Here is the post where I detailed the specific grinder:

http://www.mechmate.com/forums/showthread.php?t=741

Purchased at HomeDepot for $99.00 USD.

It didn't fit without opening up the inside hole for the head with a die grinder. The orginal ID of the skate is 1.714" and the Milwaukee and Ryobi are both around ~1.82" OD. There was discussion of the nead for 1/4" spacers between the plate and the head but they shouldn't be neccessary if you put the #8 screws in all four spots. (BTW - the Ryobi screws are metric, the Milwaukee is inch)

I also HIGHLY recommend the handles for the sides - they are from McMaster-Carr and are part number 57455K76, you'll need two of them. Drill and tap the end holes to 1/2". See my other posts for more details.

I also highly recommend the SteelMax saw for cutting the rails down. It was completely accurate and took less than 30 minutes to cut down all the rails.

I also wrapped a web shop towel around the head of the grinder (to each side of the handles) and this seemed to work well. It also helped cut down on the number of sparks hitting my hands.

hi there, some news, . . . . . . . i've started to grind Y rail and i think finished the gantry next week.

Some picture of my last work

Cutting rails to 1.1 with grind head top plate.
 

We ordered 2.5X1.5X.25 angle for the rails instead of the recommended 2.5X2.5X.25. Reason: only 1.725 of working height between bottom of grind head top plate and work surface (grinder is Bosch 1710). By using 2.5X1.5X.25 you get more life out of the cut wheel because the uncut rail will completely slide under the bottom of the grind head top plate. Am I making any sense? We used the pferd cut wheels and only used a few wheels cutting 40' of rail to height.

Justin

This post copied from Drawing Corrections thread as a heads-up on using a lower angle iron to prevent multiple passes.

Smith and Arrow cutoff disks
 

First time poster, long time lurker. :)

Does anyone have experience with these cutting disks?

At $47 (including shipping) for a box of 50, these would appear to be a good value for those in the US. (I didn't see the pferd disks readily available)

FYI - in my complete BOM, I have listed the individual screws and washers required to mount the Milwaukee to the skate. It also has all the other screws, bolts, bearings, handles, etc - the BOM can be found here:

http://www.dmoore.com/mechmate/bom.xls

Jeff,

I've never used them but I agree with you. Don't see how you can beat the price.

Would anyone want the hole in the skate cut slightly bigger for a non-Bosch grinder? We might be able to decide on a standard hole size before the next round of Joe's laser cuttings. A slightly bigger hole will not degrade the use of a Bosch grinder.

Gerald,
Good recommendation and change. As you know, I had to oversize my hole slightly, but I was still able to use the RYOBI and BOSCH grinders selectively with the same (4) BOLT pattern. Great idea to make the skate more "universal".

Any other volunteers?

I have never used the skate so I'm not exactly sure what I should be measuring. Are y'all talking about the round part of the motor housing through which the spindle passes? The part that the guard clamps to? That's what I'm guessing.

I have two grinders. A Dewalt DW402 and a Black and Decker Quantum Pro. Both of them measured 1.502"

For all of you lurkers out there that are planning to build a MM one day, now is the time to chime in with your measurements. Go out in the garage and measure your grinder and post the results.

Thanks Doug.

Well, unless someone has a common grinder at bigger than 1.82", the hole size is now firmed up at 1.85" (as per Sean's first prototype, of which he gave me a dxf file)

That works for me as it's not the hole ID that holds the grinder in place, it's the screws into the head. On a side note - the Milwaukee and Ryobi which are basically the same head sizes, the screws on the Ryobi are 6mm and the Milwaukee are #8 screws.

I presume that all grinders have 4 screws placed in a square. What it the thickest screw (surely not 6mm)?

Got some courage to cut the rails
 

Started cutting the rails down. Look at a carpenters method of building a slide to cut down the rails again some off cut material and bobs your uncle.
Kobus made the gadget with the same tape we are talking about put some screws on top just in case it moves.Took me longer to get the hight right then to make it.

Took +/- 15 min to cut through the first rail with one & half disks.The objective is to cut both rails from one side.Had to go home the boss called they wanted to go and watch whales.

I hope that yellow grinder is not an Einhell from Trade Centre. They are fine for cutting the rail but grinding the bevel they are not very strong. Nice going Hennie

No, it is a De Walt Last much longer! I try to keep the el cheepo`s on display for affirmative shopping purposes,You know what I mean:). I have a Bosch for the bevel grinding on my laser cut gadget.Reason why I made the funny wooden block is that my angle iron is 60 x 60 and you have experiance in using the grinding skate ,hight is a problem and I wasnt prepaired to pay more for other angle iron.
Would like to do some more but I am baby sitting today.

Did some more cutting on the y-rails (second one ).It is not such a bad job,dirty yes!I did manage to cut both rails down from one side. wil post pic`s tomorrow,will try and do the x-rails also.

Rails drilled, cut and grind
 

Thank you for the welcome words.
I made this adaption for my Makita grinder form offcut MDF and a few screws, the grinder fits snug into the MDF supports, I made sure that no high squeezing pressure is exerted onto the housing of the grinder body. It worked well for me, the cutting and grinding is off to a great start and completed, the temperature is not of the cutting disc, it is our 11h00 morning temperature in full shade.

nice grinder attachment though!

rails
 

Pic 1 shows what was left of the disk for the back rail did not even finished the disk only used that one disk.
pic2 &3 shows rails back to back cut from one side

It looks like you're grinding angles in the middle picture of post 79, how did that work?

Leko,
The picture with the disc horizontal is a illustration of cutting the angle iron down to size, I did cut the angle iron from both sides, that way I found the cutting disc lasted longer, by preventing the cutting disc from slicing through the metal ensures that the disc remain the same thickness and does not grind thinner between the angle iron and the off-cut, the final “flat “grinding was done with a grinding disc. Keep in mind the difference between the use of a cutting and grinding disc.
The picture showing the grinding in action is the actual 45 deg grinding, with a 45 degree conversion to the grinder adaption. I found that discs made by Makita and De Walt is top quality and outlast most other brands.

Disc info
 

Hi guys,

Has anyone ever head, tried or tested SAIT Z-tech (the "Z" is for zirconium grain) cutting wheels ?
How can/do they compare to the preferred PFERD ?
Thanks, Robert ;)

Pferd
 

some updates and trouble
 

. . . . we were trying to cut the angle iron today (see pic in the zipped file, donno why but always the cuts went one mm below as if the cut was digging into the L - angle rail.

May be I did not have a sturdy enough clamp made for the angle grinder.

will try again on monday though - any comments and help are welcome - meanwhile I did not laser cut the grinding attachment - thought would borrow it from vishnu - since vishnu is down with high fever I will be postponing the angle grinding or may be ask sharma to lend his.

will keep all posted though.

RGDS
IRfan

I think you have the wrong grinding technique if your disk is that deep through the metal. . . . .


The idea is to cut a shallow groove over a long distance, come back and cut it a bit deeper, come back again and cut it deeper again, etc. You may take 10 to 20 "steps" or oscillations to get through the metal.

Irfan, I used that method and it did work for me.
Screw your rail against some flat surface,maybe the spoil board and get your friend to hold some safety glases in front of you:(, use both hands on your grinder.Looks like you are holding the grinder down with your right hand on the handle( might be that you are pushing it down.Your clamps look ok I used one of my extractors hose clamps )

Like Gerald`s reply don`t force the cutting disk into the angle iron just, just let the cutting disk touch the metal you will be amazed how much it takes of. Take it from side to side running the full length of the rail. you will do some serious exersise behind the rail but it works.

Look at my thread it should show you.Try putting your rails back to back then you cut them together same hight and they are straight.

Some PICs of progress
 

Here are some PICs of the progress.
I burned the Chicago cheap grinder and had to buy higher amper grinder.
I wanted at least 8A grinder but could not find any that would fit my skate so I end up with the 6A Bosch with a little grinding on the skate to make it fit. I had the older version skate with hole size of 1.72.

Hey, this is all good stuff!

(except for the dead grinder - which is becoming a rite of passage for a typical MM builder)