Topic: ... tubing bender question ... Machinists also. STEVE F ROCKS!

[550_ko]

Has anyone used this bender from northern tool?

Northern Industrial Tools Tubing and Conduit Bender
http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&productId=200256024&R=200256024

I need an inexpensive light duty bender for occasional uses like making handle bars, or bending tubing to gussy up a frame.   If this one works. . . 

 And for you machinists out there, one of the reasons I bought my house is that it had a machine shop attached to it.  We got them to leave the tools in exchange for not having to clean the property.  Even though I have been using the tools and reading  about maching parts for the last two years, I am still very new to it.  I have successfully made simple parts on the lathe and mill (wheel spacers, swing arm pivot sleeves, top hat bearing spacers, spikes, auto carb plates . . .  BUT I CAN'T FIGURE OUT HOW TO KNURL A PIECE OF STEEL OR (especially) A PIECE OF TUBING.

Anyone have any experience and feel like helping me?   I can post pictures of the tools I have and the set ups I've tried.

Thanks in advance.

[Steve F]

Don't know about the tubing bender stuff, but in regards to you wanting to knurl tubing......
Tubing isn't easy unless it's really thick wall.  Do you have any knurling tools for the lathe?  If you do, try practicing on some scrap first.  Use a COLLET if you can in place of a 3-jaw chuck, it's more solid.  Turn the O.D. to get it concentric first, keeping in mind that the O.D. will expand after knurling by as much as .020 to .030.  Knurling, (if you're using the "bump type" tool) requires LOTS of cross slide pressure to get satisfactory results without "double tracking" the knurl.  That means that you have to have the knurl tool points tracking back into the same groove previously made on each revolution.  If you're using the two-roller knurl tool, turn the tool just slightly to the right so the leading edge of the rollers are contactacting the work (2 degrees is about all you need).  With the spindle off, and in backgear (low speed), crank in the knurls very hard without bending the work.  Jog the spindle until you get at least two turns, and check that you have single tracks from each knurl roller.  If you do, great.  If not, back the tool off and manually place the knurl points in a known good groove and try it again. Don't forget to keep it well oiled, and manually feed the tool towared the headstock to the desired knurled length.  Keep the tool really tight in the compound, the compound cranked in until it bottoms out, and the stock as short as possible.  Remember, rigidity of all things are required to get good results.  There are also "balanced" knurling tools available that have 3 rollers, but are very expensive and were designed for screw machines.  There are also hand knurling tools, but don't do a very good job.  Good luck with your projects.

Steve F

[oldbiker]

550 ko, bending tubes for frame parts is not too difficult if you pack them tight with very dry sand ( if it's not dry, it turns to steam and blows the plugs out) and block the ends with hardwood plugs. leave overlong and cut to correct length afterwards. Heat to red heat with oxy acetylene for the bending. The sand will help stop the tube from kinking.
For handlebars the tubing needs to be  MUCH heavier guage and I don't think you will be able to bend successfully.
I agree with Steve on the knurling.

[cb650]

I think that would be a little lite for bending handle bars and frame materials.  Even the one we have might not do it and it was 250/300 bucks. 




             Terry

[dusterdude]

one of the chopper boards i have on my work computer shows an inexpensive way to build a good bender.i think it was chopperweb but im not sure.

[cb650]

I dont know the brand. I'll ask the boss when he gets in.  We've had it about 10 yrs.
I'm almost sure we got it at harbour or northern.



         Terry

[cb650]

Seen that on a old 750 honda at the race track one of the first times I went. Kinda stuck with me.




               Terry

[oldbiker]

Further to my previous post, I have a mate (Dave Kerby) who makes his living building frames and making experimental exhausts for Formula 1 cars using the sand in tube technique and I've seen him bend a 2" tube to a radius of 3" without a kink.

[Terry in Australia]

Those conduit benders are only really good for very thin wall soft tube, don't waste your $100 mate, you can buy a lot of bars for that much, I tried the same thing years ago, and wasted my moola, and surprisingly, i've never had a need to bend some conduit, boo hoo! Geez, for $100.00 a good used oxy welder and a big bucket of sand, ha ha! Cheers, Terry.

[cb650]

Forgot to get back yesterday.  Well a screwed up.  What we have is a scroll bender for ornamental fence crap.  Might work for tubing if you modify the dies.
Nortern part #  144208-2505.   Cheaper than I remembered though.




                 Terry

[dusterdude]

550,i think the other chopper forum is chopper underground.

[Steve F]

Congrats on your attempt!  But, judging by your photo, it looks like you're still "double tracking".  As an example of the typical knurl, look closely at say, a ratchet wrench handle and compare that knurl with what you have in the photo.  A non-double tracking knurl will have well defined "diamonds" pressed into the metal, with all sides of the diamond equal in appearance.  In the photo, you have the type of knurl that is indexable to different pitches.  When the knurl rollers contact the work, they should be at the same pressure.  You can adjust that pressure on the rollers by tilting the tool up or down.  Too far down, and the lower roller will not have the same pressure as the top roller and vice-versa.  Practice and experimenting like you're doing is the best way to get the hang of it.  Just remember to turn the diameter to a clean finish before you start knurling.
Steve F