Help with CW Bottom Slide Removal

I am refurbishing the $150 Monarch... I've searched the posts on slide removal and I am not finding the help I need. My Bottom Slide is being stubborn. I've removed the Crossfeed Dial Assembly from the front and disconnected the Crossfeed Screw Bearing (between the Taper Attachment and the Carriage) at the back end. The slide gib has also been removed. Despite gobs of clearance in the gibs, the Bottom Slide and Draw Bar will not lift off.

From the attached photo, what the Monarch parts manual calls the Clamp Screws are removed. The slotted "Crossfeed Nut Lock Screw" won't budge with a manual impact driver, at least in the normal RH direction.. I quit before I tore up the slot. This isn't a LH thread is it?

From what I can see it is the only thing holding the Crossfeed Nut in place. If this won't come out, it looks like the Taper Attachment would need to be partially disassembled to slide the Feedscrew, Draw Bar, and Bottom Slide out the back.

Anyone know how to get this thing apart?

That slotted screw does have to come out try a blue wrench on it to see it it will free up. It is not threaded in to the nut but only threaded into the cross slide not into the cross feed nut.

Success

Fire, the magic elixer! Thank you labeeman, a little heat did the trick. Everything has come off pretty easy up until now, so I though I'd err on the side of caution and seek advice. Haven't screwed up any parts yet and I'm not about to start..

Cleaning and painting continue. Need to see how much wear is in the leadscrew and nut tonight.

jlkunka said:

Need to see how much wear is in the leadscrew and nut tonight.

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That'd be low on my priority list to repair but if you decide to do so, it's a pretty easy lathe project.

This gives thermite a coronary, last year when I replaced the leadscrew and nut on my 12CK I opted to try building a delrin nut. Here's my order of operations-

Turn short length of acme thread from 1144 stressproof, this was then relieved and fluted to create rudimentary tap.
Bore and tap a large-ish chunk of delrin, then cut away whatever isn't needed to reveal you new x-feed nut.
Turn your new feed screw, using the nut as a gage.

The hardest part of it was creating an accurate acme threading tool. Good luck!

Pipe plug in your photo suggests the PO never knew how the T/A worked. Supposed to be a bolt that tightens up the clamp on the slotted flat steel draw bar

You will find the anchor point for the back end of the screw is in the thrust bearing block out-of-sight riveted to bottom face of flat steel slotted draw bar

johnoder said:

Pipe plug in your photo suggests the PO never knew how the T/A worked. Supposed to be a bolt that tightens up the clamp on the slotted flat steel draw bar.

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I wondered about that. When you get a chance, would you be so kind as to pop that bolt out and post a close-up photo of it so I can duplicate it? I assume it has an extended nose to reach the drawbar. I'm also hoping it has a 7/8-14 thread, because that is the only thing remotely close to the 1/2" NPT plug that was put in there. If the threads are screwed up I'll be making a custom one...

johnoder said:

You will find the anchor point for the back end of the screw is in the thrust bearing block out-of-sight riveted to bottom face of flat steel slotted draw bar

Click to expand...

Yup - my leadscrew, bronze nut, and rear carrier block just lifted out as one complete unit.

jlkunka said:

I wondered about that. When you get a chance, would you be so kind as to pop that bolt out and post a close-up photo of it so I can duplicate it? I assume it has an extended nose to reach the drawbar. I'm also hoping it has a 7/8-14 thread, because that is the only thing remotely close to the 1/2" NPT plug that was put in there. If the threads are screwed up I'll be making a custom one...



Yup - my leadscrew, bronze nut, and rear carrier block just lifted out as one complete unit.

Click to expand...

That bolt does not thread into the cross slide but into a piece of metal that is below the draw bar I have a feeling yours is missing due to the use of the pipe plug.

Cole2534 said:

That'd be low on my priority list to repair but if you decide to do so, it's a pretty easy lathe project.

This gives thermite a coronary, last year when I replaced the leadscrew and nut on my 12CK I opted to try building a delrin nut. Here's my order of operations-

Turn short length of acme thread from 1144 stressproof, this was then relieved and fluted to create rudimentary tap.
Bore and tap a large-ish chunk of delrin, then cut away whatever isn't needed to reveal you new x-feed nut.
Turn your new feed screw, using the nut as a gage.

The hardest part of it was creating an accurate acme threading tool. Good luck!

Click to expand...

For what it is worth, we did a test on one of our wastewater products that used a submerged ACME rod driving a cleaning plate up & down over a 60" stroke. I made up a Delrin AF nut (Delrin AF has teflon) and an Ampco 18 bronze nut. We ran both experimental parts until failure. This was unlubricated, and submerged in wastewater, which can be greasy but also can be gritty. To my surprise, the Delrin AF nut lasted almost twice as long as the bronze. This was a 3/4" single-start ACME rod and the loads were significant, about 50 lbs linear force in both directions.

I think Delrin has good potential to replace bronze in some cases if you can successfully fasten it where a metallic part was the original design intent. Not a lot of room in the slot of the drawbar to add a steel bushing in the Delrin to increase the bearing area of the clamp bolt... But you could easily lengthen the nut 50% to get more bearing area on the ACME thread.

The machine shop tapped it with a four-flute ACME tap and had no issues, but complained about tapping the bronze!

I wondered about that. When you get a chance, would you be so kind as to pop that bolt out

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Thru hole in slide, threads are in the strange shaped clamping nut item 40 in Taper Attachment Parts List. Basically a tee nut, but with clearance for screw to pass under it. I'll have bolt out today and report thread, and no, clamping nut will not be available without major disassembly efforts. Its important specs would be it has tapped hole for bolt, its "tongue" must slide in bar's slot, its width must not hang up in carriage saddle, and its bottom face must clear screw when bolt is loosened, and its length must not bump into bronze nut for screw

On second thought, I'll only loosen bolt and report diameter. If I take it out, clamping nut may tilt and require too much effort to get it restarted. With the bolt out, it's just laying there on the curve of the screw's OD

ON EDIT - bolt is 7/8 hex and 5/8 shank. Since there is no reason to neck it down, I'll assume 5/8-11 or 5/8-18 on business end

Thrust block and ball thrust bearings......

My hard thrust washers were thoroughly "Brinneled" (dented), so I surface ground them flat again

MAJOR slop apparently in nut/screw interface can be traced DIRECTLY to slop in thrust block assembly. Tighten the nut on end of screw until it turns freely but without end play. I would imagine my Brinneling came from over zealous tightening

johnoder said:

On second thought, I'll only loosen bolt and report diameter. If I take it out, clamping nut may tilt and require too much effort to get it restarted. With the bolt out, it's just laying there on the curve of the screw's OD

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I understand completely. Looking at the diagram and with your description I see this isn't a rocket science part. Of course it's probably fit to the slot width within .001" like everything seems to be on this lathe, but I can make/have made a tee nut that will do the job.

johnoder said:

Thrust block and ball thrust bearings......

My hard thrust washers were thoroughly "Brinneled" (dented), so I surface ground them flat again

MAJOR slop apparently in nut/screw interface can be traced DIRECTLY to slop in thrust block assembly. Tighten the nut on end of screw until it turns freely but without end play. I would imagine my Brinneling came from over zealous tightening

Click to expand...

My leadscrew/bronze nut/bearing block are all a frozen mass of crud right now.... but that's been the fun part - everything has been in amazing condition once this is cleaned off. The Taper Attachment came off easily with the help of gravity, just eased it down on a couple blocks resting on the chip try. I'm at about the limit of what a 12' bench can hold now with the parts I've removed for reconditioning. Have to work through those to make room for the apron & saddle.