Convert a 2 axis Cross Slide to CNC-comments appreciated!
This $120.00 Cross Slide has great potential in providing a very fine “low cost” X-Y Table for
Manual and/or CNC use. With a Table size of 6” x 18.5” and travels of 12” x 7.5” it
would provide a major element in the construction of a sturdy Benchtop Mill.
The Grizzly & Shars "Taiwanese" Cross Slide is well made but has some serious
shortcomings “out of the box”.
Making the following modifications will convert your Cross Slide into a valuable asset for
manual operation or a future CNC retrofit!
See the Illustrated Parts List enclosed.
1. The leadscrews are of excellent quality, but are not riding in bearings.
This oversight can be corrected by boring bearing pockets in
the Longitudinal Screw Brackets (item 24) and the Transverse Screw Bracket (item 4)
The Base (item 1) can be modified to support the rear end of the leadscrew which
must be turned down to match the bearing (or bushing) you select. The NSK Bearing
I used is 6000ZZCE. Dims: 26mm x 10mm x 8mm.
2. The acme nuts (5/8-10) are inferior and should be replaced with
Delrin nuts. The Y axis nut (item 3 ) is a press fit into the Base and is easily removed.
3. The X axis nut is cast into the Saddle (item 16) and will have to be machined out and replaced.
If retaining the existing dovetails you may want to machine oiling grooves
and add a one shot oiler.
Step I: Disassemble the Cross Slide.
My thanks to “doorknob” for the wake up call!
Similar Threads:
I've done something similar, but spent $220 on ball screws from linearmotionbearings on eBay. I've been pretty happy with it. Looking forward to seeing the rest of your design & assembly instructions!
My table is pretty flat in the X direction, but is bowed in Y... being about 0.004" low in the middle relative to the edges. A 4" glacern vise fits nicely on it.
I have this same table on an old drill press... It is a good candidate to convert to an CNC table... I would also remove the table and face it on a decent mill first... Mine has a bow in the Y travel and i assume the majority of them do..
There is also another cross slide table that's been modified much like what your doing.. http://www.cartertools.com/cross-slide.html
http://www.quarterscaleprostreetberetta.com/
Step 2
HansG & QSPSB,
After reading your posts I went out to the shop & placed the castings on a surface plate.
All three are very flat & straight........Lucky I guess. I have 2 enco's & 1 Grizzly and they are
all very high quality product. Are yours from Taiwan?
Observe the photo's in my first post you can tell that the table top is nicely finish ground.
Step 2- X axis Modifications:
The two #24 Longtudinal Screw Brackets are bored to capture the 26mm O.D. Bearings.
This operation requires 4 # 6000 metric bearings. See enco Photo
Disclaimer: The enco bearings I bought are not NSK
2 Flange nuts 5/8-10 plastic # 91984 $19.25 (www.roton.com) 1 for ea. Axis
I add a support bracket to the flange nut which wiill be shown on my next post.
For the motor mount side: Nema 23 motor mount for Acme CNC Router $24.00
http://stores.ebay.com/Precision-CNC-Router
This completes the X axis modifications..The Y axis is a little more challenging!!
W. Smith Mission Viejo, CA
More X axis Stuff
Step 2 - continued
The X axis motor mounting configuration requires an additional modification
on the LH #24 Longtudinal Screw Bracket. Three #10-32 threaded holes were added to
support the .25 in. thick Motor Mounting Bracket.
The Nema 23 motor mount @ $24. is a nice item because it protects the coupler from
chips & coolant but the economy solution is $3. and consists of 4 steel Hex spacers.
The Acme Flange Nuts are encased in a support bracket: see Photo's for details.
W Smith, Mission Viejo, CA
That looks like a very nice finish on the bore of the AL cube.
Great job.
aucran:
Yes, the alum. Cube is nicely done. And it only cost $24.
If you check their site you will see they also make a nice selection
of Acme Lead Screws and Delrin Nuts and Bearing Mounts at very reasonable prices. Unfortunately they don't offer 5/8-10 Acme nuts!!
http://stores.ebay.com/Precision-CNC-Router
Enclosed is the Modification Drawing described in Post 5
Next time the milling operations on the Base Casting will be implemented.
W. Smith
Step 2 Continued:
Before installing the X axis lead screw, the thread on the Step Motor side will have to be removed.
(in my case- turned down to .250 Diameter, to match the step motor shaft- and the 250/250 dia. Coupler.)
Then the lead screw can be installed on the bottom side of the Table (item 23)
Step 3:
Saddle Modification (item 16) for X & Y axes.
Press out the Transverse feed collar (item 3) on the bottom side of the Saddle.
Surface mill a flat area around the hole to provide a flat surface to mount the Lead Screw nut. (Photo 6 )
2 threaded holes will also be added to each side for securing the two LS nuts to the Saddle.
Machine off the integral X axis nut on the top side of the Saddle ( Photo's 3,4 & 5).
More on Step 3 next time........
W. Smith, Mission Viejo, CA.
Hy there,
since you have a big mill, why not run a dovetail cutter through the parts and make new gibs from CI? It really makes a huge difference in smoothness and more important, stiffness.
To see where you are cutting, use a sharpie pen. You may wonder how bad these angles are cut in the original setup. Both angle and parallelity leave a lot to consider. The gibs are less than perfect, too.
Afterwards, even slight finger pressure on the gib locks will lock down the axis rock solid compared to where you had to bend the gib by turning a quarter turn or more to lock it down beforehand.
Cheers,
Johann
Step 3 continued.
Johann,
You are the third person on this thread that has remarked about the poor workmanship
on your 6” x 18” Cross slides.
My experience is quite different on the two ENCO, and one Grizzly I purchased.
However: I will zero my Bridgeport 2J machine, and then check the Table, Saddle
and Base castings for the problems you, Hans G and QSPSB described, and
report back to you.
As noted in an earlier post, the Acme 5/8-10 nuts are BAD and should be replaced!
The first Cross Slide I Modified was an “Ultra” Model. The Build starts on page 1,
post 9.
See: Will build a Benchtop mill including Castings! Comments appreciated.
The dovetails were machined off to accommodate linear Rails on both axes.
The saddle was removed and replaced with a 6” x 6” x .5” CRS Plate.
Step 3 continued:
2 mounting holes were drilled on the Lead Screw center line on the top & bottom
side of the Saddle.
Step 4:
The Base was positioned in the vise and the Bearing pocket was bored for the 26mm x 8 mm+.
The Base was turned over and the “as cast”surface was milled flat,
Then the bearing pocket was bored and two mounting holes were drilled and tapped for the bearing retaining plate.
The X axis lead screw is ready to assemble, the Y axis LS needs to have about 1.125
of thread removed from the rear x( 8mm Dia) to mount the Bearing.
Next 2 Motor Mtg. Plates will be fabricated, then some assembly is in order.
W. Smith Mission Viejo, CA
Don´t get me wrong,
I don´t own one. I played with such a cross slide in a shop. It was sloppy in front and would bind in the middle and worse towards the end. As would all the other cheap ones.
I reworked a X2 clone that was doing okay but not great and found out that the ways were crooked like a politician. They were not in the same plane nor were they parallel. Let´s not talk about dovetail angles either. Checked my cross slide table: the same. Threw it on the mill and reworked it.
Mine looked like this one:
http://www.cartertools.com/kbcrosssl...ross-slide.jpg
As soon as you throw out the thin and therefore flexible gib and the setscrews that are undersized by 0,01" to the threads they rest in and put in a stiff piece of cast iron or brass as a gib you´ll have binding issues in one spot and play in another.
I don´t complain because for the price payed one gets a decent piece of cast iron with enough meat for a rework.
To do a quick check, you can place two dowel pins in the slides dovetails and measure across them with a micrometer. No need to square up the table on the Bridgeport. If everything is parallel down to below 0,0005", forget what I said. But I seriously doubt it.
In case you don´t have a micrometer that size, use a DI on the side of the table and see how much it travels when you lock it down.
Cheers,
Johann
Updates?! I am doing the same thing, but I lack access to the much larger mill. I guess I have to improvise.
I am just starting out.
Let's make Parts!!
After the Base Casting was modified to accept the bearings( in my case NSK 6000ZZ)
It was time to machine the Y axis Motor Mounting Bracket & the Rear Bearing Support.
An Oiler was purchased from McMaster-Carr. Now the big problem arises, Where to put it??
W. Smith Mission Viejo, CA
I'm continuing to watch your progress with interest...
I've never seen an oiler 'in the wild' (until I saw your photo, that is). Didn't know that you could even get such a thing...
Continuing the Assembly of the “Standard” Cross Slide.
The Lead Screws, Nuts and associated Hardware for the X axis are common
to both the Ultra and Standard Models. (Standard Model uses the stock Dovetail Slides)
The Y axis Kit is also common to both Models as are the base modifications which support
the Y axis lead screw & bearings. A flat CRS Plate is used on the ULTRA model in place of the
saddle which is supplied on the Standard Unit.
W. Smith Mission Viejo, CA.
It's good to see that you are continuing with this project.
I was looking at my cross slide earlier this afternoon. I'm planning to do a CNC conversion of my 7 x 10 mini lathe before putting my attention into the cross slide, but I still plan to go ahead with that upgrade.
I know its an old thread but on my table I didn't have an extra mill to take the x axis nut down flat.
So I drilled two holes just under the nut parallel to the nuts threaded hole. I then was able to center punch the nut right off.
Then the hard part was taking an end mill in the drill press and drill down flat 3/8 at a time and reclamping so many times I thought I would pass out. Finally angle grinder and a file to get it down to the correct depth. Used black acetal for my new nuts.
Zipsnipe:
I'm impressed with your tenacity...this mod and the Spindle you machined were quite impressive!
W. Smith, Mission Viejo, CA
Re: Convert a 2 axis Cross Slide to CNC-comments appreciated!
This post is intended to finish the Base assembly for the "Ultra Model"
CNC Cross Slide which will incorporate Linear Rails and Bearings on both X and Y axis.
The mounting slots were removed previously, but required a finish cut on each side to insure parallelism. The dovetails were also removed to prepare the surfaces for the linear rails and the tapped retaining screws.
The Linear Rails were Installed on the base as were the 4 bearing blocks.
The Motor Mounting Bracket and the Cog Belt components were added and checked for fit.
Next time work will proceed on the X axis Table and associated hardware.
W. Smith Mission Viejo, CA
Re: Convert a 2 axis Cross Slide to CNC-comments appreciated!
The .5 inch CRS Plate was machined and installed in place of the saddle casting because it's only function is to position the bearing blocks for the X & Y axis.
Next time the Standard version with the modified saddle casting will be addressed,
W. Smith, Mission Viejo, CA
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