X Rails

2X3- 1/4" Angle is readily available here in the US. Other than adding an inch to plan 1020454 do you see any other concerns why this wouldn't work? I assumed the 1 inch high rail was to keep backwards compatibility with the shopbots.

Thanks for all your hard work.
DocTanner

I think you will find that 1.5 x 2.5 x 1/4 is also fairly standard (it is actually available here in this metric country as well). I think the early PRT shopbots used 1.5 x 2.5 x 3/16.

The main reason for cutting it down was to remove the surplus mass on the moving gantry. If you leave it high now, the motors won't fit down to the racks, the stops at the rail ends become tall and may break off. I didn't see the trimming as a major headache, the v-shaping is the big factor.

Hello, Been reading a lot of the previous posts on how to make the rails, and had a question. Would it be possible to cut the angles on the rails with a drill press and a cutter purchased from Enco provided you set up your jig(s) and then feed it against the cutter?

Welcome "Mr Gadget"!

I believe it would be possible. Would be very interesting to get your feedback.

Thank you Gerald. If I attempt to go this route I will keep you posted.

Just curious...
If one was to have a grinding wheel machined to the proper angles with the 1 mm flat area in the center, would it be possible to use it on a table saw with the angle iron attached to a long piece of square stock for "milling" the rails? (See attachment)
Or would the danger of burning instead of cutting be too great?
thanks for the input...

Bill, the 1mm flat is not critical because it is for clearance in the corner of the roller. A "stone" like you sketched would wear quite quickly and would need "dressing" too often. Dressing the groove will be a specialist job.

However, this wheel will need less dressing:

......just another idea....

Gerald and Bill,

How about this one.

Tom

I found this little jewel and thought I could get a grinding wheel and do my x rails with this. What do you think?

Thanks for the excellent input... as always!

Interesting machine Jay. Not quite sure how it would help though, but you aren't called mrgadget for nothing!

Anyway, while we are talking of grinding wheels, it must be said:

1. WATCH THE MAX SPEED RATINGS ON WHEELS

2. DON'T BUMP THE HEAVY RAILS AGAINST THE WHEELS - THEY MAY SHATTER.

Bill, I don't think we need special wheels. Just tip/cant the guides or wheel by 45 degrees.

Benchgrinders generally have very low power and cannot remove material fast. Angle-grinders have a high power (short-life brush motor) spin fast and therefore need fibre-reinforced wheels. DO NOT MOUNT PLAIN STONE WHEELS ON ANGLE-GRINDERS

Some ideas on angle-grinders.....

Great tips on the grinding wheels Gerald as this is what I'm planning on doing with this machine. It is an old knife grinder by Yates American. The whole head pivots around and has degree markings up to 45 degrees. I figured I could acquire a grinding wheel of the proper size and turn the head to grind a 45 degree angle on the rails. I'll have to clamp and reclamp to do it. Now I've just got to find a source for grinding wheels. The search never ends......

MrGadget

What do you guys think of this supplier http://www.metricmetal.com/product_l...ual_angles.htm for the x-rails? They have a 60 x 30 x 6 (millimeters btw!) unequal length leg angle iron. Would it be possible to just purchase this and then all you would have to worry about is just grinding the 45's. Might be something to consider. They have it in cold drawn and hot rolled. I would have to defer to someone else's expertise in this area. Don't know if one or neither would work.

60x30x6 angle would work fine with small pinion gears. If you guys feel that cutting the height down is the big issue, I could revise the design a bit to accommodate the 40mm [1.5"] tall legs.

The cold-drawn 60x30 angle seems to be a max thickness of 5mm? But cold-drawn is perfect for attaching the V-tracks because it has a proper shoulder at the corner edge and is perfectly parallel to start with.

Gerald, how thick is the x rails on your Mechmate? The reason I was looking at the abovementioned company was to eliminate a step (thus time) and help me get my Mechmate together a little quicker. I will have the capabilities to grind the angles later, but to cut it down would require me to buy another tool. (not that there's anything wrong with acquiring another tool!) If these rails are thick enough (5mm) I will seriously consider going this route, otherwise I'll have to get a bandsaw and cut them down as the original plans call for. I don't know how much it would affect the other parts of the Mechmate to raise the X rails to 40 mm, and I don't want to cause you more work Gerald, you've already done more than enough just to get us all where we are now. What all would raising the height to 40 mm encompass? Would it be more trouble than anything? It just may be a viable solution to cutting the rails for those like me who don't have the capabilities to cut the rails, and all they would have to do is come up with a solution (many presented here on this forum) to grind them.

Jay

Jay, before I look at all the implications of going to 40mm high rails, can more people tell me if:
- they will be seriously interested in this option
- this height of angle iron with a 60 to 65mm [2.5"] horizontal leg is freely available in all areas

The big snag is the laser cut slots that allow for the screwheads when hanging Oriental Motor gearboxes. (Less elegant solutions can be found easily).

I have been reading everything on this forum for a couple of months and this is my first post. I also cannot believe the quality of the information and people found here. Especially you Gerald!! I own a bandsaw, but only the little 4 x 6" from Grizzly and I think it would be a very long day of cutting to make my rails. If it is a simple process to update the design for the higher rails then I too would be interested. If it is hard, then, I agree that I will spend the long day cutting.

I am thinking of building the fixture that the holds an angle grinder like you have drawn above. Maybe it could be shipped around to the US builders as well and shared. Anyone?

When I start my build, I will post in the 'Personal' pages. Thanks again everyone for sharing the wealth of your experiences!

Marc Shlaes

Welcome Marc, thanks for the kind words. Have you (and Jay) phoned around your local steel stockists and asked what they actually stock, or what they are willing to get for you (2x 20' lengths)? What are the prices like?

I've looked a little locally, but not too much in depth. For some reason, I've not had too much luck locally sourcing steel components. You would think living around a large city like Atlanta you would find stuff easily. Got a couple more places to try. I really don't want to buy large steel components online because shipping charges are horrendous. I was kind of hoping to find a local supplier and get them to order what I need, such as the metric metal pieces if they'll work. If I find a good, reliable local source for the steel I'll post it in the Golden Resources area for others around here.

There are 85 Steel Distributors & Warehouses listed for Atlanta GA at yellowpages.com - should I make some calls when I get there in 4 weeks time?

I am willing to put in some effort to design something that works with your local materials, but then I want to be sure you've done a bit more than a web search and are 100% what you can collect with your truck, or get delivered to your door. Yeah, buying steel via the internet would be about as silly as buying lumber from an armchair in front of the PC.

I live in Cleveland, OH, USA and I haven't yet started looking for the 'big iron'. I am in the middle of the build of a 'hobby' CNC router to learn about control systems and Mach. I started that before I found this forum. It makes sense to finish it and to use it for about a year. I will start to build my MechMate in a few months by (1) building the "dining room simulation" and (2) building the fixtures, jigs, and tooling so that I do a good job on my MechMate.

Gerald
I'll admit I've mostly looked via the PC more than getting out there. Just not quite at the point yet where I can go buy, then build. Guess you could say it's easy to get trapped into planning too much beforehand. Wish I could commence my building right now, but for the moment I'm just trying to get everything lined up, so that when I can begin it's gonna go as quickly as possible!! I'll do a little more research locally (via truck and phone!) and let you know what I find.

Marc
Sorry for not mentioning before.....welcome aboard!