Hey, I had to look up alfalfa to figure out what it is. Turned out to be the stuff we call lucerne and of course there is a lot of it here too. Do you feed it to your own animals or do you sell it?

Good Morning Gerald (as least here),

Both. There are allot of dairies so we sell mostly to them. Our friend has two dairies and 10,000 head of cows.

Oops, getting off subject (sorry). I'll look for an inexpensive angle grinder today or maybe get a flash of genius and figure out a way to use either of the two that I already own.

There is a connection between cows, dairies and CNC routers, so by luck we have hit on something that could be very useful to you.........

Holding boards down to CNC tables and auto-milking of cows use vacuum pumps, big vacuum pumps. You might starting lining up an old vacuum pump to fall in your direction . . . . . :)

I sure like the way think. I wouldn't have thought of that in a million years.

You also wouldn't believe what people throw away. Rebuilding pumps is right up my alley. I will keep my eyes open for an old vacuum pump.

Thanks and have a good day/evening.
Greg

Things are looking up. I found an angle grinder with a good metal frame that can be modified. Locally!!! and for 21 USD :D

Will start the mods tonight. I wonder if there is a self help group for the MechMate/CNC addiction. :)

Good going Greg... I am still working on my design, that problem with holding the angle of the grinder is also concerning me but some lateral thinking will get it sorted.;)

the best support you are going to get is right here amongst fellow addicts :D

Greg my main plate is 1/4". If I have any flex in the bearings that ride the sides of the angle I can't tell it. Because your main plate is only a little over 1/16" it seems to me there would be a problem with this type of flexing. I would suggest you check this on a scrap piece of 1/4" material. If these bearings spread any it will cause a problem in the finished rail. Just a thought.

Thanks J.R.

I don't think its a problem, but, if I've learned nothing else, I have learned that "The proof is in the pudding".

I will take your suggestion and verify. I've got everything needed to modify the skate, but time. Hopefully I'll have some "leisure" time this weekend.

Greg

J.R Nice peace of art. :)Because you are capable of doing such a beauty, I want to ask you if you have seen working . . . . . . . . .

This moved to the thread where milling (not grinding) of the rails is being discussed. link

Hugo I have never seen either of these tools. I think the smaller one could work if some modifications were done. As it is right now I agree with you, it would not cut the inside bevel. When do you plan to start your venture?

hugo, if you want i've got this link.

http://www.gullco.com/more_kbm.html

Michel

Go to my thread and you will see how I used the "skate" to grind my rails. However afterwards I realized how simple it would have been to have built the MechMate base then attached the rails as if they were already ground. At this point you will need to leave them extra long. Using the skate you will grind the rails on the machine then remove the extra length. If you choose this way contact me first there are some minor details. If anyone wants close up pictures let me know. J.R. ps I realized I could have the bottom plate laser cut if anyone is interested, possibly even a kit?

whooo J.R a kit !!!!!

For me, i jusr need the size of the board, i do the rest, but i've got an idear last night, why not twice the bearings on the long side, you can start right the first time of grind.

Michel

Mickey at first glance I said that is a great idea BUT then I realized the skate has to be turned around to grind the other side:(.
My base is 1/4" (6mm) X 4" (102mm) X 16" (406mm).
One of the reasons I chose the Hitachi was because it has a 7 amp motor.

All along the plans said to attach and align the rails with extra length. :)

(I envisaged the "outrigger" running on the opposite side rail . . . . )

Talking about stability. I see Gerald's outrigger being a welded 4" length of 1/2" pipe (w/ a thumb screw mid way[nut welded to pipe]) across the skate plate. Then a 1/2" piece of cold roll (w/ a bearing attached to the end) thru that to the other side. I wish I could draw.

JR, now I've got you thinking. :):)

1/2" cold roll to the other side, which is 7 ft away on our x-axis, is a bit light. . . . . . don't rush into this one . . . . . .

My thoughts on "assemble with extra-length" rails have many origins. From the times with our ShopBot and its "too thin" rails, I have been thinking of a "rail-rider" to dress those rails but the rails had no "extra-length". So, I thought one could lay a temporary rail near the original rail and use that to ride on accurately. Maybe an alu extrusion? But the big idea was to have a piece of 30mm [1.25"] cold-roll (there is a "precision" version) as the temp rail. This "rod" supported in adjustable "V-blocks" about 300mm [12"] apart. One would adjust the V-blocks with the help of a dial gauge and the known sag of this rod under its own weight, and turn it under the dial gauges to find its last errors. . . . . . .
For the first rail, one would use the aligned cold-roll rod to give line and height to the real rail being made, while the outrigger which stabilises the twist of the "rail-rider" could happily run on an un-ground rail on the far side. However, as the grinding gets better and better, the outrigger also forces the "parallel", or distance, between the rails. . . . .
These were all schemes which I thought would never be accepted by the MechMate builders because they sound so exotic. Then a bloke called JR Hatcher comes along and shows a "skate" like the darn "rail-rider" that had kept me awake before. I think; "Nice, but everyone else is going to find that too exotic...." However, most think it is great and a couple are being built. Shows how I just cannot predict what the folk here will think is easy or difficult! :):)

With JR's permission, I would like to use his ideas and do drawings for a "skate" as part of the total drawing package. A lot of the parts could be laser cut. Only snag is to do it for a grinder that is available across the world. Is the Bosch brand available everywhere? Or Metabo, Makita. These big names are easily available here.

Can guys from around the world please jump into this thread and tell us which grinders are easy to get in their countries?

Gerald you are more than welcome to use or adapt any of my ideas posted to this forum. J.R.

You might want to leave off the entire adjustment thing across the base. Maybe have it slotted but do away with the threaded rods, handles and the angle hanging off the back. It sure did look good it just didn't work very well. The skate exceded my expectations but the adjustments leave somthing to be desired. I have an idea that would raise and lower those top bearings (cam action) to do the same thing with much more accuracy. Off to the shop.

Do you all have any of these Bosch 115mm [4.5"] 11 000 rpm grinders easily available in your country?:
(all appear to have have similar aluminum gearheads)

230Volt countries:
GWS 11-125 (1100 Watt) (125mm)
GWS 10-125 (1000 Watt) (125mm)
GWS 9-125 (900 Watt) (125mm)
GWS 8-115 (800 Watt)
GWS 7-115 (750 Watt)
GWS 6-115 (650 Watt)

115V countries:
1810PS (8.0 Amp)
1810PSD (8.0 Amp)
1800 (7.5 Amp)
1375A (6.0 Amp)
1347A (6.0 Amp)

I could design a system that fits to their gearheads . . . .

a picture is more explicit. It's not very important upgrade but i think is a good idear.

Attachment 356

thanks J.R. for your information and your pictures.

Gerald,

I've done allot of preliminary work in AutoCAD. Let me know if you want any of those files.

I'm currently waiting on screws to finish my skate. So, today, I'm working on the X-beams and welding to the table.

Greg

Gerald,
I think that JR was thinking of something a little different from what you are, 4" long vertical. Here is a rough sketch, correct me if I'm wrong JR.

Tom the pipe w/ the screw and nut is right but the orientation is horizontal like Gerald was saying.
As I have stated before, since the side bearings are cam design they can be tightened to the point you can't move the skate along the rail because of friction.
My personal belief is an outrigger is not needed.
May I suggest designing the tool without one and adding one later if needed.

This is what I came up with for the heigth adjustment. I'll follow up with a picture of it on the tool when the paint dries.
For reference, the bearing OD is 1 5/16", ID is 3/4", turned down stud is 9/16", rod is 1/4", Cam is 1/8" off center. Adjustment capability is 1/4".

Gerald,

I easily found all of the 110V grinders you listed except the 1810PSD and it may be out there somewhere.

Doug

This is it on the tool.

Doug is the only one that answered when I posted the following before:

Do you all have any of these Bosch 115mm [4.5"] 11 000 rpm grinders easily available in your country?:

(all appear to have have similar aluminum gearheads)

230Volt countries:

GWS 11-125 (1100 Watt) (125mm)

GWS 10-125 (1000 Watt) (125mm)

GWS 9-125 (900 Watt) (125mm)

GWS 8-115 (800 Watt)

GWS 7-115 (750 Watt)

GWS 6-115 (650 Watt)

115V countries:

1810PS (8.0 Amp)

1810PSD (8.0 Amp)

1800 (7.5 Amp)

1375A (6.0 Amp)

1347A (6.0 Amp)

I could design a system that fits to their gearheads . . . .

Would it help if the laser-cutting kit included parts that fitted to a Bosch grinder as above?

J.R I will be very interested in buying one of those tools (the set would be great) you are making as soon you confirm it is trust able for the job. They have a very professional look.

Gerald I will check as soon as possible.

GWS 6-100 - MINI ANGLE GRINDER
Part No. : 0 601 375 060
Grinding Disc Dia :100 mm
Power Input : 670 W
No-load Speed : 11000 rpm
Spindle Thread : M 10
Weight : 1.4 Kg

GWS 10-125 C - MINI ANGLE GRINDER
Part No. 0 601 702 755
Grinding Disc Dia. : 125 mm
Power Input : 1020 W
No-load Speed : 11000 rpm
Spindle Thread : M 14
Weight : 1.6 Kg

GWS 850 CE - MINI ANGLE GRINDER
Part No. 0 601 803 574
Grinding Disc Dia. : 125 mm
Power Input : 850 W
No-load Speed : 11000 rpm
Spindle Thread : M 14
Weight : 1.5 Kg

GWS 11-125 CIE - MINI ANGLE GRINDER
Part No. 0 601 823 200
Grinding Disc Dia. : 125 mm
Power Input : 1100 W
No-load Speed : 2800-11000 rpm
Spindle Thread : M 14
Weight : 2 Kg

GWS 14-125 CI - MINI ANGLE GRINDER
Part No. 0 601 824 200
Grinding Disc Dia. : 125 mm
Power Input : 1400 W
No Load Speed : 11000 rpm
Spindle Thread : M 14
Weight : 1.8 Kg

A laser cut kit would definitely help!

These are the available Bosch angle grinders in India.

RGDS
Irfan

ideas for the grinder sled
 

Hi all,

this is my first post here.

I have been making CNC machines for a number of years and probably spend more time thinking HOW to do a thing than actually doing it.

In driving out today to get some metal for a project, I was thinking about the skate and I have a suggestion that might help a bit.

First bring the rollers in closer to the grinder, the handles can go outboard. that will increase how much of the rail gets ground.

second, make the sled longer and add another set past the end. this way, the grinder can go all the way to the end, or past.

of course this means a second set of top rollers.

As for the top rollers, using 4 .. stay with me... it's my first design and all in my head at this point...

using two on each side, the outboard ones would be set to the finish height, the inboard ones being adjustable so as to allow the grinder to take off layers until it reaches the final depth. the adjustable ones would need to have a fixed minimum setting.

The other idea was to mount the grinder on a sub-sled that would feed in until the desired depth was cut.

Anyway, there are a couple ideas to kick around.

Dave

here is a drawing

I think a very basic parameter to have available for a skate design, is the fillet radius inside the corner of your angle iron. If your angle iron producer puts a big radius in there then you will have a "wobble" problem because the side bearings will have too little flat surface to run on.

Therefore, let's establish this basic parameter first. . . . . .

Our mills out here put anything from a 6mm to 9mm radius in there, leaving a flat vertical surface of 7 to 10mm. The 7 is too small - the 10 might do.

Maybe it is time to modify the finished rail dimensions on the M1 10 110 drawing to make it more friendly for a JR Skate? Increase the 24mm [1"] to 30mm [1.25"]? . . . . . This will involve quite a few lasered drawing changes because the stepper motors will have to reach lower down . . . . . . .

J.R.'s rails ended up at 1.125 (1-1/8") in order to accomodate exactly the problem you described. I don't believe that, at that height, he ran into too many problems with the lasered metal. I know that his stops should have been a little higher. He didn't think of the rail height difference when he made them. I know he will be back in a couple of days and I am sure that he would love to jump into this discussion.

It does sound like 1.25 would alleviate any issues.

Haven't had much time lately to work on the "skate", but here's what I've learned.

The 1.00 inch (25.4 mm) height of the rail should not be a problem. The first pass at making an edge on my "test rail" went good. Nice 45 degree surface, etc. When I went to grinding on the second surface (other side), it didn't produce the same nice 45 degree surface. I think my side rollers may have loosen. I didn't want to take the chance and get half way through a rail and adjust a side roller. So, I'm adding Gerald's "outriggers" to the skate.

I think adding outriggers is much simpler than re-doing the rail design and drawings, etc.

I'll have allot more time and be back to work on the skate and rail in a couple of weeks. Let me get caught up on all my other "fun stuff" and I'll be able to post pictures.

Greg

skate modification suggestion
 

MM fans & JR.
Well, after some playing around, I think I have come up with a fairly unique workaround for the skate board vertical adjustment issue I have been experience in testing. The issue was the eccentric cams for the vertical (depth of grind) was changing on me. SO, I quickly drafted the following which I plan on testing later in the week for repeatable performance. The best part of the adjuster is that it does so equally. Let me know if I am crazy or not....sometime I get to involved in the engineering and loose all my common sense. Sean

That won't necessarily do it equally - the skate will be free to rock.

You think so? The only thing I have changed is the vertical cam to a divergent bell crank for vertical adjustment on the outboard wheels. The lateral rollers and cam adjusters are still intact. Maybe I am missing something. Sean