Flat Plate fabricated slide

[Gerald_D]

After finding that linear bearings are exhorbitantly expensive, plan B.....

"Gauge Plate (http://www.westyorkssteel.com/Product_Info/Tool_Steel/gfs.htm)" is very precise, high-quality, slightly hard tool steel that can be hardened even further. Running pre-loaded big V-rollers on this stuff should work okay.

Typical standard sizes (http://www.westyorkssteel.com/Product_Info/Tool_Steel/gfssizes.htm)./. More (http://www.peterstubs.com/precision.html)

Thinking of a 6mm x 100mm plate, ground as per the pics in this thread (http://www.mechmate.com/forums/showthread.php?t=311) and screwing a backing/stiffener to it.

[Gerald_D]

http://www.mechmate.com/Forum/messages/1168/1864.gif

Yellow is the hard plate with a green 50x25x3mm [2x1x.125"] tube screwed to it. Rollers BWC size 3. For this route, I'd ask to spindle maker to put more tapped holes in the top end of the spindle - that would add a lot of stiffness to the assembly. (I will drill and tap the spindles here already).

[Brian Backner]

For those stateside, you might consider Starrett precision ground oil hardening flat stock (tool steel). It would need to be ground to shape, i.e., it can't be milled, but it has the advantage of tremendous strength, very precise tolerances (typically 0.0001"/ft) and is widely available.

A good outlet is WT Tool (www.wttool.com (http://www.wttool.com)):

1/4" x 4" x 18" is $42

http://www.wttool.com/product-exec/product_id/10206

1/4" x 4" x 36" is $85

http://www.wttool.com/product-exec/product_id/10394

They have many additional cross sections available.

Brian
Walpole, MA

[Gerald_D]

Hi Brian, I think that is the same stuff that I am talking about, but we don't have big problems milling/drilling/tapping it?? Sure, at 230 Brinell it is harder/tougher than "mild steel" which is around 120. (If memory serves me right).

Your prices match those over here.

[Sheldon Dingwall]

By the time you pay for the material and modifications, would it not be easier/cheaper to just buy BWC rail?

[Brian Backner]

Gerald,

You are right about the oil hardening stock being machinable; in my post above, I was thinking of the high carbon air hardening steels - while they're still machinable, barely, they are much more unforgiving of tooling. I've typically had this stuff precision ground.

[Gerald_D]

Sheldon, that is a typical view of the BWC rails, but it is not that easy....

http://www.mechmate.com/Forum/messages/1168/1867.gif
BWC rails have a nice edge, but they are actually very flexible and flimsy. (a size 2 track is only 16x6mm [5/8x1/4"] overall) You still have to drill a lot of holes in them to screw them to a firm base. And then they end up being only as straight as the base that they are screwed to.

http://www.mechmate.com/Forum/messages/1168/1866.gif

My logic is to put the V-edge directly onto the "firm base" if we have to go to trouble of making the base fairly precise. It saves a lot of drilled holes. (My Hepco literature avoids recommending screw sizes/spacings).

It is not that difficult to put a passable V-edge onto a short flat bar for the z-slide. We might not end up with something as "precise"(?) as BWC but it is going to be simpler, cheaper and still do a great job. And, if we work around a "flat bar" design, people can still easily add BWC rails to it. The basic "gauge plate" tool steel used all over the world is the perfect stuff for screwing BWC/Hepco rails to.

[Sheldon Dingwall]

I was thinking of their double edge flat slide. It's available up to 76 mm wide.

[Gerald_D]

How thick is it? The 76 direction is probably adequate, but I guess it is going to need something more to stop it from bending in the x-direction, or from twisting when you take a heavy y-cut. Price?

[ralph hampton]

Sounds like Hepco GV3:
http://www.hepcomotion.com/db_pages/products/proddetail.php?id=0001&cat=comp
They are the UK link to bwc.

R/

[Sheldon Dingwall]

I was thinking flat re-inforced by your tube idea. They spacer slide is thicker - 19 mm I believe. But probably not thick enough.
http://www.mechmate.com/Forum/messages/1168/1878.jpg

[Gerald_D]

If you reinforce the thin plate with a backing tube that should work fine. Just remember that the plate should be soft enough so that you can drill it.

A side note: Hardening of steel does not make it any "stiffer". For this slide application, the hardening is solely to improve wear resistance.

[Gerald_D]

Here is some progress this afternoon:

http://www.mechmate.com/Forum/messages/1168/1887.jpg
http://www.mechmate.com/Forum/messages/1168/1888.jpg
http://www.mechmate.com/Forum/messages/1168/1889.jpg
http://www.mechmate.com/Forum/messages/1168/1890.jpg

The grinding (http://www.mechmate.com/forums/showthread.php?t=311) in the table saw was surprisingly easy (20 minutes) A 175mm wheel protruding 26mm above the table surface gave the 2x45 degrees, albeit very slightly concave. Then some draw filing (http://images.google.com/images?as_q=draw+filing&svnum=10&hl=en&output=images&rls=GGLD%2CGGLD%3A2005-07%2CGGLD%3Aen&btnG=Google+Search&as_epq=&as_oq=&as_eq=drawer+cabinet+hanging+office+storage&imgsz=&as_filetype=&imgc=&as_sitesearch=&safe=off) with a fine file and a bit of emery stone (20 minutes). There is scope for refining this process, but already the results are an A-class "pass".

If I had to do a lot of these, I would use a thicker(wider face) stone of a finer grit, but the 3mm thin cutting disc (coarse) was not too bad. The biggest job was to make a centralising bush for the disc in the table-saw.

Can I suggest you guys try it with any old piece of flat bar before you believe me? http://www.mechmate.com/Forum/clipart/happy.gif

[Gerald_D]

I drilled some holes in that plate tonight. It sure is much harder than mild steel, but not impossible to work with. (Some stainless steels are much worse)

(The stockist of those $1200 linear IKO bearings came to me with a $500 price today. I think he is trying to move dead stock.)

the grinding discussion moved back to here (http://www.mechmate.com/forums/showthread.php?t=311)

[Gerald_D]

A rough assembly.......
http://www.mechmate.com/Forum/messages/1168/1898.jpg
(the big hole in the tube is for this quick change system (http://www.talkshopbot.com/forum/messages/2/4095.html))
http://www.mechmate.com/Forum/messages/1168/1899.jpg
Those 4 screwheads seen above are of screws going all the way through into the spindle's alu body. (2 long (shiny heads) and 2 short (black heads))
http://www.mechmate.com/Forum/messages/1168/1900.jpg
http://www.mechmate.com/Forum/messages/1168/1901.jpg
The countersunk screws above are tapped into the 3mm [1/8"] wall of the rectangular tube. Some extra holes in case positions need to be adjusted (and to see how long the tooling lasted while cutting the gauge plate - no problems)
http://www.mechmate.com/Forum/messages/1168/1902.jpg
The cut-away of the rect. tube is for the dust hose. The screws into the spindle body are near the collet end. I am tempted to drill+tap the spindle body near the top end for more screws - the spindle body is a nice flat, strong extrusion.

[Gerald_D]

http://www.mechmate.com/Forum/messages/32/1965.gif


The eccentric bushings and rollers for the z-slide:

http://www.mechmate.com/Forum/messages/32/1954.jpg
The eccentric bushes are modified bolts (drawing will be provided). Unlike BWC/Hepco, these bushings and support collars are relieved to avoid contact with the seals.


http://www.mechmate.com/Forum/messages/32/1961.jpg
http://www.mechmate.com/Forum/messages/32/1962.jpg
http://www.mechmate.com/Forum/messages/32/1963.jpg

[Gerald_D]

Some progress:

http://www.mechmate.com/Forum/messages/1168/1978.jpg
http://www.mechmate.com/Forum/messages/1168/1979.jpg
http://www.mechmate.com/Forum/messages/1168/1980.jpg

[Evan Curtis]

paraphrasing Tony the Tiger "It look's GGGRRREAT!

[Gerald_D]

Thanks Evan, that encouragement earns you one more pic: http://www.mechmate.com/Forum/clipart/happy.gif

http://www.mechmate.com/Forum/messages/1168/1993.jpg

[Gerald_D]

The weekend's work - first prototype fully assembled (almost):

http://www.mechmate.com/Forum/messages/1168/2008.jpg
http://www.mechmate.com/Forum/messages/1168/2009.jpg
http://www.mechmate.com/Forum/messages/1168/2010.jpg
http://www.mechmate.com/Forum/messages/1168/2011.jpg
http://www.mechmate.com/Forum/messages/1168/2012.jpg
http://www.mechmate.com/Forum/messages/1168/2013.jpg
http://www.mechmate.com/Forum/messages/1168/2014.jpg
http://www.mechmate.com/Forum/messages/1168/2015.jpg
http://www.mechmate.com/Forum/messages/1168/2016.jpg
http://www.mechmate.com/Forum/messages/1168/2017.jpg

[Robert Cheal]

It looks awesome and very well thought out.

Just curious what is the expected life on the "Gaslift". And also is it difficult to get the correct tolerances on the mounting holes after the bracket has been bent into shape. I guess a good shop could bend it right the first time.

[Gerald_D]

Hi Robert. The matching holes in the Y-car are oversize and slotted. (You also need the slotting for adjusting the Z perpendicular to the table.) This "tower" will not work in a ShopBot y-car because that car can't support the 4 legs of the "spider" firmly. With the stiff car of the MechMate, the four attachment points of the spider are slightly flexible so that they can conform to the car. The stiffness of the y-car is used directly behind the V-rollers.

I don't know the life expectancy of a gas-lift in this application. We have nearly run one year with the first one and so far, so good. However, I will design a conventional spring system as well - anybody have a skyhook to hold the top end of a spring? http://www.mechmate.com/Forum/clipart/happy.gif

(apologies for the home welding quality on those nuts)

[Alan Conolly]

Hi Gerald

Very neat design - n boer maak n plan!

How do you maintain pressure on the pinion gear to hold it into the rack, or will that become apparent once it is mounted into the Y car?

[Gerald_D]

Hi Alan. You can see a capscrew sitting next to the motor on the motor-mounting plate. A spring is hooked around it and the other end of the spring goes down to the Y-car. Same as the situation with the current linear bearing version:

http://www.mechmate.com/Forum/messages/329/813.jpg

[Dirk Hazeleger]

Hey Gerald
I noticed the motor on the new Z your using direct drive. Is that what your planning on? What are your thoughts as to direct drive vs geared motors for all axis.
Dirk

[Gerald_D]

Hi Dirk, my suggestions on motor selection are in this thread (http://www.mechmate.com/forums/showthread.php?t=254). However, that thread actually applies more to the x and y axes than the z. We must recognise that the demands on the z-axis are a bit different....

The z-axis accels/decels. a lower mass, but that mass could be unbalanced. The cutting forces should be lower. General impression is that the z-axis is less demanding on a motor than the other two main axes. Even debatable whether a micro-step driver is needed for the z-axis.

Having said that, our one table runs a direct drive motor and the other runs a geared motor. I really can't say that one is better than the other. But, for a heavy router/spindle the geared version should be better. The gearing gives a bigger "detent" when the motor is switched off, and the router/spindle mass doesn't need to be compensated that accurately.

I plan to run this axis with an ungeared motor as an experiment with the heavy spindle, but I could run into problems with the gas-lift's weight compensation. I have to design a coil spring alternative in any case, because everybody won't be able to locate gas-lifts as easily.

That motor mount plate can take either geared or ungeared motors - the pinion location will stay the same.

[Paul A]

Hi All

If you were not happy about beveling your Guage Plate you could aways form the Z slide with a few pieces of sheet steel and a couple of BWC rails bolted between.

Just a thought

http://www.mechmate.com/Forum/messages/1168/2024.jpg

[Gerald_D]

If you want to go that route, it would be better to reverse the BWC rails so that their shoulders butt against the stiffer plate, the flat one. I would just put the rails on the edges of a thinner gauge plate, and still go for the box-section backing.

[fabrica]

In drawing number 10 40 330 (SA). You have given two sets of dimensions. One set for the Inch option and the other for the metric option. What does it mean?

[Gerald_D]

The inch guys sell that plate as 4"x0.25"x18" and the metric guys sell it as 100mm x 6mm x 500mm. Both those sizes will work without sawing the plate any shorter.

[Charlie T]

I think I'd rather have a router for the cost of them. But Im wondering about mounting it and the clearance on z slide. Spindles ?? hmmmm. BTW why do you have a metric and imperial option on the dimentions of the gauge plate, metric is way larger than the imperial one. Options are great but the plan becomes distorted and hard to follow.

[Charlie T]

Nevermind ... what is the matter with me? The last posts talk of this very thing. You say either "Will" work but,, how does this effect drawing 10 40 360 and 10 40 330. This is what becomes hard to follow. Those drawings have no option but if cut will not work if you went with the 18" imperial option. Help me understand what Im missing. Its just hard to know what it will effect not being the one who drafted them.

[Gerald_D]

Charlie, what length plate is readily available to you?

[Charlie T]

The place Im getting my gauge plate says it can be larger than 18"x4" also he tells me its A2 tool steel. Is that the right stuff ??? See now Im all worried that Im headed down the wrong path. I wanted to buy it today and get it to the fab guys.

[Charlie T]

I wish we had an all metric plan and a all imperial plan. This guy told me that he cant work in the tenths of an inch or metric. Thats going to be a real bummer.

[Gerald_D]

Drawing 10 40 330 shows an arrow where the 18" plate will end. I could have told all the metric guys to cut their plates shorter to 18" just to have a standard set of drawings, but why should I waste their time? (or do a second set of drawings in units that are foreign to me?)

[Charlie T]

Yea I know what you mean its kinda up to us USAers ( I hate inches metric is so much better)
Laser cutter guy said no problem he can work in tenths of an inch but some are just dumbfounded by the thought of this.

[Travis H]

I don't find it a problem working in either or. Just use the magic number 25.4 to convert the numbers.

Gerald, keep up the good work Mate.

[Gerald_D]

Charlie, in this thread (http://www.mechmate.com/Forum/messages/2/2071.html) I got the impression that the inch folk are okay with decimal inches. Maybe you should look for another fabricator?

Thanks Travis.

[Charlie T]

Im thinking thats it , come to find out the linked "precision ground" ones are way nicer than what I could get from him. But I guess it could work if It had one nice factory edge, the quote was 64$. Ill just wait on this peice for now.

[fabrica]

Gerald, Have you given the width of the slide plate after machining the V rails. What I find is only the sawing dimensions given. Please educate me on this.

The sawn width of the plate was 100 mm. The drawing was given to my machinist and since he could not find the final dimensions (width) of the plate after machining, he had finished the plate to a 94 mm width. When we tried to put the rollers in today we found that even after making adjustments to the extreme with the ecentric busings the rollers would not fit into the plate.

The overcome this situ the easiest way out was to make new holes in the spider plate. We plugged the exisiting holes by screwing in bolts onto the existging holes and the grinded them flat. Then we increased the width between holes by 2 mm on all two sides. We were able to overcome the problem by doing this.

After doing this alteration we are in a situ where the motor mounting screws are hitting the spider bracket while moving. To overcome this we are planning to contersink the bolt which is clashing with the spider plate.

The ideal final width (after maching the V rails)of the plate should be around 90 mm. The ecentric busings will take in widths between 88mm and 93 mm according to our calculations.

[Gerald_D]

Gauge plate is very exactly 100mm wide, and there is no need to machine it any narrower. Therefore, the finished size is 100mm (as originally supplied).

Then, for drilling the holes in the spider plate, according to drawing 1040430D, the dimension is given as (132) in brackets with a note "To suit slide and V-rollers". Maybe I should have made it clearer that dimensions in brackets are only a guide and must be checked against other parameters. In this case, the choice of V-roller will make a difference, and whether the gauge plate is 100mm or 4 inches.

The eccentric bushings are also used to get the z-axis perpendicular to the table.

I am concerned about collisions between your router (and bracket) with the z-axis rollers....?

[fabrica]

I am using the rollers from supremebearings. Maybe their are dimensional differences between BWC and Supreme rollers.

The collision between router and rollers cannot be that difficult to overcome. The bolt head just has to be taken care of. Since we have come this far this minor thing cannot be a big issue.

[Marc Shlaes]

Gerald,

There hasn't been a post in this thread in quite some time so I thought I'd break the silence.

I have been studying this section and I'm missing something in the purpose of some of the machining to the guage plate.

Can I assume that most of the pairs of holes are for a range of adjustment for the attachment of a router bracket? It surely doesn't take that many cap screws to attach the tube. I also don't understand the purposes for the 6mm dowel holes or the 10.5mm hole for the drawbolt.

... and I apologize if this is obvious but I did search for the answer before I asked.

[Gerald D]

Marc,

As many holes as possible must be used for screws to form a very tight sandwich between the plate and tube. (To stiffen a phone directory you need to clamp the pages together tightly). When mounting a Fimec or HSD spindle, 4 of those holes are bored threadless right through, but all the rest are "filled" with screws.

The 2 dowel holes and drawbolt are what I used in this thread (http://www.mechmate.com/forums/showthread.php?t=315) (last 2 pics in post # 16) to have those routers interchangeable. It allows a "quick-change" bracket needing only one bolt.

[J.R. Hatcher]

Gerald what is the down side to using mild steel for the Z plate? when I was putting my Z slide together I noticed the spider plate performs like a spring because of the way it's bent, you can actually put some pressure on the guide rollers against the plate and it doesn't seem to interfer with anything. When there is some wear the spring action will take care of it, or so it seems to me. What are the thoughts on this, anyone?

[Gerald D]

I think mild steel will be okay if you can find a very straight piece. It can be replaced if it does wear out.

[ekdenton]

I used 6" channel on my table, and I am not sure which of the slide plate and tubes I should use for my table.
Should I go with the 10" slide, or would there be any advatage in making it longer since I didn't use 7 or 8 inch channel?

On plan drawing 10 40 330 there is a metric option on the 10" slide that is about 2-3/4" longer. So I wasn't certain which one of those to go by, the short or long one.

[Doug_Ford]

I guess it really depends on what you plan to cut. If you know you will only cut 3/4" sheet goods, there is no need for a longer slide. On the other hand, if you think you might like to do some 3D work, the ability to go higher will definitely come in handy.

I built the Classic MM and I didn't realize that in the uppermost position, the bottom of my bit would only be a few inches from the top of the table. That's my fault because Gerald was very clear from the beginning that the MM will carve 3-4 inches. I guess it just didn't sink in. No big deal in my case because I don't expect to cut anything thicker than 1" or so.

Hope that helps.

[Gerald D]

Well said Doug.

There is no harm in building the longer z-slide - it might increase the re-sale value one day :)

On a serious note, I added the longer versions as options so that folk could see what is involved when they kept on asking "How can we extend the z-axis?" Hopefully I have left enough warnings around that things will flex a lot more in this case. But Ed, with your 6" channels on the table sides, you can can only use a short end of the slide, the longer bit sticking out the top doesn't cause you any more flex.

[domino11]

Gerald,
If you build the longer Z slide, do you need taller side rail to take full advantage of it? Or does it just allow you to retract the Z farther up than the shorter one? :confused:

[Gerald D]

Good question Heath,

1. The longer z-slide needs taller "side rails" before you get any advantage out of it. The gantry must be higher above the table top and the longer slide lets you "reach" further down. (Downside is more flex when cutting sheets lying further below the gantry.)

2. For retracting the router further up, the extra pair of rollers (and longer rack) allow you to do that without actually lengthening the z-slide. It is more a case of pulling a long cutter out of a workpiece. (Downside is that your dust system might not go up that far, and the difficulty of aligning 6 rollers)

[domino11]

Gerald,
Would it be practical to make the longer Z slide with the standard side rails, and later if the need came about , add another C channel to the sides to gain the extra clearance? Or would you need to replace the side channels with taller ones. I am thinking stiffness and rigidity, not ascetics.

[Gerald D]

You could put a "spacer" on top of the standard side rails to lift the gantry higher off the table (maybe a square box tube). At this point one is not too worried about the stiffness of the side rails because your biggest headache is the z-slide losing its stiffness. You would only do this for cutting lightweight material anyway.

[Alan_c]

Having done some more assembly on the Y-car today I noticed one small item that may need a mod. Once the gas strut (Gabriel Gaslift mod 4047 - 257mm stroke) is in place and the Z slide moves up to the max up position, the pinion is on the very end of the rack and when the Z slide is moved to the lowest position, there is still about 15mm of rack exposed at the top.

I know this will not affect the performance as I am getting the full 250mm stroke (actually slightly more) but it might be worth considering either moving the rack slightly lower on the slide or making the offset on the upper strut bracket longer. If the offset is made longer the slide will be able to plunge a little lower but will also sit lower when fully up.

[Gerald D]

Alan, I have been hacking at the drawings today (you can see a lot of posts disappear from this thread as I tackle the issues), and the whole z-slide/spring has me pulling my hair out. Can you see some common ground between what you are getting today and this thread: http://www.mechmate.com/forums/showthread.php?t=755?

[Alan_c]

Gerald, most of that thread is redundant as stated, its late now but I will do a more detailed assesment of my situation tomorrow and report back with accurate numbers.

[Alan_c]

Sorry it took so long to get back on this but I took the family out to lunch at Dassiesfontein (http://www.dassies.co.za/restaurant.php), been spending too much time in the garage and the mood was getting testy...

Here are some pics of the situation, as I said, it does not affect the performance but the pinion does get very close to the end of the rack in the fully up position

1662
pinion on end of rack when slide fully up

1663
rack still exposed when slide fully down

1664
distance from lowest point on spider to bottom of slide when fully up - 54mm (this shows that the middle wheels could be positioned a little lower if required)

1665
distance from lowest point of spider to bottom of slide when fully down - 200mm. (photo has parallex error)

[Gerald D]

Ah Dassiesfontein, one of those gems that 80% of tourists to this country drive past and don't bother to stop.

Alan, you couldn't have made it clearer than that!

If that was mine, I would like:
a. the rack to be longer to the bottom so that,
b. the slide could go further up until it nearly gets to the center of the middle rollers, to achieve this I would
c. Mount the upper strut anchor bracket lower down on the rect. tube., because
d. I would be happy to lose some of that 200mm because that puts the collet against the table.

Does that make sense?

[Alan_c]

That sounds like a good plan, I think I have some spare rack I can cut and drill to suit...watch this space :)

[Robert M]

Ah Dassiesfontein :eek:
Woawy woaw, now that is a very nice place to go indeed. Some nice photos to look at from that web site.
Anyone in your “neck of the woods” in need of a “talented” :rolleyes: woodworker for a short trade-guild exchange period.
Very nice place to be !!
Robert ;)

[Gerald D]

Alan, I found the "missing" dimension ...... racks needs to be 300 long and not 280. (Well, you did get 250 stroke, so you can't really complain ;)). I see that Kobus sommer stuck all his leftover rack behind the slide - that's not a bad idea either!
http://www.mechmate.com/forums/showthread.php?p=13229&postcount=159

[Kobus_Joubert]

I had the extra rack, so just used it...Boer maak 'n Plan...

[hennie]

Gerald what is the substitute for gauge plate?

Phoned all the steel supplyers in my area and walked straight into a wall.
Some of them don`t know the product even tried P.E. but no help.

[Gerald D]

100 x 6 mild steel flate bar, provided that it is straight over that short length. The life will be a bit shorter that that of gauge plate. You might 5 years instead of 10 years. :)

Promise you that you will get gauge plate in PE. That town is vrot with toolmakers for the motor industry. Gauge plate for a toolroom is like chipboard for a cabinetmaker - it is a staple diet.

Edit to add:
Sanderson Steel, 041 453 9645, have stock, R249.40 excl.

[Alan_c]

Rack and upper strut mount modified:

a) made rack longer - 315mm
b) placed first mounting hole 45mm from top end of rack
c) moved upper strut bracket down by 15mm

1667 1668
full travel with equal amount of rack to spare

1669 1670
slide almost in centre of middle pair of wheels 67mm above spider, slide at lowest point 187mm below spider = 254mm of travel (10")

That looks better ;)

[Gerald D]

If it wasn't for the limitation imposed by the gas spring, there would be a lot more travel offered by the rack.

Can't stop admiring the photography!

[Lex]

The Z-slide tube, drg 10 40 360 ask for a 50x25x 3 wall thickness. I am having difficulties in sourcing the 3mm wall, cut to size off 490+10. My supplier can only sell it to me in 6 meter lengths.
Gerald, will the same profile with 2mm wall have to much twist in it.( or maybe not stiff enougth) ?
I saw a photo somewhere of a bend up lipped 'u'. That could work?

[Gerald D]

Lex, there is a big difference in stiffness/strength between 2mm and 3mm wall in this case. You also need to tap threads into it. If you really must take 6 meters, use the rest in the underside of the table.

[jhiggins7]

I'm wondering how folks have fabricated the Z slide.

I've checked into tool steel. Sort of expensive, about $40 for a 1/4" x 4" x 18", but not out of the question. Wouldn't want to mess up a piece, though.

I see comments that tool steel can't be milled, must be ground. Too short to use the skate. I see that Gerald used the table saw. What have folks done that you feel worked well?

I see that some folks have used a "flat" piece of mild steel. Have you used the skate? Did you have it hardened?

I would appreciate any input on what has worked and what hasn't worked for making this piece.

Regards,
John

[Gerald D]

. . . I see comments that tool steel can't be milled, must be ground. . .

Not true - it mills, drills, taps beautifully. Tougher than mild steel, but no problems with normal cutting tools in standard mill or drill press or hand tapping or filing or sanding.

[domino11]

John,
Some have used mild steel and the skate, some have used mild steel and the superior rails, (which is the way I am planning on going) and others have used the tool steel and used the skate ( by tack welding some donor angle iron to extend the tool plate so the skate would work) this was done by a member who is no longer around though.

[Gerald D]

Mine (tool steel/gauge plate) were bevelled on a milling machine and finished with draw filing and emery (sand) paper.

[jhiggins7]

Post #3, in this thread, quoted below, is where I picked up the idea that it couldn't be milled. Glad to hear I was mistaken.

For those stateside, you might consider Starrett precision ground oil hardening flat stock (tool steel). It would need to be ground to shape, i.e., it can't be milled, but it has the advantage of tremendous strength, very precise tolerances (typically 0.0001"/ft) and is widely available...



If you welded on a donor strip, wouldn't you mess up the hardening?

I don't have a mill. Would grinding it on the table saw with an abrasive blade work? Or, do I need to get someone to mill it for me?

Regards,
John

[Gerald D]

John, he changed his mind on the machineability in his next post.

I did grind a sample on a table saw - it does work. The biggest issue is to decide whether you are happy to do that to your saw and whether you can get a grind disk that is suitable.

[jhiggins7]

Very helpful, thanks.

So, Gerald, with the draw file, were you just soothing the milled bevel? If more than that, how did you control the angle of the draw file to prevent over cutting into the bevel. It seems to me that the most important dimension of the slide would be the distance from one bevel to the other as seen by the V-rollers of the spider. So if there was a gouge or raised place in one of the bevels, this equi-distance would be affected and cause the slide to move slightly left or right as it is traverses up and down through the spider. And since the spindle is on the end of the Z slide, this unwanted motion would be amplified.

Am I just worrying over nothing here?

Regards,
John

[Gerald D]

The draw filing was only to "sooth" as you say (maybe you meant smooth). Only to remove the small tool chatter marks left by my milling guy - I didn't tell him I wanted it smooth.

[jhiggins7]

Thanks Gerald, yes I meant smooth. And iespell checker didn't help. I guess there's no help for a confused brain.:confused:

Regards,
John

[Oleks]

Hi all
Is it a big difference for using O1 Tool Steel, Hardness: Rockwell B85-B96, Width tolerance +0.005" from McMaster-Carr pn 9516K91 (www.mcmaster.com/#9516k91/=19aq5f) compared to mentioned here Starrett precision ground oil hardening stock (hardness: 230 Br, Width tolerance is +0.0001") from Wttool.com? For me 9516K91+delivery will cost some $30 less...

Also another case - will A2 tool steel plate 0.3125"thick go instead of 0,25"?

And third possible case: as per drowings the plate's length is 18" or 500mm because of standart stock sizes, but how short it may actually be for Z stroke 250mm?

[Gerald D]

Mild Steel is about Rockwell B70 (Brinell 120)
O1 Tool steel: Rockwell B90 (Brinell 185)
A2 tool steel plate : Rockwell B95 (Brinell 210)
Starrett precision ground oil hardening stock Rockwell B98 (Brinell 230)

You will have to decide if you have the tools to cut the steel.

Plate 0,3125" thick can be used instead of 0,25"

The plate's length is also decided by the mounting of the gear rack. There is very little that you could reduce the length. You can cut away the side opposite to the rack if you want to reduce mass.

[vanja.ivancic]

Ihave the same problem. The type of my wheels is Pacific Bearings

[Robert M]

Little survey I’d like to get….
I’ m surprised at the price differences I’m getting out of a few (4) local machining shops I’ve requested a quote for the Z-slide steel plate.
I’m requesting it without any holes, just the chamfer on both side of the plate for the DualVee bearing and getting prices from 125$ to 550$ Can. ( machining work in US or Can is +/- at par in value ).
Can some of your guys tell me how much you paid for this, material included?
Thanks ;)

[sailfl]

Robert,

You know I used preground rails and I think most every one else that ground their X and Y rails also ground the Z Slide.

[smreish]

Robert.
On my two builds, I bought the hardened tool steel stock and then clamped runoff material the same thickness and ground away like the rails.
It was very quick and easy to do. All the work was done in a shop vise and the grinding skate that we all have come to love and adore! LOL

I wouldn't go to a machine shop at all....just grind away.

Sean

[Robert M]

Sean, Nils… Some guys here opted theirs done at a machine shop.
I also understand many did theirs with the great skate & grinder set up :D:eek:
But I'm just trying to buy time wile being frugal, my thought after getting this shop quote at 122$, material incl, was it may be worth all my efforts to make one :cool:
For me, a 4” x 36” in A2 flat bar will cost me the same ( +/- 125$) out of some local steel vendors.

So…since I’m painfully discuvering that I just may lack time in my project to meet my goal date ( oct 26)…. I figured even for a few bucks more it can/will help me….. It’s also called delegate :p:eek::D
But obviously not at a substantial cost increase !!
Anyhow, I'm still curius to see what those who got theirs machined by a shop, how much they got charged for :confused:

[sailfl]

Robert,

I don't think I paid more than $25 for my Z slide plate. That price seems high. Don't you have any surplus or places that sell drops. If I am correct, it would be cheaper for me to buy it and ship it.

[Robert M]

Nils….Thanks for the offer…..
BUT from little expertise I have in this steel field (called soooo many steel distributors), I can tell at 25$ is must be (and pretty sure it can only be) std mild steel.
O1, A2 or D2 tool steel is LOSTS more, 3 to 5x more…. :o

[sailfl]

Robert,

I will call my source today and see what the price is.

[Greg J]

Robert,

I had my Z slide plate fabricated from a local shop at a cost of approx. $100. Material included, no holes, no paint, etc.

I like to think my time is worth more than what I pay someone else to do a job. :rolleyes:

[Robert M]

Greg, thanks for your input & reply... I think alike , for +/- 100 mat. incl...it's not worth my time, trouble & risk missing it !
Rails...that's a hloe other story... It really pays DIY ;)

Anyone else sub this plate !??

[sailfl]

Robert,

I didn't forget you I just forgot to post. I called my supplier and they wouldn't give me a price over the phone. Sorry.

[Robert M]

Not to worry nils, after all I’m not wondering where is, or what is the cheapest piece for raw tool steel. I’m simply curious and interrogative on prices for this Z-plate to those who got them machined at a local machine shop ( mat. included).
Raw tool steel sells in std sizes, and that would mean you would have to pay for the extra 48 sq inch not needed ( one of the std sizes is : 4” x 36” = 144 sq inch ). A machine chop may actually have much bigger piece and cut only what is needed / you request, thus making it lower cost per sq inch, making the total prices not such a big difference after all.
Let’s not forget Nils, O1 tool steel may be one of the cheapest at +/- 70$-USd for a std 4 x 36”.
No... what I’m curious about is I mention earlier is why such a huge price gap in the quotes i was given ( 120$ to 550$) for this flat without holes, only material ( tool steel) & chamfers…. although I have my suspension :(

….I’m simply curious as maybe some others too :confused:…. It's slipping & getting out of the topic / reason of my survey questioning :o

[riesvantwisk]

hey All,

is the method shown here : http://www.mechmate.com/forums/showthread.php?t=311

still the preferred method for grinding the z-plate, or can I simply use the skate which was used to grind the X and Y rails?

If I use the skate, should I add an extra 150mm orso to the length of drawing 10 40 330 S so I can grind it properly?

Ries

[Robert M]

Hi Ries
Since photos a worth more than words…. Here is a link to my answer (http://www.mechmate.com/forums/showthread.php?p=32037&postcount=38)
Needless to say more I believe, BUT, if you’d like more, let us know !
Amicalement, Robert ;)

[riesvantwisk]

Robert,

indeed... that pictures tells is all!

Did you buy the z-plate to long so you could grind the end parts properly?

Ries

[Robert M]

Ries,
They come in std length. You what a 36inch ( +/- 914mm). Check your local source for O1 or A2 steel plate or look at those : http://www.mcmaster.com/#89705k282/=4q8aiz
http://www.mcmaster.com/#90175k174/=4q8b6h

Good luck, Robert ;)

[riesvantwisk]

Robert,

thank you for that info... now I understand now where you get these beautiful plates!

I am not sure if I can get that quality of steel here, so I might need to go for mild steel. However, we do have a mill here in the shop so we can rectify it.

From what I did understood is that we will buy the (mild) steel 900x105mm that is cut on a guillotine, then we will rectify it to the correct size.
For my kinda work this will work just fine.

Ries

[MetalHead]

I see in one of the photos the Mamba Wheels drop off the top of the plate. Could I just make the slide and tube 70mm longer to keep the wheels on the plate?

PS - I am finally learning something scholl could never teach me... the metric system :)

[smreish]

Mike you could...the point of the slide tracking out of the lower rollers is to get the TOOL BIT attached to the spindle/router at a higher Z off the table and clear of your part.

Not so important when cutting things under 2" thick...but on thicker material cuts, it's imperative that you have this high tool retraction height.

Did this make sense?

[MetalHead]

I understand that. I just figured that making everything a littlr longer would make it stronger...

[GaryS]

Why not tilt the table saw blade at 45 degrees and use the existing rip fence? There would be no noticable wear on the metal cutting disc, no setup, and the resulting cut would be flat.

[Gerald D]

That table saw could not tilt.

[Red_boards]

I've had some difficulty tracking down a shop that will do me a z-slide out of guage plate, and the price is in the $hundreds. So before I go to Queensland to get one fabricated where SurfCNC got his, I'm considering getting a harder grade of steel (350 grade) cut by a plate processing plant @ $32 and grinding my own rails and drilling the various holes. I've read that this is possible and the only consideration is that it might wear a bit faster than the guage plate. Any other advice?

[Alan_c]

If you go the route of the steel plate, have it cut longer to allow for the skate overrun, and then trim it to size after grinding the bevel. (cant remember exactly but I think its 100mm at both ends)

[smreish]

Yes, you need min 3.8 inches over over run...thus, 100mm longer on each end. SO, if your ordering steel, you need to order a piece 200mm longer.

I actually have fabricated the slides in 2 different fashions. One, I used cold rolled flat steel and just cut the ground area to length. The second one I used the standard 24" long piece and added via a bench vise and clamps some extra material on both ends for over run during the grinding.

Sean

[Red_boards]

Hi Alan and Sean.
Thanks for that. Yes, the 1m strip is coming in at that price. Sean, I had seen your clamp to extend solution, but that looked too hard for me:o
No problems with wear on the home made versions, then?

[smreish]

No issues, all still working just fine - as designed!

[delco]

I've had some difficulty tracking down a shop that will do me a z-slide out of guage plate, and the price is in the $hundreds. So before I go to Queensland to get one fabricated where SurfCNC got his, I'm considering getting a harder grade of steel (350 grade) cut by a plate processing plant @ $32 and grinding my own rails and drilling the various holes. I've read that this is possible and the only consideration is that it might wear a bit faster than the guage plate. Any other advice?

Red_boards , what did you finally end up doing about the Z slide ?

[Red_boards]

Hi Daniel,
I bought the higher grade steel and ground the rails. It looks like it turned out fine. After grinding 3m rails, the short Z was really easy and quick to grind down (no walking involved, for a start!). Drilling and countersinking was not an issue at all.

[Zouave]

So, I had a curious thought. Why not bolt the grinder skate to a piece of plywood with a hole cut in it, fix a fence to it, and slide the Z plate over the exposed (and 45 degree) wheel, referencing the fence. Final passes would be very light, so minimal force lifting it away. Should give a very nice finish with no material loss on the ends. Am I missing something in thinking through this?

[smreish]

The grind might be correct - or not.
The point of the skate design is to be a TOP reference grind and relative to the base metal itself. The key to the skate accuracy is actually in cutting the rails to the proper height BEFORE profile is ground.

By using a fence system (and it has been done successfully) you introduce an additional error in the grind by moving the material. Moving 10+ feet of rail successfully without waves in the profile is difficult to do repeatedly.

Much R&D was done to perfect a way to accurately grind the Vee profile - (ie) A table saw set at 45 deg with grinder wheel, fence system. A grinder set at 45 deg like you suggest with fence....all had challenges with repeatability.

Good luck with your choices. But from experience of 4 table builds.....the skate is quick and accurate with the correct set up. (read about 36 grit sanding disks backed by grinding disk to grind the rail) SUPER FAST.

[Zouave]

I agree, for the rails, the material lost on the ends is of little consequence because of the overall length. With the Z-slide, however, I think it is worth doing because of the short length, which makes it less prone to the errors encountered with longer rails. Loved the skate on my rails, not so much on the Z-slide. I know a lot of people (myself included) get the Z-plate in the length needed, which means something has to be clamped onto the ends to allow the skate to run over. So it seems like, for the Z-slide, and ONLY the Z-slide, this may be a better way to go.

[Gerald D]

I would also move the z-slide along a fence and leave the grinder static.

[smreish]

Eric,
For the Z-slide I absolutely agree with a static fence.
On all my builds, I built a run off area from HRS flat stock outside the Tool Steel area.

Thank you for the clarification on use. I seem to be pretty short sighted lately. Must be age or overworked....not sure which one! :)

[Brain]

Hey folks, just a quick question about the rectangular tube mounted onto the z plate..

I can not buy the 50*25*3 mm tube anywhere local, and the next big merchant is only willing to sell me the tube if i buy at least one whole tube (6m)..

My option is 50*30*3 mm...

Is this going to be a problem??

I have studied the drawings and i think it should work...

Any ideas/solitions to this problem?

[Gerald D]

From memory, the extra 5mm will touch the bent stop of the spider plate. You can increase the height of the pedestals under the bearing rollers to move the slide further from the spider.

[Zouave]

I will check when I get home, but I think Gerald is correct.

[Brain]

Thats what i also suspected when i looked up the z slide in the sketchup model whoch is featured somewhere on the forum... Later on i thought the only possible solution should be to increase the distance by 5 mm relative to the z plate... Since i am going to turn the suport bushes myself i think that if i make them 5 mm thicker it should work fine... One more issue will apear and thats the holder os the gas spring.. It wont be centrical to the tubes 25 mm ... My guess is that this also can be fixed by making a new one where the bended "ear" is 5 mm longer.. As far as i can see those are the two main concerns...

Also , why do we need nuts on the spider if we tapped a m6 thread right through the 6 laser marked spots?

[danilom]

I use 50x30, don't remember if I had to change anything but think not. I also have a 10mm thick Z plate so it would introduce more problems if it was too tight to fit.

[KenC]

Omit the M8 thread on the spider. just drill a 8mm or 8.5mm through hole.

I can't get hold of 3mm thick 25 x 50mm M.S. RHS either. I opt for an aluminium instead. I hope it will hold for my Plasma table.

[Gerald D]

. . . . why do we need nuts on the spider if we tapped a m6 thread right through the 6 laser marked spots?

The plate is rather thin and may strip when the bolts are tightened