Well it has been a long time in getting to this point. The rail cutting and grinding isn't fun but it is doable.....

Our (Ted and Stan) thoughts on grinding.... Ditch the bolt for height adjustment and go for a bearing... Adjust depth of cut (err. grind) by sliding plate with grinder (in/out, angle). Little to no glazing of wheels, cut much faster.

I'll see if I can get some pics up later (per my schedule probably next month).

Onto to the table....

long beams cut, cross bearers cut, both drilled (we're doing a bolt together table).... We may have to weld later, but the machine is being built in one location to be moved to another location later.....

Stan

I agree the bearing is the way, but the height adjustment system needs work.

moving forward in Littleton
 

Yep, but consider that the first ones were built w/o the skate, we are making progress.

What Ted and I found was that the height adjustment is not all that much of an issue because we twisted the grinder plate (looking down at the top of the skate) a bit to get a bigger/better bite on the grinder wheel. We drilled a new hole on the grinder plate in the arc that the slot (older skate drawings) circumscribed.

Before that we'd glaze up a wheel in just a few passes. It took us HOURS to get the first rail to passable. The other three took less time combined than the first.

It may have been the infamous "learning curve" but I don't think so.

Stan, Some time ago, Joe (jehayes) told me grinding the rails is the rite of passage. Now you had earned it, Congrats.

This IMHO is the most laborious & messy part of the build, it took me 3~4 full working day to have them done. (To me the Kitchen table project comes next on the list).

I actually found the kitchen table project more daunting because electricity scares the s**t out of me!:)

Congratulations on getting over the rail grinding hump. It's all smooth sailing downhill from here!

Joe

That makes at least 2 of us ;)

Boy I hope so as I was "fearing" the rail grinding. Even though I had been lurking around here for a year or so, I didn't really think it would work (even though there were pics to prove).

Finally, I (we) just had to do it. For me the "kitchen table" project is less daunting as I have built several cnc machines (foam cutters, a small table cnc router w/ ac servos, even a laser cutter) so this part of the build is much less scary.

At this point the thing that I dread (not scared) is drilling/taping all the holes, and then the paint (I'm not a ford guy ;-)

For those that are a bit timid on the kitchen table/control system, just be patient and OCD (ok anal) about the connections (double check, and then check again). The idea of doing the control cabinet as a kitchen table project helps one to focus on the smaller picture for a moment. I'm not sure anyone has mentioned this but theoretically the control box could be moved with a bit of fuss to a small mill/lathe. There is nothing "mechmate" specific about the control system other than Gerald et. al. good choice in components.

Stan

Stan,
Drill tap is less dreadful if you treat it as dynamic meditation like I did. Don't forget to prepare suitable lubricant for both drilling & tapping, I used WD40 as that was the only "oil" in the shop at that time, I would use cooking oil if I have too ;)
Like many others, paint before fully assemble is what I did, it sure saved me from some serious yoga exercise & weight lifting. It turn out quite a bit of fun for me too. (I hand paint with roller brush, used up 2 pint of top coat (3 coats) without dilution for 1220x4400 table)

Hi Stan.

About 20 years ago I felt the same way about taping holes.. I would have rather used nuts than tap a hole. THEN I found the right tools!

Attachment 8713

I was out in the shop and just finished taping a few holes when I read this post so I gathered up a few items and took this picture.. This is the secret to easy taping! First off you need a set of SPIRAL POINT Taps... These suckers cut metal like hot butter and push the metal out in front of the tap so you do not have to make a turn and then back up... With a spiral point tap you just start twisting and don't look back... They are so good that I hardly ever put one in a tap wrench and instead stick them in a power drill... Takes me about 30 seconds to tap almost any size hole!

The next item you need is something to keep the tap square to the hole as you perform the operation.. Years ago a friend made the Tap Guide you see in the picture... .750" thick aluminium with all the tap sizes drilled through ( well almost all, you see he forgot one :D ) ... Easy to make and use...

The last item is a good cutting fluid.. The can on the right is for aluminium and is easily found. The Jug on the left is the very last of my supply of Tap Heavy :( This stuff is the best I have ever used and I have not found any in the last 5 years.. It's made by Trim and is a thick, sticky fluid.. It makes drilling holes a pleasure even with a hand drill... I have had that jug for about 15 years and would kill for a new one!

If you pick up a few taps and give them a try I promise you'll never dread another tap again :)


UPDATE :

After posting this message I got to thinking about my serious shortage of Tap Heavy and went searching on the internet... I FOUND THE COMPANY !!!! It is now being made by Master Chemical and here is a link to their product pages... As soon as some of their distributors open Monday morning I will be on the telephone! Oh Happy Days :)

I have had that jug for about 15 years and would kill for a new one!

UPDATE :

After posting this message I got to thinking about my serious shortage of Tap Heavy and went searching on the internet... I FOUND THE COMPANY !!!!

Steve, we're all happy to see know that the world is a safer place to be thanks to this this "new supplyer" ! :eek: :D

Robert ;)

Yes, you can all rest easier tonight :D

Ok I promised pics....
 

This set is the mods (VERY CRUDE) to the skate.... Worked a whole lot better. I believe the "newer" skate plates are drawn with the possiblity of using bearings front/rear....

Height adjust may not make sense but it works by twisting the wheel into the rail as opposed to up/down.

still more pics....
 

some of the drilling...

We are making a portable MM :D Yeah, right! It is a beast even now. It will be moved to its next home after painting..

last pic....
 

We've got the frame basically assembled. I took a pic before the legs went on and bracing... Got to get those pics....

As for size. This was where Ted's TR3 sat including the oil puddle (couldn't resist that one). Makes one think about sitting on the gantry on a machine that is built in a garage that is bigger/heavier than a TR3....

I just couldn't convice Ted to build the table and park the TR3 underneath.:D:D

Stan how easy was it to make the height adjustments with your skate ?

Adjusting the depth was a piece of cake... Put the skate on the rail, loosen the pivot bolt a bit (the one with the nut welded on), loosen the bolt that sits on the arc a little more, press the plate till the wheel lightly touches the rail, tighten, turn wheel to make sure did not go too deep (should rotate with drag).

Grind both sides of rail...

Next adjustment is same way....

You can take as much/little as you want. We also used a very light tap by a hammer on the plate when getting close.

Thats right! No real height adjustment, Just a twisting movement into the beam. The old way the grinding disk would become glazed over. I have always used angle grinders on a angle. So this way you can really make a aggressive cut. When I got close to the finished dimension, I switched to a new disk and then made lighter cuts. If done the old way, well I was going to kill something!!!!! This way I would even cut rails for friends. Not bad at all.

update...table framed...
 

finally through the "dead bug" stage.....

I was (we were)..... Framed....

Stan, I see you enjoy playing trampoline with the table! Good progress, the hard work is over. The works will be a breeze from here on.

It's looking good guys. With warmer weather on the way maybe it won't be so painful to work on it now.

Richard

Yeah, the hard (at least the heavy work) is over...

Now it is bolt part A on Part B, using bolt C in hole D or is it Bolt D part using D Bolt in D hole (read D as 'the')..

Seriously, my thoughts were that the table (and rails) would be the demanding part for us.

Now we have a small decision as to what area to focus on next, carriage cars or go ahead and mount the rails...

decisions, decisions, decisions.....:rolleyes:

I focus on 2 parts,
1) the fabrication &
2)Installation.
Fabrication is heavy & dirty; A clean & tidy working area is helpful during installation. So I did all the "dirty" work while the floor still covered with steel chips & grinding dust. You don't want to constantly look out for drill chips or dust during installation, do you?

Sticking to the "ground-up" approach, i.e. work from what ever that is nearer to the ground automatically eliminate lots of decision making ;)

fabrication finished....
 

Well the pictures have been slow because the progress has been slow. One of us (Stan) just had to go scuba diving in the caribbean for a week :D

But the major fabrication is finished, now onto the small parts (stopper blocks, etc), transmissions, and other...

Kitchen Table err Dining Room Table done....
 

three days of work, including going back and forth to town (1hr round trip) for wire to test with....

Then I realized that I ordered 270ohm instead of 270K ohm.. Over to my other shop (I have too many shops).... Use a bit lower value, wth, this just testing......

things that are supposed to click, click and things that are supposed to turn, turn.

Time to finish the transmissions...... order belts (since I ordered the wrong ones). Come to think of it, I haven't ordered the wrong thing more than once, just different wrong things....

Notice I managed not to get a photo of my feet..:D

More progress.....
 

transmissions complete, just got to put belts on.....
z slide complete, just mounted tonight.....
tool mount complete (used k2cnc from other machine)....
wire run completed, time to start stripping and connecting...
PC configured and tested with control panel....

Sorry for the bad pic.....

Where's that blue paint?:)

Looking good. You'll be cutting soon.

rushing.....
 

My buildmate and I are pushing to finish this thing as there is already work to be had...

I was thinking this morning that this might be a situation in which the machine gets pressed into service, make some money, build a second one in order to get one painted.... ;-)

Probably a pipe dream. Seriously, we will have to get this thing running and usable and then consider painting in the future. I don't like the idea of having to clean it up in order to paint, but we all live in the real world.

Stan

Hector.....
 

I tried to send you an email but it would not go through.

I bought the zslide from Leo Jones aka Castone? I would definitely NOT want to make that part. Also if we (I) build another one (yes, it is remotely being considered), I'd get as many parts pre-fab'd as possible. Check out MetalHead's post in the marketplace section.

Stan

Stan,
Thanks...ill try to contact Leo...
Hector

we got motion.....
 

With the nephew's help got the transmission belts adjusted, mechmate wired (basic only at this point)...

AND WE HAVE MOTION.....

Now to the part I dread -----> finish and tuning...

Any good reference on the forum concerning feed/speed? I understand the YMMV clause but ....

Can we post videos or do we do that on youtube and link to it?

Stan

Stan,

for posting video's we usually use youtube or vimeo.

About feeds/speeds... I am still playing around with that and I am still cutting slow (to slow??), but I like to take my time, I just make sure I don't cut to slow because of heating up my bits.

Facing I do at 8000mm/minute and cutting between 2000-4000mm/minute. I have HSS bits currently and a deWalt router. And since I don't have any collets but 1/4", this is what I currently cut with.

If I want to cut faster I listen to my router and when I notice the RPM's go down, then I know I hit my feed limit. Some people sayed that when cutting wood, you need to do this as fast as people to remove heat as fast as possible.
I know Kobus cut's at no more then half the bit diameter, I started to do this to with good results. Less hit on my bits and they stay sharp. It just takes a bit more time, but I am not in a hurry.

I never broke a bit myself, just a collet but there is a big chance in the beginning you will do something wrong and you might break something, lot's of people start with the cheap bits (HSS) , then buy the carbide stuff.

About tuning, did you tune your Gecko's? I didn't do in the beginning, but later did... Honestly I didn't notice a difference.

Make sure your e-stop works! Might come in handy ;)
Check your manual feed rate so it's not to high for moving the machine around, yes it can go very fast!!! Also, start slow here...
Make sure your soft-limits (in software) are setup correctly so you will not run into your end stops. Later I made auto-homing, and I love it :) Specially when you hit teh e-stop and need to find your touch-off position again.

Lastly, I am not a pro! They are just my experiences....

BTW.. great job, and I am glad you found work already for it!

Ries

Paint, ain't......a big problem. I am sure it will be easier than painting triumphs. Besides we will have to move it, if I ever want to get a car back in my garage, and what a better time to pull apart and paint and finish.

Grab a paint bucket & a roller brush. Paint were used to be painted with paint brush ;)
Besides, it is a small but good way to pay tribute to a good design & keeping rust off.

video posted
 

short vid here....:cool:

http://www.youtube.com/watch?v=aBiZTg8uBAE

Stan

BHMDF now onsite....
 

Big Heavy MDF --- 121" x 61" x 1"..

Tuning the movement....

Will cut the pockets and drill points for the MDF soon....

Yes. My table had that too. 4 guys to load on table from delivery truck.

Surfacing Table issues
 

Ok people... Tried to use the Mach Surface wizard, finally gave up after a bit, used the code but created my own pgm...

The table is scalloped (about 7-10 thou) as the bit passes down and back. We are using a 0.75 carbide 2flute to surface the MDF (removing about 0.1 at 300 ipm).

My leading thought is that the "plus (towards xmax)" pass is deeper than the "minus (towards X0)" pass due to one pass being climb and the other conventional cutting.

Any thoughts as this is not really acceptable. I have thought of creating a gcode that goes round n round the square. Ted thought of cutting off the table back around the edge and back onto the table. I thought of making one pass, up the z a bit, return, drop the z, and do it again.

I'm also thinking of places in the mechanics that would cause this issue (spider play, z play, runout on the router). The gantry and ycar seem well seated without noticable twisting (but of course we are only talking of a few thou. here and there).

:confused:

Sounds like the Z axis is out of square with the table in the Y axis. This could cause the scallops you are seeing.

Or the Spindle itself...

I remember there was a thread about it, initiated by Gerald but I cannot find it. There is a small 'trick' to test this squareness very easy. Although easy modified at the spindle, one should also check the z-plane for squareness.

I forgot the correct terms to search on, I know 100% sure it's on the forum, somewhere... I can clearly see the pictures of teh methods, however Google doesn't have any Mechmate pictures during search.. :confused: