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.

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.

Charlie, what length plate is readily available to you?

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.

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.

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?)

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.

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.

Charlie, in this thread I got the impression that the inch folk are okay with decimal inches. Maybe you should look for another fabricator?

Thanks Travis.

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.

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.

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....?

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.

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.

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 (last 2 pics in post # 16) to have those routers interchangeable. It allows a "quick-change" bracket needing only one bolt.

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?

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

Zslide
 

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.

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.

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.

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:

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)

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.

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.

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.

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?

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.

Sorry it took so long to get back on this but I took the family out to lunch at Dassiesfontein, 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

Attachment 1662
pinion on end of rack when slide fully up

Attachment 1663
rack still exposed when slide fully down

Attachment 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)

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

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?

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