Mark 7 vibration at high speeds normal?

[adrianpglover]

I bought a Mark 7 new just over a year ago now. I didn't get a lot of time in the shop last year, but now I'm starting to have more time to work on projects, so I'm finally able to utilize the Mark 7 more and get more familiar with it. In making some raised panel doors, I had need to use a router table. I setup both the router table extension wing on my table saw and the SS as a second station. When I turned the SS on at the recommended 10k RPM I started to notice a good deal of vibration. The tool itself didn't seem to be bouncing around or anything like that, it was more that the screws that weren't tightened down (the far end base lock screw, the base tilt lock knob that was above the table while in under table router mode, etc) would vibrate loose and end up on the floor if not restrained.

So my question to the forum: what level of vibration should I be expecting from a Mark 7 running at 10k RPM while setup in under table routing mode as outlined in the owners manual?

[DLB]

I've noticed that there are two (or more) versions of the DT Base. The current(?) version has an O-Ring on the lock screw and I'm thinking that could not or would not vibrate out when loose. I don't know anything about how the original(?) version is put together or what, if anything, limits the screw travel. I've wondered why there are two versions and you've got me wondering if this is the answer. But given the age of your machine I suspect you'd have the same version I have.

It is sure difficult to be objective about vibration without some instrumentation. My Mark 7, an upgraded 520, does not have objectional vibration at high speed but it does have more vibration than either my router table running roughly 2X to 2.5X RPM or my shaper running about the same speed. My screws won't vibrate out due to said O-Rings. I haven't really used my M7 in this mode often, I'm not completely sold on the thermal aspects.

- David

[wa2crk]

There has not been very much discussion about vibration when running at the 10k speed level. I have only run mine at that speed once and had no problem. That was only for a short period of time. I did have a problem with the set screws on the auxiliary power hubs and the set screw in the motor pulley loosening when I used the machine at normal speeds. It was cured by applying some blue Loctite to those screws. I don't know if that will work in your instance. Blue Loctite was also used on the saw blade arbors and drill chuck set screw and is working well.
Bill V

[garys]

A forum probably isn't a good place to get a definitive answer to your question. You are likely to get answers like. "Mine has some vibration too." and "Mine doesn't vibrate a lot." Vibration is almost impossible to measure so asking someone to quantify the vibration in text is more an opinion than fact and probably useless to you. Or, they can take a picture of the vibrating unit on their iphone and that picture would be even more useless.

The best way for you to get some idea on vibration would be if you are lucky enough to have another Shopsmith Power Pro owner near you so you can visit him and have him run his machine while you inspect it.

[adrianpglover]

All true about vibration being subjective without measurement. The machine itself doesn't seem to be vibrating in this mode to the point where I think it would fail the penny test (start the machine up with a penny standing on edge and see if it falls over). It's just that I've found these two screws to back themselves off. I think it has to do with how the unit seems slightly unstable when in the vertical mode (not much weight on the far legs allows for the vertical setup to wobble a little bit if forced).

The lock screw was missing the o-rign. I was able to find something at the local hardware store that got me close - the screw won't back itself out anymore but the o-ring will slide off the screw if you try to unscrew it too far. They were out of the correct size at the time.

I was more wondering if others with the Power Pro have noticed that when running in vertical mode with the speed up at 10k RPMs that the screws that aren't locked into place will eventually back out or not.

[RFGuy]

I am not a PowerPro owner, but there are definitely a few threads on this forum regarding setscrews and hubs coming off because of it. If you do a little digging on self reluctance motors (PowerPro) online, like I did, you will find that there are modes of resonance inherent to this type of design (causing more vibration than a comparable induction motor). In addition, operation at 10k rpm may exacerbate hardware coming loose. The thread below has more details. If I owned a PowerPro myself, every fastener that I could get to would have blue loctite as a precaution.

viewtopic.php?p=265716#p265716

[DLB]

All true about vibration being subjective without measurement. The machine itself doesn't seem to be vibrating in this mode to the point where I think it would fail the penny test (start the machine up with a penny standing on edge and see if it falls over). It's just that I've found these two screws to back themselves off. I think it has to do with how the unit seems slightly unstable when in the vertical mode (not much weight on the far legs allows for the vertical setup to wobble a little bit if forced).

The lock screw was missing the o-rign. I was able to find something at the local hardware store that got me close - the screw won't back itself out anymore but the o-ring will slide off the screw if you try to unscrew it too far. They were out of the correct size at the time.

I was more wondering if others with the Power Pro have noticed that when running in vertical mode with the speed up at 10k RPMs that the screws that aren't locked into place will eventually back out or not.

I confirmed that my Mark 7 (upgraded 520) is similar. The same screws turn on mine in the under-table router setup at high speed. The DT Base knob that is up stops turning when it hits the O-Ring limit as expected. The regular tilt lock turns very slowly but would eventually hit the floor since there is nothing else to limit its travel.

- David

[adrianpglover]

@DLB - Thanks for confirming this. I thought it might be normal, but wanted to be certain as I wasn't expecting to hear large screws hitting the floor when operating the machine.

[DLB]

@DLB - Thanks for confirming this. I thought it might be normal, but wanted to be certain as I wasn't expecting to hear large screws hitting the floor when operating the machine.

Yea, that's a little disappointing. In my first response to this post I had arrived at the idea that perhaps this, the addition of the O-Ring, was the reason for the change in the DT Bases. If it is, they should have addressed the tilt lock screws as well since they are part of the same major assembly. A person could be disappointed to invest this kind on money and have the screws falling out be seen as 'normal.' I thought I had a source for Nylok or nylon patch setscrews in reasonable quantities but when I tried to submit my order they popped up as unavailable. I have no objection to loc-tite but prefer it on screws that are intended to stay put, like the pulley and fan. I'm going to try some nylon tip setscrews on hubs, I'll report back here if I think they are any good.

- David