Qctp Holder Review Part 1

jbolt

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I have read a lot of discussions on the pros and cons of QCTP holders from various manufacturers but never a head to head comparison so I collected four of the commonly used BXA-1 holders for review. I have had inexpensive import QCTP's and more recently a new Aloris QCTP . Just from an operational point I can tell the quality difference. This review will not be comparing QCTP's. It will be comparing the standard truing tool holders to see how the inexpensive holders perform to the pricier higher end holders. Are they really worth the 5-6 times as much for our hobby lathes?

Part 1 will cover general observations, trueness and repeatability

Costs (as of 12/2/16) Shipping & Taxes excluded.
Dorian - $57.35 (MSC)
Aloris - &62.70 (MSC)
Shars - $17.50 (Shars.com) $12.00 (ebay)
CDCO - $11.00 (CDCO.com)

Fit and finish wise the Dorian is the hands down winner. Very clean with almost no tool marks. Second is the Aloris with some tool marks and good quality bluing. The Shars and CDCO are a toss up. The CDCO holders look like they get handled roughly with nicks and dings and the bluing is of lesser quality. The Shars has a better appearance but the tool slot in the Shars holder looks like it was cut with a damaged cutter where the CDCO is much smoother.

Dorian - Very nice.
BXA-07.png

Aloris - Looks good
BXA-08.png

Shars - Outside looks okay but a bit rough in the slot where the tool sits.
BXA-09.png

CDCO - slot looks good but the outside is a bit beat up.
BXA-10.png

Here are the dimensions and general characteristics of each holder.
BXA-Gen.png

The Shars is the widest at 3.5", similar to the -XL holders by other manufacturers, followed by the Dorian at 3.25" with the Aloris and CDCO being both a little over 3". The CDCO holder appears to be an almost direct knock off of the Aloris.

Height wise the Shars, CDCO & Aloris are the same at 1.75" with the Dorian being much taller at 2.23".

Width wise the Shars is the thinnest at 1.145", the CDCO and Aloris are in the middle at 1.25" and the Dorian is the thickest at 1.5"

For the tool slot the Shars, CDCO & Aloris are all similar in height averaging about 0.66". The Dorian on the other hand is nearly 3/8" taller at 1". This becomes a problem on the my lathe (PM-1440GT) where the thumb nut bottoms out about 0.2" before a standard 5/8" tool holder can be centered requiring a 1/4" shim under the tool.

For the slot depth the Shars is the shallowest at 0.5" followed by the Aloris & CDCO at 0.55" and the Dorian at nearly 0.6"

BXA-03.png

BXA-06.png

The height adjusting thumb nuts for the Aloris and Dorian have a better fit and finish than the imports with the import thumb nuts having a looser fit. This comes into play when making a tool height adjustment. The looser fit thumb nut will move more when the lock nut is tightened causing the tool height to rise so it takes more trial and error to get the height set properly.

The Shars, CDCO & Dorian holders use height adjusting studs with hex key heads where the Aloris does not. I have had the studs come loose before when loosening the lock nut and the hex head makes quick work of re-tightening. It will be interesting to see if the Aloris ever comes loose.

The Shars & CDCO use a wavy spring washer between the thumb nut and lock nut. The Dorian uses an internal tooth-lock washer which I find annoying and not necessary as it digs into the thumb nut. The Aloris does not use a lock washer per say but instead uses a internal tabbed washer that fits into a key-way on the stud.

For adjusting the height I found the Aloris to be the easiest with little or no change in height when tightening the lock nut. The Dorian came in second with the fairly rigid lock washer and both the Shars and CDCO take more trial and error to get set properly due to the loose fit of the thumb nut.

BXA-01.png

The Shars and CDCO, being imports, have 10mm set screws. The US made Dorian and Aloris use 3/8-16 set screws. Quality wise I would say they are all similar with the Dorian & Aloris being slightly better than the imports. I have seem other import holders with terrible set screws that needed to be thrown away and replaced out of the box but I see no need to replace the Shars or CDCO set screws. I have used several CDCO holders for many years with no issues with the set screws.

The CDCO set screws use a 5mm hex key whereas the Shars, Aloris and Dorian use a 3/16" hex key.

BXA-02.png

For testing the trueness of each holder I first used an 0-4-0 Tenth's TDI to check the top of the cross slide as well as the top of the compound slide. Both showed no change in measurement through the full range of motion in the X-axis as well as the Z distance across the top of each. The QCTP was removed and cleaned and all mating surfaces were cleaned before measuring.

Each tool holder was then mounted on my Aloris BXA wedge type QCTP and a precision ground 4" vise jaw was mounted in the tool holder. I used the vise jaw because I had them ground a while back and know they are flat and parallel. It also provides a larger surface to measure.

The jaw was held forward in the tool holder to simulate the minimum projection of a common insert tool holder. Measurements were taken on top along the X & Z for parallelism.

BXA-05.png

From the results you can see there are three holders with nearly identical results. This tells me the QCTP has a slight tilt to it causing a 0.003" back slope. Assuming that to be true the only holder that has any error in the X-axis is the CDCO with 0.0037".

For the Z direction the Dorian was perfect and the Shars had the most tilt at nearly 0.006". The CDCO did better than the Aloris.

BXA-Par.png

Next was the ability to repeat. Each holder was zeroed on the TDI, removed, re-inserted and re-measured 10 times. Measurements were taken at the top surface at the center line of the QCTP, the top at the simulated tool tip location and at the front edge.

BXA-04.png

The results below are the maximum deviation over 10 cycles.
BXA-Rep.png

While the Dorian performed the best the Aloris was a close second. The Shars and CDCO also performed very well with the maximum deviation being well within the tolerance of most hobby level lathes.

In Part 2 of the review I will test rigidity of each holder while taking cuts in steel and aluminum at different DOC's.
 

Bob Korves

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Good test process and well documented. The Dorian holder is a different style than the others, but is likely fine for comparison testing for fit and finish and handling details. Dorian almost certainly makes one closely similar to the others, but it is not worth buying one just for these tests. I will wait for part 2 before possibly commenting further. Thanks!
 

jbolt

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Good test process and well documented. The Dorian holder is a different style than the others, but is likely fine for comparison testing for fit and finish and handling details. Dorian almost certainly makes one closely similar to the others, but it is not worth buying one just for these tests. I will wait for part 2 before possibly commenting further. Thanks!
Hi Bob,

Do you know the model number of the other Dorian? I didn't see it their catalog but I could have missed it.
 

Bob Korves

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Hi Bob,

Do you know the model number of the other Dorian? I didn't see it their catalog but I could have missed it.
No, just guessing they would build one like the common style all the other manufacturers make. Does anyone here know which is actually the first version of this tool post style that was copied by all the others?
 

sanddan

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Great write up so far.

It would be nice to also compare the Phase II brand. I have Phase II, Aloris and CDCO holders and the Phase II is nicer in all respects than the CDCO.

One other comparison you might consider is the fit to the tool post. I found the CDCO holders to vary, one to another, more than the others with some of mine a tight fit to get on. It was more of an issue with the Phase II tool post than it is with the Aloris.

Thanks for taking the time to do this.
 

mksj

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Nicely done. Aloris is probably the prototype that others copied, they state they are the originator of the QCTP. Dorian use to work for Aloris and at some point split off to start his own company, it has been a contentious rivalry.

I am not sure there is a comparable BXA holder from Dorian that matches the Aloris (or other copies), there catalogue only shows the 1" tool holder dimension for the BXA. They are also different depending on the type of tool post used, so Dorian Quadra are very different then there standard, and there are various through the holder coolant options. Of the 4 Dorian #2 BXA holders, 3 of the 4 are all different. Because of the larger size of Dorian holders, they have less vertical adjustment, and standard 5/8" holders cannot be adjusted to the lathe center-line without a shim in my experience. Agree that Dorian fit and finish is up there, but pretty frustrating the standard holder variations and being oversized. The height adjustment thread post on the Aloris has a grove to lock the washer in one position, this prevents the locking nut from turning the adjustment nut from changing position when tightening. A bit easier to fine tune small height changes. Aloris does carry oversized BXA holders that will hold up to 3/4" tool holder for BXA, compared to Dorian which is 1". Can't really see needing a 1" holder on a BXA post, but I do use 3/4" shank height for my cutoff holder as this has a larger diameter cutoff ability, and for my scissors knurling tool (which still needed a shim in the Dorian holder).

Dorian Holders.jpg
 
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4GSR

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If I could afford Dorian tooling I would buy it over Aloris any day. I have have a few holders and other tooling I've snagged on eBay over the years. Have nearly a full set of dovetail cutters they make and boy are they nice. Their manufacturing plant is just up the road from me. Passed by it for nearly 30 years before I realized it was just off the main drag about a mile on my route to Houston.

But it's nice to know how nice and good the others hold up to the test. I've bought many of the Shars and CDCO brand too. The only comment's I've had over some of the older ones is the sloppy set screws they used to supply with them. They were the first thing I did when I received them, replace with some decent ones.
Ken
 

Sandia

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If I could afford Dorian tooling I would buy it over Aloris any day. I have have a few holders and other tooling I've snagged on eBay over the years. Have nearly a full set of dovetail cutters they make and boy are they nice. Their manufacturing plant is just up the road from me. Passed by it for nearly 30 years before I realized it was just off the main drag about a mile on my route to Houston.

But it's nice to know how nice and good the others hold up to the test. I've bought many of the Shars and CDCO brand too. The only comment's I've had over some of the older ones is the sloppy set screws they used to supply with them. They were the first thing I did when I received them, replace with some decent ones.
Ken

Ken, where is the Dorian plant from Victoria. I have been down 59 a jillion times, never noticed it either.
 
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Alan H.

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Jay, thanks for the testing and reporting. Lots of work on your part to do this and it is much appreciated. I am in the early throws of acquiring some tooling for my new PM1340GT and this is very helpful to me.

BTW, I spoke directly to Dorian last week before I ordered one of their BXA QCTPs and found them to be keen to speak to and help customers.

Meanwhile, I look forward to Part 2 of your testing.

Thanks again for your efforts on this.
 
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