CNCToolCat's Cat-House

So the new QT28 proves to be run-ready, except for a bum tailstock body clamp mechanism.

I noticed in the pics before buying a hydro line feeding the tailstock manifold was plugged off, so I new something was up.

Only way to find out: I re-connected the hydro line to the tailbody manifold, and powered up the QT.

Whoa! Hydro oil spewing out the bottom of tailbody.

So off comes the cover plate:




Low and behold, the problem was easy to figure out. The hydraulic clamping bolt was broken clean off!



In the above pic, I have already removed the pancake piston, and that’s the broken bolt you see in the center. It connects to a large clamping plate (in the rear) that locks the tailbody when the piston is activated.

Here you can see where the 40 mm bolt broke right at the corner of one of the o-ring grooves:




Mazak had the bolt in stock in Kentucky, but @ $700 that wasn’t happening. [emoji44]

Even worse, the lock nut was $900!

(Although for a 1995 machine, for the builder to have obscure parts in stock, that’s pretty amazing really).

So, I set out to machine a new bolt, nothing difficult really.



One design improvement was a minimum .05” corner radius in the 2 o-ring grooves!

Here’s the Mazak o-ring groove:
(Notice the ID corners)



And here’s the Cathouse version:



Next post will show how I use a 1988 Mazak QT15 using Mazatrol to make a new bolt, stay tuned.

ToolCat Greg

Where'd he go ?

So I took the family down to southwest Virginia (Damascus) in early August for a short vacation. Intent was to do some hiking, fly-fishing, bike riding, etc. There was a lot of rain but we got all the planned activities done by missing rain and being flexible.

I've always had the location on Greg's shop in the back of my mind (we both went to Virginia Tech), so I decided to call him up to see if I could stop by and meet an actual PM member face-to-face. I didn't want to take too much of his time, but I did just that! Spent a couple hours talking about machining, his Mazak's, the economic climate etc. The Barber Coleman gear hobbling machines were super cool. I had a blast!!

Anyway, thanks Greg for taking the time to let me stop by! I really enjoy meeting you (there are actual humans behind PM identities!) and the shop tour.

Been busy at the Cathouse, thus no posts as of late. (I still read PM about every day though!)

So, I picked up this 2012 Toyota Tundra regular-cab, long-bed, 2WD w/4.0 V6 back in August for hauling parts for the shop. Truck had 225k TX and SC highway miles, not a spec of rust, paid only $7K. Plus it had the nice fold-up tonneau cover.

I replaced the brakes at all four corners with Powerstop “towing” pads, rotors, and calipers, added a set of SumoSprings to the rear, and added LT tires.

I also changed all the fluids, and FluidFilm treated the frame and underbody.

She routinely hauls up to 2,000 pounds of parts around the hills and mountains of southwest Virginia and eastern Kentucky...not bad for a "1/2-ton" truck, eh?

The standard engine in the smaller Tacoma truck and 4Runner (and others), people talk about the all-aluminum 4.0 twin OHC V6 being a “dog”, but I think Toyota’s engine tuning and transmission programming (Aisin 5 speed---bulletproof), combined with lighter empty weight, make this truck fairly peppy.

Even with a load she gets up to speed and holds it plenty well enough for our use.

Plus, she gets a very respectable 20mpg when running without a load.

During the build years of the Gen2 truck (07-21), Toyota produced about two million Tundras, yet only 6,000 of those were regular-cab, long-bed models!

ToolCat