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View Full Version : Will the sharpening companies help us with rails


Gerald_D
Mon 22 January 2007, 12:41
There are companies who sharpen long guillotine blades....
www.hamiltonknife.com (http://www.hamiltonknife.com/) Hamilton, Ohio
www.cut-riteinc.com (http://www.cut-riteinc.com/) Slidell, Louisiana
www.jorsonandcarlson.com (http://www.jorsonandcarlson.com/industrial_knife_sharpening.htm) Elk Grove Village, Illinois
www.extremeknife.com (http://www.extremeknife.com/sharpening.htm) Salem, Ohio
www.glknife.com (http://www.glknife.com/products/applications/machine.html) Akron, Ohio (also mention (http://www.glknife.com/products/applications/hardened.html) hardened precision rail/ways)
www.cknife.com (http://www.cknife.com/straight_blades.htm#guillotine) Asheville, North Carolina
www.federalknife.com (http://www.federalknife.com/shearblades.htm) Palmyra, IN (Near Louisville, KY)
www.florida-knife.com (http://www.florida-knife.com/resharp.html) Sarasota, Florida
www.cambknives.com (http://www.cambknives.com/) Houston, Texas
www.atlas-knives.co.uk (http://www.atlas-knives.co.uk/services.html) Golcar, Huddersfield
www.tskgrinding.com (http://www.tskgrinding.com/shear_blades.asp) Memphis, TN
www.workbladesinc.com (http://www.workbladesinc.com/id8.html) Warren, MI
www.detroitedge.com (http://www.detroitedge.com/) Detroit, MI
http:www.bachknives.com (http://www.bachknives.com/shear.htm) Port Washington, NY
www.nowthatssharp.com (http://www.nowthatssharp.com/SHEARBLADES.htm) Fort Lupton, CO
www.knifemaker.com (http://www.knifemaker.com/index1.html?131_oprod.html)
http://www.askoinc.com/asko/skb_squaring.asp Homestead, PA
etc.
(Google industrial knife sharpening, grinding shear blades, grinding services knife, etc)

These guys might help us put an edge onto some angle iron?

vadeem
Tue 13 February 2007, 12:11
I have spoken to a few sharpening companies. They say the lengths are no problem, but they all want to know what level of "finish" is required. What do I tell them?

On a good note, they said not to cut the 2.5"x2" angle iron down to 1" for them ahead of time, as the mill will remove the waste on the second pass.

Gerald_D
Tue 13 February 2007, 12:52
This is sounding encouraging! http://www.mechmate.com/Forum/clipart/happy.gif

Defining the finish, let's think how to do that.. It is not a "mirror" finish. What I get from using 100 grit cloth is good enough. What I have seen of knife blades used by printers is plenty good enough! In general, these guys do stuff a lot better than what we need.

reza forushani
Tue 13 February 2007, 17:41
Vadeem
If you go this way, I am with you. Maybe ordering 2 sets will be cheaper.

Charlie T
Tue 13 February 2007, 22:02
http://www.superiorgrinding.com/

Gerald_D
Wed 14 February 2007, 11:08
I've added a few more links up top. This Google search (http://www.google.com/search?q=grinding+service+knife+shear&hl=en&safe=off&rls=GGLD%2CGGLD:2005-07%2CGGLD:en&start=100&sa=N) was useful. Your Yellow Pages under Grinding could also help.

vadeem
Thu 15 February 2007, 01:50
Telling the guys that "100 grit cloth" finish was all that was necessary gave them a good laugh! They said that it was "too easy".

They said that hardening treatment was out of the question because there was not enough carbon in the angle iron.

Next week I am taking them a sample rail that they want to run to make sure that it meets our standards.

I assume I want to drill all of the holes before milling to avoid damaging the milled edge.

If any others want to get in on a "bulk buy", let me know the lengths needed here. That way I can go in armed with some #s and get the best leverage.

Gerald_D
Thu 15 February 2007, 02:20
Vadeem, we are really looking at a fairly low-tech device here. Not hardened. Not polished. Final dimensions not critical. Important only to get edges parallel to the base - everything is adjusted with shims at the end because we bolt these rails to un-machined rolled iron foundations. Tell them that the only inspection tool at the end will be a steel rule or vernier caliper - definitely not a micrometer!

Drilling holes is tedious and low-tech - the most economical will obviously be if the MechMate builders do this themselves. Anyway, everybody's hole spacing will not necessarily be the same. The edge can be protected with split hose, but it take a very careless person to make serious marks in those rails. The ends are the most vulnerable parts and that is another reason why the drawings show "green" ends that are trimmed shorter after final assembly.

reza forushani
Thu 15 February 2007, 08:29
Vadeem
I would go with you.
2X10' and 2X5'

Gerald_D
Thu 15 February 2007, 08:53
Reza, that short rail sounds a bit short. What size material do you want to cut in the machine? (The rails you have mentioned will cut less than about 8' x 3' max.)

reza forushani
Thu 15 February 2007, 09:04
I was thinkinh 8'x4' boards. Am I calculating something wrong?

Gerald_D
Thu 15 February 2007, 09:17
For Y-axis, see drawing 10 20 246 M.
You need to add an absolute minimum of 500mm [20"], but 700mm [27"] is useful for setting up, clamping, taking knocks (the extra 200mm [7"]trimmed off later). Your 4' wide board needs 68" to 75" of rail - 6' will be okay.

For X-axis, see drawing 10 10 246 M.
You need to add an absolute minimum of 600mm [24"], but 800mm [32"] is useful for setting up, clamping, taking knocks (the extra 200mm [8"]trimmed off later). Your 8' long board needs 120 to 128" of rail - 10.5' will be okay.

reza forushani
Thu 15 February 2007, 09:46
thanks Gerald
Vadeem make that 2X6' and 2X10.5'
Only if I could find some wire for less money now.

Gerald_D
Thu 15 February 2007, 10:34
Take your time to find the right wire - it could be a long time before you need it

It seems as if 10' x 5' boards are also a common size, while 20' is the standard angle iron length. Therefore, a 20' length of angle iron can produce a single x-rail and a single y-rail. If the production company cuts 12.5' and 7.5' lengths out of the 20' then this will cater for table sizes 10'x5' and smaller. Giving a bunch of special sizes will probably negate the effectiveness of a bulk buy, so maybe standardize on 12.5' and 7.5'? (will someone please check my maths, logic and assumptions of standard sizes?)

reza forushani
Thu 15 February 2007, 16:54
Great suggestion

vadeem
Wed 04 April 2007, 16:27
It looks like things are crapping out as far as getting the knife sharpening guys to do the work around here.

When each really looked at what was involved, they said "Sure we can do it, but it's gonna cost ya".

They are quoting $1200 a set(I told them I would need 6 sets, for guys on this forum). And I had to provide the raw materials. That seems crazy to me for the level of finish I was asking for.

It seems that no shop with a mill that I call "wants" to do the job, so they are just quoting me high too.

I hate to say it, but the only way I can see getting this project done (without buying a metal cutting bandsaw and a mill) is to mod the plans and go with pre-made track.

Sorry about that guys....

Arthur Ransom
Wed 04 April 2007, 16:58
My machine will do 128" so theredicly I should be able to do the rails once I get the gantry redone. I am not a metal guy so would it be possible to mill the rails using my PC 3.5hp router? I could put a metal cuting blade on my extra table saw to cut down the rails. Any suggestions on specific saw blade and mills would be appreciated. Anyone have a WAG on how mamy hours of labor/machine time involved? As a FYI my usual shop fee is $25/hr which is great money for a retired guy being paid to have fun.

vadeem
Wed 04 April 2007, 17:20
I don't think you can get the router down to a slow enough speed.

DocTanner
Wed 04 April 2007, 17:36
Arthur,
I cut the angle iron down with thin blades from Harbor Freight. 10 pack was $5 on sale. Get 2
Lower heat = less warpage.
Not recommended but, I used a router to power the blade. About an hour to cut them all down.
The grinding of the 45's took me a long day.
Using a bench grinder with a jig built at a 45 degree angle on the MechMate table. Pushing it through like a tablesaw.
I'm now getting into the Vcarving and 2 1/2 dimensional work.
No complaint here about quality of finished products.
Precision ground rails may do any better job.
But at some point it's like "hunting rabbits with an elephant gun"
I wouldn't do it inside my garage again. Wow, Lots of nasty black grit.

DocTanner

Arthur Ransom
Wed 04 April 2007, 18:59
Never used an elephant gun for rabbit hunting but sounds fun. The new Army .50 cal, now that I would trade my wife for and maybe even my dog. Beats the M1 Garadd Match I used.
Bet I could rig a cutting table on my horzonal band saw and jig for angle grinder on Z axis.

Greg J
Wed 04 April 2007, 21:32
Gentlemen,
On another post, I suggested that a metal cutting "skil saw" would do the job quite easily. My "skill saw" arrive today and I bought the angle today. Give me to this weekend and I'll send pic's of my jig and setup. I purchased the saw for 300 USD and I figure 4 hour to make jig and cut metal.

Gerald_D
Wed 04 April 2007, 21:38
Vadeem, there are other alternatives to a re-design, see this thread (http://www.mechmate.com/forums/showthread.php?t=17). If you do want to re-design, there is starter info for you here (http://www.mechmate.com/forums/showthread.php?t=22).

vadeem
Wed 04 April 2007, 23:52
Thanks Gerald,

I have read that post too, and again $1150 dollars + non hardened makes all those "real" linear rails on Ebay start to look like good deals.

I never thought that the rails would be such a problem when I started out on this project. Our woodworking club has a few guys who all were going to build the MM. None of them have been able to find a way to get them made either. None of us want to damage our $2K table saws.

I wonder what ShopBot would charge for a set?

Gerald_D
Thu 05 April 2007, 00:08
The pre-conceived notion that the rails should be hardened is interesting..... I don't believe this is necessary unless the wheel diameter is small and the rail is thin. My experience with the ShopBot rails was bad because they are only 4mm [3/16"] thick and have 30mm [1.25"] diameter rollers running on them. That's why I went to 6mm [1/4"] rails with 40mm [1.625"] wheels. After more than a year's hard use their is no sign of wear on the "soft" rails. Why would folk want hardened rails?

Gerald_D
Thu 05 April 2007, 00:13
Has Charlie_T's souhttp://www.mechmate.com/forums/showthread.php?p=269&postcount=5rce (http://www.mechmate.com/forums/showthread.php?p=269&postcount=5rce), at $130 per ground rail, disappeared?

Charlie T
Thu 05 April 2007, 01:29
I received my bearings and of course ran them by hand on my rails and Im very pleased with them.
Both the bearings and my rails. Very smooth, and I could feel that angle settle in and ride sweet.

Gerald_D
Thu 05 April 2007, 01:38
Charlie, do you think that your supplier, Superior Grinding (http://www.superiorgrinding.com/commercial.html), would be willing to make more rails at a similar price?

Charlie T
Thu 05 April 2007, 01:48
Yes. Im sure they would. They run about two weeks.

Charlie T
Thu 05 April 2007, 01:51
What about that angle grinder that someone linked.
It put a 45 down a length for welding. Ill see if I can find it.

http://www.mechmate.com/forums/showthread.php?p=1737&postcount=40
That thread has those welding prep angle grinder jigs and jillywigs. That is what I was going to do if I couldnt find anyone that could grind over 10', but I did find them. Those look easy to use and could be well within budget.

vadeem
Thu 05 April 2007, 20:02
I think people worry about un-hardened rails because of post like this guy's who made sixty 8x10" plaques in one week and ruined his rails:

http://www.talkshopbot.com/forum/messages/26/17834.html#POST45426 (http://www.talkshopbot.com/forum/messages/26/17834.html)

Here (http://www.talkshopbot.com/forum/messages/26/17921.jpg) is a pic of a guy who used hardened rails on regular angle iron rails.
(Pic replaced with link - copyright issues)

Charlie T
Fri 06 April 2007, 00:11
Dont they use the smaller bearings though? Size two not three?

That picture looks like it would have alot of flex with that leg so long.

Gerald_D
Fri 06 April 2007, 06:16
That tall leg was for a special application. But I would be more worried about the thin rail "cap" flexing to the right between its mounting screws.

Vadeem, you will have to recognise that guy's experience is very rare compared to the thousands of other people who have SB's. As Charlie points out, they use size 2 rollers. And they used bent 3/16" plate as the "angle iron".

Here is a comparison, to scale, of the two different systems and why an un-hardened rail does give excellent results with a MechMate:

http://www.mechmate.com/Forum/messages/11/3763.gif

The small wheel is the size 2 used by ShopBot, the big one is the size 3 used by MechMate. However, ShopBot did not grind a very accurate and sharp "point" on their 3/16" rails - when new, the rails still had quite a large flat area on top. After bedding in, the SB rails developed a much sharper "point"....and then tended to stabilise with no further "wear". (Actually, they were not wearing as much as smearing - like putty)

By using a thicker rail, and specifying that it must be "sharpened" with only a 1mm point on top, there is maybe twice as much steel in contact with the wheel when new, and there is no bedding in or smearing. Plus, the bigger diameter is also much kinder to the rail surface - compare different wheel diameters rolling on sand....

Gerald_D
Fri 06 April 2007, 09:47
Here is the tale of the tape:

http://www.mechmate.com/Forum/messages/11/3765.gif

The 1.5mm on the left is what we see on the tips of our original ShopBot rails where no roller has run before. Where the rollers have bedded down, that increases to about 2.5mm. The MechMate rails start with a lot more than that (+3.5mm) and just stay there.

Our MM rails, made on a milling machine, have some tiny tool marks on the surface. We originally thought they would disappear with time, but there is absolutely no change.

J.R. Hatcher
Sat 07 April 2007, 20:08
Does anyone know how shopbot grinds their rails??

Gerald_D
Sat 07 April 2007, 23:48
Apparently they built their own grinder. Controlled it with their own controller and stepper motors. The grinding head is said to consist of a pair of belt-sanders. Quite few shopbotters spoke of the need to dress the rails with an oil (or diamond) stone to improve the ride even when new.