Sheared Screw on Retractable Caster

oldcary · Post by **oldcary** » Tue Aug 30, 2011 10:09 am

I have owned a Mark V model 500 since 1978 and recently purchased an 50th Anniversary Edition 520 (10-23-01) at an estate sale. A 1/4 in.-20X 5/8 screw that holds the drive rod of the retractable caster and the base in place has sheared off. I would welcome any suggestions on how to repair and replace this screw.
Thanks in advance for any assistance.

SDSSmith · Post by **SDSSmith** » Tue Aug 30, 2011 1:19 pm

oldcary wrote:I have owned a Mark V model 500 since 1978 and recently purchased an 50th Anniversary Edition 520 (10-23-01) at an estate sale. A 1/4 in.-20X 5/8 screw that holds the drive rod of the retractable caster and the base in place has sheared off. I would welcome any suggestions on how to repair and replace this screw.
Thanks in advance for any assistance.

On the newer style casters, I was able to remove the sheared off screw with a drill and an easy out screw extractor. The screws I was working with were #8 x 1/2" long. It is on small screws like these that I wish I had a small left handed twist drill bit. If your casters have 1/4" diameter screws they may have been drilled out and re-tapped.

I prefer the older caster design that used roll pins for the cams and did not need screws in the end of drive rods. On the newer design, I find the cams 'slip' and get out of time and the little screws shear off.

oldcary · Post by **oldcary** » Thu Sep 01, 2011 5:33 pm

Thanks for the advise and comments. I attempted to extract the headless screw without success. I have a friend who owns a machine and tool shop that I hope will drill and tap this caster bar.
BTW, I looked at old 500 and the casters appear to be better than the failed ones on my 520. ShopSmith does not sell caster parts but will sell me a caster set for about $100. I did order a set of the new 3" poly wheels they had on special and they are already on backorder...go figure. http://www.shopsmith.net/forums/images/ ... lleyes.gif

SDSSmith · Post by **SDSSmith** » Thu Sep 01, 2011 6:49 pm

oldcary wrote:Thanks for the advise and comments. I attempted to extract the headless screw without success. I have a friend who owns a machine and tool shop that I hope will drill and tap this caster bar.
BTW, I looked at old 500 and the casters appear to be better than the failed ones on my 520. ShopSmith does not sell caster parts but will sell me a caster set for about $100. I did order a set of the new 3" poly wheels they had on special and they are already on backorder...go figure. http://www.shopsmith.net/forums/images/smilies/rolleyes.gif

Sorry to hear that the screw piece did not come out. I know someone that will sell you a set of used casters for $40. Email me if you are interested.

charlese · Post by **charlese** » Thu Sep 01, 2011 9:57 pm

When my end screws failed, I also couldn't drill out the remainders. So I went to HD and bought a steel rod of the same diameter and drilled holes through it for the roll pins. Has worked great for more than a year.