DIY Tubing Straightener

[wilsjay]

After seeing Deve’s work and how awesome it looked I really wanted to try my hand a stainless steel lines. To do that I need to upgrade tools as I just have the old butterfly type flaring tool and a cheap brasscraft (homedepot) bender. On a limited budget and since I was also helping a buddy re-plumb his 1938 Chevy Master Deluxe, I splurged and bought a flaring tool similar to the Brakequip version Deve used. I purchased mine from Summit Racing. It was their house brand as I got them to match the same price as Eastwood. Long story short just under $200 I had it in my hand the next day. I then bought a roll of ¼” stainless tubing and was able to bend it no problem with just my cheap homedepot/brasscraft bender.
That only left a tube straightener to go in order to get my lines straight. Needless to say the flaring tool was a BIG splurge for me so I was too cheap to buy a straightener. I looked all over the web for a cheap one and not finding one. After looking at them I decided they were quite simple so I decided to make my own. I did a google search for DIY tubing straighteners and this simple version was a big influence on mine. (https://www.jalopyjournal.com/forum/...549153/page-12 ) I made most of it out of spare stuff I had lying around in the garage. I think I spent ~$25 making this and modeled it after this $216 Brakequip version (https://www.eastwood.com/tube-straig...MaAsmvEALw_wcB).

Materials:
2x –12 inch pieces of square tubing
2x- ~3 inches of scrap steel (almost anything will work you could even weld bolts on their side in place)
3x – Sliding Door Rollers (2 in ea. Pack) https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
5x – ¼-20 x 2in bolts
10x – ¼ washers
5x – ¼-20 lock nuts with nylon insert
1x- 3/8 all thread (cut to ~ 8 inches)
3x - 3/8-16 nuts
1x- 3/8-16 lock nut with nylon insert
1x- ¼ -20 thumb screw

Steps:
1. Stack your two pieces of square tubing together and mark the center line. Drill a 3/8” hole all the way through both pieces. This hole is for the main tensioner adjustment screw.
2. Keeping the pieces stacked lay them on their side and layout the holes for the rollers. Mark a line every 2 inches. The key is to off center them approximately ¾” so that the center one does not line up with the 3/8 hole that you drilled in step 1. You need to have enough offset so that hole will miss the 3/8 all-thread bolt with a nut on it.
3. Drill ¼” holes every 2 inches staggering between the two pieces of square tubing. I did 3 in the bottom piece, 2 in the top piece on mine.
4. Now for a small bit of welding. Keeping the tubes stacked, I put a nut on the piece of all thread and then slid the all-thread through the two pieces of square tube and then welded the nut to the top piece of square tubing (the one with two ¼” holes for the rollers).
5. Next I welded the 3 inch pieces of scrap steel to the back side of the bottom piece of square tubing on each end. All this does is keep the top piece of square tube parallel to the bottom piece and keep it from spinning. You can use absolutely anything for this. I chose a couple pieces of flat stock I had. You could even weld bolts, washers or anything really.

6. This is and the next step is the trickiest part of the build. What you cannot see in the picture is there is a hidden nut inside the middle of bottom piece of square tubing. You need this to allow the all-thread to spin freely in the bottom piece. What I did was take the all thread and about 1-1/2 inches up from the bottom take a chisel punch the threads so that a nut will spin past it.

7. Drop a 3/8” nut down the middle of the bottom piece of square tubing and thread the all-thread through the holes you drilled in step 1 and into the nut you just dropped down the middle of the tube. Slow and steady wins the race. I was able to use a long screw driver to maneuver the nut in place and get it started on the all-thread. I then used the screw driver as a wedge between sidewall of tube and the nut to hold it in place as I threaded it down to where I chiseled the threads in the previous step. On the bottom of the all-thread now thread the 3/8” lock nut. Tighten it as much as you can against the nut inside the square tube from the previous step but still let the all thread spin freely.
8. Next thread the top piece of square tubing onto the other end of the all thread with side with the nut you welded on in step 4 facing away from the bottom piece of square tube. Spin the all thread while holding the top square tube to thread it down until it gets past the scrap steel stop pieces you welded on in step 5.
9. Thread a regular 3/8-16 nut on the all thread an inch or two from the top piece of square tubing. Then thread the 3/8 thumb screw into the all thread. Once you have it where you want it, then tighten the nut you put on first against the thumb screw to lock it in place.
10. Last step is to put the ¼ bolts with washers on either side of the rollers through the holes in the square tubes and tighten them down with a lock nut on the back side.
11. This step is optional, but I ground all the “extra” bolt lengths down to keep from catching on my clothing/me.
12. Try it out! I found my best results were when I mounted it in the vice by clamping the end of the bottom square tube.