C&H M48 PRO Curved bevel cut

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djogon

Grumbler in Training
Joined
Apr 4, 2008
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6
Hi all,
I am new to this forum, so please forgive me if this was asked several times.

I just got a brand new C&H M48 PRO at cutter, but every time I cut a bevel cut it comes up curved so that the cut is about 1/16" larger in the middle.

I checked to make sure that the blade is not set to long, but can't figure out what am I doing wrong.
I can't believe that the bog steel bar is actually not 100% straight!

Does anyone have any tips or advice on this.
:shrug:

Thanks!
 
First, make sure you are pulling straight along the bar. Sometimes newbies will have a tendency to pull toward the body rather than along the length of the bar.

Practice, Practice, Practice. :beer:
 
Thanks guys,

I'll definitely try to follow your advice and see what happens. I was just wandering if there is some sort of "adjustment screw" on the head tht I need to possibly tighten? Tehre are some hex screws there and I got the matching tools for it...

Thanks again...
 
I have never heard of a problem like this and cannot see how anything the operator does could produce a curved cut in a "straight line" manual cutter. Does this happen all the time or just occasionally?

If the machine is brand new it could possibly need a bit of tweaking. Grip the cutting head and wiggle it up and down and from side to side. In a perfect world the slider should move freely along the bar but there should be no movement in either direction. If there is, fiddle with the adjustments until it is perfect.

However, looseness in the head (common among framers???) usually causes hooks at the start of the cut, not a bow in the middle. Rare though it is it could be a manufacturing fault and the cutter bar is not straight.

To test this cut a strip of card like a slip sheet but make the edges as perfectly parallel as you can. Now set your blade fairly shallow so as to cut only about half way through and score a line down the card just short of the centre. Turn it around and repeat the process. If all is well the two lines should be parralel, or at least as parralel as the card's eges are. Any curvature or widening at the centre should be blindingly obvious. You could also repeat this test using a pencil against the edge of the bar to see if the problem is in the raised part of the cutter bar which the head runs on or in the whole assembly. If you have a long enough straight edge this may also show up any irregularity.
 
I have a C&H. Found that if I use double edged blades (1200), my mats will bow in the middle. I have no problem with the single edged. Also, I only use the C&H brand.
 
Make sure your blade only goes into the slipsheet to the top of the bevel
keep your arm parallel with the bar. Plunge the blade in the mat, pause, draw it towards you using your shoulder and elbow only; keep your wrist locked. When the head of the cutter gets near the end of the cut, use your fingers to draw the head to the bottom of the cut, pause and then remove the blade from the cut.
 
Check the last comment, that is the problem. When I first bought my Logan, I made the same mistake: pushing down on the handle.
 
adkres said:
make sure you are not leaning on the handle.
this will pull the head off straight line.
Click to expand...

When I first got my old C&H Pro it had an overly bowed bar. I was told to press down on the handle otherwise my mats had a bow to them. But I found that the bar was overly bowed and my dist, who I bought it from, picked it up and replaced the unit. It was bent, probably from shipping, and they replaced it. The replacement unit had a little bowing in the bar, but with the right amount of pressure it cut straight.

I was given the impression that it was supposed to bow, but when I lined up a straight edge on it there was a definite "warped" spot. The bowing wasn't uniform. So when I showed the rep for my dist they OKed the return.

With my Fletcher 2200 the bar is flat the whole length, but I miss using the "just so little bit" of pressure I used on the C&H. When I first got the F2200 I pressed down onthe bar as I was cutting, and the bowing mat issue returned, at least until I stopped pressing down on the bar!
 
I have used a 48" C&H for 20years. Beautiful machine. The idea of the bowed bar is to prevent slippage of the matboard while cutting. Something that my previous cutter was prone to do. The trick is to apply light pressure (not too much) with the left hand on the handle to flatten the bar along the mat before you dig the blade in. If you look carefully this causes the cutter bar to creep forward slightly. Keep the same pressure while cutting. Avoid relaxing the pressure or pressing harder. Like everything else, it needs practice.
 
Make sure your slip sheets are longer or equal to than the mat you are cutting
 
Prospero, I loved the C&H. the F2200 roller bearings are too loud to me, whereas the C&H was quiet and smooth to work with. I used to take the bar off and use it to cut pieces that were longer than 48". No problem with bowing either. Can't do it with the F2200, don't know why.

However I use the measuring pins on the F2200 all the time, the one feature I thought I would never use!
 
nikfrz said:
I have a C&H. Found that if I use double edged blades (1200), my mats will bow in the middle. I have no problem with the single edged. Also, I only use the C&H brand.
Click to expand...

I second that along with not pulling the cutting head along too fast. It tends to bow on me when I'm in a hurry and am not giving the blade ample time to smoothly cut through the mat. If I pull too fast, the blade wants to flex and then I get the curved cut.
 
I want to thank all of you for your suggestions and comments.

Today I tried MANY differentpressures on the handle, on the head itself, move the cutter to a different table, tried 1200, 1200SE and 1500 blades. The result was inconsistency all the time.
For a professional cutter like this, that costs this much money - I would have hoped for a bit more consitency even if the user does not do it perfectly every time.

At this point - it seems that the first part that is cut off is slightly narrower than the rest.
This seems to look a bit better if I do not press hard on the head while pulling down.
However - If I puss/pull too light - I do not cut all the wat through. It is almost impossible to make a "perfect cut" with this.

I alo consulted a person who used a pro mat utter before and she said that it should definitely be this sensitive to pressure.

Should I try something else or try to call C & H and see if they can help.

One a side note - you guys are just awsome - thank you all again and please - do not shy away from giving suggestions no matter how silly they may seem.
 
I just watched this video on YouTube

http://youtube.com/watch?v=fJygHmTPz4E

I know it is Logan, not my C&H, but I noticed a few things

1) He is not holding the handle bar with his left hand and applying pressure!
2) He is using both hands to move the head back!
3) There is NOTHING under the mat he is cutting. Isn't ot normal to put a piece of mat underneath so that the cut is cleaner?

I can't dismiss the possibility that I am doing something wrong, but again...
Is it really this hard to do this with a professional tool or is there something wrong with this machine?

Any other tips you guys have - specially from someone using C&H?
 
I had this problem some time ago and by carefully watching I found that the mount (mat) was moving away from the guide rail as the blade moved along the cut.

It was easy to fix, I stuck a piece of barrier paper (1 or 2 ply board) to the baseboard under the cutter bar with double sided tape and then placed the slip mat and mountboard to be cut on top of this as per usual.

The extra friction stopped the mount from moving while being cut.
 
I was the C&H tech rep for 12 + years. I would recommend using the CH1200SE blade as this is honed on only one side and does not flex as much as the other blades. Also the surface the cutter is on needs to be totally flat. Sometimes you can put two thicknesses of mat board - about 30" in length and 15" wide under the center of mat cutter. This will help shim up the baseboard if the surface it is on is not totally flat. But mostly, if this is a brand new cutter, you should call Gritsko at Nielsen & Bainbridge - the manufacturer (800-631-5414) ext. 3243. I am always curious as to why people with new equipment do not call the manufacturer first. As mentioned in the posts, there are many things that contribute to a curved cut - blade type, blade depth, mat cutter surface, material being cut, mat cutter head adjustment etc. Just call Gritsko.
 
I contacted my sales person and he assured me that we will take care of things.
A C+H technician should call tomorrow so that we can see if the cutter has a problem or if we are not doing things right.

I will keep you guys posted anyway ...
 
Well - it seems that the table that the cutter was on is to be blamed.
The tech said to try to level the table and then try it and it seems to have made a huge difference.

Thank you all for your advice - I think we finally got this one and I definitely learned a lot about this stuff from you also picked up some good advice overall.

Do you guys have a preferred way to "mount" the cutter or advice on what surface is the best to use as the base for a mat cutter like this?
 
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