radial arm saws

[wladrog]

just need a little advice,has anyone any experience of Charnwood RAS and Shopmate RAS. At moment have got a old dewalt 10" one with only 3 bearings on the arm, Iam finding consistant accurate cuts are impossible due to the amount of movement in the motor carriage and in the arm as the saw is pulled. Ihave spent hours adjusting, lining up and building a stable table and holding devices. I am using a Freud blade , but still have problems with accuracy , I know these machines are not liked by many but the idea should work well I think the dewalt is poorly constructed and wonder if any of the other manufacturers are any better ,
thanks for any advice ; wladrog

 

[Scrit]

Hi wladrog

Sorry I can't help you with the Charnwood, but from memory it appeared very similar to the now defunct Eumania RAS. The Eumania is, if anything, luighter than the DW offerings so I'd be surprised if it was less prone to vibration and/or drift.

As to your DW, at least one of the bearings should be mounted on a cam bolt. Have you tried cleaning the V-tracks inside the arm with a brass wire brush (like a SPID brush or a narrow suede brush, for example) then adjusting the bearing(s)? Also, have you taken the end off the arm (two allen keys) and examined the bearings for wear and flats? Before consigning the RAS to the scrapheap or eBay I'd take a look at the whole bearing/arm situation. Unfortunately the bearings are DW specials, so you're unlikely to find an equivalent elsewhere, but fortunately DW still supply spare bearings for most RASs built since the 1970s. Whilst you're about it the tracks should be inspected for signs of wear and tear as these are the only thing which can't be repaired because they are machined straight into the casting. If they are badly worn it will require a replacement arm - not good, as they are expensive!

Finally, might I ask the model number and also ask if you use the RAS for lots of mitre cutting and ripping, etc in addition to crosscutting.

Regards

Scrit

 

[wladrog]

thanks for reply; model number DW 320. all bearings and track cleaned everything adjusted just cant stop the thing flexing. I dont move the arm for mitre cuts , use a mitre board and I do use it for ripping , have more success with this as the unit remains rigid, I have made feather boards,hold downs , riving knifes and use push sticks ,this seems to work reasonably well. It appears that as soon as any force is applied to the motor unit via the pull handle the arm twists, I think it is just not rigid enough. Another observation if I set the blade at 90` to the table top it results in a cut of about 85`, so Iadjust the blade using trial cuts,achieve nice 90` edges but on checking the blade find it is angled at 95`-100`. Does the inertia of the rotating blade actually move the whole motor assembly? Frustrated ? just a bit .
wladrog

 

[mailee]

wladrog I don't mean to doubt your problems but the DeWalt/Elu RAS should have locks on the 90 degree angle and also the motor should lock into the vertical position. I can't see why the motor should move as you pull it or indeed the pillar rotate? I have the ELU version of this saw the 1251 and although old it is sound and locks into position with no problems. Occasionally it will drift over time but this is just a matter of re-setting now and then. I am at a loss to explain your problem. I have to admit I don't use the saw for ripping though just cross cutting.

 

[superunknown]

I use a dewalt one everyday, I have to spend lots of time keep setting it up. It drives me crazy too, I can sympathies with you. I never use it to rip, only to cross cut. I have found that it does seem to depend on the blade and what I am cutting. Good luck!

 

[Scrit]

thanks for reply; model number DW 320. all bearings and track cleaned everything adjusted just cant stop the thing flexing.

Was the 320 by any chance the fold-away RAS tha DW made for a while? I am trying to place the model number - the "old" DW 10inn radial arm saws were referred to as DW 125 - 150 - 175 (or 1251/1253, etc) and the Elu ones were called RAS... etc.

What I am wondering is about the chassis at the base of the upright column. On the standard DW saw there are two sheet metal pieces, welded to the back of the perimeter frame running forwards to the front. Stretching between these towards the rear is a bolt which passes through a plastic yoke piece, the middle of the rise and fall rod (which in turn runs up the inside of the column) and then through a second yoke. If this bolt is loose or the frame welds have been broken then that is a source of flexing. I'm convinced that the generally thin frame at this point and the use of plastic yoke pieces are key to the flexing experienced in lightweight radial arm saws as this isn't an issue on heavier industrial machines (like the Wadkins) which have proper boxing and use heavier gauge metal for the chassis.

Does the inertia of the rotating blade actually move the whole motor assembly?

It shouldn't. My feelings are that the frame distorts slightly when you move the arm into the mitre position then back again because of the thiness of the metal, but that is conjecture. I'm afraid that what I did with my DW1751 was to get a local fabricator to weld me up a new chassis from 5in deep U-section steel - that cured most of it's ills and also helped absorb vibration. Probably a bit extreme but in my case it was a favour for a favour.

Scrit

 

[wladrog]

many thanks for feedback,
agree with most ,yes it is the fold down model,but i have checked and set all fixings everything tight , have bolted the unit to steel box section frame and table, but i like the idea of massive welded frame and i will probably weld the rear collum to it. I have tightly bolted the top yoke to the collum and do not move this for mitre cuts in order to avoid having to reset each time it is moved. I agree that probably the best option would be something as substantial as a wadkin but Icant get 3 phase. Possibly time for a complete rethink, have lost confidence in table saw due to digit removal,ouch!
wladrog

 

[Scrit]

....but I like the idea of massive welded frame and I will probably weld the rear column to it.

This problem must affect other makes as well, but the blade angle shifting pit from 90 degrees to the extent you have described doesn't seem to occur quite so much with the bigger models like the DW1251 and the "hybrid" I have with a DW1751 mounted on a substantial welded base works brilliantly. I suspect that your feelings about the arm casting twisting is right - I recall having a look at the DW320 when it appeared and thinking how light it was in comparison to a DW1251 - and that weight reduction must come from somewhere.

I agree that probably the best option would be something as substantial as a Wadkin but I cant get 3 phase.

Some Wadkin BRA radial arm saws were made in single phase, but they are rare. If you are looking for a RAS again then maybe one solution might be something like a bigger deWalt, such as the DW1370, although if you are looking to be able to rip, crosscut and mitre then I'd suggest a table saw with a sliding carraige might be a more suitable option. It all depends on budget.

Possibly time for a complete rethink, have lost confidence in table saw due to digit removal, ouch!

:shock:

Scrit