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View Full Version : Arrrggg ..3/4" is not always 3/4"



rsisson
06-15-2008, 04:50 PM
Found a place that had 3/4" round mild steel rods locally (45 min away) so I wouldn't have to pay shipping...

Drove there, got the rod and some other stuff, and drove home...

Well, cold rolled isn't ROUND... it is ALMOST round, and since my Pillow blocks ARE round... it don't fit...

All that driving and gas...now to order the good one from McMasters...

trikeman
06-15-2008, 05:26 PM
You may be able to make them round enough to fit with some sandpaper or emory cloth. There is a thread on the old forum (almost impossible to search now due to server timeouts) that talks about the trouble some of us had getting them to fit.

It would sure be nice if AZ could get all those files and put them into one big searchable text file or something. Lots of good info there that will be lost to posterity soon.

gbbwolf
06-15-2008, 07:28 PM
Yeah colled rolled 3/4 may not be exactly 3/4" found that out myself.
Just take some emory cloth about 4 inches wrap it around.
Then sand up and down like you are stroking your @#$# LMAO
Trust me it will work I was outside holding it between my legs,And sanding, Girl across the street thought I was doing the nasty in my yard.
Had my back to her sitting in my chair. So you get the picture she had in her head. I told her I wish it was that long but it is way too skinny LMFAO

TheKid
06-15-2008, 08:16 PM
That's surprising. Cold rolled is used for shafts and axles because it 's round and fits nicely into bearings and bushings etc. Perhaps your dealer is trying to pass off hot rolled as cold rolled, or maybe they're selling a low quality steel. Other possibilities are that it was stored improperly and has a slight bend, (I believe Joey had this problem) or it was sitting on the shelf for a long time and oxides have formed on the surface. Another possibility is that just the ends are out of round from being cut improperly.
I had an axle laying around for over a year. When I bought it, it fit perfectly into the bearings, but one end was out of round from the cut. I cut a little off and beveled the edge and it was fine. When I tried to use it after it was sitting around, it wouldn't fit into the very same bearings. It turned out that there were oxides that formed on the shaft, AND the inside of the bearings. I used a little naval jelly with #400 sandpaper and lightly rubbed the bearings and the axle, then wiped them with clean rags. Perfect fit, with no elbow grease.

Big Moe
06-15-2008, 08:38 PM
I had the same problem when building my DW. I you have access to a lathe, either metal or woodworking, chuck the rod and you can sand off the rust and size the rod with coarse grit. Get the end sized and then use the pillow block as your guage and work on down the line. Keep the rpm down and work carefully.
MOE - three wheels and an old crank

gbbwolf
06-16-2008, 12:48 AM
There are 3 grades of cold rolled that I have seen.
Regular which can be off by a lot.
Stress proof Not usually off much.
And Precision ground. Ain't ever seen a piece of this off at all.
Built plenty of go-karts with stress proof and precision ground.
Oxidation will throw your cold rolled off real quick.
If very humid I have seen it take less than a day.
Fit in bearings perfect one day.
Next day wont fit at all.

trikeman
06-16-2008, 06:13 AM
Here is the post I was thinking of from the old forum

http://www.lucidscience.com/forum/topic.asp?TOPIC_ID=899

Patrike
06-16-2008, 10:14 AM
My cold rolled fit ok but was too warped -- spend the extra and go with machined.

Patrick

TheKid
06-16-2008, 01:49 PM
I have several cold rolled shafts from metalsdepot.com, and they all fit perfectly when new. If left for a long period of time, naval jelly wiped on with 400 grit paper does the trick. Thanks for that link to the old forum, Trikeman. Lot's of useful information, and Gil's method of reducing the size of washer holes is a gem.

Richie Rich
06-16-2008, 11:45 PM
For my Delta Wolf, I used galvanized rod for the axles which I got at Home Depot. It's been over a year and there's no sign of any corrosion and they still slide on the pillow blocks with no problem.

....Richie Rich >>
.
.

gbbwolf
06-18-2008, 02:32 AM
I could have used galvanized from doitbest hardware but I thought I needed A 38 inch axle If I had read farther and seen that The 38 Inch was getting cut down at the end anyways I would have just bought a 36 Inch from there.
And done some creative cutting lol.
Live and Learn.....

TheKid
06-18-2008, 09:29 AM
On the other hand, it depends on the galvanized shaft. Some have a thicker coating than others, especially hot dipped. In the old forum, there was one thread that dealt with this. Your best bet is, next time, take a bearing to the store to check the fit. Bring a file as well, just in case the ends are burred.

Sparky
06-18-2008, 07:29 PM
just found im having the same issue with mine. glad i ran a search before posting!

it would be less work to grind out the pillow blocks... but probly harder cause its hardened steel. guess i'll be spending some time with my axleshafts in front of the TV tonight.

gbbwolf
06-18-2008, 07:44 PM
Took me less than 20 minutes with some emory cloth.
After I ground the edge down from the cut.

rsisson
06-19-2008, 10:01 PM
Well I got my shaft into my pillow blocks and everything aligned and bolted down.

Cut the Axle in two and went to pull the axles to work on the next stage, the Hubs AND...

Everything was SIEZED. It had only taken a light tap to get the pillow blocks on, and now they were SEIZED...

Unbolt everything and use a pipe over the axle and a SLEDGE HAMMER to remove one bearing... that one is gone... the other on that side was OK...

Used DRY ICE on the axle on the other side... YEA...HEAVY TAPPING got everything off that side...

Built a Reamer out of an old 3/8" shaft covered in plumbers sanding strip....grabbed the inner collar with vice-grips, and sanded the INSIDE of the bearing...took off about .002... Now the axles ALMOST slide in place... a bit more and some grease and they will be removable if necessary... SOMETHING scratched the shafts... I think the Pillow-block bearing were undersized..my Collar locks slide fine, but the bearings were just too tight...china strikes again...

My pillow blocks have two setscrews each, combine that with some locking collars and I will be set... I want them to be loose enough to be removed, even with the scratches caused by the setscrews if needed for flats or damaged rims.
(We have potholes that eat small cars, never mind bikes)

Next is to work on some Hub alternatives... I really want a removable Wheel...

See my post about JB-Weld and filling a Hub next...

Bob

SirJoey
06-19-2008, 10:54 PM
Have you tried cleaning the axles & oiling them up before sliding them in the bearings? That's what I did every time I removed or inserted them during the building process, for fear of the very thing you're describing. I had no probs.

Bearing tolerances are extremely close. Cold rolled rod USUALLY is, too. It only takes a speck of crud to make 'em seize, especially if they're dry. Keep 'em clean & lubed!

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

Sparky
06-19-2008, 11:40 PM
only a few minuites with the angle grinder and a 60 grit flap disc and mine slide beautifully. im sure that within a week that bare steel will have some oxidation, but it sure is shiny now!

TheKid
06-20-2008, 12:25 AM
Try using anti-seize compound in the bearings before you slide the axles in.