Warco S\Mini lathe gibs

[Michael Ford 6Participant @michaelford6]

I have had a Warco Super Mini Lathe for a couple of years and tried to carry out all the important mods listed in videos on YouTube but find if I adjust the gibs to eradicate movement then it is too tight to move comfortably. I am not happy with the accuracy of the std gibs so feel I need to replace but don’t have a mill to cut new ones so can I buy a good quality replacement or is there any negative reason not to make a shim to eliminate the play in the std gibs?

[MikeKParticipant @mikek40713]

I just used shim stock to get the best fit possible.  And it sure wouldn’t hurt to check the gibs for flatness and sand/scrape if necessary.

Mike

 

[David George 1Participant @davidgeorge1]

Hi What style are the gib strips on your lathe. Are they grub screw on side adjustment or tapered strip with a screw from one or both ends.. If they are tapered style you can measure a gap with feeler gauge on each end and scrape or file to adjust to thickness

[Michael Ford 6Participant @michaelford6]

I checked the flatness and used a flat plate to ensure this but the material and finish of them seem a bit “Chinese”

[Michael Ford 6Participant @michaelford6]

Yes three screws with locking nuts but I dont think they are tapered. As I said to @mikek40713 I have checked for flatness and I think my problem is not to scrape or file as they appear to be too small anyway that was the reason I asked if inserting a measured shim would be detrimental in any way?

[MikeKParticipant @mikek40713]

The common Chinese mini-lathe had a very active Yahoo Group for a number of years that has since moved to Groups.io: https://groups.io/g/7x12MiniLathe/topics

Many of them have used shims to cure the poor gib fit.

Mike

 

[HopperParticipant @hopper]

Shims in gibs? Does not make sense.

Are you talking about the two lift plates on the bottom of the carriage that stop the carriage moving upwards? In that case, yes shimming can work well. Aim for about a half to one-thou (0.02mm) gap between lift plate and bed at the tightest point. Also look at the mating surface on the bed. On many they are rough machined and could use a careful clean up with a flat file. Ditto the lift plates themselves.

[bernard towersParticipant @bernardtowers37738]

Don’t really understand the poor gib fit thing surely thats what the adjusting screws are for.

[MikeKParticipant @mikek40713]

Oh.  I was assuming this was the carriage.  And after re-reading the original post, I realized that it wasn’t clear where Michael Ford was having trouble.

Is this the top slide, the cross slide, or the carriage?

Mike

 

[Michael Ford 6Participant @michaelford6]

No my saddle is fine as I have done the Steve Jordan mod including the saddle lock. I am concerned about the two gibs on the cross & compound slides. I seem to have far too much movement on these and to get rid of the looseness it is almost impossible to move the slides as I have to tighten up the three gib screws that tight to take out the play. The gibs tilt over when they are tightened normally that is why I think they are poor manufacture and would like to change them or I did think that maybe I could shim them to get them sitting correctly?  By the way many thanks for all those people that replied to me.👍

[SillyOldDufferModerator @sillyoldduffer]

When Chinese Hobby lathes first appeared they were often found to be a bit rough, to the point that some described them as a ‘kit of parts’, needing a lot of fettling.   The original motor control boards weren’t very reliable either.

These deficiencies led to a lot of corrective suggestions being put on the web, maybe creating a folk-lore that corrective action will be necessary or good to do.   20 years later Chinese hobby lathes are still made down to a price, not perfect,  but mostly they work out of the box.  Occasionally minor fettling is needed.   I wonder how many new owners are lured by the internet into starting by ‘improving’ the lathe rather than learning how to drive it.    Dangerous move, because inexperience leads to chasing non-existent faults and creating new ones.   I recommend learning the machine first, warts and all.  Then decide what needs fixing.   Though it makes machining considerably easier, the best lathe in the world won’t fix operator errors.

Possibilities are faulty machine and/or faulty assembly.

How experienced are you Michael?  I ask because lathes aren’t as simple to work on as they might appear, containing a number of booby traps liable to catch beginners.   Gibs are one of them!   Rather easy to assemble incorrectly and then tricky to adjust.

Assembly, make sure the gib is the right way up and the gib screws are engaged in the dimples.  (Beginners often fail to notice there are dimples drilled into the gib.)  In addition to adjusting the tightness of the fit, the adjuster screws have to sit correctly their dimples to stop the gib sliding.  This is vital!  May be worth improving the dimples: a photo was posted the other day of some probably unsatisfactory shallow gashes, manufacturing defect.

Adjusting gibs can be downright fiddly.   Whilst Gibs are a cheap and effective mechanism, they aren’t easy to adjust.   Three or four screws have to carefully tweaked to align the gib with the dovetail with equal pressure across the full range of movement.   Getting the balance right can be a pain.  Though my Minilathe worked well enough, I wasn’t entirely satisfied with the feel, a bit lumpy rather than silky smooth.    Whipped the gib out, put a slightly better polish on it, and replaced it no problem, adjusted correctly first time.  Still not silky, so I took it out for another mild polish.  This time, with me apparently doing the same thing as before, reassembly went horribly wrong.  Tool an hour of effing and blinding to get the slide moving properly again.

Shims might help, but I suspect they will complicate adjustment and be liable to slip.   Could be wrong: I’ve not followed MikeK’s link.  If a thicker gib is needed, and Warco can’t supply a spare, they’re tedious rather than not difficult to make by hand.   The width of the needed being a standard strip stock size will save a lot of time.

Dave

[Michael Ford 6Participant @michaelford6]

Dave  As you have probably guessed not very experienced but give me a single seater race car suspension and feel totally at home! I bought a pair of brass gibs from arc and they have no indents drilled so think I may try fitting them after checking straightness and a polish but they do look a lot better quality than the original gibs? I also wondered if using ball bearings on the end of the adjusting screws might help or not?

[KEITH BEAUMONTParticipant @keithbeaumont45476]

There was a tip in MEW some months back, that suggested putting a fibre washer between the lock nut on the gib screws. You then tighten the lock nut onto this and adjust the screw until satisfied with the slide action. Makes it a simple,one handed operation to get fine adjustment. I fitted all my gib screws this way and can confirm that it works.

Keith.

[HuubParticipant @huub]

I adjust the gib screws of both my lathes at every job. I just loosen and tighten the adjustment screws with my finger tips until I feel they start “locking”. That is enough for a smooth and “play less” operation. It only takes a few seconds to do. I don’t lock the adjustments screws. The drawback is, that sometimes the adjustment screws get loose when running a long job.
I have seen pictures where the adjustment screws are secured/locked using a short spring. That is something I want to try also.

[Michael Ford 6]

On Michael Ford 6 Said:

Dave  As you have probably guessed not very experienced but give me a single seater race car suspension and feel totally at home! I bought a pair of brass gibs from arc and they have no indents drilled so think I may try fitting them after checking straightness and a polish but they do look a lot better quality than the original gibs? I also wondered if using ball bearings on the end of the adjusting screws might help or not?

Check with the guys at ARC – they are very helpful and know their stuff – but that type of gib strip usually has indents drilled in them to locate them. Usually these are made by carefully poking a drill down one gib adjuster hole at a time while the gib strip is clamped in place on the assembled machine, usually using the other adjuster screws.

Not worth the faff with ball bearings IMHO. I just round the ends of the adjuster screws with a file in the lathe, into a nice hemisphere. They sit nicely in the angled dimples left by the nose of a the drill bit. You may need to turn the end of the screws down to slightly under the diameter of the drill bit you use on the gibs before rounding the ends.

If you want to go one step further you can go the GH Thomas method of drilling and reaming two small dowel pin holes through the slide and into the gib strip. Dowels are made a tight fit in the slide and neat sliding fit in the gib strip so it can move in and out but not laterally.

[Ketan SwaliParticipant @ketanswali79440]

Hi Michael,

We tried to find details of your purchase of brass gibs in our system to give you a call, but couldn’t, so please read the response below.

Here are some comments:

1. An extract for a post I made in 2018:

“Before you consider scraping or making something else, consider making vertical slots at the places wherever your dimples on your current gib strips are. Most of the time this solves misalignment issues. If it is a newish lathe, better to avoid OTT on scraping… the gibs… as most of them look like crap and they are meant to…. and they will bed in over time. However if you want a bedded in feel, just go over it with some wet and dry Emory mounted on a block and rub. Also don’t over do it. Try the simple solutions first, is what I would suggest.”

2. The gap between the two dovetails into which the gib strip sits can be variable, based on who the manufacturer of the machine is, and when the machine was made. The brass gibs are designed to deal with the gap on SIEG made machines. Yours is a WARCO, and the brass gib may or may not fit into the gap.

3. The key difference between the brass gib and the original gib you have is that it gives a better ‘bedded-in’ feel due to the ‘lubricating properties’ of the brass gib. Your original gib can still achieve the same over time.

4. The brass gib does not have dimples in it for locating grub screws, because these will be different on most mini-lathes or mills, as the holes drilled and tapped to accept the grub screws are a manual process. So you need to figure it out for your specific machine. If the brass gib is thick enough to take up most of the gap in between the dovetails, it is more likely to locate correctly onto the mating dovetail. If the thickness of the gib is far less than the gap, it may tilt, depending on how and where the grub screws locate on the gib. So at that point consider making vertical slots at the places wherever your dimples on your current gib strips are, on the brass gib. The grub screws supplied with the brass gibs are M4 Cone Point Hexagon Socket adjusting screws which are hard enough to form small location dimples in the brass gibs… as stated on the bag in which the brass gibs set are supplied. Do consider following the fitting information stated on the label BEFORE making different dimples/slots, and adapt to suit your machine.

Hope the above information helps. If you still find difficultly in operation after following the above, then there is a whole different process to consider, such at looking at the dovetails and the alignment there off, and/or working on the 55 Deg. dovetails themselves… a can of worms best left to people with a little more experience on the subject, especially as 55 deg. dovetails on these machines are made via specific machining process, which does not use an off the shelf dovetail cutter.

Ketan at ARC.

[Michael Ford 6Participant @michaelford6]

Ketan   Thanks for your post and will consider your suggestions carefully as with the other posts I appreciate all your higher levels of experience over mine.  My Warco is about 3 years old and has metal gears etc and I just realised that checking the spec on Marco’s website it also has taper head bearing? The vertical slots sound sensible to me as it will allow a small amount of movement to allow the gib to sit properly in the slide dovetail.  I have a weekend taped out for me, many thanks everybody.

[Michael Ford 6]

On Michael Ford 6 Said:

Dave  As you have probably guessed not very experienced but give me a single seater race car suspension and feel totally at home! I bought a pair of brass gibs from arc and they have no indents drilled so think I may try fitting them after checking straightness and a polish but they do look a lot better quality than the original gibs? I also wondered if using ball bearings on the end of the adjusting screws might help or not?

No shame in being inexperienced!  I’ve been machining for ten years now and am still learning.  Didn’t know until reading Ketan’s post that their ArcEuro gibs are soft enough to dimple with the adjuster screws rather than spotting them with a drill.   Extra consideration for beginners!   The booby trap though is that Brass is an alloy family and many of them are too hard for that trick.   The brass strip I bought from a DIY store is!

Long history of experienced mechanics new to lathes and mills being caught out on first contact.  Not due to lathes being rocket science, more a deceptive simplicity in which some apparently innocent part of the implementation is trickier than expected. I hope racing car suspensions have fewer fiddly gotchas!

Dave

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