PM-1440GS or PM1340GT lathe or maybe a PM1440GT

I'm trying to figure the best way to open up the gear cover, something like Jay (jbolt) did to his, to allow the cover to be used with the spider and keep the spindle as short as possible

One issue to consider on the 1440GT is that the upper cover retaining stud bolt is directly above the spindle and a very short distance away. In other lathes like the 1440GS (and Grizzly models) the cover retaining stud bolt is offset to the rear of the spindle so it will not interfere with the spider bolts. On my 1240GT spider with a 1.59" bore and a spider OD of 2.5" I usually use 1.5" cap screws with an added brass tip or aluminum fingers, you would probably need 1.75"cap bolts. So I would check if this is going to present an interference problem with the cover bolt, and also take into account if external to the cover the interference with the knurled screw on finger nut that retains the belt cover. On my 1340GT I cut down the length of the upper finger nut about 1/4" so it would not interfere with the spider bolts. You might determine if the extra ~1.5 " closer to the headstock is necessary vs spider bolts a just outside the cover. One suggestion to consider is to cut a rectangular window in the gear cover similar to what is seen on the 1440GS, this could be done with a dremel or die grinder with a thin cutoff blade and you could use epoxy metal glue to attach two vertical strips of aluminum to the cover back in the front and rear sections of the window, tap some threaded shafts into the strip and use small thumb screws to retain the window in place when not using the internal spider bolts.

One other consideration on the spider, is two have two sets of holes for the spider bolts, one set is internal to the cover, the other is external to the cover. I have done something similar to this on my spider. Most of my work is done with longer stock, so it makes it very easy to use the external spider bolt holes. If I need to need as close as possible to the headstock, I use the second set of bolt holes closer in, I also used brass tipped allan set screws which are have 1/4" shorter threaded section and no cap than the Allan cap screws (see below). This allows them to not interfere with the upper cover retaining bolt. If you used the latter, you would pop off the cover, set the spider bolts and replace the cover (or add a window). Last but not least for very short barrel work, I have seen a sleeve attached to the barrel and then the sleeve extends past the spider and is used to set the alignment.
Cap screw vs. Allan screw spider bolts.
20160401_090533.jpg


1440GS vs. 1440GT upper belt cover retaining bolt location, multiple spider location bolt holes.
Spider cover modifications .jpg
 
The cover on the 1440gt is about .090" steel so it fabricates and welds well. I cut mine on my little CNC router but it could be done easily enough with a cut-off wheel and a die grinder. I did shorten the upper stud and knurled nut for more clearance.

The other option is to just open up the cover hole for clearance and then remove the cover when you need to use the spider.

For barrel work on short barrels I just use the steady rest.
 
Thanks guys, I will review your ideas. I appreciate your thoughts/experience.
 
Got that first ten thousand dollar part done yet? :cautious::D They get less expensive the more you make. ;)
 
Hi Jay, actually I started the spider yesterday. I had a little trouble finding something with a large enough diameter to start with locally, that was affordable LOL, then I stumbled on to a 4" piece, pretty cheap, (it's $70.00 per foot here regularly).:eek:

Now just deciding how much to reduce it to. After I opened up the cover to ~3.6", the diameter of the recess cutout, I turned the OD to 3.4" to see what it looked like and to figure metric bolts for the attachment points and alignment bolts. It's pretty massive. 3" may have been a better choice but I'm not done yet either. So not quite $10K, but a start. I know I didn't need to start out with 4" but I got lots of practice trying out the new carbide inserts I got from Matt, I got his master set with the lathe. They work great. Now I want a threading set in BXA also.

I mounted the sensor and ran the wiring out to the tach location. I need to mill out the AL box that holds the tach soon. I have a 12VDC power supply to power the tach in my electronics stuff. That's all from here for now.

I can't believe how smooth and powerful the PM1440GT is. I easily cut .060" depth, fast. This is my first time with indexable inserts, wow. The 10x30 will probably be for sale soon, unless I decide to keep it for really short work.
 
Does anybody in colorado have a PM lathe of any kind that I can look over amd play with a little bit. I would prefer a 1440gs with dro but my shop fox is junk and needs replaced

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