Cutting compound angles - Not really a welding question

[Andy249]

Hey guys,

As I said above, not a welding question, but Hawk posted a non welding question so I thought it was ok I have a lot of compound angles that I need to cut (fence rail). Stepping the rails isn't an option as this isn't what the client wants, so unfortunately I am left with the angles. Anyone know of any metal cutting saws on the market (prefer abrasive wheel versions as the work is on site). I was even thinking of making a jig for a 9" grinder that I might be able to cut the angles with. The material in question is approx 2" x 5" (48mm x 120mm).

If anyone has any tips or ideas, please share!! I promise to post photos to the web of the finished product!

Regards,

Andy249

[HAWK]

Andy249,

What about something like a 14" abrasive blade chop saw? Milwaukee makes a nice saw for about $150. however, it does not miter and bevel simultaneousy. Here's a link to a full featured type chop saw with cabide tipped cutting blades rather than an abrasive wheel. Take a look. Let me know if the link works.

http://www.northwestpowertools.com/chop/dw872.htm

Here's another cool tool:

http://www.northwestpowertools.com/chop/1410.htm

[Wheels]

Andy

Could you fabricate a wedge to attach to a chop saw that would allow you to set it up for compound angles?

Just a thought.

Mike

[hankj]

I'm very new at this craft, and I do not make my living with it, but I'd still suggest an O/A torch if terrain and fire conditions permit that process.

Be well.

hankj

[Paul Seaman]

Andy249:
Depends on how many cuts are required and the quality of the fit up needed. If compound cuts are required then I would buya wood cutting compound miter saw, put in a new style carbide tipped blade and rock and roll. The key is to go slow during the cutting. Patience is a virtue.
Peace,

[fun4now]

DW708

i think pjs hit it on the head i have the dw708 sliding miter saw and would highly recomend it.

http://www.northwestpowertools.com/miter/dw708.htm

although a little pricie it is a fine tool that has a quick release clamp (accessery) that works wonders through a fiber disk or a new carbide type (i have never tryed the new carbide for steel blades so i cant say good or bad)and you can cut real sweet compounds on well over 2x6 stock i do 1x10 all the time.
hope this helps
james

[HAWK]

Andy249,

All these compound miter wood saws are great tools. I would suggest you call the manufacturer before installing a steel cutting blade to see if the motor will handle the load. I tried this on a 10" compound miter saw and it failed miserably!

[fun4now]

power

halk
i understand you're concerns in the power department thats why i sugjested the 708 as it is a 15 amp saw same as bolth the steel cut saw's you showed. power has never beeen a problem with this saw.
hope this helps

[dseman]

There are some important differences between metal cutting and wood cutting that may not be apparent at first glance.
Metal cutting carbide blades (or their cousin the cermet type) are c-5 or c-6 carbide which are harder than the wood cutting variety of c-3 or c-4. Metal cutting with these blades requires careful attention to clamping and proper rpms. For example, the dw-708 previously mentioned for wood cutting has a 12" blade traveling at 4000rpm. The equivalent metal cutting saw, either porter-cable, dewalt, or makita, use 12" or 14" blades and spin at 1300-1400rpm--a significant difference which if ignored will result in a ruined blade and teeth strewn across the shop. Lastly, the metal cutting blades rely on cutting material, not grinding as the abrasive blades do and thus do not take side-loading kindly. Secure clamping of the stock and cutoff (if long enough) are necessary for good results. Longer life can be achieved by using common sense, such as centering the stock under the blade's center of rotation, keeping the motor's rpms up and not bogging the motor, and allowing the blade to come to a stop before lifting the blade out of the kerf. These blades are not intended to be throw-away, and are priced accordingly. They can be re-sharpened, but it may take a few phone calls before you find a competent shop.

-dseman

[Andy249]

Thanks everyone for their comments and feedback. I'm not really sure that I want to push down the road of using a compound saw that is really designed for cutting timber. I've heard all of the stories about motors and gearboxes not handling the shock of cutting steel and I don't really want to put too many hard earned dollars in that direction. I think I'll probably end up persevering with my metal cut off saw to get the angles fairly close and resort to the good ole grinder to do the rest.

I can't seem to recollect where I have seen this, but somewhere I saw a 9" grinder that acts just like a metal cut off saw that was bolted into a frame that allowed compound cuts to be made. I'll let you know how I go.

Kind Regards,

Andy249

[Qrazy]

You might want to search for twin cutter on the hobart forum. Someone over there mounted one of them to his radial arm saw, and it looks like an ingenious setup....Check it out...Not sure if it will handle the size stock you are looking at...You could also make a jig to hold it at the correct angles if you have a bandsaw....

[H80N]

AS dseman pointed out... you cannot just put a metal cutting carbide blade in a compound power miter saw intended for wood.... However I have had some success in using abrasive cutoff blades in them... but would caution ... to make sure to match acceptable blade rpm to that of the saw.... and make your cuts slowly and carefully... insuring that the workpiece is securely clamped... would expect that binding might cause a grenaded blade... and do not know if the bladeguard on a wood saw would withstand and contain the results...
another possible avenue.....if there are not too many cuts.. a sawzall might be used for this job..
just some thoughts
hope this helps
Heiti

[mlicoasty]

You might try and check out Porter Cable. They have a portable dry cut saw that is designed like a circular saw. Another option is to make the cuts on a band saw. You could angle the table and use the miter guage at whatever angle. This will get you a nice compound angle.

Mark

[paulrbrown]

Just a thought, the small Portaband type saws are very efficient at cutting square and round tubing and angle. Just scribe the angle and hold steady, don't know your tolerences, but a grinder can usually clean any discrepency up. They are also a lot quieter. The woodworking Chop saws do make great saws for cutting aluminum though, make sure you get a negative kerf blade, the teeth slant backwards about 5 to 8 degrees, this keeps the blade from climbing. Also a triple chip grind will make the blade last much longer, I have easily cut 4x4 inch .125 thickness 6061 without clamping in about 6 seconds on a delta 10" $150 saw. I have found that abrasive cut off blades do not work that well on radial arm saws or table saws, I have Dewalt 'good old 60's' and Tatry 12inch 3 horse 3 phase saws, the RPM's are too slow for abrasive. Be very careful cutting round stock on any Chop,Radial,Tablesaw, or even unclamped Bandsaws as the teeth will grab, rotate your tube and send it flying much faster than you can even blink, I found out the hard way just once, better to not even try even with good clamps!!!!! By the way, I started out and still do cut wood, and that leads to the sugestion about cutting shims the right angle, I have done this with wood,on a toothed chop saw,then used these to positon steel on an abrasive chop saw, you can get away without clamping also because the blade has no teeth to catch. BTW, I once spent 3 weeks in Queensland rounding up cattle on horseback on a 100,000 acre station, Film at Eleven....Paul

[Qrazy]

Originally posted by Qrazy
You might want to search for twin cutter on the hobart forum.

Here is a link to the thread I was talking about:
Twincutter thread at weldtalk