WOW, I thought with all that mass, there was no way in hell you would feel vibration. I believe you, but now I'm worried about my welds in the long run. Only one way to find out. Start cutting wood. :)

Thanks for the comments every one, the shop belongs to my brother, so I can't comment on the stop sign.;) Gerald, it just happens that I've had some spare time from work (2 weeks off) so I'm trying to make the most of it. :) I got the table drilled and tapped tonight, also drilled the rails to 1/2" and picked up some paint for the table. My brother is the painter in the family, so I think he might be painting the table tonight. It will be nice to get paint on it, then I can kick it outside for a while. Next on the agenda is to get the grinder skate working. I have to make some modifications to it to work with my grinder, but they will be minor mods. The eccentrics will have to be made by a local machine shop if they have the time to do it. Anyway, thats it for now. Pictures will follow later.

John

Remember that the eccentrics for the grinder and the eccentrics for the z-slide are the the same ones. First use them in the grinder and then move them to the z-slide. The grinder uses 4, the Mamba z-slide uses 6. Get 6 made, if you havn't purchased them from Superiorbearings yet.

Gerald,

I've already got the kit that Superior Bearing offered, and I think that it has six eccentrics in it. That's great if they will also work in the grinder skate. If I remember correctly the bearings are 6001?

John

Yes, 8 off 6001 bearings sealed against the grind dust. 6001.2RSR is a typical number for a sealed bearing (12mm ID, 28mm OD, 8mm Width). Yes, they are metric bearings, but the Superior eccentrics are also metric.

Well, here is another update. The table is painted Ford New Holland Blue, one rail is ground and the table is drilled and tapped for the X rails. I haven't yet welded the gantry stops on the rails or drilled the proximity sensor holes but that can come later. The skate works very well, but has a tendency to climb the rail. I have to always keep fairly firm down pressure on it to make it cut evenly. The grinding discs I have been using have been frustrating me. They seem to smooth out after a while and stop cutting and just make heat. I have been roughening them with a bench grinder just to make them cut again. Anyone else have this experience and any remedies? Anyway, that's all for now, have to get grinding the other rail.

John

I had the same experience and do have some advice on the grinding. Adjust the skate height screw so the skate is not level. This make the contact point a tangent and not a flat grind. I am talking about a very small change in height. Additionally I "dressed" the grinding wheel with another of the same type on a spare grinder when the not big sparks not shooting off the rail. All acceptable and didnt slow me down. I didnt have the climbing issues you mention. I did find that the first pass on a new grind depth I traveled with the disc rotation essentially making the skate self propel down the rail. The next pass would be a climb cut and seat fairly well. Good luck. It looks like a great effort and well crafted machine.

I found if I moved the skate faster and not allow the metal to heat up it didn't burnish the wheel as bad. This next tip is very dangerous (to material not personal) I took another side grinder and took off most of the angle metal by eye balling it :eek::eek: then used the skate, makes it very fast, but be carful not to take toooo much.

Everything is looking mighty fine John.

One other note, if the bearings that sandwiches the rail are to tight it will climb.

JR.
I see you added your official affiliation to your login description. Nice!
I forgot about that getting to tight, but true. If you bearing eccentrics are too tight it did want to climb. Good note.
Yep, move it quick and make MANY passes per depth setting. I found I was taking about 8-10 passes per setting - total time for all 4 rails was about 10-12 hours with coffee breaks.
Sean

10-12 hours is great!!! I know I spent more than that when I milled mine on a Bridgeport and I think y'all probably have rails that are more precisely ground. The skate is definitely the way to go.

John, She's looking beautiful. Keep up the good work.

Well, here is a small update. I have the gantry welded and drilled, have the rails mounted for grinding and the racks came on the UPS truck day before yesterday. I am back to work at my regular job so progress has slowed down a bit on the Mechmate. My next order of business is to finish grinding the rails and I will try and track down some of that double sided tape.

John

John,

Doug found this source for the VHB tape. I ordered mine from there also.

Uline.com,
S-10148,
3M4955 1/2"X36 YD VHB TA,
$56.80

Haven't use it yet, but getting close.

Greg,

Thanks for the info. I had already decided to order from them last night, so the tape should be on it's way. It's probably the most expensive tape I've ever bought though.:eek:

John

Yea, it's industrial strength!!

Don't get any on the fingers. Although, there are a couple of individuals around where I live that could use some across the mouth. :)

When I posted my source, someone replied that I probably could have beat that price if I had contacted a local signmaker. I think they are probably right because I have a huge roll left over. It would have been better to buy just the right amount and pay more per foot. Oh well, live and learn. Maybe I can use it on my next two MMs.

Is that tape too strong for use to hold down smaller cutting projects? If not having extra may be a good thing.

Might be a little expensive for hold down jobs. Two sided carpet tape can work for that I would think. Hand held router guys use it for holding templates.

Quite frankly, that tape is even too strong to hold the racks! A weaker tape also does the job fine (provided the surfaces are clean), but I gave up on explaining that the racks can be simply taped on with plain old double-sided type. So, had to up the spec for "plausibility" ;)

Gerald,
No worries with that VHB tape. I had a sample from the company once that had two mylar tape pieces held together with the vhb tape. The innstructions said "try and pull the tabs apart." Nobody I work with could do it. We had two guys each grab the tabs with visegrip pliers and they broke the tabs but not the tape. :eek: amazing stuff. I know why they say it can be used in some situations instead of welding. :)

That does raise the issue of removing the racks at a later date. How does one remove the racks from the rails.

Greg,
Pretty easy.

• Take a razor knife and cut the foam layer.
• Release the rail
• use solvent to remove residue with paint scraper/putty knife.
• Repaint the area if needed.
• reattach new rail.

Trust me....I did this a few weeks ago on my machine. It's a great learning experience!

Sean,
Sorry to hear you had to remove your racks. That tape hold pretty good doesn't it? :)

Here is another small update. The gantry is nearly completed and the Y car still needs to be welded.

Attachment 982

Attachment 983

Heath,
Now worries about the rack. I was absent minded when I was laying it up to the angle and "stuck to early". It's like laminate and contact adhesive....you only get one chance!

Nice looking machine - I like the mamba parts. I can't wait to build machine # 2 next month :)

Here is a long overdue update. Things have been busy at work so I haven't been able to work much on the machine, but the gantry is welded, the Y-car is welded and the whole shooting match is painted. The X racks are mounted and I also have moved it out of my brother's shop into my own garage. My garage isn't heated, but it is out of the weather and I have warm clothes. :) Anyway, I am as of right now trying to get the rails levelled and parallel so the gantry rolls the way it should. Anyway, I am still plugging along and every day is one day closer to me cutting something with it. I'll have some new pictures in the near future.

John

Here are some updated pics of the machine in it's new home.
Attachment 1069
Attachment 1070
Attachment 1071

John,

It looks nice and clean. When are you going to get it dirty?

You raised the level of work area.... panel walls.

Nice work John.

We're at the same stage of progress. I know how is goes with the day job and everything. Same here.

Hi John,

very good work.......can we call you JR Jr. :) or is it the camera is just too good :D

RGDS
Irfan

It's a beauty! Nice to see the Mamba cable chain supports in real life - hope they do the job. :)

Looking great. It won't be long and you'll be cutting away. She's beautiful.

oh, looking nice, i whait for my manba parts, it's good pictures for me to place the cable chain support.

Hey, thanks everyone for the comments, I actually thought that the pictures were kind of poor because I don't have a very good camera. I have a long way to go yet though, I have to build the Z-slide yet and I am waiting for the cable chains to come and I have yet to order the flexible cable so I will keep plugging away and you will all see my first cut when it comes. :)

John

John, my ex-welder bloke who emigrated to Saskatoon (at Siemens Laser) sent us a postcard yesterday. Mentioning the weather, he said "Everyday I have to dress myself like a dummy for attack dog training" :)

:D Yes, we have had some fairly cold weather here this winter (-50 sometimes with windchill). Your friend at Siemens will be glad to know it is almost over for another year. :)

John,
Don't feel bad, we are still digging out from 50 cm of snow on the weekend. :(

Heath.

very nice! And yes domino, the snow is crazy, I'm not going to start my table until we get some melting!

Here is what I was working on this afternoon.
Attachment 1089
It took me 3 tries to get all the holes in the right spot on the slide tube, but I finally got it. I decided to go with mild steel on the slide plate as tool steel is not easily available here and it is harder for me to machine. Slowly but surely. :)

John

John,

I used mild steel also. Easy for us DIY guys. :)

As for matching up holes, were you using a pin punch? (I call it a center punch, but that's not correct).

The pin punch makes it easy.

Also, why 6 V rollers?

Nicely done John.
Greg, the 6 rollers are the Mamba configuration that allows for the z-slide to retract slightly higher up. You can actually retract the slide out of the lower set of rollers to get more clearance above the table. Gerald has the thread on the z-slide part of the forum (I think) I know I read a whole lot of information on why the extra set of bearings...but can't remember where! :confused: