CX701 Lathe Report

[Mike Bondarczuk]

Hi Brian,

Very comprehensive update on eh eCX701 and can anyone confirm whether this is the same design as the Warco WM 290V which happens to be on offer at the moment with a DRO fitted as standard.

I am deciding between the WM 290 and the GH 1236 gear head lathe also from Warco. Does anyone have any experience of the gear head lathes as my first impression when visiting last week is that it is quite noisy in operation.

Thanks in advance,

Mike

[Jasonb]

Basically the same but it does not have the more powerful AC motor and inverter drive that the latest Warco 290 has. And you get a micrometer carrage stop with the Warco too

[Mike Bondarczuk]

Thanks Jason,

Will visit the Warco stand, as well as the Chester stand, at the Midlands Show this week-end.

Mike

[Brian Rupnow]

Yesterday marked my first true test of the longitudinal power feed on this lathe.  I had a 12" length of cold rolled round steel that I wanted to use on my bandsaw conversion, and for some strange reason the entire length was .003' to .004" larger than .625".--Not much, but enough to keep it from sliding into the sheaves or bearings I was using. I chucked it up in the new lathe and made two cuts, each .001" deep over the full unchucked length using the power feed. It was a delight to see the fine chip coming off and the resulting smooth finish. I held about 6" in the chuck and turned the first 5 1/2" from one end, then flipped the part around in the chuck and did the other end. It left a small difference in the center where nothing rides on the mandrel, but nothing that some emery cloth wouldn't quickly take out. This was due to about a .002 TIR on the chuck itself, which is about the same TIR as my older lathe.--I was very impressed!!!

[Jasonb]

Probably was a bit of 16mm bar

[Brian Rupnow]

Probably was a bit of 16mm bar

Jason--You are probably correct. I hadn't even thought of that.---Brian

[Brian Rupnow]

Today, with heart in mouth and hand on E-stop button, I tried out the power cross-feed for parting off steel. It was a 3/4" diameter piece of 1018 cold rolled, with a 9/32" thru hole in the center. The lathe was turning at 400 rpm. The piece parted off beautiful---no squealing, no chattering, nice 3/32 wide chip rolling off the top of my 3/32" parting off tool. I used lots of squirt on cutting oil. I am very impressed. I actually parted off two pieces for a machine I am building.--So--another milestone reached with the new lathe.

[Jasonb]

I knew you would like it.

If on larger stuff you do start to get that high pitch squeel just gently turn the speed knob up and down a bit, this changes the frequency before it can build up to anything that sounds nasty. If nothing else it gives your spare hand something to do

I find it sbetter to keep a hand over the feed lever than the stop.

[Brian Rupnow]

I have reached the conclusion that even though the dials on this machine read in sensible increments, to really get any worthwhile usage out of it, I am going to have to put a set of DRO's on it. There isn't really any good way to utilize the longitudinal power feed with any degree of accuracy without a set of digital readouts. I can't use the power feed to bring the carriage to a stop up against a "carriage stop" the way I could on my old lathe (on which there was a handle on the end of the leadscrew to move the carriage longitudinally by hand).  The travel on the top-slide is only 1.6", which isn't enough for many things. I did add a small digital scale on the top-slide, but it simply isn't enough travel to be really worth-while. The overall robustness and  accuracy of the lathe seems to be great, but if you don't know how far the tool is travelling, then the lathe has little value. I also miss being able to rotate the top-slide for chamfering and tapering operations.---I can still do it, but then I need to use a dial indicator to reset the topslide perfectly parallel  to the "ways" if I only use the topslide with it's limited travel for longitudinal movement. I am still learning when it comes to lathework in general, and some of this learning curve is expensive.

[Hugh Currin]

Brian: If I understand correctly, you're trying to accurately measure distance along the lathe bed (Z axis). A DRO would be nice but a lot of folks use a dial indicator for this. A support can be built that clamps to the lathe bed, quick connect, that holds the indicator. The indicator plunger works against the saddle to measure distance. I made one as shown.

There are many examples on the Internet. I did a search for "lathe dial travel indicator" and found many examples. Here for one and here (down a few posts) or this. If you switch the browser to images you can see a lot of options.

I use a 2" indicator which works for most of my parts, though with a move or two you can accommodate measurements over 2". I designed mine so it could go on either side of the saddle, with a switch of the indicator 180deg. (I can't use of the left side when using a collet.)

Hope this is of use.

Hugh

[Jasonb]

Brian I have no problem machining to a shoulder with the power feed. If using a bed stop disengage the feed just before it touches and then use the carrage handwheel to bring the carrage upto the stop. Most of the time I don't use a stop and just stop approx where needed and then finish turn teh face or end of teh work to length.

Industrial machines don't have handwheels on the end of the lead screw only some hobby ones and industry has mannaged for years to use these machines without DROs. Learn to use what you have and it won't cost a dime

[Jo]

Brian I have no problem machining to a shoulder with the power feed. If using a bed stop disengage the feed just before it touches and then use the carrage handwheel to bring the carrage upto the stop.

Why don't you just leave it alone and let the clutch automatically disengage the feed.

Jo

[Brian Rupnow]

My bad, guys!!! I had mistakenly made the quick change toolpost nut about 0.140" too thick. It worked fine, but interfered with the travel of the topslide. I gained almost exactly 1" by trimming the thickness of the nut. It still isn't the full 3" as the literature specifies, but it's much better than it was. My total top-slide travel now measures  2.630". Sorry about that!!! I have updated the drawing I posted earlier in this thread to show the correct dimension.-----Jo--There is no clutch on my lathe. If I overshoot a hardstop it takes out the gearcase or (hopefully) a shear pin.---Brian

[jadge]

The 2-axis DRO on my Bridgeport mill is probably the single most useful accessory I have bought. However, I don't have a DRO on the centre lathe, don't miss one, and have no plans to fit one.

Pretty much the same as Jason I don't sweat the dimensions to start with when machining a shoulder. I start by setting the basic length by holding a rule near the cut while the auto traverse does its work. Once I am at the correct diameter I clean up the shoulder and then face off to the appropriate length. If it doesn't need to be accurate, say ±10 thou, I just use a ruler and 'tweak' the saddle handwheel. If I need better accuracy I lock the saddle and use the top slide and a depth micrometer.

I have never used an indicator to reset the top slide parallel, I just use the 'protactor' scale engraved on the base of the slide. Of course I have a slight advantage when machining non-critical chamfers in that my 4-way toolpost sits on a serrated base that allows me to repeatably rotate the toolpost in ~8º (?) increments. It's late, the workshop is locked and I'm not going to go and check the increments now!

Andrew

[Tennessee Whiskey]

Brian, first of all I just want to say that I don't find anything wrong in using the compound ( topslide) in the manner you are using it,  just something I'm not accustomed to and have actually enjoyed pondering it since you brought it to the forefront.  I do agree with Jason.  I have no problems disengaging my power feed as close as. 005" from my mark when using an indicator setup such as the one Hugh posted and creeping to "the number" with the big carriage wheel. Actually,  if it's the first shoulder on a part,  I'll turn a little long and face out the shoulder,  zero the indicator,  traverse the carriage past my dimension in the reverse direction, come back to my number ( backlash ) and face the part off to dimension. Kinda like upgrading a hot rod from a lineloc to a trans brake,  just gotta get used to the difference.

Cletus