learning experience for me being first use of a rotary table and a lot easier than chain drilling and filing.
Robert.
Does anyone know of stockists for Seig C6 parts.
Both Axminster and Arc Eurotrade seem to have little on no stock.
I’m specifically looking for a saddle leadscrew and back nut.
TIA