Page 1 of 1

Main Table Movement?

Posted: Wed Jan 16, 2019 7:33 am
by RFGuy
I have a 510 that is upgraded to the 520 table system. I have double-checked all table hardware and it is tight. Also, locks are solid and look to be holding. My question is how much play should be expected in the main table assembly when mounted for table saw operation? Now that I am working with some thicker, heavier stock I am noticing some table movement. For example, I can stand on the end of the Shopsmith and apply gentle pressure to twist the main table clockwise and counter-clockwise. When doing this, the main table rotates maybe +/-1mm or 2mm. Guessing here, but it is enough to be perceptible to the eye. I have a dial indicator that I will try to mount firmly and measure it, but that will take some effort to setup. It appears that the headstock and more importantly the blade remain fixed, so this is "play" of the table relative to the sawblade which is not good. I know the Shopsmith doesn't have a large mass cast table like a cabinet saw and this is by design. However, I am wondering if what I am seeing is normal or something that I can fix. Could it be that what I am seeing is flex of the tubes that connect the main table to the carriage? Any tips or suggestions? If my description of the problem is not clear, I can try to make a rough picture to illustrate this.

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 8:34 am
by dusty
Under the conditions that you describe, the Main Table is definitely not "rock solid" but .039" of an inch does not seem excessive. You say this was not noticed until you began cutting heavier stock. The Shopsmith IS NOT meant to be a saw mill. It has been designed to function as a hobby machine. Maybe you have not chosen the righ tool for the job.

I have cut a lot of 3/4" sheet goods with no real problems that could be attributed to the machine and especially not to the table.

I'll be watching to see how this works out.

Good Luck and WORK SAFE!

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 8:46 am
by RFGuy
dusty wrote:Under the conditions that you describe, the Main Table is definitely not "rock solid" but .039" of an inch does not seem excessive. You say this was not noticed until you began cutting heavier stock. The Shopsmith IS NOT meant to be a saw mill. It has been designed to function as a hobby machine. Maybe you have not chosen the righ tool for the job.

I have cut a lot of 3/4" sheet goods with no real problems that could be attributed to the machine and especially not to the table.

I'll be watching to see how this works out.

Good Luck and WORK SAFE!
Thanks Dusty. I appreciate it. I did do some 4"x4" redwood about a decade ago on it, but I don't remember if I noticed it then or not. In the distant past, more of my work was all 3/4" finished stock for the most part. Recently I am doing some projects with 1 1/2" thick stock. I guess the difference between now and then is that the redwood project was rough cut and finished cuts didn't have to be precise, whereas now I need more precision for a project. I know the flexibility offered by the Shopsmith design means that the table isn't going to be rock solid like a much more expensive cabinet saw. I just didn't know if I am missing something or if there are any tips/hacks for this problem. Sounds like the movement that I am seeing in the table is normal.

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 9:10 am
by rpd
Are you using the connecting tubes between the table and the extension table? Doing so will make things more rigid.

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 9:31 am
by dusty
rpd wrote:Are you using the connecting tubes between the table and the extension table? Doing so will make things more rigid.
Excellent advice!! Regret that I didn't provide it. I use extension tubes as a matter of course.

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 10:18 am
by RFGuy
rpd wrote:Are you using the connecting tubes between the table and the extension table? Doing so will make things more rigid.
Thanks, Ron. That was it! After a long pause in woodworking, coming back to it now I remember most of it, but still I forget little things like this. There is still a tiny bit of play now, but it is significantly reduced from what I first described. Being in a small shop, I try not to install the extension table unless needed so I don't accidentally whack into the corner of the extension table walking around it. Thanks again for all of the help.

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 10:46 am
by dusty
RFGuy wrote:
rpd wrote:Are you using the connecting tubes between the table and the extension table? Doing so will make things more rigid.
Thanks, Ron. That was it! After a long pause in woodworking, coming back to it now I remember most of it, but still I forget little things like this. There is still a tiny bit of play now, but it is significantly reduced from what I first described. Being in a small shop, I try not to install the extension table unless needed so I don't accidentally whack into the corner of the extension table walking around it. Thanks again for all of the help.
Whacking the table or the tubes has become a big issue for me. As I get older and older I have gotten prone to easy bruising (both my skin and my feelings). To avoid the bruises and resulting blood blisters I put rubber tips on the exposed ends of the tubes.

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 11:07 am
by JPG
I have to raise one question. Has this 'observed' deflection led to any inaccuracy in any thing you have actually sawn?

Also "standing on one end" and push/pulled causing the table to 'rotate'.

Why are you doing that?

I would suspect play between the table mounting tubes and the carriage.

Now what effect does that play have? For both ripping and cross cutting it only affects the angle of the blade relative to the forward motion of the workpiece. The rip width and cross cutting angle are minimally affected.

In other words I consider it a nit. ;)

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 11:17 am
by RFGuy
JPG wrote:I have to raise one question. Has this 'observed' deflection led to any inaccuracy in any thing you have actually sawn?

Also "standing on one end" and push/pulled causing the table to 'rotate'.

Why are you doing that?

I would suspect play between the table mounting tubes and the carriage.

Now what effect does that play have? For both ripping and cross cutting it only affects the angle of the blade relative to the forward motion of the workpiece. The rip width and cross cutting angle are minimally affected.

In other words I consider it a nit. ;)
I only tried rotating the table after noticing some play while jockeying some large boards on the Shopsmith (before and after cutting). Don't know that it affected the cut at all, but it was unstable enough for me to investigate. As was pointed out, this was user error on my part for not installing the extension table and connecting the main table with tubes.

Re: Main Table Movement?

Posted: Wed Jan 16, 2019 11:53 am
by chapmanruss
I use my 520 without the extension table for narrower cuts. With the height and carriage locked it requires more pressure from me to get any movement described than I would put upon the table cutting even thicker stock.

Not long ago I did change my Mark V 520 to a Mark 7 with the DVR headstock and double tilt upgrades. Maybe the new table posts are tighter than a more used set.

You may also want to check the teeth on the Carriage Pinion gear for damage.