KX3(Novakon 135)

Getting over being ill and coming off a long break working on my NM135. It's essentially a KX3/X3 with minor changes here and there. Picked it up on ebay missing all the electronics so I have a 1.5kw AC Servo, Centroid Acorn, 80v linear power supply and two generic 12nm closed loop steppers for X and Y. For the Z I have left the stock motor and picked up a generic DM860.

The 1.5kw servo is rated for 3000 RPM but in testing I have had it hold 3200. The stock NM135s came with 3,500 and 5,000 models. Mine looked to be a 3,500 with two 38 tooth 5M pullies for 1:1. I am hoping to increase the RPM to around 5000-6000 and move to micro/poly v belt.

One of my two problems is the spindle pulley. I have looked for set screws, clips or any other method of mounting but it looks as if it may be pressed onto the spindle shaft. I see a key notched into the pulley as it extends down into what I assume is the top spindle bearing. If I look from inside the head stock casting I can see a small opening that shows inside the spindle cavity. On the lower side of the opening I see the spindle shaft with a lock nut(same type you see on ballscrews that tension against bearings) and under that a round plate that appears to be threaded into the spindle housing itself likely maintaining bearing tension. Looking in the top side of the casting hole I see the bottom of the spindle pulley and a notch in it with large C clip. I have tried opening the C clip while pulling up on the spindle pulley but it did not budge.

The second problem I have is the X axis gib. This model has tapered gib strips that are adjusted by screws on either side. The gib strips have a notch in them that the adjustment screw heads slot into. I removed one gib adjustment screw but while trying to remove the notched side screw the gib broke at the notch.. The X axis does moves but is very very tight. I have tried using different lubes to free the strip along with a rubber mallet and steel pin tapping as hard as I dare go. The Y axis gib and Z gib were very easy to remove but this one is stubborn and now broken. I haven't found a replacement so I'm considering drill and tap a screw then JB weld the notch combined with screw. Worst case just shorten it and try to use a gib tension system similar to the G0704/PM45 has.

Attaching a picture of KX3 pulley which is what I believe my spindle pulley looks like. The second photo shows what a KX3 spindle pulley looks like mounted. I will add a photo of my NM135 spindle pulley in the next post. https://uploads.tapatalk-cdn.com/202...a1e1b147db.jpghttps://uploads.tapatalk-cdn.com/202...80cdc5d37c.jpg

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Photos of my NM135. Should have pictures of the X gib later today. https://uploads.tapatalk-cdn.com/202...abb54457b2.jpghttps://uploads.tapatalk-cdn.com/202...9c8bfc9c4f.jpghttps://uploads.tapatalk-cdn.com/202...cfa8ae513b.jpghttps://uploads.tapatalk-cdn.com/202...102c78825f.jpghttps://uploads.tapatalk-cdn.com/202...50391f6b50.jpg

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I have a Smithy 622, which is also based on the KX3. Page 34 of the manual (link below) shows a blown up view of the head assembly. Might give you a few ideas on possible disassembly. There is more than one version of the spindle (R8 and integrated ER20 at a minimum), but there's a pretty good chance most of the assembly is identical with only a few things swapped around.

https://drive.google.com/file/d/1aOr...ew?usp=sharing

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Originally Posted by y0da900

I have a Smithy 622, which is also based on the KX3. Page 34 of the manual (link below) shows a blown up view of the head assembly. Might give you a few ideas on possible disassembly. There is more than one version of the spindle (R8 and integrated ER20 at a minimum), but there's a pretty good chance most of the assembly is identical with only a few things swapped around.

https://drive.google.com/file/d/1aOr...ew?usp=sharing

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Thank you! Mine is indeed a R8 version but ideally I'd prefer BT30. I had no idea there was a Smithy version as well. I have seen a early machine by Syil that looked similar, Bolton looks to have had one, Harbor Freight, Novakon and Little machine shop but I never knew about Smithy's which I have assumed are all/mostly made to order from Sieg. The manual seems to be one of the best that looks very close to mine.

How is your 622 doing? Spindle motor? They seem like a better option then the G0704 which I converted to CNC in the past. Of course the travels are a limited but it looks like mine will do about 8.5" on Y with a small notch. Found posts saying later NM135s had a change that reduced it to 6 to 6.5".

I also noticed the X and Y limit switches were crumbling apart bad from coolant I guess. The two Z switches appear to be fine but I'll replace those as well.

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It works well enough most of the time. The biggest issues is the PC used in the controls; it's getting a bit unreliable due to the age and finding direct replacement of the parts isn't always easy without taking a gamble on the replacement parts since most of them are also used. And I see the cost going up very quickly if I replace them with modern equivalents).

It has the 5,000 RPM spindle, which was a pleasant surprise when it arrived. Also had some limit switch issues, I think the Sieg factory must have really cut some corners on those - incorrectly assembled conduit fittings on the X-axis so liquid got in and shorted it out and earlier models came with a normally open switch for the Z-axis but eventually changed to normally closed in later versions (the default HAL settings in LinuxCNC set to the more common NC version, so that was fun to figure out).

Quote:

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Originally Posted by y0da900

I have a Smithy 622, which is also based on the KX3. Page 34 of the manual (link below) shows a blown up view of the head assembly. Might give you a few ideas on possible disassembly. There is more than one version of the spindle (R8 and integrated ER20 at a minimum), but there's a pretty good chance most of the assembly is identical with only a few things swapped around.

https://drive.google.com/file/d/1aOr...ew?usp=sharing fnf

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Regarding the spindle pulley, it does sound like it may be pressed onto the spindle shaft, which could make it difficult to remove. You could try applying heat to the pulley to help loosen it or using a puller tool designed for removing pressed-on pulleys.

As for the X axis gib, it sounds like it may be too tight due to the broken gib strip. You could try using a file or sandpaper to smooth out any rough edges on the broken gib strip and see if that helps it move more smoothly. If not, you could try drilling and tapping a new screw, as you suggested, or looking for a replacement gib strip.