help with shallow angle cutting jig.

[@Turbo]

I made/botched this pipe holding jig so that I could cut shallow angles. well it manages 20 degrees before it runs out of travel. would of liked 15 but 20 will do for now. the 2" galv pipe here is so far back to miss the travel of the blade.

anyway it flexes a little/lot when cutting and vibrates alot I am worried it will break the blade.

any tips for me in regards to making this jig better? This is the mark II the mkI is lolworthy for sure.

I have some 1/2 bar about I am thinking it will be better than the thin stuff I used here and then more angle iron to stiffin it abit more?

any tips would be great.

p.s the hole to the left was originally for a bolt but the vice being cast it was stripped so I just put a big G clamp on it.

 

[@Turbo]

I am trying to make these collectors.

 

[@Turbo]

few moar

 

[carlos420uk]

Here is my jig for making collectors on an abrasive chop saw.
It works very well for holding parts at the angles required for collector cutting.
I used an angle of between 15* for the merge which can be adjusted with a slight tweak to how the jig is bolted down if required.

Making the jig is the easy part. Actually cutting the collectors using an abrasive saw at that acute angle and basically along the length of the pipe is what makes this challenging.
You WILL get blade deflection no matter how slow you go on the cuts, you'll make lot's of noise, excess heat in the ss, and nasty dust doing so. At the end of it you will end up with parts that still need a fair amount of fettling before they fit how you would like.

Long story short after making this first collector I got a Clarke bandsaw, and using the same style of jig on that produces 10x better fitting parts straight from the saw with very little fettling needed.

Also another tip I'll give you is that when you rotate the pipe between cut 1 and cut 2, you need to rotate slightly more that 90*, or the subsequent collectors will not fit up correctly. Try 92* rotation as a starting point.
To test your cuts you should be able to put a square against the 2 cut edges of the pipe and the "Point" of the 2 cuts should rest directly in the inside corner of the square.

Bit of a rush as need to go to work now, but hopefully this will help you a little.

 

[@Turbo]

looks good pal. I gave those collectors zero feetling lol they didnt fit up too nice lol.

will try a few extra degrees as well tbh I only rotated those collectors 45 instead of 90 so that is why they dont fit up too good.

I dont had a chop say with an abrasive wheel sadly. however I have use of a bandsaw never thought about using it if you have any pics of the jig on it I would be real keen to see it.

 

[@Turbo]

found some of these examples on a honda forum gave me some ideas to work with on the bandsaw front.

just incase anyone was wondering.

 

[carlos420uk]

It was early this morning and I thought it was an abrasive saw you were using in your pictures, but now I see it's not. What type of saw is that?

The pics with the bandsaw and jig are exactly how I do it on mine, and it works very well.

If you have access to a bandsaw then make up a jig the same and you will be set.

I wasted 3m of 304L schd. 10 just to make one good 4-1 merge on an abrasive saw as I cocked up so many times due to deflection of the disc / bad fit-up. With the bandsaw no problem.

I assume you want to Tig these up when done, or were you planning on Mig?

 

[@Turbo]

It was early this morning and I thought it was an abrasive saw you were using in your pictures, but now I see it's not. What type of saw is that?

The pics with the bandsaw and jig are exactly how I do it on mine, and it works very well.

If you have access to a bandsaw then make up a jig the same and you will be set.

I wasted 3m of 304L schd. 10 just to make one good 4-1 merge on an abrasive saw as I cocked up so many times due to deflection of the disc / bad fit-up. With the bandsaw no problem.

I assume you want to Tig these up when done, or were you planning on Mig?

the abrasive discs on the bench were abit of a red herring lol

I know it as a cold saw its a solid steel blade needs coolant on it. looks like this

not a bad saw pretty quick at cutting solid bar.

that is good to hear I had a look at the band saw today looks like it will work ok once i get a jig made up for it.

I am using schd 40 mild steel and weld els I was just going to mig them I don't have a tig. bought a 6M length so lots to practise with.

do you keep the tape on them to weld them? any tips on welding, they seem to flop about abit being round and all that.

 

[carlos420uk]

I see, I did think it might have been a cold saw. Saying that then I should think that that saw could do the job also as they are far more accurate than the dry and abrasive equivalents. The thing is like you say though whether you can plunge the whole cut without the saw catching on the part.

When you say you turned the piece 45* did you mean start from point A, rotate 45* (To the right say), cut, rotate back to point A, then rotate 45* to the left, then cut again? If so then that's the same as starting at point A, cut, rotating 90*, cut again.

I use 304 schd.10 instead of mild, but tbh mild is easier to work with both cutting and welding wise.
I use tape to mock up and hold parts together, then I put little nicks in it where I want to tack, tack up the parts then remove the tape.

I have never migged any of this sort of stuff tbh, but as far as the weld els go I personally like to grind a nice uniform 37.5* knife edge bevel on mine with a belt linisher prior to welding. The better the bevel and subsequent fit the better the weld will turn out in my experience.

I think the main problem you'll have with using Mig is the hard to access area's, make sure you plan ahead and don't end up in a situation where you can't sew up the last few welds.

Seen as you have a 6m piece of the pipe I'd be cutting up some practise pieces, bevel up, then practise welding them using different techniques and setting's till you get results you are happy with.

 

[stevieturbo]

Found this thread on another forum, same idea though. Blade flex with a carb blade would likely be a problem though.

http://www.dtaforum.com/viewtopic.php?f=15&t=305&hilit=collector