JR's rail grinding skate in a Lasered & Bent format for 4.5" grinders

[Marc Shlaes]

There are a lot of inspirations in this MechMate Community. Sean, you surely are one of them.

With you, JR, Mike Richards, Gerald, Fabrica, Doug Ford, and Greg J leading the way, us mere mortals have a chance of success. Thanks!

[Gerald D]

Good feedback Sean!

Where did you find yourself holding the skate? Did you feel the need for handles? Did you think the thing to be dangerous in any way?

All the above for the red notes to be added to the drawing!

Marc, those guys on your list considered themself as mere mortals in the beginning as well - it is a state of mind to break out of. (Was very impressed by Doug who started off all meek and mild with electrics, and then recently he tells a guy how to parallel a transformer - wish I had that courage! )

[Gerald D]

Originally Posted by smreish

Little note on making the skate slide easier....the 1/2-13 UNC bolts for vertical adjustment...it's not reflected in the above picture, but it was necessary to grind a small crown on the end of the bolts to keep the threads from wanting to dig in the rail surface. It only happened when I reached the adjustment part that let the lead of the threads be perpendicular to the rail. A quick grinder wheel action and I was back in business.

Remember our earlier discussion on a brass screw? After some real time on the skating, don't you think a brass screw with a crowned tip (hand-ground) would be better? That would be on the soft side to prevent damage to the reference surface on the top of the rail.

Or, to prevent stickyness between the steel screw and rail (galling?), one could try and go over to the really hard side for the screw. How about a capscrew (they are a tough steel usually) with a crowned tip?

JR, you know your metals, what do you think? (aside from a ball bearing, which is obviously the best )

[J.R. Hatcher]

Sean when the rail is finished and the skate is still in place, how much space is between the top of the rail and the bottom of the skate? In other words how much of these adjusting bolts do you see? What is the size (diameter) of the adj bolts?

I'm thinking if you used a small adj bolt, maybe 10-32 and there is enough space between the rail top and the skate bottom you could use a acorn or cap nut (bottom it out on the bolt, the bolt would still be the adjustment). You could try brass, steel, nylon or chrome to see which one worked the best. They would already be rounded and easy to replace when they wear.

[smreish]

JR and Gerald
I tried a bullet tip socket head cap screw and worked perfectly! The brass bolt really deforms quickly. I will post pics when I get to the office.
The cap screw is something I tried a few weeks ago on scrap and was great. The only challenge was I only had 1 in the shop and I forgot (kept forgetting) to get more in. My brain isn't totally with me these days.
sean

[Roadkill_321]

. . . . . .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. . . . . .

[Gerald D]

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.

[Roadkill_321]

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

[Gerald D]

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.

SuperiorBearing.com (where you can also order your v-Roller bearings and bushings) also carries the bearings for the skate. You will need 8 of the 6001-2RS and they are $2.45 each. These are sealed on both sides. You will not need the bushings as you can re-use the ones from the z-slide bearings.

These bearings can also be purchased from McMaster-Carr (www.mcmaster.com) for 6.43$ Part Number: 5972K82

In the laser cut kit I purchased, I also received the plates for building the skate. When I started to go through the plans, it appears there is a minor missing item (see red boxes on attached image) - the "spacer bolt". The test version appears to have the "spacer bolts":



It's not a major issue - I just though it might throw some people off if they just looked at the drawings.

Also, there was some discussion of adding handles to this "spacer bolt" to better support and angle the grinder - was there any final decision?

Much thanks!
david

Originally Posted by Gerald D

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.

In talking with Rick from Superior Bearings, I was refering to the double-vee bearings as 12mm metric (bore) and he mentioned they were not metric - that his supplier sells an actual metric version of the same bearing. I find this odd since .472440" IS 12mm. He must be right since GW2 is .3750 (9.52mm). Though GW4 is .5906 which is 15.001239mm. So, technically they are not 12mm but in reality they are. Odd...

There is not a parts list for building the rail skate M610100A so I did my best to make one up:

Bosch Grinder (US): 1347A
Bearings: 8 of 6001 Bearing (12mm ID, 28mm OD, 8mm Width (www.superiorbearing.com part 6001-2RS)
Eccentric Bushings: 4 of M1 20 210 T (www.superiorbearing.com part B3X)
Bearing Posts: 4 of 5/16" x 2" long - Pan/Flat head
Bearing Posts: 4 of 5/16" nuts
Bearing Posts: 4 of 5/16" washers
Plate bindings: 2 of 5/16" bolts
Plate bindings: 4 of 5/16" washers
Plate bindings: 2 of 5/16" nuts
Angle Adjustment: 2 of 5/16" x 3" full body thread
Angle Adjustment: 6 of 5/16" nuts
Angle Adjustment: 8 of 5/16" washers
Rail Rider Height Adjustment: 2 of 1/2" x 1 1/2" Stainless Steel Bolt (requires drill/tap hole to 1/2")
Rail Rider Height Adjustment: 2 of 1/2" nuts

[lunaj76]

David,

Are you sure the Bosch 1347A will work? We bought the 1710 because the 1375A didn't work with the skate. The 1710 has a 7.5 amp motor.
Thanks for the lists!


http://www.toolking.com/category/pow...--45-inch.aspx

[Gerald D]

David was probably (mis)lead by:

Originally Posted by Gerald D

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 . . . .

Justin, are you saying that the 1347A had a different gearhead that would not fit the lasered skate? How well did the 1710 fit? Realise that I have never done it myself . . .

Is there a 1710 model? I only see 1810.

[lunaj76]

I believe we checked the 1375A it could have been the 1375-01. It had a 6Amp motor and didn't fit lasered skate. If you use my link and go to page 2 you will see the 1710 this is the one we purchased (fit perfectly). We did not check the 1347A. Just wanted to make sure the 1347A did work.

Thanks for the update! I'll update my "master" BOM.

Originally Posted by smreish

The mamba skate works really well, and at this time appears to have ample clearance with the new 1.125" tall rail section. PLEASE NOTE - my rail right now is 1.25.

Sean -

You mentioned that you changed your rail height to 1.25" instead of the 1.10" (28mm) in the plans. Did you change this because you could get angle in 2x1.25"? Having already tried cutting the rail down and failing, it seems the best solution is to just use rail that is already the right height - which here is 2x1.25" (they don't have 2.5"x1" or 2.5"x1.25"), then grinding it down from there. Of course this changes a few other things but it seems other than the motors dropping down, nothing major. Any suggestions are welcome!

Thanks,
david

[Gerald D]

The motors drop down and the stop blocks inside the rails need to get taller.

The secret to cutting the rail down is a quality cutting disk. See posts #87 to #90 in this thread. The equivalent disk in the USA appears to be EDP #63157 on this page

I've come up with a solution that seems to solve two problems at once - the grinding down of the 1/2" bolt on the ends of the skate that ride on top of the rail and a way to hold the skate down and level.

Start by taking a 1/2"-13 bolt and smoothing the head (if it has any part numbers, grade markings, etc) flat. This head will then ride on top of the rail you are grinding. Take the skate an drill and tap for a 1/2"-13 in the large holes on the ends/edges of the skate (your skate is 1/4" thick plate right?). Insert the bolt with the head facing down. This then leaves a stud sticking up. Put a 1/2"-13 nut on this to form a "jam nut". Then you should still have about 3/4" of threaded bolt sticking up. Order two of these: 57455K76 from McMaster-Carr. Problems solved. Note - this should require a little grinding of the top plate to make room for the handles.

Here is a sample photo (less the handles):

[smreish]

Good solution.
I my beta version - before the laser cut profiles - I tried this arrangement.
The head on the adjustment bolt sometimes cleared. I found that the eccentrics when shifted all the way towards grinding centerline there was interference. I am glad it works for you!
Good solution.
Sean

[J.R. Hatcher]

I need info from anyone that has it. How much does the bolt that rides the rail during grinding protrude from the bottom of the plate, from (start) to finish?

[domino11]

Has anyone verified if either the
Bosch
1375A (6.0 Amp)
1347A (6.0 Amp) grinders will fit the skate? I am trying to find one here that will work. Just wondering if someone is using one of these part numbers.

thanks

[Gerald D]

Drawing M6 10 115 Rev A was tailored for Bosch grinders, but folk modified that for other brands of grinder. The Rev B version of that drawing is now more general pupose. I don't think it is critical to get Bosch grinders per se. But I do think it is important to get a fairly high powered grinder because we have had a couple of reports of burnt out grinders.

[jeffh]

Hi Heath, can't help you with the Bosch grinders as I haven't used either of those model numbers but I know for a fact that the recent skate drawings (Not sure of the specific version) also fit the Milwaukee 1648 8.5A grinder perfectly.
(Probably the same gearhead mfg for both...)

just my $0.02 (USD) :-)

[Tailgunner]

Where can i find the latest skate-drawings. The files on the first page are deleted.

[sailfl]

Tailgunner,

The skate drawings are the last drawings in the last PDF of the drawings that you download. M6 10 100 through 10 20 456.

Hope that helps and that is what you are looking for.

[domino11]

The link for the last pdf file is here

http://www.mechmate.com/forums/attac...9&d=1215014708

The laser cut profiles which have the profiles for the skate parts are here.

http://www.mechmate.com/forums/attac...6&d=1214853734

[Gerald D]

Food for thought:

Clipboard01.gif

If a standard 115mm [4.5"] disk is held vertical, but 45 degrees across the rail, it will cut a 45 degree bevel if the wheel is held 9mm [0.4"] below the top of the rail. The bevel will be slightly hollow, by the amount of 0.044mm [0.002"]

[TonyBert]

Gerald,

The only problem that I see is as the disk wears, the cutting depth will decrease and the wear surfaces will not be the same height along the length of the rail.

Tony